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Einstein

His Life and Times

Einstein

His Life and Times

BY

PHILIPP FRANK

TRANSLATED FROM A GERMAN MANUSCRIPT BY

GEORGE ROSEN

EDITED AND REVISED BY

SHUICHI KUSAKA

ALFRED A. KNOPF: HEW

4 7

THIS IS A BORZOI BOOK,
PUBLISHED BY ALFRED A. KNOPF, INC. &

Copyright 1947 by Alfred A. Knopf, Inc. All rights reserved. No part of this
boo\ may be reproduced in any form without permission in writing from the
publisher, except by a reviewer who may quote brief passages and reproduce not
more than three illustrations in a review to be printed in a magazine or news-
paper. Manufactured in the United States of America.

PUBLISHED SIMULTANEOUSLY IN CANADA BY THE RYERSON PRESS

PUBLISHED FEBRUARY 20, 1947
SECOND PRINTING, APRIL 1947

The most incomprehensible thing about the
world is that it is comprehensible.

ALBERT EINSTEIN

ACKNOWLEDGMENTS

THE PHOTOGRAPHS reproduced in this book were obtained with
the friendly help of Miss Helen Dukas of Princeton, Professor
Rudolph W. Ladenburg of Princeton University, Professor Har-
low Shapley of Harvard University, and Dr. and Mrs. Gustav
Bucky of New York. The diagrams were designed by Mr. Gerald
Holton of Harvard University, and the Index compiled with
the co-operation of Miss Martha Henderson of Cambridge,,
Massachusetts.

CONTENTS

I. EINSTEIN'S YOUTH AND TRAINING

1 Family Background 3

2 Childhood 6

3 Gymnasium in Munich 10

4 Intellectual Interests 12

5 Departure from Munich 15

6 Student at Zurich 18

7 Official of a Patent Office 21

II. CONCEPTIONS OF THE PHYSICAL WORLD
BEFORE EINSTEIN

1 Philosophical Conception of Nature 25

2 Organismic Physics of the Middle Ages 27

3 Mechanistic Physics and Philosophy 28

4 Relativity Principle in Newtonian Mechanics 30

5 Ether as a Mechanical Hypothesis 32

6 Remnants of Medieval Concepts in Mechanistic

Physics 34

7 Critics of the Mechanistic Philosophy 36

8 Ernst Mach: The General Laws of Physics Are

Summaries of Observations Organized

in Simple Forms 38

9 Henri Polncarl: The General Laws of Physics Are

Free Creations of the Human Mind 40

10 Positivistic and Pragmatic Movements 42

11 Science at the End of the Nineteenth Century 45

HI. BEGINNING OF A NEW ERA IN PHYSICS

1 Life in Bern 49

2 Interest in Philosophy 50

3 The Fundamental Hypotheses of the Theory of

Relativity 53

vli

Contents

4 Consequences of Einstein's Two Hypotheses 55

5 Relativity of Time 57

6 Relativity of Other Physical Concepts 63

7 Equivalence of Mass and Energy 65

8 Theory of Brownian Motion 67

9 Origin of the Quantum Theory 69
10 Theory of the Photon 71

IV. EINSTEIN AT PRAGUE

1 Professor at the University of Zurich 74

2 Appointment to Prague 77

3 Colleagues at Prague 80

4 TA? Jews in Prague 83

5 Einstein's Personality Portrayed in a Novel 85

6 Einstein as a Professor 89

7 Generalization of the Special Theory of Relativity 91

8 Influence of Gravity on the Propagation of Light 94

9 Departure from Prague 98

V. EINSTEIN AT BERLIN

1 The Solvay Congress 101

2 Trip to Vienna 103

3 Invitation to Berlin 106

4 Einstein's Position in the Academic Life of Berlin 109

5 Relationship with Colleagues 112

6 Relationship with Students 116

7 Outbrea^ of the World War 119

8 German Science in the War 121

9 Lz'jfe iVz Wartime 123

VI. THE GENERAL THEORY OF RELATIVITY

1 New Theory of Gravitation 127

2 .R0/<? 0/ Four-Dimensional Space 130

3 Einstein Suggests Experimental Tests of His Theory 133

4 Cosmological Problems 134

viii

Contents

5 Expeditions to Test Einstein s Theory 137

6 Confirmation of the Theory 140

7 Attitude of the Public 142

VII. EINSTEIN AS A PUBLIC FIGURE

1 Einstein's Political Attitude 147

2 Anti-Semitism in Postwar Germany 149

3 The Zionist Movement 151

4 Einstein as a Pacifist 153

5 Campaigns against Einstein 158

VIII. TRAVELS THROUGH EUROPE, AMERICA,
AND ASIA

1 Holland 167

2 Czechoslova'kia 169

3 Austria 174

4 Invitation to the United States 176

5 Reception by the American People 178

6 England 187

7 Einstein Tower and the Rathenau Murder 190

8 France 194

9 China, Japan, Palestine, and Spain 198
10 Nobel Prize, Alleged Trip to Russia 201

IX. DEVELOPMENT OF ATOMIC PHYSICS

1 Einstein as a Teacher in Berlin 205

2 Structure of the Atom 208

3 Mechanics of the Atom 209

4 Boh/s Complementarity Principle 212

5 Einstein's Philosophy of Science 214

6 C/m'/z^ Field Theory 218

X. POLITICAL TURMOIL IN GERMANY

1 Einstein's Fiftieth Birthday 220

2 Visiting Professor at Pasadena 224

ix

Contents

3 Racial Purging in German Universities 227

4 Hostility toward Einstein 231

5 Last Weeks in Europe 239

6 Einstein's Views on Military Service 243

XL EINSTEIN'S THEORIES AS POLITICAL WEAPONS
AND TARGETS

1 Scientific Theories and Political Ideologies 248

2 Pro-Fascist Interpretation 250

3 Einstein's Theories Attached as Expressions of Jew-

ish Mentality 251

4 Attitude of the Soviet Philosophy toward Einstein 256

5 Einstein's Theories as Arguments for Religion 262

XII. EINSTEIN IN THE UNITED STATES

1 The Institute for Advanced Study 265

2 Einstein's Decision to Join the Institute 268

3 Einstein's Activities at the Institute 270

4 Refugee Scholars 276

5 Einstein's Attitude toward Religion 280

6 Beginning of the Atomic Age 289

7 Life in Princeton 293

Index follows page 298

ILLUSTRATIONS

facing page

Einstein s paternal grandfather 18

Einstein V paternal grandmother 18

Einstein at four 19

Einstein and his sister 19

Einstein s graduating class 50

Einstein and his first wife 51

Einstein in 1905 51

Einstein in the years of his greatest productivity (1913) 82

Einstein and prominent physicists at Leyden, the

Netherlands 83

Einstein with Harvard scientists on the occasion when he

received his honorary degree 114

Einstein and Rabindranath Tagore 115

Eclipse of the sun (1922) 140

Einstein and Steinmetz 141

Five winners of the Nobel Prize in physics 210

Recent portrait of Einstein 211

Einstein at the Michelson celebration in Berlin 242

Michelson, Einstein, and Million 243

Einstein in his Princeton office 295

Einstein in his Princeton home 296

XI

Einstein

His Life and Times

EINSTEIN'S YOUTH AND TRAINING

i. Family Bacl(ground

As far back as Einstein's memory extends, both his
paternal and his maternal ancestors lived in small towns and vil-
lages of Swabia in southwestern Germany. They were small
merchants, shopkeepers, and artisans, and none of them had ever
attracted attention in consequence of any intellectual achieve-
ment. Einstein himself remarks on occasions when he is ques-
tioned about his ancestors : "The circumstances under which they
lived were much too restricted to permit them to distinguish
themselves." They did not stand out in very bold relief against
their environment.

This background of southwestern Germany is very important
in the understanding of Einstein's character. The Swabians
merge almost imperceptibly with the French through the
mediation of the neighboring Alsatians, and they are reflective,
are practical in daily life, and participate joyfully in every kind
of art and pleasure as well as in philosophical and religious specu-
lations; but they are averse to any kind of mechanical order.
Their nature is different from that of the sober, practical Prus-
sians, interested in order and domination, and from that of the
earthy, merry, sometimes rather coarse Bavarians.

The differences in the character of these people are quite evi-
dent from their dialects. The Swabian speech is melodic and
flows slowly like a rippling, murmuring brook, unlike that of
the Germans of the ruling class of officers and officials, which
sounds like a bugle in a military camp. Neither is it like the cyni-
cal bleating of the Berliner, critical of everything in heaven or
on earth, nor like the pompously precise literary German of the
pastors and professors.

Elements of this friendly dialect are still to be heard in Ein-
stein's speech, although it has now been greatly blurred and al-
most obliterated by his travels in many different countries. In
particular his speech contains an admixture of certain tones de-
rived from the Swiss, which is indeed related to the dialect of

Einstein: His Life and Times

southwestern Germany, but lias a somewhat rougher tone. But
anyone listening to the speech of Einstein's second wife, who Is
descended from the same family as her husband, could still hear
the genuine, pleasantly agreeable Swabian idiom. For her he
was always "Albertle," the land was "landlc" the city (Stadi)
"Stddtle" Everything received the diminutive suffix "le" which
gives the dialect a quality of tenderness and affection.

The fact that Einstein's ancestors were Jewish made a dif-
ference, but not to so large an extent as one might expect. Dur-
ing the period when his parents were growing up, the Jews in
these small towns of Swabia did not differ greatly from the rest
of the population in their mode and way of life. They no longer
clung so firmly to their complicated customs and usages, which
rendered difficult the growth of any intimacy between them and
the rest of the population; and with the disintegration of these
barriers they tended, to an ever increasing degree, to lose their
position as a separate and unique group. The life of the Jews
in these districts was not similar to that in Berlin, where there
was a class of rich, educated Jews, who themselves developed
a specific variant of Berlin culture. There was none of this in
the small Swabian towns. Here the Jews, like the other inhab-
itants, led a quiet life, associated with their natural environ-
ment, and were but little influenced by the nervous hustle and
bustle of the metropolis.

In progressive circles at this time the reading of the Bible and
other books dealing with the doctrines of the Jews was no longer
the only source of truth. The Bible was read like other belles-
lettres and edifying literature, and in Jewish families the classi-
cal German authors appeared beside the prophets as teachers
of morality and conduct. Schiller, Lessing, and Heine were
honored like the preacher Solomon and the Book of Job. Fried-
rich Schiller particularly, with his moral, almost Biblical pathos
and glorification of a general love of mankind, became ex-
tremely popular among Jewish families and was an important
element in the education of their children. That he was a Swa-
bian was another reason for regarding him as something of a
close relative. In Einstein's family this Schiller cult and the
admiration for the Enlightenment, which was bound up with
it, also played a large part in the training of the younger gen-
eration.

The writer Berthold Auerbach, who was active between 1840
and 1870, is perhaps characteristic of the life and intellectual
temper of the Jews in Swabia in the time of Einstein's parents

Einstein^s Youth and Training

and grandparents. He was the first to portray the daily life of
the peasants of the Black Forest. These Schwarzwalder Dorfge-
schichten (Tales of the Blac% Forest} are probably somewhat
too Idealized and artificial for present-day taste, but they were
considered by contemporaries to be a gratifying counterpoise
to what was later called "Berlin gutter literature" and was re-
garded as a characteristic contribution of the Jews to German
literature.

It must also be mentioned that after 1871, as a result of the
Franco-Prussian War, Prussia became the predominant power
in Germany, and has profoundly affected and influenced the
character of the Germans. The unification of the majority of
the German tribes and the restoration of a powerful German
Empire was not initiated by the intellectual class. Writers and
scholars had long dreamed and sung of this goal, but they had
hoped that, as the Swablan poet Uhland put it, "the Imperial
crown of the new Germany would be anointed with a drop of
democratic oil." But the dream did not come true. Bismarck
carried out his work not with "democratic oil/* but with "blood
and iron," and with methods that were opposed by all the in-
tellectually progressive groups in Germany. Furthermore, the
new Germany did not arise from the national elements possess-
ing an older culture: the Swabians, Rhinelanders, and Austrians
who had produced Schiller, Goethe, Mozart, and Beethoven.
The rulers came from the tribes of the east, which were com-
posed of those who had settled on soil won by conquering,
Germanizing, and partially exterminating the original Slavic
population, and of those descended from the subjugated tribes.
They thus formed an amalgamation of oppressors and oppressed
well able to command and obey.

This situation placed the intellectual groups of all Germany,
and particularly those of the older, cultural sections, In an am-
biguous and partially mortifying position. They could not avoid
admitting that the methods of the new rulers were more effective
than their own, since they had been so successful; yet they could
not overcome their aversion to the adoration of force and the
glorification of order as ends in themselves. Such an empty
mechanical arrangement of life was repugnant to them, with
their inclination and aptitude for art and science. The new mas-
ters were not to their liking, but they were compelled to admire
and to some extent to imitate them. The German scholars ac-
quired a feeling of inferiority toward the Prussian officers, and
learned to restrict themselves to their own "subject," to leave

Einstein: His Life and Times

public life to the ruling group as their "subject/' and to stand
at attention, even intellectually, at the sound of a command-
ing voice.

All this was equally true of the Jews. They, too, admired the
new Empire and the energetic methods of its rulers. Even
though in their homes they cultivated the intellectual tradition
of the Jews and of the German classical period, yet in public
life they tried to assimilate themselves to the ruling class in con-
duct and ideas.

Only for those who were strong enough not to accord recog-
nition to outward success and who could not be compensated by
any external manifestation of power for the loss of freedom and
the cultural atmosphere was it possible to maintain an inde-
pendent attitude and to resist the prevailing trend. We shall see
that from his youth Einstein belonged to these people. Even
though later he frequently came into conflict with the prevail-
ing tendencies in Germany, yet he always retained a certain
attachment for his Swabian homeland and its people.

2. Childhood

Albert Einstein was born on March 14, 1879 at Ulm,
a middle-sized city in the Swabian part of Bavaria. This city is
of no significance in his life, however, since a year after his birth
the family moved to Munich. A year later a daughter was born
and there were no other children. Munich, the city in which
Albert spent his youth, was the political and intellectual center
of southern Germany. Thus the family had already departed
from the romantic nooks of Swabia and had made a transition
to a more urban life. Their house, however, was a cottage sur-
rounded by a large garden in the suburbs. Albert's father, Her-
mann Einstein, had a small electrochemical factory that he
operated with the aid of his brother, who lived with the family.
The former attended to the commercial side of the enterprise,
while the latter acted as technical director.

Hermann Einstein was an optimistic person who enjoyed life.
He was not a particularly good business man and was frequently
unsuccessful, but such failures did not change his general out-
look on life. His mode of life and his Weltanschauung differed
in no respect from those of the average citizen in that locality.
When his work was done, he liked to go on outings with his

6

Einstein's Youth and Training

family into the beautiful country around Munich, to the roman-
tic lakes and mountains, and he was fond of stopping at the
pleasant, comfortable Bavarian taverns, with their good beer,
radishes, and sausages. Of the traditional Jewish fondness for
reading edifying literature he had retained only a love for Ger-
man poetry, especially that of Schiller and Heine. The dietary
laws and other customary usages of the Jewish community were
to him only an ancient superstition, and in his house there was
no trace of any Jewish custom. Or, to put it more concisely,
the ancient customs themselves had disappeared, but several
humane usages connected with them were retained. For in-
stance, every Thursday the Einstein family invited a poor Jew-
ish student from Russia to share their midday meal with them
a reflection, no doubt, of the old Sabbath custom. Similarly,
their preference for the dramas and poems of Schiller, replete
with moral pathos., was a substitute for the reading of the Bible.
In his political views, too, Einstein's father, like most others, was
afraid of the dominant Prussians, but admired the new German
Empire, its Chancellor Bismarck, General Moltke, and the old
Emperor Wilhelm I.

Einstein's mother, born Pauline Koch, was of a more serious
and artistic nature, with a fine sense of humor. But the rather
meager material conditions under which she lived led her to be
satisfied with a tolerably secure existence for herself and her
children. She found much happiness and consolation in her
music, and when engineers from the factory dropped in for an
evening visit, they accompanied her on the piano. Above all she
loved German classical music, especially Beethoven's piano
sonatas.

The uncle who lived with the family was a man whose interest
in the more refined aspects of intellectual life was greater than
that of the father. He was a trained engineer, and it was from
him that Albert received his first impulsions in mathematics.

There can be no doubt that this origin in a provincial, semi-
rural milieu was of the greatest significance for Albert Einstein's
entire psychological development. He has never become a com-
pletely urban person. He was always somewhat afraid of Berlin
and later also of New York. Connected with this attitude is a
certain trait that characterizes his artistic taste and that certainly
appeared old-fashioned to modern Berliners. Einstein's prefer-
ence for the German classics in literature as well as in music was
expressed at a time when the intellectual circles of Berlin de-
clared that such tastes had long since been superseded. His

Einstein: His Life and Times

predilection for Schiller is a particularly characteristic feature,
by which one recognizes a member of a culture not that of
twentieth-century Berlin.

On the whole, little Albert was no child prodigy. Indeed, it
was a very long time before he learned to speak, and his parents
began to be afraid that he was abnormal Finally the child did
begin to speak, but he was always taciturn and never inclined to
enter into the games that nursemaids play with children in order
to keep both the children and themselves in good humor. A gov-
erness entrusted with Albert's childhood training even dubbed
him Pater Langweil (Father Bore). He did not like any strenu-
ous physical exertions such as running and jumping, perhaps
for the reason that he considered himself too weak for such
activities. From the very beginning he was inclined to separate
himself from children of his own age and to engage in day-
dreaming and meditative musing.

He disliked particularly playing at being a soldier, which the
children of most countries engage in with the greatest delight,
and which especially in the Germany of Bismarck and Moltke
was imbued with an almost mythical splendor. When the sol-
diers marched through the streets of Munich accompanied by
the roll of drums and the shrill of fifes, a combination, charac-
teristic of the German army, that gives the music an exciting,
compelling rhythm and a wild tonal quality, and when the pave-
ments and the windowpanes rattled from the pawing of the
horses' hoofs, the children enthusiastically joined the parade and
tried to keep in step with the soldiers. But when little Albert,
accompanied by his parents, passed such a parade, he began to
cry. In Munich parents would often tell their children : "Some
day, when you grow big, you, too, can march in the parade," and
most boys were spurred to greater and more ambitious efforts by
this prospect. Albert, however, said to his parents : "When I grow
up I don't want to be one of those poor people." When the ma-
jority saw the rhythm of a happy movement, he observed the
coercion imposed upon the soldiers ; he saw the parade as a move-
ment of people compelled to be machines.

At this time Einstein apparently already revealed one of his
most characteristic traits: his intractable hatred of any form of
coercion arbitrarily imposed by one group of people on another.
He detested the idea of the oppressor preventing the oppressed
from following their inclinations and developing their natural
talents, and turning them into automatons. On the other hand
Albert was also conscious of the natural laws of the universe; he

8

Einstein's Youth and Training

felt that there are great eternal laws of nature. As a child he was
able to understand them only in the form of traditional religion,
and felt attracted toward it and its ritual precepts, which sym-
bolized a feeling for the laws of the universe. He was offended by
the fact that his father always scoffed at religion, and he regarded
this derision as resulting from a type of thought that is in a cer-
tain sense disharmonious and refuses to submit to the eternal
laws of nature. This dual attitude hatred for the arbitrary laws
of man and devotion to the laws of nature has accompanied
Einstein throughout his life and explains many of his actions
that have been considered peculiar and inconsistent.

At that time the German elementary schools were conducted
on a denominational basis, the clergy of each religious group con-
trolling its schools. Since Munich was for the most part Catholic,
most of the schools were naturally of that denomination. Nomi-
nally Einstein's parents probably adhered to the Jewish religion,
but they were not sufficiently interested in a Jewish education
to send their children to a Jewish school since there was none
near their home and it would have been expensive. His parents
may even have felt that by sending their boy to a Catholic school
he would come into more intimate contact with non-Jewish
children. At any rate, Albert attended the Catholic elementary
school, where he was the only Jew in his class.

Young Albert experienced no unpleasantness because of this
situation. There was only a slight feeling of strangeness resulting
naturally from the different religious traditions, and this factor
was definitely of secondary significance and did not increase to
any marked degree his difficulty in forming intimate friendships
with his fellow pupils. The difficulty was due fundamentally to
his character.

Albert received regular instruction in the Catholic religion and
he derived a great deal of pleasure from it. He learned this sub-
ject so well that he was able to help his Catholic classmates when
they could not answer the teacher's questions immediately. Ein-
stein has no recollection of any objection having arisen to the
participation of a Jewish pupil in Catholic religious instruction.
On one occasion the teacher attempted a somewhat strange kind
of object lesson by bringing a large nail to the class and telling
the pupils: "The nails with which Christ was nailed to the cross
looked like this." But he did not add, as sometimes happens, that
the Crucifixion was the work of the Jews. Nor did the idea enter
the minds of the students that because of this they must change
their relations with their classmate Albert. Nevertheless Einstein

Einstein: His Life and Times

found this kind of teaching rather uncongenial., but only because
it recalled the brutal act connected with it and because he sensed
correctly that the vivid portrayal of brutality does not usually
intensify any sentiments of antagonism to it but rather awakens
latent sadistic tendencies.

It was very characteristic of young Einstein's religious feeling
that he saw no noticeable difference between what he learned
of the Catholic religion at school and the rather vaguely remem-
bered remnants of the Jewish tradition with which he was famil-
iar at home. These elements merged in him into a sense of the
existence of lawfulness in the universe and in the representa-
tion of this harmony by means of different kinds of symbols,
which he judged rather on the basis of their aesthetic value than
as symbols of the "truth."

On the whole, however, Einstein felt that school was not very
different from his conception of barracks that is, a place where
one was subject to the power of an organization that exercised a
mechanical pressure on the individual, leaving no area open
within which he might carry on some activity suited to his na-
ture. The students were required to learn mechanically the mate-
rial presented to them, and the main emphasis was placed on the
inculcation of obedience and discipline. The pupils were re-
quired to stand at attention when addressed by the teacher and
were not supposed to speak unless asked a question. Independent
questions addressed by students to the teacher and informal con-
versations between them were rare.

Even when Albert was nine years old and in the highest grade
of the elementary school, he still lacked fluency of speech,, and
everything he said was expressed only after thorough considera-
tion and reflection. Because of his conscientiousness in not mak-
ing any false statements or telling lies he was called Biedermeier
(Honest John) by his classmates. He was regarded as an amiable
dreamer. As yet no evidence of any special talent could be dis-
covered, and his mother remarked occasionally: "Maybe lie will
become a great professor some day." But perhaps she meant only
that he might develop into some sort of eccentric.

3. Gymnasium in Munich

At the age of ten, young Einstein left the elementary
school and entered the Luitpold Gymnasium in Munich, In Ger-

10

Einstein's Youth and Training

many the period between the ages of ten and eighteen, the years
that are of decisive importance in the intellectual development
of adolescents, are spent in the gymnasium. The aim of these
institutions was to give the young people a general education
based upon the acquisition of ancient Greek and Roman cul-
ture, and for this purpose most of the time was devoted to learn-
ing Latin and Greek grammar. Because of the complications of
these subjects, and since the students were required to learn all
the rules pedantically, little time was left to acquire a real under-
standing of the culture of antiquity. Furthermore, it would have
been a much more difficult task for the majority of the teachers.
It was claimed that the process of learning the grammar of one
or two complicated languages is an indispensable training for
the mind and a disciplining of the intellect hardly attainable
otherwise. For Einstein, however, aspiring to learn the laws of the
universe, this mechanical learning of languages was particularly
irksome, and this kind of education seemed very much akin to
the methods of the Prussian army, where a mechanical discipline
was achieved by repeated execution of meaningless orders.

Later, when speaking about his impressions of school, Ein-
stein frequently said: "The teachers in the elementary school
appeared to me like sergeants, and the gymnasium teachers like
lieutenants." The sergeants in the German army of Wilhelm II
were notorious for their coarse and often brutal behavior toward
the common soldiers, and it was well known that, with the troops
completely at their mercy, sadistic instincts developed in them.
The lieutenants, on the other hand, being members of the upper
class, did not come into direct contact with the men, but they
exerted their desire for power in an indirect manner. Thus when
Einstein compared his teachers to sergeants and lieutenants, he
regarded their tasks to be the inculcation of a certain body of
knowledge and the enforcing of mechanical order upon the stu-
dents. The pupils did not view the teachers as older, more ex-
perienced friends who could be of assistance to them in dealing
with various problems of life, but rather as superiors whom they
feared and tried to predispose favorably to themselves by be-
having as submissively as possible.

There was one teacher in the gymnasium, named Ruess, who
really tried to introduce the students to the spirit of ancient cul-
ture. He also showed them the influence of these ancient ideas in
the classical German poets and in modern German culture. Ein-
stein, with his strong feeling for everything artistic and for all
ideas that brought him closer to the hidden harmony of the

ii

Einstein: His Life and Times

world, could hardly have enough of this teacher. He aroused in
Hm. a strong interest in the German classical writers, Schiller
and Goethe, as well as in Shakspere, The periods devoted to the
reading and discussion of Hermann und Dorothea, Goethe's
half-romantic, half-sentimental love story written in a period of
the greatest political unrest, remained deeply engraved in Ein-
stein's memory. In the gymnasium the students who had not
completed their assignments were punished by being made to
stay after school under the supervision of one of the teachers. In
view of the tedious and boring character of the ordinary instruc-
tion, these extra periods were regarded as a real torture. But
when Ruess conducted the extra period, Einstein was happy to
be punished.

The fact that in the midst of all the mechanical drilling he was
sometimes able to spend an hour in an artistic atmosphere made
a great impression on him. The recollection of this class re-
mained very vivid in his mind, but he never stopped to consider
what sort of impression he had made on the teacher. Many years
later, when he was already a young professor at Zurich, Einstein
passed through Munich and, overcome by his memories of the
only man who had really been a teacher to him, decided to pay
him a visit. It seemed obvious to him that the teacher would be
happy to learn that one of his students had become a professor.
But when Einstein arrived at Ruess's quarters dressed in the care-
less manner that was characteristic of him then as well as later,,
Ruess had no recollection of any student named Einstein and
could not comprehend what the poorly dressed young man
wanted of him. The teacher could only imagine that by claiming
to be one of his former pupils the young man thought he could
borrow money from him. Apparently it never entered Ruess's
mind that a student could pay him a visit to express a feeling of
gratitude for his teaching. It is possible that his teaching had not
been so good as it appeared in Einstein's memory and perhaps he
had only imagined it. But in any case the visit was very embar-
rassing for Einstein and he departed as quickly as possible.

4. Intellectual Interests

When Einstein was five years old his father showed
iim a pocket compass* The mysterious property of the iron
needle that always pointed in the same direction no matter how

12

Einstein's Youth and Training

the compass case was turned made a very great impression on
the young child. Although there was nothing visible to make the
needle move, he concluded that something that attracts and
turns bodies in a particular direction must exist in space that is
considered empty. This was one of the impressions which later
led Einstein to reflect on the mysterious properties of empty
space.

As he grew up, his interest in natural science was further
aroused by the reading of popular scientific books. A Russian
Jewish student who ate at Einstein's home on Thursdays called
his attention to Aaron Bernstein's Naturwissenschaftliche Volfys-
bucher (Popular Boo\s on Natural Science}, which were widely
read by laymen interested in science about that time. These books
discussed animals, plants, their mutual interdependence, and
the hypotheses concerning their origin; they dealt with stars,
meteors, volcanoes, earthquakes, climate, and many other topics,
never leaving out of sight the greater interrelation of nature.
Soon Einstein was also an enthusiastic reader of such books as
Biichner's Kraft und Stoff (Force and Matter}., which attempted
to gather together the scientific knowledge of the time and to
organize it into a sort of complete philosophical conception of
the universe. The advocates of this view, frequently called "ma-
terialism" although it should rather be called "naturalism,"
wanted to understand and explain all celestial and terrestrial
occurrences by analogy with the natural sciences and were par-
ticularly opposed to any religious conception of the nature of
the universe.

Today such books as Biichner's Kraft und Stoff are considered
superficial and we may wonder how at that time young people
like Einstein who were capable of independent thought could
have been stirred by them. Yet if we have any sense of historical
values and justice, we should ask ourselves what recent books
are to be regarded as the analogues of those earlier works. In
reply we can point to such books as Sir James Jeans' s The Mys-
terious Universe. Probably a really critical judge would not be
able to say that Biichner's book is more superficial than those
of similar contemporary writers. At any rate, we find a very
good popular presentation of the scientific results themselves,
and a rather vague philosophical interpretation, which may be
accepted or not according to one's taste.

Einstein's interest in mathematics was also aroused at home
and not at school. It was his uncle and not the teacher at the
gymnasium who gave him his first understanding of algebra.

Einstein: His Life and Times

"It is a merry science/' he told the boy; "when the animal that
we are hunting cannot be caught, we call it x temporarily and
continue to hunt it until it is bagged." With such instruction,
Albert found a great deal of pleasure in solving simple problems
by hitting upon new ideas instead of just using a prescribed
method.

He was impressed most, however, when at about the age of
twelve he obtained for the first time a systematic textbook on
geometry. It was a book to be used in a class that had just started,
and, like many children who are curious about the new subjects
they are going to take up in school, he tried to delve into the
subject before it acquired the unpleasant and irksome quality
that teachers generally imparted. Having begun to read the
book, he was unable to put it down. The clarity of the exposition
and the proof given for every statement, as well as the close
connection between the diagrams and the reasoning, impressed
him with a kind of orderliness and straightforwardness that he
had not encountered before. The world with its disorder and
uncleanliness suddenly appeared to him to contain also an ele-
ment of intellectual and psychological order and beauty.

Ever since Albert was six years old his parents had insisted
that he take violin lessons. At first this was only another kind
of compulsion added to the coercion of the school, as he had the
misfortune to be taught by teachers for whom playing was
nothing but a technical routine, and he was unable to enjoy it.
But when he was about thirteen years old he became acquainted
with Mozart's sonatas and fell in love with their unique grace-
fulness. He recognized that his technique was not equal to the
performance of these compositions in the light-handed manner
necessary to bring out their essential beauty, and he attempted
repeatedly to express their light, carefree grace in his playing.
In this way, as a result of his efforts to express a particular emo-
tional mood as clearly as possible and not through technical
exercises, he acquired a certain skill in playing the violin and a
love for music, which he has retained throughout his life. The
feeling of profound emotion that he experienced in reading the
geometry books is perhaps to be compared only with his ex-
perience as a fourteen-year-old boy when for the first time he
was able to take an active part in a chamber-music performance.

At the age of fourteen, while he was still reading Biichner's
books, Einstein's attitude toward religion experienced an im-
portant change. While in the elementary school he had received
Catholic instruction, in the gymnasium he received instruction

14

Einstein's Youth and Training

in the Jewish religion, which was provided for the students of
this sect. Young Einstein was greatly stirred by the comments
of the teachers of religion on the Proverbs of Solomon and the
other parts of the Old Testament dealing with ethics. This ex-
perience made a permanent impression and left him with a pro-
found conviction of the great ethical value of the Biblical
tradition. On the other hand Einstein saw how the students were
compelled to attend religious services in Jewish temples whether
they had any interest in them or not. He felt that this did not
differ from the coercion by means of which soldiers were driven
to drill on the parade ground, or students to unravel subtly
invented grammatical puzzles. He was no longer able to regard
ritual customs as poetic symbols of the position of man in the
universe; instead he saw in them, more and more, superstitious
usages preventing man from thinking independently. There
arose in Einstein an aversion to the orthodox practices of the
Jewish or any other traditional religion, as well as to attendance
at religious services, and this he has never lost. He made up his
mind that after graduation from the gymnasium he would aban-
don the Jewish religious community and not become a member
of any other religious group, because he wanted to avoid having
his personal relationship to the laws of nature arranged accord-
ing to some sort of mechanical order.

5. Departure from Munich

When Einstein was fifteen an event occurred that
diverted his life into a new path. His father became involved in
business difficulties, as a result of which it appeared advisable to
liquidate his factory in Munich and seek his fortune elsewhere.
His pleasure-loving, optimistic temperament led him to migrate
to a happier country, to Milan in Italy, where he established a
similar enterprise. He wanted Albert, however, to complete Ms
studies at the gymnasium. At this time it was axiomatic for
every middle-class German that an educated person must have
a diploma from a gymnasium, since only this diploma entitled
him to become a student at a university. And as a course of study
leading to a degree was in turn necessary before one could
obtain a position in one of the intellectual professions, Einstein,
like all the others, felt compelled to complete his course at the
gymnasium.

15

Einstein: His Life and Times

In the field of mathematics Einstein was far ahead of his fellow
students, but by no means so in classical languages. He felt
miserable at having to occupy himself with things in which he
was not interested but which he was supposed to learn only
because he had to take an examination in them. This feeling of
dissatisfaction grew greater when his parents departed and left
him in a boarding-house. He felt himself a stranger among his
fellow students and regarded their insistence upon his participa-
tion in all forms of athletic activities as inconsiderate and coarse.
He was probably friendly to all, but his skeptical attitude toward
the organization and the spirit of the school as a whole was quite
clear to the teachers and students and aroused a sense of uneasi-
ness in many of them.

As he developed into an independently thinking man, the
thought of having to submit for some time yet to the pedagogical
methods of the gymnasium became more and more unbearable.
Although he was good-natured and modest in personal inter-
course, nevertheless then as well as later he stubbornly defended
his intellectual life against the entry of any external constraint.
He found it more and more intolerable to be compelled to
memorize rules mechanically, and he even preferred to suffer
punishment rather than to repeat something he had learned by
rote without understanding.

After half a year of suffering in solitude Einstein tried to leave
the school and follow his parents to Italy. To Einstein, living
in Munich, which was dominated by the cold, rigid Prussian
spirit, colorful Italy, with its art- and music-loving people living
a more natural and less mechanized life, appeared to be a beckon-
ing paradise. He worked out a plan that would enable him to
run away from school, at least for a while, without forfeiting his
chances of continuing his studies. Since his knowledge of mathe-
matics was far ahead of the requirements of the gymnasium, he
hoped that he might perhaps be admitted to a foreign institute
of technology even without a diploma. He may even have
thought that, once he was out of Germany, everything would
take care of itself.

From a physician he obtained a certificate stating that be-
cause of a nervous breakdown it was necessary for him to leave
school for six months to stay with his parents in Italy, where
he could recuperate. He also obtained a statement from his
mathematics teacher affirming that his extraordinary knowledge
of mathematics qualified him for admission to an advanced insti-
tution for the study of such subjects. His departure from the gym-

16

Einstein's Youth and Training

nasium was ultimately much easier than he had anticipated.
One day his teacher summoned him and told him that it would
be desirable if he were to leave the school Astonished at the turn
of events, young Einstein asked what offense he was guilty of.
The teacher replied: "Your presence in the class destroys the
respect of the students." Evidently Einstein's inner aversion to
the constant drill had somehow manifested itself in his behavior
toward his teachers and fellow students.

On arriving at Milan he told his father that he wanted to re-
nounce his German citizenship. His father, however, kept his
own, so that the situation was rather unusual. Also, since Ein-
stein could not acquire any other citizenship immediately, he
became stateless. Simultaneously he renounced his legal adher-
ence to the Jewish religious community.

The first period of his stay in Italy was an ecstasy of joy. He
was enraptured by the works of art in the churches and in the
art galleries, and he listened to the music that resounded in every
corner of this country, and to the melodic voices of its inhabit-
ants. He hiked through the Apennines to Genoa. He observed
with delight the natural grace of the people, who performed the
most ordinary acts and said the simplest things with a taste and
delicacy that to young Einstein appeared in marked contrast
to the prevalent demeanor in Germany. There he had seen
human beings turned into spiritually broken but mechanically
obedient automatons with all the naturalness driven out of them;
here he found people whose behavior was not so much deter-
mined by artificial, externally imposed rules, but was rather in
consonance with their natural impulses. To him their actions
appeared more in accord with the laws of nature than with those
of any human authority.

This paradisal state of delight, however, could exist only as
long as Einstein was able to forget completely as he did for a
while * the urgent demands that the practical necessities of life
made upon him. The need for a practical occupation was par-
ticularly urgent since his father was again unsuccessful in Italy.
Neither in Milan nor in Pavia did his electrical shop succeed.
Despite his optimism and happy outlook on life, he was com-
pelled to tell Albert: "I can no longer support you. You will have
to take up some profession as soon as possible." The pressure
that had hardly been released appeared to have returned. Had
his departure from the gymnasium been a disastrous step ? How
could he return to the regular path leading to a profession ?

Einstein's childhood experience with the magnetic compass

17

Einstein: His Life and Times

had aroused his curiosity in the. mysterious laws of nature^ and
his experience with the geometry book had developed in him a
passionate love for everything that is comprehensible in terms
of mathematics and a feeling that there was an element in the
world that was completely comprehensible to human beings.
Theoretical physics was the field that attracted him and to which
he wanted to devote his life. He wanted to study this subject
because it deals with the question: how can immeasurably com-
plicated occurrences observed in nature be reduced to simple
mathematical formuk?

With his interest in the pure sciences of physics and mathe-
matics and the training required for a more practical profession,
together with the fact that his father was engaged in a technical
occupation, it seemed best that young Einstein should study the
technological sciences. Furthermore., since he lacked a diploma
from a gymnasium but had an excellent knowledge of mathe-
matics, he believed that he could more easily obtain admission
to a technical institution than to a regular university.

6. Student at Zurich

At that time the most famous technical school in cen-
tral Europe outside of Germany was the Swiss Federal Poly-
technic School in Zurich. Einstein went there and took the
entrance examination. He showed that his knowledge of mathe-
matics was far ahead of that of most of the other candidates, but
his knowledge of modern languages and the descriptive natural
sciences (zoology and botany) was inadequate, and he was not
admitted. Now the blow had fallen. What he had feared ever
since leaving Munich had come to pass and it looked as though
he would be unable to continue in the direction he had planned.

The director of the Polytechnic, however, had been impressed
by Einstein's knowledge of mathematics and advised him to
obtain the required diploma in a Swiss school, the excellent, pro-
gressively conducted cantonal school in the small city of Aarau.
This prospect did not appeal very much to Einstein, who feared
that he would again become an inmate of a regimented institu-
tion like the gymnasium in Munich.

Einstein went to Aarau with considerable misgiving and ap-
prehension, but he was pleasantly surprised. The cantonal school
was conducted in a very different spirit from that of the Munich

18

Einstein* s Youth and Training

gymnasium. There was no militaristic drilling, and the teaching
was aimed at training the students to think and work inde-
pendently. The teachers were always available to the students
for friendly discussions or counsel. The students were not re-
quired to remain in the same room all the time, and there were
separate rooms containing instruments, specimens, and acces-
sories for every subject. For physics and chemistry there were
apparatuses with which the student could experiment. For
zoology there were a small museum and microscopes for observ-
ing minute organisms, and for geography there were maps and
pictures of foreign countries.

Here Einstein lost his aversion to school. He became more
friendly with his fellow students. In Aarau he lived with a
teacher of the school who had a son and a daughter with whom
Einstein made trips to the mountains. He also had an oppor-
tunity to discuss problems of public life in detail with people
who, in accordance with the Swiss tradition, were greatly inter-
ested in such affairs. He became acquainted with a point of view
different from that which he had been accustomed to in
Germany.

After one year at the cantonal school Einstein obtained his
diploma and was thereupon admitted to the Polytechnic School
in Zurich without further examination. In the meantime, how-
ever, he had abandoned the plan of taking up a practical profes-
sion. His stay at Aarau had shown him that a position as a teacher
of physics and mathematics at an advanced school would per-
mit him to pursue his favorite studies and at the same time enable
him to make a modest living. The Polytechnic had a depart-
ment for training teachers in physical and mathematical sub-
jects, and Einstein now turned to this pursuit

During the year at the cantonal school Einstein had become
certain that the actual object of his interest was physics and not
pure mathematics as he Had sometimes believed wHile still in
Munich. His aim was to discover the simplest rules by which, to
comprehend natural laws. Unfortunately, at that time it was
just this teaching of physics that was rather outdated and pedan-
tic at the Polytechnic. The students were merely taught the physi-
cal principles that had stood the test of technical applications
and been accepted in all the textbooks. There was little if any
objective approach to natural phenomena, or logical discussion
of the simple comprehensive principles underlying them.

Even though the lectures on physics were not marked by any
profundity of thought, they did stimulate Einstein to read the

19

Einstein: His Life and Times

works of the great investigators in this field* Just about this time,
at the end of the nineteenth century,, the development of physi-
cal science had reached a turning-point. The theories of this
period had been written in stimulating form by the outstanding
scientists. Einstein devoured these classics of theoretical physics,
the works of Helmholtz, Kirchoff, Boltzmann, Maxwell, and
Hertz. Day and night Einstein buried himself in these books,
from which he learned the art of erecting a mathematical frame-
work on which to build up the structure of physics.

The teaching of mathematics was on a much higher level.
Among the instructors was Hermann Minkowski, a Russian by
birth, who, although still a young man, was already regarded as
one of the most original mathematicians of his time- He was
not a very good lecturer, however, and Einstein was not much
interested in his classes. It was just at this time that Einstein lost
interest in pure mathematics. He believed that the most primitive
mathematical principles would be adequate to formulate the
fundamental laws of physics, the task that he had set for himself.
Not until later did it become clear to him that the very opposite
was the case: that for a mathematical formulation of his idea
concepts derived from a very highly developed type of mathe-
matics were required. And it was Minkowski, whose mathemati-
cal lectures Einstein found so uninteresting, who put forth ideas
for a mathematical formulation of Einstein's theories that pro-
vided the germ for all future developments in the field.

At this period the Polytechnic enjoyed a great international
reputation and had a large number of students from foreign
countries. Among them were many from eastern and southeast-
ern Europe who could not or would not study in their native
countries for political reasons, and hence Zurich became a place
where future revolutions were nurtured. One of these with
whom Einstein became acquainted was Friedrich Adler, from
Austria. He was a thin, pale, blond young man who like other
students from the east united within himself an intense devo-
tion to his studies and a fanatical faith in the revolutionary de-
velopment of society. He was the son of Viktor Adler, a leading
Social Democrat politician of Vienna, who tried to keep his son
out of politics by sending him to study physics at Zurich.

Another of Einstein's acquaintances was Mileva Maritsch, a
young woman from Hungary. Her mother tongue, however,
was Serbian and she professed the Greek Orthodox religion. She
belonged to that group of her people who lived in considerable
numbers in southeastern Hungary and always carried on a vio-

20

Einstein's Youth and Training

lent struggle against the Magyar domination. Like many of the
women students from eastern Europe, she paid attention only
to her work and had few opportunities to attract the attention
of men. She and Einstein found a common interest in their pas-
sion for the study of the great physicists, and they spent a great
deal of time together. For Einstein it had always been pleasant to
think in society, or, better perhaps, to become aware of his
thoughts by putting them into words. Even though Mileva
Maritsch was extremely taciturn and rather unresponsive, Ein-
stein in his zeal for his studies hardly noticed this.

This student period at Zurich, which was so important for
Einstein's mental development, was not such an easy time for
him with regard to practical living. His father's financial situa-
tion was so difficult that he could not contribute anything to his
son's support, Einstein received one hundred Swiss francs
monthly from a wealthy relative, but he had to put aside twenty
of these every month to accumulate the fee necessary for the
acquisition of Swiss citizenship, which he hoped to obtain soon
after graduation. He did not experience any real material hard-
ships, but on the other hand he could not afford any luxuries.

7. Official of a Patent Office

Einstein completed his studies just at the turn of the
century and now faced the necessity of seeking a position. When
a young man with extraordinary interest and ability in science
has completed the regular course of study at a university or tech-
nical academy, it is important and generally desirable for him
to obtain further training to become an independent investigator
by acting as assistant to a professor at a university. In this way he
learns the methods both of teaching and of making scientific
investigations by working under an experienced person. Since
this appeared to be the appropriate path for him, Einstein ap-
plied for such a position. It became evident, however, that the
same professors who had praised his scientific interest and talent
so highly had no intention whatever of taking him on as an
assistant. Nor did he receive any direct explanation of this
refusal.

With no possibility of a teaching position at the Polytechnic,
the only alternative was to look for one in a secondary school.
Here again., despite excellent letters of recommendation from

Einstein: His Life and Times

his professors, lie was unsuccessful The only thing he obtained
was a temporary position in a technical vocational school at
Winterthur, and after a few months he was again unemployed.

It was now 1901. Einstein was twenty-one and had become a
Swiss citizen. Through a newspaper he found that a gymnasium
teacher in Schaffhausen, who maintained a boarding-house for
students, was looking for a tutor for two boys. Einstein applied
for the job and was hired. Thus he came to this small city on
the Rhine whose famous waterfalls resounded throughout the
vicinity and where numerous tourists stopped to see the natural
phenomenon, which received three stars in the Baedeker.

Einstein was not dissatisfied with his work. He enjoyed mold-
ing the minds of young people and trying to find better peda-
gogical methods than those he had been accustomed to in school.
But he soon noticed that other teachers spoiled the good seed
he sowed, and he asked that the teaching of the two boys be left
completely in his hands. One can well imagine that the gym-
nasium teacher who conducted the boarding-house regarded
this request as a rebellion against his authority. He felt there was
an atmosphere of revolt and discharged Einstein. By this action
Einstein now realized that It was not only the students but
teachers as well who were crushed and made pliable by the
mechanical treadmill of the ordinary school.

Einstein was again in a difficulty. All his efforts to find a teach-
ing position failed despite the fact that he held a diploma from
the Polytechnic and Swiss citizenship papers. He himself could
not quite understand the reason for his failure. It may have been
that he was not regarded as a genuine Swiss. With his recent
citizenship, he was what the genuine Swiss patriots called a
"paper Swiss." The fact that he was of Jewish ancestry caused
additional difficulty in being accepted as a true Swiss.

In the midst of this dark period there appeared a bright light.
A fellow student of Einstein's at the Polytechnic, Marcel Gross-
mann, introduced him to a man named Haller, the director of
the patent office in Bern. He was a very broad-minded, intelligent
man who knew that in every profession it is more important to
have someone capable of independent thinking than a person
trained in a particular routine. After a long interview he was
convinced that although Einstein liad no previous experience
with technical inventions, he was a suitable person for a position
in the patent office, and gave him a job.

In many respects Einstein's removal to Bern was an important
turning-point in his life. He now liad a position with a fixed

22

Einstein's Youth and Training

annual salary of about three thousand francs, a sum that at that
time enabled him to live quite comfortably. He was able to spend
his leisure hours, of which he had many, in scientific investiga-
tion. He was in a position to think of marriage and of having a
family.

Soon after his arrival in Bern, Einstein married Mileva
Maritsch, his fellow student at the Polytechnic. She was some-
what older than he. Despite her Greek Orthodox background
she was a free-thinker and progressive in her ideas, like most of
the Serbian students. By nature she was reserved, and did not
possess to any great degree the ability to get into intimate and
pleasant contact with her environment. Einstein's very different
personality, as manifested in the naturalness of his bearing and
the interesting character of his conversation, often made her
uneasy. There was something blunt and stern about her charac-
ter. For Einstein life with her was not always a source of peace
and happiness. When he wanted to discuss with her his ideas,
which came to him in great abundance, her response was so
slight that he was often unable to decide whether or not she was
Interested. At first, however, he had the pleasure of living his
own life with his family. Two sons were born in rapid succes-
sion, and the elder was named Albert after his father. Einstein
was very happy with his children. He liked to occupy himself
with them, to tell them what went on in his mind; and he ob-
served their reactions with great interest and pleasure.

Einstein's work at the patent office was by no means uninter-
esting. His job was to make a preliminary examination of the
reported inventions. Most inventors are dilettantes, and many
professionals are likewise unable to express their thoughts
clearly. It was the function of the patent office to provide legal
protection for inventions and inventors, and there had to be
clearly formulated statements explaining the essential feature
of each invention. Einstein had to put the applications for
patents, which were frequently vaguely written, into a clearly
defined form. He had to be able, above all, to pick out the basic
ideas of the inventions from the descriptions. This was frequently
not easy and it gave Einstein an opportunity to study thoroughly
many ideas that appeared new and interesting. Perhaps it was
this work that developed his unusual faculty of immediately
grasping the chief consequence of every hypothesis presented, a
faculty that has aroused admiration in so many people who have
had an opportunity to observe him in scientific discussion.

This occupation with inventions also kept awake in Einstein

23

Einstein: His Life and Times

an interest in the construction of scientific apparatus. There still
exists an apparatus for measuring small electrical charges that
he invented at this time. Such work was for him a kind of
recreation from his abstract theoretical investigation in much
the same way as chess and detective stories serve to relax other
scientists. Quite a few mathematicians find amusement in the
solution of chess problems and not in some sport or in the
movies, and it may well be that a mathematical mind finds
the best relaxation by occupying itself with problems that are
not to be taken seriously but still require a modicum of logical
thinking. Einstein does not like chess or detective stories, but
he does like to think up all sorts of technical instruments and to
discuss them with friends. Thus even today he is often in the
company of his friend Dr. Bucky of New York, a well-known
physician and specialist in the construction of X-ray machines,
and together they have devised a mechanism for regulating auto-
matically the exposure time of a photographic film depending
on the illumination on it. Einstein's interest in such inventions
depends not on its practical utility but on getting at the trick of
the thing.

24

II

CONCEPTIONS OF THE PHYSICAL WORLD
BEFORE EINSTEIN

i. Philosophical Conception of Nature

The philosophical conception of nature that prevails
in any given period always has a profound influence upon the
development of physical science in that period. Throughout its
history natural science has been cultivated according to two very
diff erent points of view. The one viewpoint, which may be called
"scientific/' has attempted to develop a system with which ob-
served facts could be correlated and from which useful informa-
tion could be obtained, while the other, which may be called
"philosophical/ 5 has attempted to explain natural phenomena in
terms of a specific historically sanctioned mode of exposition.
This difference can best be illustrated in the theory of the motion
of celestial bodies. In the sixteenth century the Copernican
theory, which maintained that the earth moved around the sun,
was useful in the correlation of the position of stars, but it was
not considered "philosophically true," since this idea contra-
dicted the philosophical conception of that time according to
which the earth was at rest in the center of the universe.

The philosophical conception itself, in the history of science,
has suffered changes following revolutionary discoveries. Two
main periods are outstanding. In the Middle Ages the under-
standing of natural phenomena was sought in terms of anal-
ogies with the behavior of animals and human beings. For
instance, the motions of heavenly bodies and projectiles were
described in terms of the action of living creatures. Let us call
this view the organismic conception. The far-reaching investi-
gations in mechanics by Galileo and Newton in the seventeenth
century caused the first great revolution in physical thought and
originated the conception of the mechanistic view in which all
phenomena were explained in terms of such simple machines
as levers and wheels. This view enjoyed great success, and be-
cause of this, mechanics became the model for all the natural

25

Einstein: His Life and Times

sciences indeed, for all science in general. It reached its acme
about 1870, and then, with increasing discoveries in new fields
of physics., there began a process of disintegration. Then in 1905,
with the publication of Einstein's first paper on the theory of
relativity, began the second great revolution. Just as Newton was
instrumental in causing the transition from organismic to mech-
anistic physics, so Einstein followed with the change from the
mechanistic to what is sometimes called the mathematical de-
scription of nature.

In order to obtain a good understanding of Einstein's work
and a comprehension of the paradoxical fate of his theories, it is
necessary to appreciate the great emotional disturbances and the
interference of political, religious, and social forces that have
accompanied the revolutions in the philosophical conceptions
of nature. Just as the Roman Inquisition characterized and
condemned the investigations of Copernicus and Galileo as
"philosophically false" because they did not fit into its concep-
tion of nature, many philosophers and physicists all over the
world rejected Einstein's theory of relativity since they could
not understand it from their mechanistic point of view. In both
cases the reason for the condemnation was not a difference of
opinion in the judgment of observations, but the fact that the
new theory did not employ the analogies required by the tradi-
tional philosophy.

It is certainly true that this rigid insistence on the retention of
a specific explanatory analogy has in some cases discouraged the
discovery of new laws that would account for newly discovered
facts. But it would be a great historical injustice to maintain that
this conservatism has always been harmful to the progress of
science. The application of a specific conception was an im-
portant instrument for the unification of the various branches of
science. According to the organismic view, there was no real
gap between animate and inanimate nature; both were subject
to the same laws. The same situation existed in the mechanistic
view, in which living organisms were described in terms of
mechanics. Furthermore, the thorough application of an analogy
frequently demanded a formal simplification, since it favored
theories that derived all experimental evidence from a few sim-
ple principles.

Since all of us absorbed the mechanistic conception of nature
in our training in school, it has become so familiar to us that
we regard it as a triviality. When a theory seems trivial, how-
ever, we no longer understand its salient point. Consequently,

26

Conceptions of the Physical World before Einstein

in order to comprehend the great revolutionary significance that
this theory possessed when it first appeared, we must try to
imagine ourselves in that period. We shall see that mechanistic
science in its early stages appeared as incomprehensible and
paradoxical to many people as Einstein's theory does today.

2. Organismic Physics of the Middle Ages

When we observe a person's action we find that he is
sometimes understandable and at other times incomprehensible.
When we see a man suddenly dashing off in a particular direc-
tion, it appears strange at first, but when we learn that in that
direction gold coins are being distributed gratis, his action be-
comes understandable. We cannot understand his action until
we know his purpose. Exactly the same is true of animal be-
havior. When a hare rushes off in a hurry, we understand this
action if we know that there is a dog after it. The purpose of any
motion is to reach a point that is somehow better adapted than
the point from which it set out.

Just as different kinds of behavior are exhibited by various
organisms depending on their nature, so "organismic science"
interpreted the movements executed by inanimate objects. The
falling of a stone and the rising of flame may be interpreted
as follows: Just as a mouse has its hole in the ground while an
eagle nests on a mountain crag, so a stone has its proper place
on the earth while a flame has its up above on one of the spheres
that revolve around the earth. Each body has its natural position,
where it ought to be in accordance with its nature. If a body is
removed from this position, it executes a violent motion and
seeks to return there as quickly as possible. A stone thrown up
in the air tends to return as fast as possible to its position as close
as it can get to the center of the earth, just as a mouse that has
been driven from its hole tries to return there as soon as possible
when the animal from which it fled is gone.

It is of course possible that the stone will be prevented from
falling. This occurs when a "violent" force acts on it. Accord-
ing to the ancient philosophers: "A physician seeks to cure, but
obstacles can prevent him from achieving his aim." This analogy
presents the organismic point of view in probably the crudest
form.

There are also motions that apparently serve no purpose. They

27

Einstein: His Life and Times

do not tend toward any goal, but simply repeat themselves. Such
are the movements of the celestial bodies, and they were there-
fore regarded as spiritual beings of a much higher nature. Just
as it was the nature of the lower organism to strive toward a goal
and flee from danger, so it was the nature of the spiritual bodies
to carry out eternally identical movements,

This organismic conception had its basis in teachings o the
Greek philosopher Aristotle. Although it was basically a heathen
philosophy, it is to be found throughout the entire medieval
period with only slight modifications in the doctrine of the lead-
Ing Catholic philosopher, Thomas Aquinas, as well as in the
teachings of the Jewish philosopher Moses Maimonides, and the
Mohammedan Averroes.

3. Mechanistic Physics and Philosophy

The transition from organismic to mechanistic physics
is most clearly and in a certain sense most dramatically embodied
in the person of Galileo Galilei. He looked upon the Copernican
theory of the earth's motion as something more than just an
"astronomical" hypothesis for the simple representation of ob-
servations which says nothing about reality. He dared to throw
doubt on the very basic principle of medieval physics.

Galileo took as his starting-point the motion of an object along
a straight line with constant velocity. This is a type of motion that
is most easily represented by a mathematical treatment. He then
considered the motion along a straight line with constant accel-
eration; that is, when the velocity increases by a constant amount
during each unit of time. Galileo tried to understand more com-
plex types of motion on the basis of these simple forms. In par-
ticular he discovered as a characteristic property of all falling
bodies and flying projectiles that their downward acceleration
was constant. He was thus able to consider their entire motion
as being made up of two components:

(1) a motion where the initial velocity remains constant both
in direction and in magnitude (inertial motion) ; and

(2) a motion with constant acceleration directed vertically
downward (action of gravity).

Sir Isaac Newton later extended this scheme to the more com-
plicated motion of the celestial bodies and then to all motion in

28

Conceptions of the Physical World be-fore Einstein

general. For the circular motion of the planets, such as the earth,
around the sun, Newton decomposed the motion into:

(1) the inertial motion, where the initial velocity remains
constant both in direction and in magnitude; and

(2) the action of the gravitational force between the sun and
the earth whereby the earth receives an acceleration that is di-
rected toward the sun and is inversely proportional to the square
of the distance between the earth and the sun.

He then developed these ideas into his celebrated laws of mo-
tion and the theory of gravitation :

Law i: Every body continues in its state of rest or of uniform
motion in a straight line unless it is compelled to change that
state by forces impressed upon it (Law of Inertia) ;

Law 2: The change of motion is proportional to the force
impressed, and takes place in the direction in which the force is
impressed (Law of Force) ;

Law j: To every action there is always opposed an equal re-
action; and

The Universal Law of Gravitation: Every particle of matter in
the universe attracts every other particle with a force whose di-
rection is that of the line joining the two, and whose magnitude
is directly proportional to the product of their masses and in-
versely proportional to the square of the distance from each
other.

The remarkable success of these laws Is too well known to
need amplification. They have formed the basis for all physics,
astronomy and mechanical engineering.

Newton and his contemporaries had already advanced theories
concerning optical phenomena. All these theories had one fea-
ture in common : they assumed that the laws of mechanics which
have been found so successful in calculating the motions of the
heavenly bodies and of the material bodies encountered in daily
life could be applied also to optical phenomena, and attempted
to explain them in terms of motions of particles. Very similar
attempts were also made for all processes in other branches of
science; for instance, electromagnetism, heat, and chemical re-
actions. In each case the particular phenomenon was explained
in terms of a mechanical model that obeyed the Newtonian laws
of motion.

The great practical successes of this method soon reached a
point where only an exposition based on a mechanical analogy
was considered as giving a satisfactory "physical understanding."

29

Einstein: His Life and Times

Any other means of presenting and calculating a series o phe-
nomena may be "practically useful/' but does not permit a
"physical understanding." Explanations in terms of mechanical
processes soon began to play the role that explanations in terms
of organismic physics had played during the Middle Ages. A
mechanistic philosophy took the place of organismic philosophy.

Yet it is obvious that, originally, mechanistic physics owed its
success only to its practical utility and not to any kind of philo-
sophical plausibility. The law of inertia when it was first ad-
vanced was not plausible from the point of view of the dominant
medieval philosophy; on the contrary, it was absurd. Why should
an ordinary terrestrial body move along a straight line and
forever strive to attain infinity, where it has no business ? Yet this
"absurd" law overcame all opposition; in the first place because
it was mathematically simple, and in the second because the
mechanistic physics based upon it led to great successes. Eventu-
ally the entire development was turned upside down and it was
asserted that only explanations in terms of a mechanical model
were "philosophically true." The philosophers of the mechanistic
period, especially from the end of the eighteenth century on,
excogitated all kinds of ideas to prove not only that the law of
inertia was not absurd, but that its truth was evident simply
on the basis of reason and that any other assumption was incon-
sistent with philosophy.

Therein lies the historical root of the struggles waged by many
professional philosophers against Einstein's theories. Allied with
them were also many experimental physicists whose outlook on
more general problems had not grown up on the basis of the
scientific principles that they used in their laboratories. They
kept their scientific investigations separated from the traditional
philosophy that they had learned in the universities and in which
they believed as in a creed rather than as in a scientific theory.

4. Relativity Principle in Newtonian Mechanics

There was one point, however, in Newton's laws of
motion that was not clear. And this point is very important. The
law of inertia states that every body moves in a straight line with
constant velocity unless compelled by external influences to
change that state. But what is the meaning of the expression
"moves in a straight line"? In daily life it is quite clear; when

30

Conceptions of the Physical World before Einstein

a billiard ball moves parallel to an edge of a table it moves in a
straight line. But the table rests on the earth, which rotates about
the polar axis and also revolves about the sun. To someone out-
side the earth the same ball would seem to move in a very com-
plicated path. Hence the ball apparently moves in a straight line
only relative to a person in the same room.

Newton explained this point by defining "absolute motion,"
as "translations of a body from one absolute position to another/'
and then saying " 'absolute 5 motion is neither generated nor
altered, but by some force impressed upon the body moved."
Thus if we observe a ball moving parallel to an edge of a table
without any force acting on it, then the room can be regarded
as resting in "absolute space." Such "resting" rooms in which the
law of inertia holds were later called inertial systems. If a room,
say on a merry-go-round, rotates relative to the "resting" room,
then a ball cannot move parallel to an edge of a table standing
on the carousel without the exertion of some force. A merry-go-
round is no inertial system.

But what if the second room performs a uniform motion in
a straight line? The ball can then travel parallel to an edge with-
out the exertion of any force in the "moving" room. In fact, all
motion that occurs with uniform velocity in a straight line in
the first system will also take place with uniform velocity in a
straight line in the second system. Consequently the law of in-
ertia also holds in the "moving system," and it is true whatever
the velocity of the system is with respect to the "resting" room
as long as it takes place in the same direction with constant
magnitude.

When forces operate on the ball and its velocity does not re-
main constant but acceleration is introduced, the acceleration
will be the same in both systems. Hence the law of force, which
determines acceleration and is independent of the initial velocity,
is the same for both systems. Thus we cannot determine the
velocity with which the room moves in relation to the original
inertial system by means of experiments on the motion of par-
ticles performed in this room; and conversely, with the law of
force and the initial velocities, we can predict the future mo-
tions of particles without knowing anything about the uniform
velocity with which the room may be moving. All systems that
move uniformly along a straight line relative to an inertial sys-
tem are likewise inertial systems. But Newton's laws do not say
which material body is an inertial system.

For most practical purposes, the effect of the rotation and revo-

31

Einstein: His Life and Times

lution of the earth is very small, and its motion can be regarded
as a uniform motion in a straight line. Within this range the
earth is approximately an inertial system and we can predict
the motion of particles on the earth by means of Newton's laws.
The same can be done on railway trains, in elevators, and in
ships as long as their motion relative to the earth is in a straight
line with constant velocity. It is a common experience that we
can play with a ball in exactly the same way whether we are on
board a train or in a ship so long as it does not jerk or roll

This law concerning the possibility of predicting future mo-
tions from the initial velocities and the laws of force may be
called the relativity principle of mechanistic physics. It is a de-
duction from the Newtonian laws of motion and deals only
with relative motions and not, as Newton's laws proper, with
absolute motion. In this form it is a positive assertion, but it can
also be formulated in a negative way, thus: It is impossible by
means of experiments such as those described above to differen-
tiate one inertial system from another.

Thus the relativity principle first appeared as a characteristic
feature of Newtonian mechanics. As we shall see, it was Ein-
stein's greatest achievement to have discovered that this prin-
ciple still applies even when Newtonian mechanics is no longer
valid. He saw that the relativity principle is more suitable than
the Newtonian laws to serve as a basis for a general theory of
physical phenomena. It continues to remain valid even when
mechanistic physics becomes untenable.

5. Ether as a Mechanical Hypothesis

The explanation of optical phenomena such as reflec-
tion and refraction of light was first given in terms of two op-
posing theories. Newton had propounded the corpuscular theory,
in which light was considered as a stream of particles that be-
haved according to the laws of motion, while a contemporary
of his named Huygens had proposed the wave theory, in which
light was considered as a vibration in a certain medium in the
same way that sound is a vibration in air. The controversy was
settled about 1850 in favor of the wave theory by the French
physicists Arago and Foucault. Then the theoretical calculations
of Maxwell and the experimental work of Hertz established the
result that these vibrations associated with light are electromag-

32

Conceptions of the Physical World before Einstein

netic in nature ; that is, that light is due to very rapid oscillations
of electric and magnetic fields.

These vibrations which give rise to propagation of waves re-
quire a certain medium in which to oscillate. Sound is due to
vibrations of the molecules in the air; there is no sound in a
vacuum. Seismic waves, by which earthquakes are recorded, are
due to the vibrations of the interior matter of the earth. Water
waves are due to the motion of the water on the surface. But light
from distant stars reaches us even though there is apparently no
material medium in interstellar space. Nevertheless, according
to mechanistic physics, it is absolutely essential that the oscilla-
tions that give rise to propagation of light have some medium in
which to oscillate. This medium was called the ether.

Two questions arise when we consider the analogy between
sound waves in air and light waves in ether. When any object
such as an airplane or a projectile moves through air, there is a
certain resisting force due to the friction, and a certain amount
of air is dragged along with the object in its progress through
the air. Hence the first question : Is it possible to detect motion
of objects through the ether, say that of the earth as it revolves
around the sun? And the second: Does the ether impede the
progress of objects that move through it, and is there any drag-
ging effect?

In order to answer these questions it is necessary to consider
the properties of the propagation of light through the ether,
since it is only by means of light that ether manifests itself. Now,
if a flash of light is just like the spread of ripples on a stagnant
pond, its velocity of propagation will have a fixed value with
respect to the ether; and to any observer who is moving with
respect to it, the velocity will be greater or less depending on
whether the direction of the propagation and the motion of the
observer are in opposite directions or in the same direction. Thus
if the earth moves through the ether without dragging it along
in its revolutions around the sun, its velocity relative to the
ether should be observable by measuring the velocity of light
relative to the earth in different directions.

The fact that the earth moves through the ether without affect-
ing it is known by the aberration of starlight. The way in which
the spread of light from a star is seen by an observer on the
earth, which revolves around the sun, is like that in which a
person watches a performance on a stage from a platform that
revolves around it. It will appear to him that everything on
the stage exhibits periodic annual changes. Astronomers have

33

Einstein: His Life and Times

long known that the fixed stars undergo such annual apparent
motions. Thus the phenomenon of aberration shows that the
ether is not influenced by the motion of the earth.

The decisive experiment to find the relative motion of the
earth through the ether was first prepared at the United States
Naval Academy in 1879 by A. A. Michelson. It was carried out
afterward at the Astrophysical Observatory in Potsdam, where
he spent a year of research, and repeated later in the United
States. Michelson, who was the outstanding expert on precise
optical measurements, had arranged the experimental conditions
so that a definite measurement could be made even if the velocity
of the earth through the ether were only a small fraction of that
due to its revolution around the sun. The result, however, was
entirely negative. It was impossible to find any relative motion
of the earth through the ether.

Thus the mechanistic theory of light led to a dilemma. The
aberration showed that the earth moved through the ether with-
out disturbing it, but the Michelson experiment showed that it
was not possible to find the velocity with which the earth trav-
eled through the ether.

6. Remnants of Medieval Concepts in Mechanistic
Physics

In medieval physics the characteristic feature concern-
ing the motion of objects had been the revolution of the heavenly
bodies around the earth taken as the fixed center. This system
represented a kind of a universal framework within which every-
thing had its proper place, and motion within this system meant
motion relative to this framework. The problem of absolute
motion hardly appeared. Also a natural measure of time was
given by the period of revolutions of the heavenly bodies.

It may seem at first that the Copernican theory and the me-
chanics of Galileo and Newton had disrupted this "closed
world" of the Middle Ages, but a careful examination shows
that a similar concept was still retained in mechanistic physics,
Newton's law of inertia implied that freely moving objects can
travel beyond all spatial limits, but it was in relation to "abso-
lute space." Since the connection between absolute space and the
empirical content of physical laws was difficult to demonstrate,
the auxiliary concept of "inertial system" was introduced. It

34

Conceptions of the Physical World before Einstein

was not possible, however,, to explain why the law of inertia
should be valid in certain systems and not in others. This charac-
teristic was not related to any other physical property o the
system. Thus the inertial system still retained something of the
character of the medieval universal framework. Furthermore,
in extending the laws of mechanics to optical phenomena, it had
been found necessary to "materialize" space with ether. This
ether was a genuine universal framework. The motion of a
laboratory relative to it should be observable by means of optical
experiments.

The physicists of the mechanistic period always felt uneasy
in using the expressions "absolute space/' "absolute time/ 5 "ab-
solute motion/' "inertial system/ 5 and "universal ether." New-
ton himself did not succeed in explaining how one recognized
the motion of a body in "absolute space" by actual observation,
and he wrote: "It is indeed a matter of great difficulty to dis-
cover, and effectually to distinguish, the true motion of par-
ticular bodies from the apparent; because the parts of that
immovable space, in which those motions are performed, do
by no means come under the observation of our senses." Con-
sequently, if one remains within the bounds of physics, one
cannot give a satisfactory definition of "absolute motion." The
theory becomes completely and logically unobjectionable only
if, as was self-evident for Newton, God and his consciousness
are added to the physical facts.

For a long time no one had realized precisely what was the
actual link between Newton's theological reflections and his
scientific work. It was often asserted that they had no logical
connection and that his reflections were significant only from a
purely emotional standpoint or as a concession to the theological
spirit of his time. But this is certainly not so. Although there
might have been some doubt about this point earlier, yet since
the discovery of the diary of David Gregory, a friend and student
of Newton's, we know definitely that Newton introduced the
theological hypothesis in order to give his theory of empty and
absolute space a logically unobjectionable form. Gregory's diary
for 1705 contains an entry concerning a conversation with New-
ton on this topic. It says: "What the space that is empty of body
is filled with, the plain truth is that he [Newton] believes God
to be omnipresent in the literal sense; and that as we are sen-
sible of objects when their images are brought home within the
brain, so God must be sensible of everything, being intimately
present with everything: for he [Newton] supposes that as God

35

Einstein: His Life and Times

is present in space where there is no body, he is present in space
when a body is also present."

E. A. Burtt in The Metaphysical Foundations of Modern Physi-
cal Science, published in 1925, interprets correctly:

"Certainly, at least, God must know whether any given motion is
absolute or relative. The divine consciousness furnishes the ultimate
center of reference for absolute motion. Moreover, the animism, in
Newton's conception of force plays a part in the premise of the posi-
tion. God is the ultimate originator of motion. Thus in the last analysis
all relative or absolute motion is the resultant of an expenditure of
the divine energy. Whenever the divine intelligence is cognizant of
such an expenditure, the motion so added to the system of the world
must be absolute."

By means of this anthropomorphic conception of God, a scien-
tific, almost physical definition of absolute motion is obtained. It
is linked with the energy expended by a being called "God," but
to which properties of a physical system are ascribed. Otherwise
the concept of energy could not be applied to the system. Funda-
mentally the definition means that one assumes the existence
in the world of a real source of energy that is distinguished
from all others. Motion produced by the energy expenditure of
mechanical systems in general is described as only "relative"
motion, while motion produced by this select being is charac-
terized as "absolute." It should never be forgotten, however, that
the logical admissibility of this definition of absolute motion is
bound up with the existence of the energy-producing being.
During the eighteenth century, in the age of the Enlightenment,
men no longer liked to ascribe to God a part in the laws of
physics. But it was forgotten that Newton's concept of "absolute
motion" was thereby deprived of any content. Burtt in his afore-
mentioned book says very aptly: "When, in the eighteenth cen-
tury, Newton's conception of the world was gradually shorn
of its religious relations, the ultimate justification for absolute
space and time as he had portrayed them disappeared and the
entities were left empty.*'

7. Critics of the Mechanistic Philosophy

Toward the end of the nineteenth century more and
more physical phenomena were discovered that could be ex-
plained only with great difficulty and in a very involved way

36

Conceptions of the Physical World before Einstein

by the principles of Newtonian mechanics. As a consequence
new thories appeared in which it was not clear whether they
could be derived from Newtonian mechanics, but which were
accepted as temporary representations of the observed phenom-
ena. Was this true knowledge of nature or only a "mathematical
description/ 5 as the Copernican system was considered in
medieval physics ? These doubts could not be resolved so long
as it was believed that there were philosophical proofs accord-
ing to which reduction to Newtonian mechanics provided the
only possibility for the true understanding of nature.

During the last quarter of the nineteenth century a critical
attitude toward this mechanistic philosophy became more and
more evident. An understanding of this criticism is an essential
prerequisite for the understanding of Einstein's theory and its
position in the development of our knowledge of nature. As
long as it was believed that Newtonian mechanics was based
ultimately on human reason and could not be shaken by scien-
tific advance, every attempt such as that of Einstein, to establish
a theory of motion not founded on Newton's theory necessarily
appeared absurd. The critics of mechanistic philosophy plowed
the soil in which Einstein was then able to plant his seeds.

As the first of these critics, we may mention Gustav Kirchhoff,
the discoverer of spectral analysis. In 1876 he stated that the task
of mechanics was "to describe completely and as simply as pos-
sible motions occurring in nature." This meant that Newtonian
mechanics is itself only a convenient scheme for a simple presen-
tation of the phenomena of motion that we observe in daily
experience. It does not give us an "understanding" of these oc-
currences in any other philosophical sense. By thus contravening
the general opinion that Newton's principles of mechanics are
self-evident to the human mind, he created something of a sensa-
tion among natural scientists and philosophers.

Furthermore, with KirchhofFs conception that mechanics is
only a description of the phenomena of motion, the mechanical
explanations of the phenomena in optics, electricity, heat, etc.
the aim of mechanistic physics became simply descriptions
of these results in terms of a pattern that had been found to be
most suitable for mechanics. Why should one describe by this
roundabout method of using mechanics instead of trying to find
directly the most suitable scheme for the description of various
phenomena? Newtonian mechanics was thus deprived of its
special philosophical status.

In 1888 Heinrich Hertz discovered the electromagnetic waves,

37

Einstein: His Life and Times

which form the basis of our modem wireless telegraphy and
radio, and he then set out to explain these phenomena in terms
of a physical theory. He took as his starting-point Maxwell's
theory of electromagnetic fields. James Clerk Maxwell had de-
rived his fundamental equation from mechanistic physics by
assuming that electromagnetic phenomena are actually mechan-
ical oscillations in the ether. Hertz noticed that in doing this
Maxwell had been compelled to invent mechanisms that were
very difficult to calculate, and found it was simpler to represent
electromagnetic phenomena directly by means of Maxwell's
equation between electric and magnetic fields and charges. Since
it was also evident to him, however, that these relations could
not be derived directly from experience, he was led to a consid-
eration of the logical character of these equations. In 1889 he
made a remark that can be regarded as the program for the new
approach to physics, a conception that was eventually to replace
the mechanistic view. Hertz said:

"But in no way can a direct proof of Maxwell's equations be de-
duced from experience. It appears most logical, therefore, to regard
them independently of the way in which they had been arrived at,
and consider them as hypothetical assumptions and let their plausi-
bility depend upon the very large number of natural laws which they
embrace. If we take up this point of view we can dispense with a
number of auxiliary ideas which render the understanding of Max-
well's theory more difficult."

Thus Hertz consciously abandoned that which during both
the organismic and the mechanistic period was described as the
"philosophical" foundation of physics. He maintained that it
was sufficient to have a knowledge of laws from which phe-
nomena could be calculated and predicted without raising any
question of whether these laws were intrinsically evident to the
human mind.

8. Ernst Mack: The General Laws of Physics Arc
Summaries of Observations Organized in
Simple Forms

The criticisms of the mechanistic philosophy by physi-
cists such as Kirchhoff and Hertz were only occasional and
aphoristic. There were others, however,, whose criticisms were

38

Conceptions of the Physical World before Einstein

based on a very precise conception of nature and of the task of
science. The French philosopher Auguste Comte advanced the
sociological theory that the "metaphysical" stage in the develop-
ment of a science is already succeeded by a "positivistic" one. This
means that the demand for the use of a specific analogy such
as the organismic and mechanistic views is abandoned and after
that a theory is judged only as to whether it presents "positive"
experience in a simple, logically unobjectionable form.

This approach was most widely and profoundly developed
by the Austrian physicist Ernst Mach, who became one of Ein-
stein's immediate forerunners. Mach carried out a thorough his-
torical, and logical analysis of Newtonian mechanics and showed
that it contains no principle that is in any way self-evident to
the human mind. All that Newton did was to organize his
observations of motion under several simple principles from
which movements in individual cases can be predicted. But all
these predictions are correct only so long as the experiences
upon which Newton based his principles are true.

Mach emphasized, in particular, the demand for simplicity
and economy of thought in a physical theory: the greatest possi-
ble number of observable facts should be organized under the
fewest possible principles. Mach compared this requirement to
the demand for economy in practical life and spoke of the "eco-
nomic" nature of scientific theories. Thus Mach, instead of
demanding the use of a specified analogy, insisted that science
be "economical."

Furthermore, not only did Mach criticize the attempts of
philosophers to make a philosophical system out of Newton's
mechanics, but he also criticized the remains of medieval physics
that it still retained. He pointed out that Newton's theory con-
tained such expressions as "absolute space" and "absolute time,"
which cannot be defined in terms of observable quantities or
processes. In order to eliminate such expressions from the funda-
mental laws of mechanics, Mach raised the demand which
is now frequently described as the positivistic criterion of sci-
ence: namely, that only those propositions should be employed
from which statements regarding observable phenomena can
be deduced.

This demand is very aptly elucidated by his criticism of New-
ton's law of inertia. If we wish to test this law experimentally,
we can never formulate a question such as this : Does a body tend
to maintain the direction of its initial velocity relative to abso-
lute space ? The question is meaningless since absolute space is

39

Einstein: His Life and Times

unobservable. If we perform, say, Foucault's pendulum experi-
ment, which gives an experimental proof of the rotation of the
earth, we observe actually that the pendulum maintains its plane
of oscillation relative, not to absolute space, but rather to the fixed
stars in the sky.

Consequently, according to Mack, all mention of absolute
space should be removed from the law of inertia, and it would
then be expressed as follows: Every body maintains its velocity,
both in magnitude and in direction, relative to the fixed stars
as long as no forces act upon it. This means that the fixed stars
exert an observable influence on every moving body, an effect
that is in addition to and independent of the law of gravitation.
For the motion of terrestrial objects this latter influence is hardly
observable in practice, since the force of gravity decreases with
the square of the distance between the attracting bodies, but the
laws of inertia will determine all terrestrial motion if the frame-
work of the fixed stars is declared as an inertial system.

9. Henri Poincare: The General Laws of Physics Are
Free Creations of the Human Mind

In consequence of the criticisms of Mach and others, it
had become clear that the laws of Newtonian mechanics and the
understanding of all physical phenomena in terms of it are not
demanded by human reason. However, Mach's assertion that the
general laws of physics are only simple economical summaries
of observed facts was not satisfactory to many scientists. Particu-
larly for physicists who thought along mathematical lines and
had a greater formal imagination, the assertion, for example, that
Newton's law of gravitation is only a simple summary of observa-
tion on the positions of the planets did not seem adequate. Be-
tween the actual observation of the position of the planets by a
telescope and the statement that the gravitational force between
two bodies is inversely proportional to the square of the distance
there seemed to be a wide gap.

Criticism of nineteenth-century physics in this direction was
carried on chiefly by the French mathematician Henri Poincare.
His writings on the logical character of the general laws of na-
ture probably exerted more influence on mathematicians and
physicists toward the end of the nineteenth century than any
other similar writings. He paved the way for a new, logically

40

Conceptions of the Physical World before Einstein

satisfying conception of nature, and his ideas also played an
outstanding part in the reception and discussion of Einstein's
theories.

Poincare's view is often described as "conventionalism." Ac-
cording to him,, the general propositions of science, such as the
theorem about the sum of the angles of a triangle, the law of
inertia in mechanics, the law of conservation of energy, and so
on, are not statements about reality, but arbitrary stipulations
about how words, such as "straight lines," "force," "energy," are
to be employed in the propositions of geometry, mechanics, and
physics. Consequently one can never say whether one of those
propositions is true or false; they are free creations of the human
mind and one can only question whether these stipulations or
conventions have been expedient or not.

This conception may be elucidated by means of two examples.
Let us first consider the geometrical theorem referred to above:
namely, that the sum of the angles of a triangle is equal to two
right angles. According to nineteenth-century tradition this is
an unshakable proposition, which is a product of human reason-
ing and at the same time a statement concerning what is actually
observed in nature. On the one hand, we can derive this propo-
sition from the axioms of geometry, which are "directly evident
to the mind"; on the other hand, by measuring the angle of an
actual material triangle, we can corroborate this relationship.
Poincare, however, says: if an actual triangle is formed from,
say, three iron rods, and the measurement shows that the sum
of the angles is not exactly equal to two right angles, one of two
different conclusions can be drawn: either that the geometrical
theorem is not valid, or that the rods forming the triangle are
not straight lines. We have the two alternatives, and we can
never decide by experiments the validity of geometrical theorems.
Consequently we can say that the propositions of geometry are
arbitrary stipulations or definitions and not statements about
empirical facts. They establish under what circumstances we
wish to call a rod a "straight line." Thus geometrical theorems
are not statements about the nature of space, as it is often ex-
pressed, but rather definitions of such words as "straight lines."

According to Poincare, the laws of mechanics are of somewhat
similar character to the propositions of geometry. Let us, there-
fore, consider the law of inertia as the second example. The pos-
sibility of verification of the law rests on our ability to determine
whether or not a body moves with uniform velocity in a straight
line. As long as we cannot do this, the law of inertia can only

41

Einstein: His Life and Times

be characterized in some such statement as this: "When a body
moves without being influenced by forces,, we call this state a
uniform motion along a straight line." It is simply a definition
of the expression "uniform motion in a straight line/' or, accord-
ing to our discussions in sections 3 and 4, a definition of the term
"inertial system."

Thus the general principles, such as the theorem about the
sum of the angles of a triangle or the law of inertia, do not
describe observable phenomena, but are rather definitions of ex-
pressions such as "straight line" or "uniform motion along a
straight line." One has to add definitions by which one recog-
nizes whether a given rod is straight or the motion of a ball
is uniform and along a straight line and which have been named
"operational definitions" by P. W. Bridgman. These, together
with the physical laws (e.g., the law of inertia), constitute a
a system of propositions that can be verified by experience.

One of the chief consequences of this conception is that it
makes no sense in science to inquire into the philosophical sig-
nificance or the "nature" of such physical expressions as "force,"
"matter," "electric charge," "duration of time," etc. The use of
such concepts is always justified if statements permitting ex-
perimental verification can be derived from the propositions in
which these expressions occur. Apart from this they have no
meaning. Because Newtonian mechanics was able to describe
very complex phenomena such as the motion of the planets in
simple statements with the aid of the words "force" and "mass,"
these terms have scientific meaning. There is no need to puzzle
one's brain over whether "force" can be explained from a "mech-
anistic" standpoint or "matter" from an "organismic" one.
"Force" and "matter" are constructions of the human mind.

10. Positivistic and Pragmatic Movements

The idea of Mach that the general laws of science are
simple summaries of experimental facts, and the idea of Poin-
care that they are free creations of the human mind, appear to
be diametrically opposed to each other; but when we consider
the intellectual currents of the last quarter of the nineteenth cen-
tury, we can see that they were only two wings of the same
intellectual movement, generally known as the positivistic move-
ment. It was directed chiefly against the metaphysical founda-

42

Conceptions of the Physical World before Einstein

tions of science. The proponents of this view asserted that the
validity of the general principles of science cannot be proved by
showing that they are in agreement with some eternal philo-
sophical truths, and they set out to investigate how the validity
can be judged within science itself. They found that two criteria
are possible, an empirical and a logical. In the former the observ-
able facts that follow from the general principles must have
experimental confirmation, and in the latter the principles and
operational definitions must form a practical and consistent sys-
tem. The emphasis put on the empirical or the logical criterion
determined one's position in one or the other wing of the
movement. Mach was on the extreme empirical wing, while
Poincare was on the extreme logical side. There was therefore
no conflict between them; it was only that two different aspects
of the same scientific method were being emphasized.

The positivistic movement exerted a great influence in central
and western Europe during the last quarter of the nineteenth
century. The central European positivism, chiefly centered in the
Austrian Ernst Mach, was to be found in the universities of
Vienna and Prague. It had but little influence and few followers
in the universities of the German Reich. At this time Germany
was completely under the influence of various versions of Kan-
tian philosophy, whose status was almost that of a state religion.
Since German was also the chief language of science in Austria,
Central European positivism developed largely as the critic and
rival of Kantian philosophy. For this reason it was more mili-
tant than French positivism, led by Poincare.

About this time there appeared independently in the United
States a movement that is related to European positivism in its
chief line of thought. In 1878 C. S. Peirce published an essay
on the logical character of scientific statements. Like Mach and
Poincare, he pointed out that the meaning of general statements
cannot be derived from agreement with still more general meta-
physical truths, but must be drawn from the observed facts that
follow from them. In contrast to the European positivists, how-
ever, Peirce emphasized particularly the role of propositions as
the basis for our actions. He therefore called his doctrine "prag-
matism." "The essence of a belief/' he said, "is the establishment
of a habit, and different beliefs are distinguished by different
modes of action to which they give rise." Like Mach, Peirce alsc
warned against the trivial metaphysics that we have imbibed
with our education since childhood. He said: "The truth is that
common sense or thought as it first emerges above the level oJ

43

Einstein: His Life and Times

the narrowly practical is deeply imbued with that bad logical
quality to which the epithet metaphysical is commonly applied."
He also emphasized that words such as "force" are only expedi-
ents for the representation of facts and that every question as
to their "actual nature" is superfluous and useless. In the same
article he said:

"Whether we ought to say that a force is an acceleration or that it
causes an acceleration is a mere question of propriety of language
which has no more to do with the real meaning than the difference be-
tween the French idiom *il fait froid* and the English equivalent
'it is cold.'"

An approach very similar to that of Mach was manifested by
John Dewey in his first scientific article: "The Metaphysical
Assumptions of Materialism/' published in 1882. Dismissing the
opinion that the reduction of all phenomena to the motions of
material bodies is an explanation of nature, he said:

"First, it assumes the possibility of ontological knowledge, by which
we mean knowledge of being or substance apart from a mere suc-
cession of phenomena. . . . Secondly, it assumes the reality of causal
nexus and the possibility of real causation. In declaring that matter
causes mind it declares that the relation is one of dependency and
not one of succession."

The struggle against materialism here is not carried on in the
service of an idealistic philosophy, as with the average professors
of philosophy in European and American universities, but en-
tirely along the lines of central European positivism, which op-
posed mechanistic physics on the ground that it is not a suf-
ficiently broad basis of science.

American pragmatism since then has developed into a power-
ful movement, finding its most characteristic expression in John
Dewey and William James. It has devoted itself more to the
problems of human life than to the logic of the physical sciences,
in contrast to the development of positivism in Europe, Consid-
ered from the purely logical point of view, however, the basic
tendency was the same on both sides of the Atlantic, The medie-
val idea of a philosophical explanation in contrast to a practical
representation of facts vital to life lost prestige to an ever in-
creasing degree. From a logical basis of science, metaphysics
developed into a means of satisfying emotional needs.

44

Conceptions of the Physical World before Einstein

ii. Science at the End of the Nineteenth Century

During the golden age of mechanistic physics it was
generally felt that outside of its application lay the realm of the
unknowable and the unintelligible, since "to understand" meant
"to represent by analogy to a mechanism." In 1872 the German
scientist Du Bois-Reymond, in his famous lecture on "Die
Grenzen des Naturerfcnnens (The Limits of Our Knowledge
of Nature)" took as his point of departure the assertion, then
regarded as self-evident, that "understanding" means "reduc-
tion to the laws of Newtonian mechanics." He indicated two
important problems of science that can certainly not be reduced
to mechanics. These are, first, the problem of what "actually
occurs in space where a force is acting" and, secondly, how it
happens that "matter in the human brain can think and feel"
Since the answers to these questions can obviously not be ob-
tained within the framework of mechanistic physics, he con-
cluded that there are "insoluble problems" that are inaccessible
to human knowledge. To these questions we should say "igno-
rabimus" ("we shall never know") instead of "ignoramus" ("we
do not know"). This word "ignorabimus" became the slogan
of an entire period, the slogan of defeatism in science, which de-
lighted all anti-scientific tendencies of the period. Toward the
end of the nineteenth century more and more facts became
known in physics and biology that could not be explained or
controlled by means of the laws of mechanics, with the result
that the catchword "ignorabimuf was soon converted into the
even more exciting slogan, "the bankruptcy of science."

This feeling of the failure of rational scientific thought was
Intensified by various social developments. Science that is,
science guided by the spirit of mechanistic physics had led men
during the eighteenth and nineteenth centuries to believe in the
possibility of continual progress. If men only acted according to
the teachings of science instead of irrational superstitions, man-
kind would be freed from all need. The political expression of
this faith was liberalism. Toward the end of the nineteenth cen-
tury, however, it became ever clearer that the attempts based on
science and the faith in progress had not succeeded in abolishing
the economic misery of the great mass of the population, or in
eliminating the psychological suffering of individual human be-
ings. A feeling of despair developed which expressed the con-

45

Einstein: His Life and Times

viction that scientific theory and practice were a disappointment.
Alongside liberalism, new political currents developed that had
their own conceptions of science, conceptions differing from the
mechanistic view. One tendency propagated a return to the
organismic science of the Middle Ages, and from it developed
the authoritarian socialism that became the germ-cell of later
fascism in all its varieties. Another movement, represented by
Karl Marx, wanted to transform "mechanistic" materialism into
"dialetical" materialism, and from it developed the communism
of the twentieth century.

It was impossible to deny that science was still the basis of
technological progress, but it was believed that it could be dis-
paraged by speaking of it as the church did about the Copernican
system of the world: that mechanistic natural science provided
only a useful guide for action, and no true knowledge of nature.
Around 1900 Abel Rey, a French philosopher and historian of
science, gave a very acute and trenchant description of the dan-
gers for general intellectual life entailed by such an attitude of
despair. He said:

"If these sciences which have had an essentially emancipating effect
in history go down in a crisis which leaves them only with the sig-
nificance of technically useful information but robs them of every
value in connection with the cognition of nature, this must bring
about a complete revolution. The emancipation of the mind as we
owe it to physics is a most fatally erroneous idea. One must introduce
another way, and give credit to subjective intuition, to a mystical
sense of reality."

There have been two ways out of this crisis of science which
had developed in consequence of the breakdown of mechanistic
physics. In his book The Idealistic Reaction against Science,
Aliotta, an Italian, described the situation in the following very
striking manner :

"Could thought rest easy in this complacent agnosticism? There
were two ways o escaping this intolerable situation: either to turn
to the other function of the mind (besides intellect) or to eliminate
the problem altogether by proving that it is due to a faulty perspective
and false conception of science. Both ways have been tried. On the
one hand, by a return to the moralism of Fichtc and the sestheticism
of the romanticists, into which the rebellious genius of Nietzsche has
breathed new life, the will as the creative source o all values and o
unfettered esthetic intuition is exalted above intelligence. On the
other hand, the bases of the mechanical conception and its chief in-
strumentsgeometrical intuition and mathematical calculation

Conceptions of the Physical World before Einstein

are subjected to a searching examination. This analysis, to which men
o science themselves were impelled by the discovery of the new
principle of energy and by metageometrical concepts, resulted in
stress being laid upon the active work of the mind in the construc-
tion of scientific laws and theories."

The second alternative mentioned here was the view taken
by the advocates of positivism and pragmatism. Their way out
of the "bankruptcy of science" was to proclaim that mechanistic
science had formulated the problem in a manner that necessarily
led into a cul-de-sac; it had not correctly defined the goal of
science. The unattainable something, for which the despairing
solution of "ignorabimus" was proposed, had been recognized as
a phantom, a chimera that has nothing to do with science.
Through an analysis of the really successful methods of science,
men such as Mach and Poincare in Europe, and Peirce and Dewey
In America, have shown that it is of no significance whatso-
ever whether observations are presented in terms of a certain pre-
ferred analogy. All that matters Is that the statements of science
are useful; the specific language and the equation by which they
are formulated do not matter. Thus with the goal of science de-
fined in the positivistic and pragmatic sense, it becomes evident
that the end of the nineteenth century does not represent a crisis,
but rather one phase of the gradual progress of science toward
its goal, which is the creation of an instrument for predicting and
controlling the phenomena.

In a certain sense this positivistic-pragmatic movement, so
characteristic of the turn of the century, belonged to the group
of movements that were directed against the overestimation of
the role of the intellect. Professor Ralph Barton Perry very cor-
rectly said:

"Much the most sophisticated form of anti-intellectualism and at
the same time the form most characteristic of our age is that form
which has now come very generally to be called 'instrumentalism'
and which is represented at present by the school of James and Dewey
in America. . , . According to this view the intellect instead of being
an oracle is a practical instrument to be judged by the success with
which it does work."

Nevertheless, the new movement, no matter whether It was
called pragmatism, positivism, or instrumentalism, could be
characterized as anti-intellectual only in so far as it warned
against occupying the intellect with meaningless problems. The
adherents said that the intellect is unable to discover the meta-

47

Einstein: His Life and Times

physical reality behind phenomena. But this is not a diminution
of its role, since to speak of such a metaphysical reality does not
make sense for science. It is sterile and leads only to confusion.
The creation of an "instrument," which is now what is meant by
"science," can be accomplished only by means of the intellect,
even though we cannot produce a blueprint for discovering gen-
eral principles. The discovery of laws such as the energy prin-
ciple or the law of inertia is the work of a genius, like the com-
position of a symphony. But when the general law has been
enunciated, it is then the function of the methodically proceed-
ing intellect to make its meaning clear to all Only the intellect
can test the principle and pronounce judgment on its truth
that is, whether it is of value in realizing the aims of science.

So ends the nineteenth century. Its faith in the ability of sci-
ence to reveal the ultimate reality behind phenomena was
shaken; but in its place appeared the sober consolation of positiv-
ism that science had become more flexible and girded for new
tasks of a boldness never dreamed of. During the twilight period
characterized by a devaluation of the intellect and an increased
regard for action, there appeared, like a silver glow on the hori-
zon, the hope that a more acute logical analysis would give an
entirely new form of science based on a methodically operating
intellect. The twentieth century ushered in this dawn.

Ill

BEGINNING OF A NEW ERA IN PHYSICS

i. Life in Bern

When Einstein took up his position at the patent office
in Bern, it was in two respects a turning-point in his life. He be-
came engaged in a practical occupation that made him finan-
cially independent and filled his time with an obligatory activity,
and he founded a family. For most people these two circum-
stances provide the most important and often the only content
of their lives. This was true only to a very slight degree for Ein-
stein, to whom neither professional activity nor a family had a
great significance. At times these activities gave him a certain
relaxation, but they never really satisfied him.

Throughout his life Einstein has been in a certain sense a very
lonesome man. He sought the harmony of the universe in music
as well as in mathematical physics and he has been engaged in
these two fields during his entire life. Everything else was sig-
nificant for him only in so far as it affected his progress toward
this goal. He sought friends with whom he could play music or
discuss ideas about the universe; yet he did not like to become so
intimate with his friends that they could in any way interfere
with his freedom. His attractive, frank, and witty personality
easily made many friends, but his predilection for isolation and
his concentration on his artistic and scientific life disappointed
many people and estranged some who had been, or at least had
believed themselves to be, his friends. We find repeatedly that
throughout his life this contrast has determined his relations to
his environment.

Much later (1930) he himself described this character trait
very precisely and strikingly:

"My passionate interest in social justice and social responsibility has
always stood in curious contrast to a marked lack of desire for direct
association with men and women. I am a horse for single harness, not
cut out for tandem or teamwork. I have never belonged wholeheart-
edly to any country or state, to my circle of friends, or even to my
own family. These ties have always been accompanied by a vague

49

Einstein: His Life and Times

aloofness, and the wish to withdraw into myself increases with the
years. Such isolation is sometimes bitter, but I do not regret being
cut off from the understanding and sympathy of other men. I lose
something by it, to be sure, but I am compensated for it in being
rendered independent of the customs, opinions, and prejudices of
others, and arn not tempted to rest my peace of mind upon such
shifting foundations."

Although Einstein did not seek much stimulation from others,
yet he did not like to develop his ideas in solitude without any
contact with other people. Frequently he has liked the presence
of a companion in order to be able to speak his mind freely. Even
during the early period in his career he liked to try out his ideas
on others to see how they reacted to them.

At Bern his chief companion in this respect was an Italian
engineer named Besso. He was somewhat older than Einstein,,
and a man of critical mind and a highly nervous temperament.
He was often able to offer pertinent critical remarks on Ein-
stein's formulations, and also responded vigorously to those ideas
of Einstein's which were new and astonishing. He frequently
remarked about new ideas: "If they are roses, they will bloom."
Around Einstein and Besso there gathered a small group of peo-
ple interested in science and philosophy, who often met to dis-
cuss such questions.

2. Interest in Philosophy

Since Einstein was chiefly interested in the general laws
of physics or, more precisely, in deriving logically the immeasur-
able field of our experiences from a few principles, he soon came
into contact with a set of problems that are usually dealt with in
philosophical works. Unlike the average specialist, he did not
stop to inquire whether a problem belonged to his field or
whether its solution could be left to the philosophers.

Einstein read philosophical works from two points of view,
which were sometimes mutually exclusive. He read some authors
because he was actually able to learn from them something about
the nature of general scientific statements, particularly about
their logical connection with the laws through which we express
direct observations. These philosophers were chiefly David
Hume, Ernst Mach, Henri Poincare, and, to a certain degree,

50

Beginning of a New Era in Physics

Immanuel Kant. Kant, however, brings us to the second point
of view. Einstein liked to read some philosophers because they
made more or less superficial and obscure statements in beautiful
language about all sorts of things, statements that often aroused
an emotion like beautiful music and gave rise to reveries and
meditations on the world. Schopenhauer was pre-eminently a
writer of this kind, and Einstein liked to read him without in
any way taking his views seriously. In the same category he
also included philosophers like Nietzsche. Einstein read these
men, as he sometimes put it, for "edification/ 5 just as other peo-
ple listen to sermons.

The philosopher whose views Einstein felt helped him most
was David Hume, who is usually characterized as the "represent-
ative of the English Enlightenment." What Einstein liked most
about Hume was the unsurpassable clarity of his presentation
and his avoidance of any ambiguities intended to give an im-
pression of profundity. Hume showed that there are only two
methods available for science: experience and mathematical-
logical derivations. He was the father of the logical-empirical
approach, and he rejected all metaphysical auxiliary concepts
if they could not be established by experience and logical
derivation. The most famous examples are Hume's criticism
of the ordinary conception of the relation between cause and
effect, and of induction the method of deriving a general law
from a few particular instances.

When we observe that a stone A strikes a stone B and sets it
in motion, we usually express this occurrence as follows: Stone
A has caused stone B to move. By experience we can only con-
firm the fact that whenever A strikes B, B is set in motion. Before
Hume it was usually said that this connection is a necessary one.
In physics, however, the word "necessary" can have no meaning
other than "regularly connected." If in addition to this we wish
to introduce the word "necessary" as "cause" in another, higher
sense, we are asserting something that cannot be proved by any
observation. Every observation shows only whether or not the
motion of B regularly follows when it is struck by A, but never
anything that can be expressed by the statement; "Motion of B
necessarily follows from collision with A! 3

According to Hume, then, to explain a phenomenon causally
means only to state the conditions under which it occurs. This
conclusion of Hume's that science knows only the regularity of
natural phenomena and processes, but nothing about any "causa-
tion" that goes beyond this, was of the greatest significance for

Einstein: His Life and Times

Einstein's scientific thought. Many of the polemics later directed
against Einstein were fundamentally polemics against Hume.
We shall see that his adherence to the 'philosophy of the Eng-
lish Enlightenment" was later used by German nationalists to
discredit him. It was used to tie up Einstein's theories with the
political philosophy of liberalism, and consequently to condemn
them.

Some of Hume's ideas also appear in the writings of Ernst
Mach, the leader of central European positivism. Next to Hume,
Mach was the philosopher who exerted the greatest Influence
on Einstein. Of particular significance was Mach's criticlsin of
the remains of medieval physics in Newtonian mechanics, which
have already been discussed in Section 8 of the last chapter.
Mach's criticism that such expressions as "absolute space," "ab-
solute time/' and "absolute motion" could not be connected in
any way with physical observations was one of the points from
which Einstein set out to replace Newton's theory of motion by
his own. "Mach's postulate" has in many instances been^a use-
ful point of departure for new theories. According to this "postu-
late," for every physical phenomenon the conditions of its oc-
currence must be sought among other observable phenomena.
Later "Mach's postulate" led Einstein to advance his new theory
of gravitation.

On the other hand, Einstein was not particularly sympathetic
to what he called the "Machian philosophy," by which he meant
Mach's doctrine that the general laws of physics are only sum-
maries of experimental results. Einstein believed that this con-
ception did not give sufficient credit to the fact that general laws
cannot be inferred from experience. In Einstein's opinion they
are to be tested by experience, but owe their origin to the inven-
tive faculty of the human mind.

It was this very point that Einstein esteemed so highly in
Kant's work. Kant's principal point was that the general laws of
science contain not only the result of experience, but also an
element provided by human reason. On the other hand, Einstein
did not share Kant's belief that human reason by itself can yield
important natural laws, and that consequently there are laws
that are eternally valid. Einstein liked to read Kant because
through him he became acquainted with many of Hume's ideas.
The views of Einstein and Kant are similar in their emphasis
on the role of the human mind, but this similarity is rather emo-
tional than logical.

52

Beginning of a New Era in Physics

3. The Fundamental Hypotheses of the Theory of
Relativity

The blind alley into which the ether theory of light
had been led by Michelson's experiment has already been men-
tioned in Section 5 of the previous chapter. Michelson had tried
to measure the velocity of the earth as it moves through the
ether, but had obtained the value zero for this velocity.

The main idea of this experiment can be explained in this way :
We know that a swimmer takes longer to swim upstream than
downstream between two points in the bank. In f act., by measur-
ing the two rates of travel,, we can easily calculate the velocity
of both the swimmer and the stream. According to the mechanis-
tic view, light should travel through the ether in exactly the same
way as the swimmer in the stream, and experiments on light
propagated through the "stream of ether" relative to the moving
earth should be comparable to observations on the swimmer
made from the bank of the stream. Thus the measurements of
the velocities of light when traveling with the ether stream and
against it should enable us to calculate the velocity of the earth
through the ether. The execution of this fundamental idea in
this simple form, however, is not practicable, since the velocity of
light is so very great 186,000 miles per second but Michelson
devised a means whereby the velocities of light that has traveled
along two well-defined paths could be compared. His idea was to
measure the diff erence in time taken by one beam, which travels
from a certain point (S) to a mirror (M ) in a direction along
the motion of the earth through the ether and then back to S
against the motion, and another beam which goes from S to an-
other mirror (JV) situated the same distance from S as M, but in
a direction perpendicular to the motion and back to S. If the
mechanistic view is correct, the first beam should take a slightly
longer time than the second, and with the sensitive apparatus
that Michelson had, the result should have been observable, even
if the velocity of the earth through the ether were only a small
fraction of the velocity of the earth around the sun. There was
no observable difference in the two times, however.

If we refuse to assume that the earth always remains at rest in
the ether, which would contradict other observations, the only
possible conclusion that we can draw from Michelson's experi-

53

Einstein: His Life and Times

ment is that the hypothesis on which the result was predicted
must be false. This hypothesis, however,, was the mechanistic
theory of light itself.

Einstein drew a radical conclusion and suggested abandoning
entirely the assumption that light is a process in a medium
known as the ether. Instead of asking what are the results of the
interaction of light and motion according to the ether theory of
light, he asked what are the chief characteristics of the inter-
action of light and motion that are known from actual observa-
tions. He condensed these features into a few simple laws and
then inquired what could follow from such laws if developed
along logical and mathematical chains.

Michelson's experiment and similar ones performed by others
showed that optical phenomena cannot be regarded as mechani-
cal phenomena in the ether, but that they do have a very general
observable feature in common with mechanical phenomena.
This feature which is common to the motion of material bodies
and the propagation of light Einstein found in the principle of
relativity.

As we have seen in Section 4 of the last chapter, Newtonian
mechanics contained a relativity principle, which stated that the
future motion of any object with respect to an inertial system
can be predicted from its initial position and velocity with re-
spect to this system, without any knowledge of the motion of
the inertial system itself.

Now, if we disregard the existence of the ether, the null
result of Michelson's experiment means exactly that the result
can be predicted from the experimental arrangement in the
laboratory without any knowledge of its speed with respect
to the celestial bodies. Since similar statements could be made
for other optical phenomena, Einstein proposed to extend the
relativity principle of Newtonian mechanics to include optical
phenomena in the following form: "The future course of op-
tical phenomena may be predicted from the conditions of the
experiment relative to the laboratory in which it is carried out,
without knowing the velocity of the laboratory in the universe."
Thus, according to Einstein, the connection between mechanical
and optical laws is not based on a reduction of optics to mechan-
ics, but rather on the fact that one and the same general law
holds for both.

Besides this "principle of relativity," Einstein needed a second
principle dealing with the interaction of light and motion. He
investigated the influence of the motion of the source of light on

54

Beginning of a New Era in Physics

the velocity o the light emitted by it. From the standpoint of the
ether theory, it is self-evident that it makes no difference whether
or not the source of light moves; light considered as mechanical
vibration in the ether is propagated with a constant velocity with
respect to the ether. This velocity depends only on the elasticity
and density of the ether.

Dropping the ether theory of light, Einstein had to reformu-
late this law into a statement about observable facts. There is one
system of reference, F (the fundamental system), with respect
to which light is propagated with a specific speed, c. No matter
with what velocity the light source moves with respect to the
fundamental system (F), the light emitted is propagated with
the same specific velocity (c) relative to F. This statement is
usually called the "principal of the constancy of the speed of
light."

The constancy of the speed of light has been confirmed em-
pirically from the observation in double stars. They are stars of
approximately equal masses, which are close together and re-
volve about each other, and are well known to astronomers. If
the velocity of light depended on the velocity of the source, then
as the stars revolve, the time taken for light to reach the earth
from the member of the pair that is approaching the earth will
be shorter than the corresponding time of the light from the
receding member. Analysis of the two beams of light has shown
that there is no observable effect from the velocity of the source.

4. Consequences of Einstein's Two Hypotheses

It was a characteristic feature of Einstein's mode of
work to deduce from his fundamental principles all the logical
consequences to the limit. He showed that from these hypotheses,
which appeared quite harmless and plausible, a rigorous de-
duction led to results that seemed very novel and in part even
"incredible." From these results he went on to others, which not
only seemed incredible but were even pronounced "paradoxi-
cal," "absurd," and "incompatible with sound logic and psy-
chology."

There are at present thousands of papers in which attempts
are made to explain Einstein's theory to the lay public. It is not
the purpose of this book to go into all the details of his theories,
but to give a description of Einstein's personality and his rela-

55

Einstein: His Life and Times

tion to his environment. It is necessary, however, to go into his
scientific work to a certain extent in order to give the reader
some idea of the manner in which he attacked scientific prob-
lems in comparison with that of other scientists. In particular
we should try to understand how it happened that his theories
not only were of interest to physicists, but also stimulated and
excited philosophers, thus indirectly stirring up a public that
had only slight interest in scientific questions but that partici-
pated in the general intellectual life of our period.

From the two basic assumptions Einstein was able to conclude
not only that the mechanistic theory of light was erroneous, but
that even the Newtonian mechanics of material objects could
not be generally valid. This result can be fairly easily under-
stood if we trace it back to the way Einstein speculated on the
properties of light as early as at the age of sixteen.

While still a student, Einstein had pictured to himself the
remarkable things that would occur if a body could travel with
the speed of light at the rate of 186,000 miles per second. Let
us consider the fundamental system (F) and a laboratory (L)
for optical experiments which moves with constant velocity (v)
with respect to F. Let there be a source of light (R) at rest in F,
from which a beam of light is propagated with velocity c in the
same direction as the laboratory (L) is moving. Now, if the
velocity (V) of the laboratory (L) is equal to the velocity of
light (c) then, according to Newtonian mechanics, the ray of
light will be stationary with respect to the laboratory. No vibra-
tion is registered in L. Since light does not move with respect
to L, there are no rays in L, and the usual experiments of reflec-
tion and refraction cannot be performed (fig. i).

It is, of course, imaginable that in such a rapidly moving sys-
tem (L) there would no longer be any optical phenomena in
the ordinary sense. This occurrence, however, would be incon-
sistent with Einstein's principle of relativity in optics. For accord-
ing to this principle, all optical experiments should give the
same result whatever the speed (V) of the laboratory may be.

The same difficulty appears if we compare directly the results
of Einstein's two principles (relativity and constancy) within
the ether theory of light. We consider again a laboratory that
is moving with the speed of light (c) relative to the fundamental
system (F) . Suppose a mirror is set up in L to reflect the beam of
light emitted by a source that is at rest in L. With respect to L
this reflection is just the ordinary occurrence of light reflected by
a mirror at rest. According to the principle of constancy, how-

2T

\

\

3T L

4T

\

\

B

FIGURE I

This diagram represents light waves propagated in a horizontal direction through
the ether. If T is a half-period of the light, the first line represents the state of the
wave at the time T after the emission from the source R. The other lines represent
the states of the same wave after the times 2T, 3T, and 4T respectively. If a device
is placed at a fixed spot in the ether it will record the state of the wave (along the
line OA) at the consequent instances of time T, 2T, 3T, and 4.T. These states are rep-
resented by the interrupted lines. They indicate a vibration. But if the device of
registration is moving with the speed of light in the direction of the wave propaga-
tion, it is recording the states of waves along OB. They are represented by a thick
line. It is clear that no vibration is recorded by the moving instrument. Briefly, there
is no light for a recording instrument moving with the speed of light

"Beginning of a New Era in Physics

ever, nothing is changed if we assume the source of light at rest
in F. Then, however, the beam of light can never be reflected,
since both the light and the mirror are traveling in the same
direction with the same velocity (c). The light can never catch
up to the mirror. Thus there would be again an influence of the
speed of the laboratory on the optical phenomena within, and
therefore a violation of Einstein's principle of relativity.

If we accept Einstein's two basic hypotheses, then the above
considerations lead us to the conclusion: it is not possible
for a laboratory (L) to move with velocity of light (c ) with re-
spect to the fundamental system (F) ; for if that were possible,
the relativity principle could not be valid. Or, since the labora-
tory is a material body like any other, no material body can
move with the velocity of light (c).

This conclusion may at first seem absurd. It is reasonable to
think that any velocity can be attained by the continual addi-
tion of even a certain small increment of velocity. For, according
to Newton's law of force, every force imparts to a body upon
which it acts an additional velocity that is smaller the greater
its mass is. One need only to let a force, no matter how small,
act long enough on a body, and its velocity can be increased
beyond any magnitude whatever. This circumstance shows the
incompatibility of Einstein's principles with Newtonian me-
chanics; the former demand the impossibility of the velocity of
light for material bodies, while the latter affords the possibility,

In Einstein's mechanics, therefore, the velocity of light in
empty space plays a very special role. It is a velocity that cannot
be attained or exceeded by any material body. We thus find an
intimate connection created between mechanical and optical
phenomena. Furthermore, owing to this circumstance, it becomes
meaningful to speak of "small" or "great" velocity without fur-
ther qualification. It means that the velocity is "small" or "great"
in comparison with the velocity of light.

5. Relativity of Time

Not only did Einstein's fundamental principles give
rise to results conflicting with Newtonian mechanics; they also
led to drastic changes in our use of the words "space" and "time."
The laws of physics contain statements about phenomena whose
effects can be observed in terms of measuring rods and clocks,

57

Einstein: His Life and Times

and much can be deduced about their behavior from Einstein's
postulates.

Let us consider a situation similar to the one in the previous
section. A laboratory system (L) moves with constant velocity
(y, smaller than c) with respect to a fundamental system (F).
There is a source of light (S) and a mirror (M) at a distance
(d) from S in the laboratory (L) such that the light from S
travels to M, is reflected, and returns to S, and such that the
direction of the ray SM is perpendicular to the direction of the
velocity v of L in respect to F. In going from the source (5) to
the mirror (Af ) and back, the light has to travel a distance zd
measured by yardsticks attached to L, but by yardsticks attached
to F the path is longer because the mirror (M) is moving with

respect to F. Let the length of this path be 2^*. The ratio -=%>

which will be designated by ^ for the sake of conciseness, is easily
calculated. It requires no greater mathematical knowledge than

the Pythagorean theorem, and its expression is ^ =

As v is smaller than c, ^ is greater than i. ^ is not much greater
than i if v is very small compared to c, but becomes very large
as v approaches c.

In order to determine the dependence of (^) upon (v) we
have to consider the time required for light to travel from
the source S to mirror M and back to S. Some sort of a time-
measuring device, such as a clock on the wall, a pocket watch on
the table, a pendulum hanging from the ceiling, or an hour-glass,
is needed in the laboratory (L). The time interval between the
starting out of the light ray from S and its return is measured
in terms of the time that the hand of a clock or watch takes
to move through a certain angle, the pendulum to make a cer-
tain number of oscillations, or a certain amount of sand to flow
through the hour-glass. The unit of time is a certain arbitrary
angle of the clock or watch, an arbitrary number of pendulum
oscillations, or an arbitrary quantity of sand.

Now, the constancy of the velocity of light means that the
quotient of the distance traveled by the light ray divided by the
time taken is equal to a constant (c\ whatever the speed (v} of
the source may be. The value of the distance is d if we measure
it with the yardstick attached to L, and d* if we use the yard-
stick attached to F. Thus if we designate the time interval for

58

Beginning of a New Era in Physics

the light to go from S to M and back by / if we use the L-yard-
stick and by 2* if we use the F-yardstick, we have c id/t

and c = 2d*/t*> and hence ///*== ^j* = k (%- 2). This
MM Mi M 2

FIGURE 2

The source of light S and the mirror M are moving with one and the same speed
v with respect to the ether, while light itself travels at speed c. The left diagram
shows a light ray emitted from S and reflected by M back to S. The line SM is the
trace of the ray on a screen that participates in the motion of S and M. The time t
of the relection is t = 2d/c, according to the principle of relativity. The right diagram
shows the trace of the same light ray on a screen that is at rest in the ether and that
does not participate in the motion of S and M. According to the principle of con-
stancy we obtain t* = . If we consider the rectangular triangle SMiSi, it follows

from the Pythagorean theorem that (d*) 2 = d 2 + (vt*/2) 2 . If we substitute the
results of the principles of relativity, d = ct/2, and of constancy, d* = ct*/2 5 we

means, however, that the result of the measurement depends
on f( f and consequently on v. The greater the velocity of the labo-
ratory (L) with respect to the system (F), the greater is the angle
through which the hand of the clock turns while the light travels
to the mirror and back. Similarly with a pendulum and an hour-
glass, the greater is the number of oscillations and the quantity of
sand. Therefore, by measuring this time interval, the observer in
L should be able to determine the velocity (y} by observations
conducted solely in his laboratory L. This, however, conflicts
with Einstein's principle of relativity.

The contradiction arises from a traditional assumption that is
based on Newton's idea of absolute time. According to Newton,
all clocks, watches, hour-glasses, and any other time-measuring
devices function at exactly the same rate, no matter what their
velocities are. In particular, a clock in the laboratory system (L)
runs at exactly the same rate as a clock firmly attached to the

59

Einstein: His Life and Times

fundamental system (JF). If this Is so, t cannot differ from /*.
On the other hand, we have derived from Einstein's two hy-
potheses that /* = ty. This means that the time ** is different
from /, and that the difference depends upon \* As \ depends
upon z>, the rate of a time-keeper depends upon the velocity (ti)
of its motion. Hence if Einstein's hypotheses are accepted, the
traditional assumption must be dropped, that the rate of a time-
keeper is independent of its speed. In order to build up a theory
of light and motion that is consistent with Einstein's hypotheses,
we have to assume that the clock In the laboratory (L) runs
slower than that in the fundamental system (F), the rate depend-
ing upon the speed (v) of L relative to F. Then, while the hands
of the clock in F rotate through an angle (a), that of the clock
in L rotate through the smaller angle a/\; while the pendulum
in F makes n oscillations, that in L makes only n/\; while q
ounces of sand run through the hour-glass in F, only q/\ ounces
run in L; hence the time interval for light to travel from StoM
and back as measured by any time-measuring device attached
to L will depend only on the velocity (ti) of L and not on the
special kind of device that we use.

Thus an entirely new property of time-keepers, which is not
consistent with the traditional view, has been deduced from
Einstein's two fundamental hypotheses. A moving clock, no
matter what its construction, runs slower than an identical clock
that is at rest. This is a physical fact that may be true or false,
but there is nothing "paradoxical" about it.

Einstein even indicated a method whereby this assertion could
be subjected to direct experimental verification. He pointed out
that atoms could be used as natural clocks since they emit elec-
tromagnetic waves of certain definite frequencies. These fre-
quencies of oscillation can be taken as natural time units for the
atom, and frequencies of one group of atoms at rest in the lab-
oratory can be compared with those of another group moving
at a great velocity. The comparison of the frequencies can
be made by means of a spectograph. The radiation of definite
frequencies emitted by atoms form distinct spectral lines on
photograph plates, with the position of the lines arranged ac-
cording to the magnitude of the frequency. Einstein's result
would be verified if the spectral lines of the moving atoms were
shifted slightly to the low-frequency side as compared with the
spectral lines of the stationary atoms. Actually tills experiment
was carried out in 1936 by H. Ives, of the Bell Telephone Labora-
tories, New York City, with positive result.

60

Beginning of a New Era in Physics

This effect must, of course,, be distinguished from the so-called
Doppler effect, which is also an alteration of the frequencies
of radiation due to the motion of the atoms. The Einstein effect,,
however, is independent of the direction of motion of the atoms,
while the Doppler effect depends critically on the direction. The
shift has the greatest value if the motion of the atoms has a
direction opposite to the velocity of the mirror or screen by
which the light is intercepted.

There was something of a sensation when Einstein pointed
out that the beat of the human heart is also a sort of clock and
the rate of its beating must also be affected by its motion. Con-
sider a person at rest in F whose heart beats at the rate of 70 per
minute. If this same person moves with velocity v relative to F,

then his heart will only beat 2- times a minute. But it must be

*

fjQ

remembered that it is ~ as measured by a clock fixed in F; if

*\

measured by a clock that travels with the person, this clock
itself will move slower and the heart-beat will then be just 70.
Since the same retardation likewise affects all the metabolic
processes in the body, it can be said that the person moving with
the system L "ages" less than a person remaining in F. Such a
circumstance may sound novel, but it cannot account sufficiently
for the impression that this new physical theory made upon the
masses of the public. For there was an impression that all our
thinking about the universe had suffered a severe shock.

In the fall of 1912 I first realized that Einstein's theory of the
"relativity of time" was about to become a world sensation. At
that time, in Zurich, I saw in a Viennese daily newspaper the
headline: "The Minute in Danger, a Sensation of Mathematical
Science." In the article a professor of physics explained to an
amazed public that by means of an unprecedented mathematical
trick a physicist named Einstein had succeeded in proving that
under certain conditions time itself could contract or expand,
that it could sometimes pass more rapidly and at other times
more slowly. This idea changed our entire conception of the
relation of man to the universe. Men came and went, generations
passed, but the flow of time remained unchanged. Since Ein-
stein this is all ended. The flow of time itself can be changed,
and at that by a "mathematical" trick. To most people this ap-
peared incomprehensible. Some rejoiced that anything so ab-
surd could happen and that traditional science, which is always
unpopular with some people, had suffered such a defeat. Others

61

Einstein: His Life and Times

were vexed that something should happen which ran counter
to all common sense. People were Inclined to regard it as a phan-
tasm of the mathematicians, or as an exaggeration by an author
desirous of creating a sensation. At any rate, it was exciting that
something of the sort could happen and that our generation was
chosen to witness the overthrow of the foundations of the
universe.

How did it happen that something of this kind, in part ex-
citing and in part absurd, was ascribed to Einstein's theory?
We saw above that it is actually a statement about concrete, ob-
servable events carried out with definite physical apparatuses.
Why did people like to present Einstein's clear deductions about
physical experiments in a semi-mystical and incomprehensive
language ?

The reason is that Einstein not only asserted the existence of
previously unknown physical occurrences, but also proposed to
describe these new phenomena in a language by which they
might be expressed most simply. The usual mode of expression
in physics was intended to present as simply as possible phe-
nomena that had already been known for a long time. To Ein-
stein this traditional language of physics proved to be too incon-
venient and complicated for the presentation of the newly
discovered or predicted phenomena.

In ordinary physics the duration of an event was defined by the
rotation of the hands of a clock or by the number of oscillations
of a pendulum. This was a clear-cut definition as long as one
believed that the functioning of such a mechanism was un-
affected by its motion. But if Einstein's deductions from his
postulates are correct, then with moving clocks different dura-
tions of time will be obtained for the same physical event. As we
saw above, the duration of the time taken for light to travel
from the source (S) to a mirror (M) and back to S depends on
whether the interval is measured by a clock at rest in the funda-
mental system (F) or by one in the laboratory (L) moving with
velocity v with respect to F.

In order to express this situation most simply, Einstein pro-
posed to speak no longer of the "duration of an event" without
further qualification, but to speak of the "duration relative to
a specific frame of reference." By this he meant duration meas-
ured with the aid of a clock firmly attached to this specific frame
of reference. The physical situation provides no basis for select-
ing one of these measurements in preference to others and
describing it as the "actual duration" in contrast to others that
are "apparent durations." For, in accordance with the princi-

62

Beginning of a New Era in Physics

pie of relativity, the duration of a specific occurrence in a labora*
tory should be independent of the velocity (V) of the laboratory^
provided clocks are used that are at rest with respect to L. By no
argument, however, one can be forced to accept Einstein's pro-
posal. One can also describe the above situation by saying: "The
true duration of an event is the duration measured by means
of the clock of a specific system of reference. Every other dura-
tion is only an illusion due to deliberate alteration in the rate
of the clock." This statement conveys exactly the same meaning
about observable facts except that a specific reference frame is
introduced, which on physical grounds is unnecessary.

Many authors have interpreted Einstein's clear and unequivo-
cal statement by the apparently profound but in reality meaning-
less statement: "Einstein said that sometimes time flows rapidly
and sometimes slowly." Indeed, to say that time flows is a figure
of speech that is only partly appropriate to the description of the
physical phenomena. To speak of "more rapid flow" is to take a
simple metaphor seriously. If one differentiates between state-
ments about new physical occurrences and the proposal for a
new mode of expression, one can formulate what is exactly meant
by claiming the "relativity of time." It means to state: if we use
the expression "time interval with respect to a specific system of
reference," we can describe the phenomena in a simpler way
than by using the traditional expression "time interval without
specification." Einstein's relativity of time is a reform in seman-
tics, not in metaphysics.

6. Relativity of Other Physical Concepts

If an investigation similar to the one on the duration
of time as measured by clocks is carried out for "intervals in
space" as measured by measuring rods, the length of a yard-
stick must also be affected by its motion. I shall not discuss this
point in further detail, since we have already become acquainted
with the method by which such results are obtained. I shall only
state Einstein's proposal that since moving measuring rods
change their lengths relative to resting rods, one should speak
only of "length relative to a specific system" and not of "length"
as such.

Another consequence of Einstein's basic hypotheses is that a
statement like "two events at different places occur simultane-
ously" is better formulated with respect to a specific system of

Einstein: His Life and Times

reference. An observer in Chicago may receive simultaneously
radio signals from two points at equal distances from Chicago.
He would say that they were sent out at one and the same time,
but an interceptor on a moving train receiving the same signals
would not receive them simultaneously if they are sent out ac-
cording to conventional clocks. Einstein therefore proposed
that the word "simultaneous" should likewise be introduced
only in the combination "simultaneous relative to a specific sys-
tem of reference." This would be again an improvement in
semantics. "Simultaneity" without specification is an expression
of little practical use.

Because of the continuity of laws, Newtonian mechanics must
become invalid also for particles with velocities near to the veloc-
ity of light. Einstein soon found out that his hypotheses could
be put to a very important task. They became an instrument for
deriving from the laws of physics that are valid only for small
velocities laws that are generally valid for all velocities. As we
have learned already, it follows from Einstein's two hypotheses
that Newton's law of mechanics cannot be valid for great veloci-
ties. For if it were, it would be possible, even by a small constant
force, to accelerate a mass gradually until it attains the speed
of light.

Einstein started from the assumption that for small velocities
(i.e., much smaller than the speed of light, c} every mass moves
according to Newton's laws of motion. By applying the pro-
cedure mentioned above, Einstein succeeded in deriving from the
Newtonian laws the laws of motion for high speed. The chief
result obtained in this way is the rather startling fact that the
mass of a body is not constant; like the duration of time and the
length of a measuring rod, it is dependent on its velocity. The
mass increases with velocity in such a way that as the velocity
becomes very great, the mass also becomes very great. A given
force will produce smaller and smaller change in the actual
velocity the more it approaches the velocity of light. For this
reason no particle can ever actually attain the velocity of light,
no matter how great a force acts on it and for how long a time.

Proceeding to the domain of electromagnetic phenomena,
Einstein was again led to the conclusion that electric and mag-
netic field strengths are also "relative quantities." Every helpful
description of electric or magnetic field strength must contain
not only their magnitude but also the system with respect to
which they are measured.

The necessity of this is easily seen. When an electric charge

64

^Beginning of a New Era in Physics

is at rest in L, it possesses an electric field only "relative to L/'
There is no magnetic field relative to L since an electric charge
at rest exerts no magnetic force. However, when this same sit-
uation is described relative to F, the electric charge is moving
with a velocity v; this means that there is an electric current.
Since every electric current exerts a magnetic force, it is appro-
priate to say that there is magnetic field "relative to F/' The ex-
istence of these fields is, of course, a physical fact. But their de-
scriptions "relative to L" and "relative to F" are different.

7, Equivalence of Mass and Energy

From the same hypotheses Einstein was able to draw
still another conclusion that at first one can hardly believe is con-
tained in them. If an agglomeration of masses is formed or falls
apart under production of kinetic energy or radiation the sum
of the masses after the agglomeration or disintegration is smaller
than before. The produced energy is given by E = me 2 , where
m is the loss of mass. This statement may be considered as a law
about the "transformation of mass into energy." In a process
where there is such a transformation from mass to energy or vice
versa, the energy of the system will not be conserved unless ac-
count is taken for the gain or loss due to the change in mass.

This law has proved to be of immense significance in the de-
velopment of our knowledge of the interior of the atom. Ac-
cording to our modern conception of the atom, it consists of a
massive central core with positive charge, which is called the
nucleus, and around it a number of negatively charged particles,
called electrons, circulating at great speed. The nucleus itself is
a complex structure built up of two kinds of particles, the posi-
tively charged protons, which are the nuclei of the simplest
atom, hydrogen, and neutrons that are exactly like protons ex-
cept for the lack of any electric charge. The various atoms found
in nature differ only by the difference in the number of protons
and neutrons they possess in the nucleus, the heavier atoms con-
taining more particles and hence being of more complex struc-
ture. As stated already, hydrogen, the lightest atom, has a nu-
cleus that is simply a proton. The next lightest atom is helium,
whose nucleus contains two protons and two neutrons. These
four particles are bound very tightly together in the nucleus by
certain nuclear forces. It is one of the most important prob-

65

Einstein: His Life and Times

lems of modern physics to Investigate the strength, character,
and quality of these nuclear forces which bind the atomic nuclei
together.

A measure of the strength with which particles in the nucleus
are packed together can be obtained by considering how much
energy is necessary to pry the particles loose and separate them
so they are all a large distance apart from one another. This
energy is known as the binding energy of a nucleus. Now, ac-
cording to Einstein's theory, this energy () which is produced
by the formation of the nucleus must appear as loss of mass due
to the agglomeration. This means that the masses of the indi-
vidual protons and neutrons added together are by E/c 2 greater
than the mass of the nucleus where these particles are bound
together. Thus by measuring the masses of the protons and neu-
trons while they are free and the mass of the nucleus, it is possible
to obtain the binding energy of the nucleus. Such measurements
have been carried out for many of the atoms found in nature,
and we are now able to classify according to how strongly the
particles in the nuclei are bound together. These results have
been of immense value in the planning and interpretation of re-
cent researches on the artificial transmutation of atoms, where
by bombarding various atomic nuclei with protons, neutrons,
and other similar particles, new atoms have been produced.

Einstein's mass-energy relation has also for the first time in
history made possible the solution of the problem of the source
of the sun's energy. The sun has been radiating heat and light
at the same rate as it is now doing for billions of years. If that
energy had come from ordinary combustion, such as the burn-
ing of coal, the sun would have cooled off by now. The problem
had the scientists completely baffled until Einstein V equation
E = me 2 appeared. The velocity of light (c) is a very large
number, and with this squared, the formula states that a small
quantity of mass can transform into a very large amount of
energy. For this reason, by losing only an immeasurable amount
of mass, the sun has been able to continue radiating for so long,
and will continue to do so for billions of years to come. The
actual mechanism of the transformation of mass to energy occurs
in nuclear reactions that are going on in the interior of the sun.
It is believed now that they ultimately boil down to the forma-
tion of helium nuclei from hydrogen. In this "packing effect"
as we have learned already, mass is lost and radiation emitted.

This possibility of using mass as a source of energy has aroused
very optimistic hopes that methods of liberating the energy

66

Beginning of a Neiv Era m Physics

stored in the atom as mass for practical use might be found.
There has also been, on the other hand, a very frightening pros-
pect that such a process might be used to produce an explosive
so devastating that a pound of it would completely annihilate
everything within a radius of many miles. This foreboding was
fulfilled forty years later when the first atomic bomb destroyed
Hiroshima.

To Einstein, however, the main value of his result was not in
the applications, no matter how numerous or important. To
himself his principal achievement was to have deduced the law
E = me 2 from the relativity principle. It was in accord with
Einstein's conception of the universe to strive continually for the
discovery of simple, logical bridges between the laws of nature.
The wealth of conclusions derived from his two hypotheses con-
stitutes what has been known since as the "theory of relativity."
Einstein had struck a rich well of information about nature,
which would yield knowledge for many decades to come.

8. Theory of Brownian Motion

In the same year (1905) Einstein discovered new fundamen-
tal laws in two fields outside the theory of relativity. At the time
when Einstein came to Bern, he was intensely occupied with the
problem of light and motion, But he saw that the final goal could
be attained only by attacking the problems from various angles.
One of the paths to the goal, he realized, was to investigate the
relations between light and heat, and those between heat and
motion.

It had been known for some time that heat is connected with
the irregular motion of molecules. The higher the temperature,
the more violent is this motion. The statistical behavior of par-
ticles in such irregular motion had been investigated chiefly by
the Scottish physicist James Clerk Maxwell (1831-79) and the
Austrian Ludwig Boltzmann (1844-1906). It had been assumed
even before, that the kinetic energy of the molecules is propor-
tional to the absolute temperature. At the time of Maxwell and
Boltzmann, however, the molecular constitution of matter was
still a hypothesis which could be doubted. It enabled many differ-
ent phenomena to be explained very simply, but there was as yet
no very direct proof of the existence of the molecule. Further-
more, it had not yet been possible to obtain an accurate value of

Einstein: His Life and Times

such a significant quantity as the number of molecules in a unit
volume of matter. Estimates of this number had been made by
such men as the Austrian physicist Loschmidt (1865), but they
were based on involved and rather indirect methods. Einstein
strongly felt the necessity of investigating this matter more
thoroughly and obtaining a more direct proof of molecular
motion.

It had long been known that small but microscopically visible
particles, when suspended in a fluid with approximately the
same density, exhibit a constant, apparently irregular zigzag
motion. It had been discovered by the Scottish botanist Robert
Brown for pollen dust suspended In water, and for this reason
it is known as Brownian motion. It is not caused by any external
influence jarring the vessel or by currents of water in the vessel,
and the agitation increases in Intensity when the temperature
of the water Is raised. For this reason it had been conjectured
that the motion is connected with the heat motion of the mole-
cules. According to this view, the kinetic energy of the water
molecules In constant collision with the microscopic particles
produces irregular forces In random directions, which give rise
to the observed motions.

In 1902 Einstein had restated Boltzmann's theory of ran-
dom motion in a simplified form. He now treated the Brown-
ian motion with this method and arrived at a surprisingly simple
result. He showed that the results of the kinetic theory of mole-
cules should also hold for particles visible by microscope for
instance, that the average kinetic energy of the particles in the
Brownian motion should have the same value as that for the
molecules. Hence, by observing the motion of the microscop-
ically visible particles, much valuable information could be
obtained about the Invisible molecules. In this way Einstein was
able to derive a formula which stated that the average displace-
ment of the particles in any direction increases as the square root
of the time. He showed (1905) how one can determine the num-
ber of molecules In a unit volume by measuring the distances
traveled by the visible particles.

The actual observations were later made by the French physi-
cist Jean Perrin, who completely verified Einstein's theory. The
phenomenon of Brownian motion has subsequently always been
included among the best "direct" proofs of the existence of the
molecule.

68

Beginning of a New Era in Physics

9. Origin of the Quantum Theory

To Einstein it was always clear that his theory of rela-
tivity could not claim (and, indeed,, it never did claim) to solve
all the mysteries of the behavior of light. The properties of light
investigated by Einstein concerned only a certain group of phe-
nomena dealing with the relation between the propagation of
light and moving bodies. For all these problems light could be
conceived along the lines of traditional physics as undulatory
electromagnetic processes which filled space as a continuum.
By the theory of relativity it was assumed that some objects can
emit light of this nature, and no attempt was made to analyze
the exact process by which light is emitted or to investigate
whether it sufficed for a derivation of all the laws for the inter-
action of light with matter.

The investigations on the nature of light and its interaction
with matter, however, were to lead to the rise of the "quantum
theory/' a revolution in physical thought even more radical than
the theory of relativity. And in this field,, too, Einstein's genius
had a profound influence on its early development. In order to
make understandable the nature of Einstein's contributions, I
shall describe briefly the situation prior to his researches.

The simplest way of producing light is by heating a solid
body. As the temperature rises, it begins to glow from a dull
cherry red to a brighter orange, and then to blinding white light.
The reason for this is that visible light consists of radiations of
different frequencies ranging from red at the low end through
the colors of the spectrum up to violet at the high end. The qual-
ity of light emitted by a solid body depends solely on its
temperature; at low temperatures the low-frequency waves pre-
dominate and hence it looks red; at higher temperatures the
shorter wave lengths appear and mingle with the red to give the
white color.

Attempts to explain this change in quality of light with tem-
perature on the basis of nineteenth-century physics had ended
in failure, and this was one of the most important problems
facing physicists at the beginning of the twentieth century. At
that time the emission of light was thought to be produced by
the oscillations of charged particles (electrons), the frequency
of light emitted being equal to the frequency of the vibration.
According to Boltzmann's statistical law, already mentioned,

69

Einstein: His Life and Times

the average energy of oscillation of an electron should be exactly
equal to the average kinetic energy of gas molecules, and hence
simply proportional to the absolute temperature. But this led to
the conclusion that the energy of vibrations is independent of the
frequency of oscillation, and hence light of different frequencies
will be emitted with the same energy. This conclusion obviously
was contradicted by the observations on light emitted by heated
bodies. In particular, we know that light of very short wave
lengths is not emitted to any great extent by hot bodies. As the
temperature increases, rays of increasingly higher frequencies
appear, but yet at a given temperature there is no perceptible
radiation above a certain definite frequency. Consequently it
appeared that somehow it must be difficult to emit light of very
high frequencies.

Since all arguments based on the mechanistic theory of mat-
ter and electricity led to results conflicting with experience, the
German physicist Max Planck in the year 1900 introduced a
new assumption into the theory of light emission. At first it
appeared to be rather inconsequential, but in the course of time
it has led to results of an increasingly revolutionary character.
The turn in physics coincided exactly with the turn of the cen-
tury. I shall sketch Planck's idea in a somewhat simplified and
perhaps superficial form.

According to Boltzmann's statistical law, the average energy
of oscillation of an electron in a body is equal to the average
kinetic energy of the molecules. The actual energies of the in-
dividual atoms or molecules can, of course, have very different
values; the statistical law only relates the average energy with
the temperature. Boltzmann, however, had been able to derive
a second result which determined the distribution of the energy
of the particles around the average value. It stated that the num-
ber of particles with a certain energy depends on the percentage
by which this energy differs from the average value. The greater
a deviation, the less frequent will be its occurrence.

As Planck realized, the experimental results indicated that the
oscillating electrons in a body cannot emit radiation with an
arbitrary frequency. The lack of high-frequency radiation
shows that the mechanism of radiation must be such that it
is somehow difficult to emit light of high frequency. Since no
explanation of such a mechanism existed at that time, Planck
was led to make the new assumption that, for some reason
as yet unknown, the energy of oscillation of the atoms can-
not have just any value, but can only have values that are inte-

70

Beginning of a New Era in Physics

gral multiples of a certain minimum value. Thus, if this value
is called e, then the energy of the oscillations can only have the
discrete values 0, e, 2e ... or ne, whose n is zero or an integer.
Consequently the radiation emitted or absorbed must take place
in portions of amount e. Smaller amounts cannot be radiated or
absorbed since the oscillation cannot change its energy by less
than this amount. Planck then showed that if one wants to ac-
count for the well-known fact that a shift to higher temperatures
means a shift to higher frequencies, one has to take values
for e that vary for different values of the frequencies of the
oscillations, and in fact e has to be proportional to the fre-
quency.

Thus he put e = fit/, where v is the frequency and h is the
constant of proportionality, which has since then been called
Planck's constant and has been found to be one of the most
fundamental constants in nature. With this assumption Planck
was immediately able to derive results in the theory of radiation
that agreed with observations and thus removed the difficulties
that had confronted the physicists in this field.

10. Theory of the Photon

Planck thought he was only making a minor adjust-
ment in the laws of physics in formulating his hypothesis, but
Einstein realized that if this idea was developed consistently it
would lead to a rupture of the framework of nineteenth-century
physics so serious that a fundamental reconstruction would be
necessary. For if the electron can oscillate only with certain dis-
crete values of energy, it contradicts Newton's laws of motion,
laws which had been the bases for the whole structure of mech-
anistic physics.

Planck's hypothesis dealt only with the mechanism of radia-
tion and absorption of light and stated that these processes could
take place only in definite amounts. He said nothing about the
nature of light itself while it is propagated between the point of
radiation and that of absorption. Einstein set out to investigate
whether the energy transmitted by light retained this discrete
character during its propagation or not. He once expressed this
dilemma by the following comparison: "Even though beer is
always sold in pint bottles, it does not follow that beer consists
of indivisible pint portions."

71

Einstein: His Life and Times

Retaining the analogy, if we wish to investigate whether the
beer in a barrel actually consists of definite portions or not, and
if so whether this portion is a pint, two pints, or ten pints, we can
proceed as follows: We take a number of containers, say ten to
be definite, and pour the beer from the barrel at random into
these containers. We measure the amount in each container and
then pour back the beer into the barrel We repeat this process
a number of times. If the beer does not come in portions, the
average value of the beer poured into each container will be the
same. If it consists of pint portions, there will be variations in
the average values. For two pints the variations will be greater,
and for ten they will be still greater. Thus by observing the dis-
tribution of beer among the ten vessels, we can tell whether the
barrel of beer consists of portions and what size they are. We
can realize it easily by imagining the extreme case that the whole
content of the barrel is one portion.

The situation is similar in the case of radiation enclosed in a
box. We can imagine this box to be divided into a number of
cells of equal volume and consider the distribution of the energy
of radiation in these cells. If the portions of radiation are large,
the variations of energy among the cells will be large, and if they
are small, these variations will be small. From the empirical law
of distribution it follows that the variations in the violet light are
greater than in the red light. Einstein drew the conclusions that
violet light consists of a few large portions, while red light con-
sists of many small ones. Exact calculations showed that the
magnitude of the portions must be hv. Thus Einstein found that
not only did emission and absorption of radiation take place in
discrete amounts, but light itself must consist of definite por-
tions. The name "photon" has since been given to the quantum
of radiation.

To this conclusion, which Einstein derived theoretically, he
was able to point out an experimental verification. It had been
known for some time that when light shines on certain metals,
electrons are given off. Electrons are fundamental particles in
physics which carry a negative electric charge and constitute the
outer portion of the atom. In 1902 the German physicist Philipp
Lenard discovered a very startling result of this emission of
electrons. He found that the intensity of light falling on the
metal had no eff ect on the energy with which the electrons are
ejected from the metal, but that this energy depends only on the
color or frequency of the light. No matter how far the source of
light is moved away from the metal, the electrons are still ejected
with the same velocity, though of course the number ejected is

72

Beginning of a New Era in Physics

smaller. But when violet light is used instead of red,, the velocity
of the electrons is much greater.

According to Einstein's view,, the explanation is quite simple*
No matter what distance light of a certain color has traveled
from the source, it still consists of the same portions of energy,
the only difference being that, farther away from the source, the
individual portions are spread out thinner. The ejection of
an electron occurs when a whole quantum of radiation is ab-
sorbed by a single electron, which then comes off with the
energy of the photon. Thus the distance between the source and
the metal has no effect on the energy of the single electron
emitted. Furthermore, the difference between violet and red
light is that a different amount of energy Is possessed by the
photon. Hence an electron that absorbs a violet photon naturally
comes off with higher velocity than one that absorbs a red
photon.

To form another analogy, let us consider the bombardment
of a fortification by machine guns and by heavy artillery. Even
if the total weight of projectiles fired is the same in both cases,
the effects produced are of a very different character. The
machine-gun bullets make a very large number of small dents,
while the artillery shells make a few big holes. Moreover, the
average intensity of gunfire has very little effect on the magni-
tude of the holes, but only on their number.

With his hypothesis on the discontinuous nature of light Ein-
stein threw doubt on the entire conception of a continuous field
of force. If light consists of photons, the electric and magnetic
fields cannot fill all space continuously, and the whole of the
electromagnetic theory of light based on this concept has to be
re-examined. The discontinuous structure is apparently incon-
sistent, however, with some observed phenomena, in particular
with interference and diffraction of light, which are explained
so well by the theory of continuous waves. Einstein, who was
well aware of this difficulty, looked upon his assumption only
as a provisional hypothesis, without any lasting value. He there-
fore entitled the paper in which he presented his discovery:
"On a Heuristic Point of View Regarding the Production and
Transformation of Light."

It is interesting to note that Einstein's new quantum theory
of light was based upon the research of two German physicists
who were later to play important roles in his life. Max Planck
was first to advocate the significance of Einstein's theory of
relativity, and Philipp Lenard was to oppose it most vehemently
on philosophical, political, and racial grounds.

73

IV

EINSTEIN AT PRAGUE

I. Professor at the University of Zurich

The researches whose results Einstein published at
Bern in 1905 were so unusual that to the physicists of the Swiss
universities they seemed incompatible with the assigned work
of a minor official of the patent office. Attempts were soon made
to bring Einstein to teach at the University of Zurich. At this
time Professor Kleiner was the leading personality in physics
there. He was a man who realized that Einstein's papers re-
vealed an unusual talent, but who did not really understand
them. He felt it his duty to do the best for his university and en-
deavored to appoint Einstein professor at Zurich.

According to the regulations in force at Zurich as well as at
other Germanic universities, no one could be appointed pro-
fessor at a university unless he had previously been a Privat-
dozent. This is a position for which there is no analogue in the
universities of western Europe and America. A young man
with scientific achievements may apply for permission to teach
at a university. He has no obligations and can lecture as much
or as little as he desires, but receives no remuneration except the
usually very small fees paid by students who attend his lectures.
Since for this reason the number of Privatdozenten does not
have to be restricted, this system has the advantage that every
young scientist has an opportunity to show his teaching abili-
ties and the universities have a large number of candidates to
choose from in appointing their professors. The disadvantage,
of course, is that in practice only persons with private means or
another position which supports them can enter this career.
With his position at the patent office, Einstein was in the latter
situation.

Professor Kleiner advised him to become a Privatdozent at the
university of Bern, so that after a short while he could then be
eligible for a professorship at Zurich. Although he did not like
the idea of giving regular lectures, Einstein followed the advice.
Consequently his lectures were not very well prepared, and

74

Einstein at fragile

since the students were not obliged to attend them, only a few
friends came. Furthermore, Einstein was then in the midst of a
veritable maelstrom of new discoveries and it was difficult to
arrange his material in a way appropriate to the capacities of the
average student. Professor Kleiner once came to Bern to hear
Einstein lecture and afterward remarked to him that such lec-
tures did not seem on a level fitted for the students. Einstein
answered : "I don't demand to be appointed professor at Zurich."

At that time the professorship of theoretical physics at the
University of Zurich became vacant, but the board of edu-
cation of the canton of Zurich, which was in charge of the
university, had its own plans for this position. The majority of
the board of education belonged to the Social Democratic Party,
and they had in Zurich a party comrade who appeared to be a
suitable candidate, from both the political and the scientific
viewpoint. This man was Friedrich Adler, Einstein's former
fellow student at the Zurich Polytechnic, who was then a Privat-
dozent at the University of Zurich. As the son of the leader of
the Austrian Social Democrats, he was held in high esteem by
the party members in Zurich. Friedrich Adler was a man imbued
with a fanatical love of truth and was interested in physics
chiefly because of its philosophical aspects. He was in every re-
spect a man who would not shrink from uttering what he re-
garded as the truth even if it was to his own disadvantage.
Learning that it was possible to obtain Einstein for the univer-
sity, he told the board of education: "If it is possible to obtain a
man like Einstein for our university, it would be absurd to
appoint me. I must quite frankly say that my ability as a research
physicist does not bear even the slightest comparison to Ein-
stein's. Such an opportunity to obtain a man who can benefit us
so much by raising the general level of the university should not
be lost because of political sympathies."

So in 1909, despite the political leaning of the board of educa-
tion and the leading professor's disapproval of his mode of lec-
turing, Einstein was appointed professor "extraordinary" at the
University of Zurich.

The call to Zurich gave Einstein for the first time a position
with a certain public prestige. Most Privatdozenten feel that
they have become important persons when they attain profes-
sorial rank, for then they can lord it over the Dozenten instead
of being passive objects to be dealt with by the university admin-
istration. For Einstein this was naturally no cause for satisfac-
tion. He had not suffered in any way while a Privatdozent, and

75

Einstein: His Life and Times

he did not have any desire to dominate others. Besides, he had
not been anxious enough for the position to derive any great
pleasure from its attainment.

From the financial point of view, the position of a professor
"extraordinary" was not very lucrative. His income was no larger
than it had been at the patent office and, moreover, he could no
longer lead an inexpensive and pleasant bohemian life now that
he had acquired a certain social status in the city. Though he
kept expenses at a minimum, he had to spend money for things
from which he derived no pleasure, but which were required
by his social position. In order to improve the financial situation,
his wife took in students to board. He once said jokingly: "In
my relativity theory I set up a clock at every point in space, but
in reality I find it difficult to provide even one clock in my room."

Einstein loved the city of Zurich, which had become his home.
His wife also felt more at home here than anywhere else. Col-
laboration with students and colleagues, which was now possi-
ble, was a great stimulus to Einstein. Administrative duties and
regular teaching, however, had few attractions and in certain
respects many difficulties. This was due not only to the constraint
a person of such great creative ability finds himself under when
required to expend his efforts on tasks that do not appear im-
portant, but also to Einstein's paradoxical relation to society,
arising from his personality.

The immediate impression that Einstein made on his environ-
ment was a conflicting one. He behaved in the same way to every-
body. The tone with which he talked to the leading officials of
the university was the same as that with which he spoke to his
grocer or to the scrubwoman in the laboratory. As a result of his
great scientific discoveries, Einstein had already acquired a pro-
found inner feeling of security. The pressure that had often
burdened his youth was gone. He now saw himself in the midst
of the work to which he was going to devote his life and to which
he felt himself equal. Alongside this work the problems of daily
life did not appear very important. Actually he found it very
difficult to take them seriously. His attitude in intercourse with
other people, consequently, was on the whole one of amuse-
ment. He saw everyday matters in a somewhat comical light,
and something of this attitude manifested itself in every word
he spoke; his sense of humor was readily apparent. When some-
one said something funny, whether intentionally or not, Ein-
stein's response was very animated. The laughter that welled up
from the very depth of his being was one of his characteristics

Einstein at Prague

that immediately attracted one's attention. To those about him
his laughter was a source of joy and added to their vitality. Yet
sometimes one felt that it contained an element of criticism,
which was unpleasant for some. Persons who occupied an im-
portant social position frequently had no desire to belong to a
world whose ridiculousness in comparison to the greater prob-
lems of nature was reflected in this laughter. But people of lesser
rank were always pleased by Einstein's personality.

Einstein's conversation was often a combination of inoffensive
jokes and penetrating ridicule, so that some people could not
decide whether to laugh or to feel hurt. Often the joke was that
he presented complicated relationships as they might appear to
an intelligent child. Such an attitude often appeared to be an
incisive criticism and sometimes even created an impression of
cynicism. Thus the impression Einstein made on his environ-
ment vacillated between the two poles of childish cheerfulness
and cynicism. Between these two poles lay the impression of a
very entertaining and vital person whose company left one feel-
ing richer for the experience. A second gamut of impression var-
ied from that of a person who sympathized deeply and passion-
ately with the fate of every stranger, to that of a person who, upon
closer contact, immediately withdrew into his shell

2. Appointment to Prague

In the fall of 1910 there occurred a vacancy in the chair
o theoretical physics at the German University in Prague. Such
appointments were made at the recommendation of the faculty
by the Emperor of Austria, who exercised his right through the
Ministry of Education. The decisive man in the selection of
the candidate was die physicist Anton Lampa, a man of very
progressive tendencies as far as education was concerned. All his
life he fought for the introduction of modern pedagogical meth-
ods, for the freedom of teaching from reactionary influences,
and for the extension of scientific and artistic education to the
largest possible number of the population. There was a consid-
erable gap between his high aspirations and his scientific capac-
ities, however, and as a result he was animated by an ambition
he could not satisfy. Since he was a man of high ethical ideals, he
consciously sought to suppress this ambition, but the result was
that it played an even greater role in his subconscious life. His

77

Einstein: His Life and Times

philosophical Weltanschauung was for the most part deter-
mined by the positivistic philosophy of the physicist Ernst Mach,
whose student he had been. It was Lampa's life goal to propa-
gate Mach's views and to win adherents for them.

When the question of filling the chair of theoretical physics
came up, Lampa thought that here was an opportunity to ap-
point someone who would teach physics in the spirit of Mach.
In addition, it had always been his dream to enter the realm of
the extraordinary and of the genius, and he wanted an outstand-
ing scientist, not an average professor. Even though he realized
that he himself was not so gifted, he was just enough to accept
the presence of an outstanding man.

Lampa had in mind two physicists who he thought would
teach in the spirit of Mach and were acknowledged to have ex-
traordinary capacities. The first was Gustav Jaumann, a pro-
fessor at the Technical Institute in Brno, and the second was
Einstein. Jaumann followed Mach in some peculiarities, chief
among which was his aversion to the introduction of atoms
and molecules in physics. Even when the atomic constitution
of matter had been generally accepted as giving the best and
simplest presentation of physical phenomena, Jaumann retained
Mach's predilection and tried to build up a theory of continu-
ously distributed matter. Since he had a great natural talent
and imagination, he considered himself a neglected genius and
developed an excessive vanity and sensitivity. Einstein, on the
other hand, was influenced more by the spirit than by the letter
of Mach's teachings. We have already seen in his work on
Brownian motion that Einstein did not follow Mach's rejection
of the atom.,

Since the regulations provided that the names of the proposed
candidates be listed on the basis of their achievements, Einstein,
whose writings in the years from 1905 to 1910 had already made
a strong impression on the scientific world, was placed first and
Jaumann second. Nevertheless, the Ministry of Education first
offered the position to Jaumann. The Austrian government did
not like to appoint foreigners and preferred Austrians. But the
ministry had not taken Jaumann's vanity and touchiness into
account. He said: "If Einstein has been proposed as first choice
because of the belief that he has greater achievements to his
credit, then I will have nothing to do with a university that chases
after modernity and does not appreciate true merit." Upon
Jaumann's rejection of the offer, the government overcame its
aversion to foreigners and offered the position to Einstein. He

78

Einstein at Prague

had some qualms about going to a foreign country., and his wife
did not want to leave Zurich, but eventually he accepted it. One
deciding factor was the circumstance that for the first time in
his life he was to have a full professorship with adequate salary.

There was one peculiar difficulty to be overcome, however, in
taking up the position. The octogenarian Emperor Franz Josef
was of the opinion that only a man who belonged to a recognized
church should be a teacher at a university, and he refused to
confirm the appointment of anyone who did not conform to
this rule. Einstein's friends at the university who had proposed
his appointment informed him of this circumstance. Since leav-
ing the gymnasium in Munich, Einstein had not been an official
member of any religious community, but in order to avoid this
difficulty, he indicated that he was an adherent of the Jewish
religion, to which he had belonged as a child. He did not go
through any formal ceremony, but in the questionnaire that he
had to fill out he simply wrote his religion was "Mosaic," as the
Jewish creed was then called in Austria.

When Einstein arrived in Prague he looked more like an
Italian virtuoso than a German professor, and he had, more-
over, a Slav wife. He was certainly unlike the average pro-
fessor at the German University. Since he had been preceded
by the reputation of being not an ordinary physicist but an ex-
traordinary genius, everyone was curious to meet him.

In Prague it was the custom for a newly arrived member of
the faculty to pay a call on all his colleagues. In his good-natured
way Einstein was ready to accept the advice of his friends and
make the necessary calls, which numbered some forty. He also
decided to take advantage of this opportunity to see various sec-
tions of the romantic old city of Prague, and so he began to make
his visits according to the location of the houses. All who made
his personal acquaintance were immediately pleased by his nat-
uralness, his hearty laughter, and the friendly and at the same
time dreamy look in his eyes. But Einstein soon began to find
the calls rather a nuisance. He felt that it was a waste of time to
carry on conversations about trivialities and suddenly he stopped
his visits. The professors upon whom he had not called were
puzzled and offended at this neglect. Some people began to
regard him as either proud or capricious, when the true explana-
tion was that these colleagues lived in sections of the city that
did not interest Einstein, or their names were too far back in the
faculty directory.

This aversion to all formality and ceremonial was a very im-

79

Einstein: His Life and Times

portant trait in Einstein's character. It was particularly marked
for ceremonies that were in any way depressing. Thus Einstein
had an intense aversion to attending funerals, and on one occa-
sion when he was in a funeral procession he remarked to his
assistant, walking at his side: "Attending funerals is something
one does to please the people around us. In itself it is meaning-
less. It seems to me not unlike the zeal we polish our shoes with
every day just so that no one will say we are wearing dirty shoes."
Throughout his life Einstein had maintained this attitude of
revolt against the customs of bourgeois life.

3. Colleagues at Prague

The University of Prague is the oldest university in
central Europe. During the second half of the nineteenth cen-
tury there had been German and Czech professors lecturing in
their respective languages, but with political quarrels creating
more and more difficulties, the Austrian government had in 1888
decided to divide the university into two parts, thus creating a
German and a Czech university. It is perhaps an interesting his-
torical accident that the first rector of the German University,
where Einstein was appointed, had been Ernst Mach.

At the time of Einstein's arrival the two universities were
completely separated and there were no relations between the
professors of the two institutions. Even professors of the same
subject had no personal contact and it frequently happened that
two chemistry professors from Prague would meet for the first
time at an international congress in Chicago. There was already
a group among the Germans who propagated the idea of the
"master race" and frowned upon any intercourse with "in-
ferior races," The majority of the German professors had too
little interest in politics or were too timid to oppose the powerful
will of this group by entering into contact with the Czechs.

Nevertheless, the general attitude of superiority and hostility
against the Czechs was quite evident in the conversations among
the German professors and their families. Comical stories were
told of how Czechs behaved in society for which, in the Ger-
mans' opinion, they were not suited. The situation may be de-
scribed by the following instances:

During a population census undertaken by the government,
a professor of political science sent a circular letter to the mem-

80

Einstein at Prague

bers of the university faculty urging them to list all their serv-
ants as German even if they were Czech. He reasoned as follows:
Servants should only speak to their masters; since the latter are
German, the language of all the servants must be German.

Another professor, while walking with a colleague one day,
saw a house sign that seemed about to fall down on the sidewalk.
"It doesn't matter much/' he said, "since it is extremely probable
that when it falls it will strike a Czech."

One of the remarkable and frequently comical aspects of this
hostility was that there was not even the slightest difference be-
tween the Germans and the Czechs in Prague so far as race and
origin were concerned. The question of which nationality one
belonged to was often a question of personal taste and which
offered opportunities for earning a living.

Anton Lampa, Einstein's closest colleague, was the son of a
Czech janitor. But, as frequently happened among the Czechs,
the son had worked his way up, driven by his ambition and a
great desire for knowledge and learning. Though his father was
a Czech, he worked in a building belonging to Germans, so
young Lampa attended German schools. He spoke Czech and
German with equal facility, and upon graduating from the gym-
nasium he was faced with the problem of deciding whether to
attend the German or the Czech university. He chose the former
and later became a student of Ernst MacL Yet despite his past
Lampa was just as hostile to the Czechs as the other Germans.
He was one of those who, for instance, refused to buy a post-
card if the word "postcard" was printed on it in both languages,
and demanded a card having only the German word on it. If
the post-office clerk was a Czech, he would frequently say that
such cards had all been sold out. The professor would then argue
that it was the clerk's duty to keep cards with purely German
text, and so a quarrel would begin.

Under these circumstances it was difficult even for a German
who disapproved of this hostile attitude to come into contact
with the Czechs. The latter were very suspicious and sensitive
and felt insulted by every thoughtless word. They suspected
everyone of wishing to humiliate and disparage them, and as a
result it was not easy for a well-meaning German to maintain
friendly relations with the Cechs. It is not surprising, therefore,
that Einstein hardly came in contact with them. He disapproved
the standpoint of his colleagues and did not join in their dispar-
aging anecdotes, but he did not become intimately acquainted
with any Czechs. But Czech students did attend his lectures and

81

Einstein: His Life and Times

carry on scientific research, under his direction, in itself a rare
occurrence at the German University.

Among his closest colleagues Einstein was attracted most
strongly by a mathematician named Georg Pick. He was some
twenty years older than Einstein and was an extraordinary per-
sonality,, both as a man and as a scientist. Pick was above all a
creative mind in mathematical research. In very concise papers
he published many precisely formulated ideas, which were later
developed by others as independent branches of mathematics.
Nevertheless, he never received much of the scientific recognition
he deserved, since he was of Jewish ancestry and had rather an
uncompromising nature. He held firmly to what he considered
was right and did not make concessions of any kind. After his
retirement at an age of over 80, he died in a Nazi extermination
camp.

As a young man Pick had been an assistant of Ernst Mach's
when Mach was professor of experimental physics at Prague.
Einstein liked to hear Pick reminisce about Mach, and Pick was
particularly fond of repeating statements by Mach that could be
interpreted as anticipating Einstein's theories. Pick was also a
good violinist, and through him Einstein became acquainted
with a group of music-lovers and was urged to participate in
chamber music. After that, Einstein had his regular quartet
evenings.

Einstein and Pick met almost daily and they discussed many
problems together. In the course of long walks Einstein confided
to Pick the mathematical difficulties that confronted him in his
attempts to generalize his theory of relativity. Already at that
time Pick made the suggestion that the appropriate mathemati-
cal instrument for the further development of Einstein's idea
was the "absolute differential calculus" of the Italian mathe-
maticians Ricci and Levi-Civita.

Einstein's immediate assistant at this time was a young man
named Nohel. He was the son of a small Jewish farmer in a
Bohemian village, and as a boy he had walked behind the plow.
He had the quiet poise of a peasant rather than the nervous
personality so often found among the Jews. He told Einstein a
good deal about the condition of the Jews in Bohemia, and their
conversations began to arouse Einstein's interest in the relation
between the Jews and the world around them. Nohel told him
about the Jewish peasants and tradesmen who in their daily
activities used the Czech language. On the Sabbath, however,
they spoke only German. For them this language, so close to

82

Einstein at the time of his most intense scientific

Einstein, Paul Ekrenfest, Paul Langevin, Kammerling-Qnnes, and
Pierre Weiss at Ehrenjest's home, Leyden, the Netherlands

Einstein at Prague

Yiddish, was a substitute for Hebrew, which had long since been
given up as the language of daily life.

Another colleague with whom Einstein became quite intimate
was Moritz Wintemitz, a professor of Sanskrit. He had five chil-
dren to whom Einstein became greatly devoted, and he once
remarked : "I am interested to see how a number of such com-
modities produced by the same factory will behave." Professor
Winternitz had a sister-in-law who very often accompanied Ein-
stein at the piano when he played the violin. She was an elderly
maiden lady whose life had been spent in giving piano lessons
and who had thus acquired a somewhat dictatorial manner.
She used to speak to Einstein as if she were addressing a pupil.
Einstein often remarked: "She is very strict with me," or "She
is like an army sergeant."

When Einstein was to leave Prague, he had to promise her
that he would recommend as his successor as professor of theo-
retical physics only someone who could also replace him as her
violin partner. When I went to Prague to replace Einstein and
was introduced to her, she immediately insisted that I keep this
promise by playing the violin. To my regret, I had to tell her
I had never in my whole life had a violin in my hands. "So," she
replied, "Einstein has disappointed me."

4. The ]ew$ in "Prague

The appointment as professor at Prague led Einstein
to become a member of the Jewish religious community. Even
though this relation was only formal and the contact was only
a very loose one at that time, it was in this period of his life that
perhaps for the first time since his childhood he came aware of
the problems of the Jewish community.

The position of the Jews in Prague was a peculiar one in many
respects. More than half of the German-speaking inhabitants
in Prague were Jewish, so that their part among the Germans,
who comprised only about five per cent of the total population,
was extraordinarily important. Since the cultural life of the Ger-
mans was almost completely detached from that of the Czech
majority, with separate German theaters, concerts, lectures, balls,
and so on, it was not surprising that all these organizations and
affairs were dependent on Jewish patronage. Consequently, for
the great masses of the Czech people, a Jew and a German were

83

Einstein: His Life and Times

approximately the same. At the time when Einstein came to
Prague, the World War I was just in the making and the Czechs
felt that they were being driven into a war by the government
against their own interests but in the interests of the hated Ger-
mans. They looked upon every German and Jew as a represen-
tative of a hostile power who had settled in their city to act as a
watchman and informer against the Czech enemies of Austria.
There is no doubt that there were some Jews, who, aping other
Germans, somehow adapted themselves to this role of being
policemen and instruments of oppression. But the core of the
Jewish population was disgusted.

On the other hand, the relation of the Jews to the other Ger-
mans had already begun to assume a problematical character.
Formerly the German minority in Prague had befriended the
Jews as allies against the upward-striving Czechs, but these good
relations were breaking down at the time when Einstein was
in Prague. When the racial theories and tendencies that later
came to be known there as Nazi creed were still almost un-
known in Germany itself, they had already become an impor-
tant influence among the Sudeten Germans. Hence a somewhat
paradoxical situation existed for the Germans in Prague. They
tried to live on good terms with the Jews so as to have an ally
against the Czechs. But they also wanted to be regarded as
thoroughly German by the Sudeten Germans, and therefore
manifested hostility against the Jews. This peculiar situation
was characterized outwardly by the fact that the Jews and their
worst enemies met in the same cafes and had a common social
circle.

At this time in Prague there was already a Jewish group who
wanted to develop an independent intellectual life among the
Jews. They disliked seeing the Jews taking sides in the struggle
between Germans and Czech nationalists. This group was
strongly influenced by the semi-mystical ideas of the Jewish phi-
losopher Martin Buber. They were Zionists, but at that period
they paid little attention to practical politics and concerned them-
selves mainly with art, literature, and philosophy. Einstein was
introduced to this group, met Franz Kafka, and became particu-
larly friendly with Hugo Bergmann and Max Brod.

Hugo Bergmann was then an official in the university library.
He was a blond young man with a gentle, intelligent, and yet
energetic personality. He was the center of a youthful group in
Prague that attempted to create a Jewish cultural life not based

Einstein at Prague

on orthodox Judaism,, which approached the non-Jewish world
with sympathetic understanding, not aversion or blind imita-
tion. Bergmann based his theories not only on Jewish authors
but also on German philosophers such as Fichte, who preached
the cultivation of the national spirit.

Even such an intelligent and ardent Zionist as Bergmann,
however, could not interest Einstein in Zionism for the time be-
ing. He was still too much concerned with cosmic problems,
and the problems of nationality and of the relation of the Jews
with the rest of the world appeared to him only as matters of
petty significance. For him these tensions were only expressions
of human stupidity, a quality that on the whole is natural to man
and cannot be eradicated. He did not realize then that these
troubles would take on later cosmic dimensions.

At this time Max Brod was a young writer of multifarious
interests and talents. He was also very much interested in his-
torical and philosophical problems, and a in his novels he de-
scribed the life of the Czech and other inhabitants of Prague and
Bohemia. His novels were characterized by clear, rather ration-
alistic analyses of psychological processes.

In one of his novels, The Redemption of Tycho Brake, he
described the last years of the great Danish astronomer Tycho
Brahe, which were spent in Prague. The chief theme of the
novel is the antithesis of the character of Tycho and of the young
astronomer Kepler, whom the former had invited to work with
him so as to have a collaborator who would add his young un-
prejudiced creative ideas to Tycho's great experience and powers
of observation. It was often asserted in Prague that in his por-
trayal of Kepler, Brod was greatly influenced by the impression
that Einstein's personality had made on him. Whether Brod
did this consciously or unconsciously, it is certain that the figure
of Kepler is so vividly portrayed that readers of the book who
knew Einstein well recognized him as Kepler. When the fa-
mous German chemist W. Nernst read this novel, he said to Ein-
stein: "You are this man Kepler."

5. Einstein's Personality Portrayed in a Novel

It therefore seems appropriate to quote several pas-
sages where Brod characterizes his Kepler and in which we may

85

Einstein: His Life and Times

perhaps find certain aspects of Einstein's personality. The words
of a poet may be more impressive than the description of a
scientist.

Kepler's cairn, quiet nature sometimes aroused a feeling of
uneasiness in the passionate Tycho. Brod describes Tycho's feel-
ings toward Kepler in a way that is probably equally true of the
attitudes of Einstein's scientific colleagues toward him:

"Thus the storm raged in Tycho's spirit. He took the greatest pains
to keep his feelings for Kepler free from alloy. ... In actual fact he
really did not envy Kepler his success. At the very most, the self-
evident and in all respects becoming and worthy manner in which
Kepler had achieved renown sometimes excited in him an emotion
bordering upon envy. But in general Kepler now inspired him with
a feeling of awe. The tranquillity with which he applied himself to
his labors and entirely ignored the warblings of flatterers was to Tycho
almost superhuman. There was something incomprehensible in its
absence of emotion, like a breath from a distant region of ice. . . .
He recalled that popular ballad in which a LandsJ^necht had sold his
heart to the Devil and had received in exchange a bullet-proof coat of
mail. Of such sort was Kepler. He had no heart and therefore had
nothing to fear from the world. He was not capable of emotion or
of love. And for that reason he was naturally also secure against the
aberrations of feelings. 'But I must love and err/ groaned Tycho.
e l must be flung hither and thither in this hell, beholding him float-
ing above, pure and happy, upon cool clouds of limpid blue. A spotless
angel! But is he really? Is he not rather atrocious in his lack of
sympathy?'"

This appearance of pure happiness, however, which the super-
ficial observer was frequently inclined to ascribe to Einstein
likewise, is certainly only an illustion. Tycho, who, as is well
known, was the inventor of a cosmic system that represented
a kind of compromise between the old Ptolemaic and the new
Copernican system, was very curious to hear Kepler's opinion
of this system. He always suspected that in his heart Kepler fa-
vored Copernicus and his radically new theory. Kepler, how-
ever, avoided the expression of any definite opinion on this sub-
ject before Tycho. He discussed only concrete astronomical
problems with him, no general theories. Tycho felt that this was
an evasion and urged him to talk about it. Finally Kepler an-
swered him:

" 1 have little to say. ... I am still undecided. I can't come to a
decision. Besides, I don't think that our technical resources and ex-

86

Einstein at Prague

pcrience are yet sufficiently advanced to enable us to give a definite
answer to this question/ "

There was a pause, during which Kepler sat completely self-
absorbed, with a blissful smile on his countenance. But Tycho
was already somewhat irritated and interrupted him:

"'And does this satisfy you, Kepler, this state of affairs? I mean
this uncertainty regarding the most essential points of our art. Doesn't
the lack of decision sometimes take your breath away? Doesn't im-
patience deprive you of all your happiness? 5

" 'I am not happy/ Kepler answered simply. 1 have never been
happy/

" 'You not happy?' Tycho stared at him with wide-open eyes. c You
not what do you lack, then? What more do you want? What
would you have in addition to that already bestowed on you? Oh,
fie, how immodest you must be if you don't reckon yourself happy,
you who are the happiest of all men! Yes, must I, then, tell it to you
for the first time? Don't you feel that you now I will put it in one
word, that you are on the right way, on the only right way ? . . . No,
now I don't mean the outward success, the applause surrounding you,
which has been accorded you. But inwardly, inwardly, my Kepler
must I really say it to you? inwardly, in the heart of our science,
you are on the right path, the path blessed by God; and that is the
noblest, happiest fate that a mortal can encounter/

" 'No, I am not happy, and I have never been happy/ Kepler re-
peated, with a dull obstinacy. Then he added quite gently: "And I
don't wish to be happy/

"Tycho was at his wits' end. . . . But even while he labored to
represent Kepler to himself as a cunning, calculating man, an in-
triguer, it was fully clear to him that this in no way tallied with the
facts, that Kepler was the very opposite of an intriguer; he never
pursued a definite aim and in fact transacted all affairs lying outside
the bounds of his science in a sort of dream. Why, he did not even
realize that he was happy. So far did his mental confusion go that
he did not even observe that. . . . He was not responsible for any-
thing that he did. . . . With all his happiness, which another man
would have had to purchase at the expense of unending suffering on
the part of his conscience, Kepler was pure and without guilt; and
this absence of guilt was the crown of his happiness; and this hap-
piness thus the circle closed did not for a moment weigh upon
him, for he was not even conscious of it. . . . He really had no inkling
of his good fortune. There he sat at the table opposite Tycho, and
while Tycho was tossed hither and thither by his thoughts, he sat
with upright, with somewhat rigid torso, in the attitude of one whose
gaze is fixed upon the distance, sat in complete calm and composure,
observing nothing of Tycto's disquiet and as usual continued
calculating."

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Einstein: Ute Life and Times

On another occasion Kepler and Tycho again discussed the
arguments favoring or opposing either the Copernican or the
Tychonian system, and this time they paid more attention than
before to the observable facts and the logical conclusions that
could be drawn upon for such proof. Brod describes the atti-
tudes of the two men as follows:

Tycho "began to despair, finding no sign of decision on either side.
Kepler, on the other hand, seemed to drink in a copious draught of
pleasure and strength from this very uncertainty. The more obscure
-ind the more difficult the decision, the more did he find himself in
the humor for jesting, this man who was ordinarily so dry. When
confronted by 'Nature,' this riddle of the Sphinx, his whole being
expanded, he seized without difficulty upon the object, jovially assail-
ing it upon every side, as it were, and firmly rooted himself in it.
His voice even took on an unfamiliar, joyously consequential bass-
note when he cried in reply to a caustic remark of Tycho's: 'Well,
perhaps the laws of nature agree only fortuitously.' "

Another discussion develops between Tycho and Kepler over
the question whether scientists in espousing a hypothesis must
consider the beliefs and opinions of rulers and rich men.

"Tycho raised himself, breathing heavily. 'Now at least the system
of Copernicus remains unproved, and as it runs counter to the Bible
and as I may not -needlessly affront the Catholic Majesty of my
Emperor, I have no reason for espousing it. 5

" That is going too far, 5 observed Kepler, still smiling. "Catholic
or not, the hypothesis alone is being considered here, not the Em-
peror^ favor. 5 . . .

"Tycho answered hotly, feeling that a fundamental principle of his
life was being assailed : 'But without the favor of princes and of the
rich we could construct no expensive apparatus, and truth would
remain uninvestigated. . . Thus the princes help us and the truth;
so it is for us in our turn to respect them and to defer to their pleasure. 5

" It is just this that I contest/ cried Kepler excitedly; c we must defer
to truth alone and to no one else. . . .'

"'Why to no one else? . . . When I have already put it before
you that one can serve the truth only if one serves princes. It is quite
true that it is more comfortable and simpler to follow your practice,
my dear Kepler. You pay regard to nothing in going your own holy
way, turning neither to right nor to left. But does it seem less holy
to you to belie oneself for truth's sake? "Be cunning as serpents and
harmless as doves 5 '; so did our Lord Jesus Himself speak to His
disciples. You are no serpent, you never belie or constrain yourself.
Thus you really serve, not truth, but only yourself; that is to say, your
own purity and inviolateness. But I see not only myself, I see also my

88

Einstein at Prague

relations with those among whom I must live in the determination
to serve truth with the aid of adroitness and every shrewd device. . . .
And I think it is a better imitation of Christ to work among men,
even though subject to the protection of princely favor, than merely
to dream away one's life in ecstasy and thus to forget all labor and
vexations.' "

6. Einstein as a Professor

Has Einstein always been a good teacher ? Did he like
the profession? Very different opinions on these points can be
obtained by asking people who have been his students or col-
leagues.

He had two chief characteristics that made him a good teacher.
The first was his desire to be useful and friendly to as many as
possible of his fellow beings, especially those in his environment.
The second was his artistic sense, which impelled him not only
to think out a scientific train of thought clearly and logically,
but also to formulate it in a way that gave him, and everyone
who listened to him, an aesthetic pleasure. This meant that he
liked to communicate his ideas to others.

On the other hand, tending to inhibit these qualities, was the
trait that has always been so characteristic of Einstein. I have
already mentioned his aversion to entering into very intimate
personal relations with other people, a trait that has always left
Einstein a lonely person among his students, his colleagues, his
friends, and his family. To this was added an absence of ordinary
academic vanity. For many professors the reflection of their own
personality in so many young people, all of whom repeat what
the teacher says, offers a kind of multiplication of their per-
sonality. This human characteristic, which may appear as a
weakness to some people, is also an asset in the teaching pro-
fession. It often leads to a devotion on the part of the pedagogue
to his job of teaching that appears selfless and even self-sacri-
ficing. Even though in the last analysis it is a desire for self-
expression, the teacher must surrender much of his personality.
He must spend a good deal of his own life in serving his stu-
dents. Einstein did not have this vanity, nor did his personality
require multiplication, and consequently he was not ready to
sacrifice so much for it. For this reason, too, his relation to his
students was likewise ambivalent, but in a very peculiar way.

Einstein: His Life and Times

This way is very obvious from his manner of lecturing. When
Einstein had thought through a problem, he always found it
necessary to formulate this subject in as many different ways as
possible and to present it so that it would be comprehensible to
people accustomed to different modes of thought and with dif-
ferent educational preparations. He liked to formulate his ideas
for mathematicians, for experimental physicists, for philoso-
phers, and even for people without much scientific training if
they were at all inclined to think independently. He even liked
to speak about subjects in physics that did not directly concern
his discoveries, if he had thought up a method of making these
topics comprehensible.

In view of this trait, one might think that Einstein was bound
to be a very good lecturer and teacher. Indeed, he frequently
was. When he was interested in a subject for scientific, historical,
or methodological reasons, he could lecture so that his listeners
were enthralled. The charm of his lectures was due to his un-
usual naturalness, the avoidance of every rhetorical effect and
of all exaggeration, formality, and affectation. He tried to reduce
every subject to its simplest logical form and then to present this
simplest form artistically and psychologically so that it would
lose every semblance of pedantry, and to render it plastic by
means of appropriate, striking pictures. To these qualities were
added a certain sense of humor, a few good-natured jokes that
hurt no one, and a certain happy mood mixed with astonish-
ment such as a child feels over its newly received Christmas gifts.

Nevertheless, it was rather irksome for him to give regular
lectures. To do so requires that the material for an entire course
shall be so well organized and arranged that it can be presented
interestingly throughout the year. It means that the lecturer
has to interest himself as much in each individual problem as
Einstein did in the problems on which all his energy was con-
centrated. The lecturer must devote himself completely to the
material that he is to discuss, and consequently it is very difficult
to find time to devote to one's own research. All creative activity
requires a great deal of reflection and contemplation, which a
superficial observer would regard as a useless waste of time.

There are teachers, especially in German universities, who
have arranged their time so precisely that they are able to work
out their lectures to the most minute detail and still find time
for their own research. But as a result their time is so occupied
that they have no place for the unforeseen, for an idea not directly
connected with science or the teaching profession, for reflection,

90

Einstein at Prague

or for a conversation with an unexpected visitor. They become
dry; any creative and imaginative qualities that they may have
are utilized in their scientific research or in teaching students. In
daily intercourse they often remind one of squeezed-out lemons
and are unable to say anything interesting in company. Such
scientists are not infrequent and are found even among the out-
standing ones, although they are rare among the truly crea-
tive men.

Einstein was always the very opposite of this type. He did not
like to grind out information for the students, but preferred to
give abundantly of what interested and concerned him. For this
reason he put the emphasis on his present field of interest. Also
he had too much of an artistic temperament to solve the difficulty
of giving a course of lectures in a wide field by the simple method
of basing them on a single good book. It was also impossible
for him to accumulate enough intellectual energy for his lec-
tures to imbue them all with his spirit. As a result his lectures
have been somehow uneven. He has not been a brilliant lecture-
room professor, capable of maintaining the same level of interest
and excellence in his lectures for an entire year. His single lec-
tures before scientific societies, congresses, and wider audiences,
however, were always imbued with a high degree of vitality and
left a permanent impression on each listener.

7. Generalization of the Special Theory of Relativity

In Zurich and Prague Einstein worked on the solution
of questions which were raised by his theory of relativity (Bern
1905). According to the Newtonian principle or relativity, the
velocity of a laboratory cannot be determined from observations
on the motion of objects within it. Einstein had in 1905 general-
ized this principle to include optical phenomena, so that obser-
vations of neither material bodies nor light rays enable one to de-
termine the velocity of one's laboratory. All this is true, however,
only if the motion occurs along a straight line with constant
speed. But it is quite consistent with Einstein's theory as de-
veloped so far to say that one can determine from experiments
in a laboratory L whether it moves with varying velocity relative
to an inertial system F. It would thus be possible to learn some-
thing about the motion of the laboratory as a whole from the
experiment carried out in L. While the velocity itself could not

91

Einstein: His Life and Times

be determined, the changes in speed and direction (acceleration)
could be found. Einstein regarded this situation as very unsatis-
factory. Ernst Mach had made a suggestion for the correction of
this situation by assuming that from the observation in L one
does not determine the acceleration relative to an imaginary in-
ertial system, but relative to the fixed stars. Then the events
in L would be influenced by actual physical bodies, the fixed
stars. Mach's suggestion, however, remained only a program.
It was never developed into a physical theory that would enable
one to calculate in detail what observable consequences result
from the influence of the fixed stars on the observable events
in L. It was Einstein's aim to close this gap.

He took as his point of departure the following question:
What does Newtonian physics assert about the possibility of
learning from experiments carried out in a moving laboratory
L whether this room as a whole experiences a change in
velocity relative to an inertial system? We have already seen
that when the system L is an inertial system, the two New-
tonian laws of motion, the law of inertia and the law of force,
are valid relative to it. On the basis of daily experience we can
likewise see quite easily that these laws no longer hold true for
L if it is accelerated relative to an inertial system.

For instance, let L be a moving railroad car. If the law of
inertia is valid for L, it means that when I am standing in the
car, I can remain standing for any length of time at the same
spot relative to the car without exerting any force. Experience
teaches us, however, that this is only true as long as the car moves
along a straight line at a constant velocity. When the car stops
suddenly, I shall fall down unless I make a special effort to
remain erect. The same thing happens when the car increases
its velocity suddenly or rounds a curve. As long as the change
in velocity persists, I must make an effort to remain upright.
When the velocity becomes constant again, I am able to stand
without any effort. This shows that the force that I must exert
to remain standing permits me to recognize whether my car L
is or is not an inertial system. Moreover, even this crudest kind
of experience shows me that the more sudden the stoppage of
the car, the greater the required force. More generally speaking,
the greater the acceleration, the greater the required force.

From these crude reflections, we can easily develop a method
of determining the acceleration (a) of a laboratory L by ob-
serving the motion of objects relative to the walls of L. Let us
consider, for instance, a little cart lying on the floor of L and

92

Einstein at Prague

free to move in any direction. As long as tlie laboratory moves
in a straight line with uniform velocity, the cart will remain
at rest in L, but if the laboratory suddenly changes its velocity,
the cart will move with respect to the walls of L as if it had re-
ceived a jolt. The acceleration (oo) of the cart due to this recoil
as seen in L will be such that its magnitude equals that of a but
will be in the opposite direction. For the cart, as described with
respect to the inertial system F (in which L has the acceleration
a) , is a free body not acted on by any force; and hence by the law
of inertia its motion is in a straight line with constant velocity.
On the other hand, the acceleration of the cart as described rela-
tive to F is also equal to the sum of the acceleration (<&>) of the
cart with respect to L, and a of the laboratory L itself with
respect to F. Since the resulting acceleration must be zero, we
have Oo + a 0. And from this follows ao = a, as stated
above. Thus the observation of the acceleration (#<?) of the cart
in L produced by the motion of L enables us to calculate the
acceleration (a) of the laboratory L with respect to the inertial
system F.

In the above consideration the cart was initially at rest in the
laboratory, but this is not necessary, and in fact it would be even
simpler to have it move initially in a straight line with constant
velocity in L. Then when the recoil occurs, the cart will in gen-
eral be deflected from its straight path and move in a curve.
From the observation on the shape of this curve we can deter-
mine the acceleration of the laboratory.

Furthermore, the acceleration of the laboratory need not be
restricted to increase or decrease in its speed. The laboratory may
rotate about a certain axis. Such a case is familiar to everyone
in the form of a merry-go-round or a railroad car rounding a
curve. Just as a recoil in the opposite direction to the accelera-
tion of L occurs in the former case, so in the latter case an impulse
directed away from the axis of rotation appears in L. This ac-
celeration is known to physicists as "centrifugal acceleration,"
and it is entirely analogous to the recoil that occurs when a vehi-
cle begins to move or stop.

In elementary mechanics this situation should be stated as
follows: The motion of a body relative to an accelerated or a
rotated laboratory cannot be calculated merely from the effect
of the gravitation or electric forces acting on it. Accelerations due
to recoil and centrifugal forces also occur and must be taken into
account. It is often said that these accelerations are due to the
appearance of "inertial forces" under such circumstances. They

93

Einstein: His Life and Times

are so called because they arise from the inertia of masses rela-
tive to an inertial system.

With Einstein's generalization of the Newtonian principle of
relativity to include optical phenomena, it should be possible to
use light rays instead of a material object (such as a cart) to find
out the acceleration of a laboratory. If a beam of light is arranged
so that the rays are parallel to the floor of the laboratory while
it is not accelerated, then when it is accelerated the rays will no
longer be in a straight line parallel to the floor, but will be de-
flected. Observations on the magnitude of this deflection will
enable us to calculate the acceleration of the laboratory.

Thus we see that according to nineteenth-century mechanics
and Einstein's theory of light and motion, advanced in 1905, the
acceleration of a laboratory L with respect to an inertial sys-
tem F has measurable influence on physical occurrences in
L, even though it is not possible to state under what observable
conditions a system F is an inertial system. But then the part
played by the inertial system is none other than that of Newton's
"absolute space."

8. Influence of Gravity on the Propagation of Light

It was Einstein's aim to eliminate this "absolute space"
from physics. This did not seem to be an easy task, in view of the
fact that such clearly perceptible phenomena as recoil and cen-
trifugal force in railroad cars could not be explained except by
the effect of absolute space. Einstein's theory of relativity of 1905
was restricted to motions in a straight line with constant speed
and had done nothing in this direction. A new idea leading to
even more profound changes had to be introduced into physics.
As so often happens, the difficulty was solved by recognizing
that it is related to another previously unsolved problem. When
one observes the motion of a cart or the deflection of a light ray
in a laboratory, the accelerations actually seen may be due to an-
other cause than to the acceleration of the laboratory itself. They
may be due to real forces that act on the cart or light ray and,
in accordance with Newton's law of force, impart acceleration.
How are we to distinguish the effects that arise from this en-
tirely different cause ? For forces delivered directly by human
beings or some mechanical device, the distinction can be made
in this way: Consider two carts of unequal masses instead of one,

94

Einstein at Prague

If the same force acts on the two, since Newton's law of force
states that the change in momentum that is, the change in the
product of the mass and the velocity is equal to the applied
force; the lighter cart will experience a bigger acceleration than
the heavier one. On the other hand, if the accelerations are due
to inertial forces, they will both be the same. Thus there is this
difference: Accelerations due to actual forces (like push or pull)
depend on the mass of the object moved; while accelerations due
to recoil and centrifugal forces are independent of the mass.

Einstein noticed, however, that there is one type of "real"
force that imparts the same acceleration to all bodies. This is the
force of gravity. Since the time of Galileo we have known that,
apart from the effects of air friction, all bodies fall at the same
rate no matter what their masses are. Newton did not regard
this as in any way inconsistent with his own law of motion. He
simply assumed in his law of universal gravitation that the force
of gravity acting on a body is proportional to its mass. The force
of gravity acting on any body on the surface of the earth is its
weight in the usual terminology. If we denote this by the sym-
bol W , then Newton's assumption can be expressed mathemati-
cally as W = Mg, where M is the mass of the object and g is a
constant at a certain point on the earth. Now, Newton's law of
force states that this force Mg is equal to the rate of change of the
momentum, which is simply the mass times the acceleration Ma.
Thus Mg = Ma, and consequently the mass cancels out and we
have simply a = g. The acceleration due to gravity is independ-
ent of the mass and has the same value (g) for all bodies which
is, again, Galileo's result.

Einstein realized that this special character of the force of
gravity made it impossible to determine the acceleration with
which a laboratory moves relative to an inertial system. When
we observe in a laboratory a cart executing an accelerated mo-
tion, we have no way of deciding whether this is due to the
acceleration of the laboratory system as a whole or to a gravita-
tional attraction caused by bodies whose presence may be un-
known to us. Into this gap Einstein penetrated with his keen
logical analysis, and laid the foundations for a reconstruction
of mechanics. As in his earlier paper of 1905, he again related
the motion of bodies to the propagation of light, and in 1911
he published a paper entitled "Ubcr den Einfluss der Schwer-
Jyraft auf die Ausbreitung des Lichtes" ("The Influence of
Gravity on the Propagation of Light").

Einstein started out from the following consideration: In a

95

Einstein: His Life and Times

laboratory L that, like an elevator, can move vertically up
or down, experiments are performed to observe the motion of
objects relative to it. If the laboratory is held by some means such
as a cable so that it is at rest with respect to the earth, any object
B falls downward with the acceleration of gravity, no matter
what its mass is or what it is made of. If, however, the laboratory
itself is allowed to fall freely owing to the action of gravity, then
no object B will have any acceleration relative to the labora-
tory. Everything would occur as if there were no force of gravity.
By observing motions with respect to L one is not able to decide
whether L is an inertial system with a field of gravity or whether
there is no force of gravity but the laboratory is falling freely.
To express the result more generally: it is not possible to distin-
guish by means of mechanical experiments carried out in a
laboratory the accelerations that arise from inertial forces and
those that arise from gravitational forces.

To Einstein this conclusion was analogous to Newton's state-
ment that in no case can the speed of rectilinear uniform motion
of a laboratory with respect to an inertial system be determined
from mechanical experiments within the laboratory. In 1905
Einstein had extended this principle to include optical experi-
ments. In a similar manner he now extended the properties of
accelerated motions of objects to include optical phenomena.
Thus Einstein advanced the hypothesis that it is impossible, even
by means of observations on the rays of light, to determine
whether a laboratory is an accelerated system or whether it is
at rest or in uniform motion and subjected to a gravitational
field, Einstein called this "the principle of equivalence of gravi-
tational forces and inertial forces," or, in short, the equivalence
principle.

With this principle Einstein was able to predict new optical
phenomena that could be observed and hence give an experi-
mental check on the validity of this theory. According to ordi-
nary Newtonian physics, gravity has no effect on the path of a
light ray, but according to the equivalence principle, gravita-
tional forces can be replaced by an accelerated motion. The lat-
ter, however, as mentioned in the previous section, certainly has
an effect on a beam of light. A ray parallel to the floor of a non-
accelerated laboratory is no longer parallel when the system is
accelerated. Hence Einstein concluded that the path of a light
ray is deflected in a gravitational field. The amount of deflection
turned out to be very minute because of the enormous ve-
locity of light and no terrestrial experiment is feasible, but Ein-

Einstein at Prague

stein suggested that the effect might be observable for the light
that comes to us from the fixed stars and passes near the surface
of the sun. In this case the force of gravity is not uniform with
the same strength and direction everywhere, but emanates from
the center of the sun with a force that decreases in strength
as the distance from the surface increases. But Einstein con-
cluded that there would be a deflection in a direction that bends
the light ray toward the sun. Since no stars are visible near the
sun under ordinary conditions, however, owing to the blinding
sunlight, Einstein pointed out in his paper that:

"Since the fixed stars in the parts of the sky near the sun be-
come visible during a total eclipse, it is possible to check this
theoretical conclusion by experiment."

By assuming that the force of gravity has the value accepted
by Newton, Einstein showed by a very simple calculation based
on his equivalence principle that a ray of light coming from a
fixed star and just grazing the border of the sun will be deflected
from its straight path by 0.83 seconds of an arc. Consequently,
if one photographs the fixed stars near the sun during a total
solar eclipse and compares their positions with those where the
sun is not near them, differences between their positions are to
be expected. Since the light rays are bent toward the sun, the
stars must appear shifted away from it, the magnitude depend-
ing on the proximity of the rays to the sun as they pass by it
Einstein concluded his paper with these words:

"It would be extremely desirable if astronomers would look
into the problem presented here, even though the consideration
developed above may appear insufficiently founded or even
bizarre."

No matter what one may think of Einstein's hypothesis, he
had brought forward a definite observational check on his
theory. Since total solar eclipses are not very frequent and are
observable only from a very limited part of the earth, astrono-
mers were stimulated to undertake interesting and adventurous
journeys. It took three years, however, until 1914, to find enough
support and money to dispatch an expedition equipped to per-
form this observation. But just as this first expedition left Ger-
many for Russia, World War I broke out, and the members of
the expedition became Russian prisoners and were prevented
from making the observation.

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Einstein: His Life and Times

9. Departure from Prague

While he was a professor at Prague, Einstein not only
founded his new theory of gravitation but also developed fur-
ther the quantum theory of light that he had begun while in
Bern. His hypothesis that a quantum of violet light possesses
much more energy than that of red light seemed to be in agree-
ment with experimental results on the chemical action of light.
Every photographer is familiar with the fact that the action of
violet light is much stronger than that of red light on a photo-
graphic plate. Einstein started with the simple assumption, very
closely related to his photon theory of light, that the chemical
decomposition of a molecule always takes place with the absorp-
tion of only a single light quantum. In his paper published in
1912 under the title "fiber die thermodynamischc Ecgrundung
des photochemischen Aquivalenzgesetzes" ("On the Thermo-
dynamic Foundations of the Photochemical Equivalence Law),
he showed that the assumption is also in accord with the gen-
eral principles of thermodynamics.

About this time, however, Einstein began to be much trou-
bled over the paradoxes arising from the dual nature of light:
the wave character exemplified by the phenomena of interfer-
ence and diffraction and the particle aspect shown by the photo-
electric and chemical actions. His state of mind over this prob-
lem can be described by this incident:

Einstein's office at the university overlooked a park with
beautiful gardens and shady trees. He noticed that there were
only women walking about in the morning and men in the
afternoon, and that some walked alone sunk in deep medita-
tion and others gathered in groups and engaged in vehement
discussions. On inquiring what this strange garden was, he
learned that it was a park belonging to the insane asylum of
the province of Bohemia. The people walking in the garden
were inmates of this institution, harmless patients who did not
have to be confined. When I first went to Prague, Einstein
showed me this view, explained it to me, and said playfully:
"Those are the madmen who do not occupy themselves with the
quantum theory."

Soon after Einstein's arrival in Prague, he had received an
offer of a professorship of theoretical physics at the Polytechnic
School in Zurich, the institution from which he had graduated.

Einstein at Prague

The Polytechnic belongs to the Swiss Confederation and is a
larger and more important institution than the University of
Zurich, where Einstein had first taught and which is maintained
by the canton of Zurich. Einstein was in doubt whether or not to
return to Zurich, but his wife decided the matter. She had never
felt at ease in Prague and was attached to Zurich, which had be-
come her ideal home while she was a student there.

Einstein informed the university at Prague that he would
leave it at the end of the summer semester of 1912. But with
his usual indifference to all official formalities, he did not send
to the administrative authorities the documents that had to be
filled out when one resigned from the service of the Austrian
state. The Ministry of Education in Vienna did not receive the
application that had to be forwarded in such cases. One can
well imagine that the official in charge was unhappy at being
unable to close Einstein's record according to regulations. For
many years the dossier for the "Einstein case" remained in-
complete in a pigeonhole. Some years later, when Einstein went
to Vienna for a lecture, a friend told him that the official in
the ministry was still unhappy over the gap in the records.
Einstein with his good nature did not want to make anybody
unhappy. He visited the ministry, made his excuses to the
official, and filled out the appropriate form. The pigeonhole lost
its blemish.

Einstein's sudden departure from Prague gave rise to many
rumors. An editorial in the largest German newspaper of Prague
asserted that because of his fame and genius Einstein was per-
secuted by his colleagues and compelled to leave the city. Others
maintained that because of his Jewish origin he had been badly
treated by the administrative authorities in Vienna and there-
fore did not want to remain in Prague any longer. Einstein was
much astonished by all this talk, as his stay in Prague had been
a very pleasant one, and he had been favorably impressed by the
Austrian character. Since he did not like to create any unpleas-
antness for anyone, he wrote a letter to the head of the Austrian
university administration in Vienna. Before taking over my
position in Prague, I paid a visit to this man. He was a Pole
and embraced me according to the Polish custom as if I were
a close friend. In the course of the call he told me about Ein-
stein's letter and said with great enthusiasm: "I received a splen-
did letter from Mr. Einstein, such as one is not accustomed to
receive from a professor of our universities. I recall this letter
very often. It gave me a great deal of satisfaction, particularly

99

Einstein: His Life and Times

since so many attacks were directed against our government on
account of Einstein."

For me Einstein's departure from Prague is bound up with
a rather humorous story, which I wish to relate because it is
linked with the checkered history of our time. Like every Aus-
trian prof essor, Einstein had had to get a uniform. It resembled
the uniform of a naval officer and consisted of a three-cornered
hat trimmed with feathers, a coat and trousers ornamented
with broad gold bands, a very warm overcoat of thick black
cloth, and a sword. An Austrian professor was required to put
on this uniform only when taking the oath of allegiance before
assuming his duties or when he had an audience with the
Emperor of Austria. Einstein had worn it only once, on the
former occasion. Since the uniform was rather expensive and he
had no use for it after his departure, I bought it for half the
original price. But before Einstein gave me the uniform, his
son, who was then perhaps eight years old, said to him: "Papa,
before you give the uniform away, you must put it on and take
me for a walk through the streets of Zurich." Einstein promised
to do so, saying: "I don't mind; at most, people will think I am
a Brazilian admiral."

I too wore it only once, when taking the oath of allegiance, and
I had it in my trunk for a long time. After six years the Austrian
monarchy disappeared and the Czechoslovakian Republic was
established at Prague. The oath of allegiance to the Emperor
was replaced by that of allegiance to the Republic, and the pro-
fessors had no uniform any more. The uniform remained only
as a memory of Franz Joseph and Einstein. Soon after the Rus-
sian Revolution, when a large number of refugees, many of
whom were officers, came to Prague, my wife said to me: "Why
should such a good coat lie unused when so many are freezing?
I know a former commander in chief of the Cossack army who
cannot buy a warm winter coat. Einstein's coat looks almost like
the coat of a high-ranking cavalry officer. It will please the gen-
eral and keep him warm." We gave him the coat, but he was not
interested in its distinguished past. The rest of the uniform, in-
cluding the sword, remained in the German University. When
the Nazis invaded Czechoslovakia in 1939, the university became
a bulwark of Nazism in the east and Einstein's sword probably
became booty of a Nazi soldier, a symbol of the final defeat of
"international Jewish science" until 1945, when the Red Army
entered Prague.

100

V

EINSTEIN AT BERLIN

I. The Solvay Congress

In the fall of 1912 Einstein entered upon his duties as
professor at the Polytechnic in Zurich. He was now the pride
of the institution where he had once failed to pass the entrance
examination, where he had studied and met his wife, and where
on graduation he had been unable to obtain even a minor po-
sition.

As early as 1910, when Lampa was considering Einstein's
appointment to Prague and seeking an opinion of his qualifica-
tions from a scientist who was generally recognized as an au-
thority, Max Planck, the leading theoretical physicist, had writ-
ten to the faculty committee at Prague: "If Einstein's theory
should prove to be correct, as I expect it will, he will be consid-
ered the Copernicus of the twentieth century." Einstein was
already beginning to be surrounded by an aura of legend. His
achievements were characterized as a turning-point in physics
comparable to the revolution initiated by Copernicus.

In 1911, when a conference of a small number of world-
famous physicists was to be convened in Brussels to discuss the
crisis in modern physics, there was no question that an invita-
tion would be extended to Einstein. The selection of the con-
ferees was suggested by Walter Nernst, a leading investigator
in the fields of physics and chemistry, and among others there
were Sir Ernest Rutherford of England, Henri Poincare and
Paul Langevin of France, Max Planck and Walter Nernst of
Germany, H. A. Lorentz of Holland, and Madame Curie of
Poland, who was working in Paris. Einstein represented Aus-
tria, together with Franz Hasenohrl, the Viennese, whose name
after his tragic death was to be linked in a peculiar manner
with the fight against Einstein. This conference was Einstein's
first opportunity to meet these scientists whose ideas shaped the
physical research of this period.

The costs of the conference, including the traveling expenses
to Brussels and the living expenses there and in addition a re-

101

Einstein: His Life and Times

muneration of a thousand francs to each conferee, was de-
frayed by a rich Belgian named E. Solvay. This man had been
successful in the chemical industry, but his hobby was a physical
theory of the outmoded mechanistic type. Although it led
to many complications and not to the discovery of new laws,
he was greatly interested in attracting the attention of physicists
to his theory and in learning their opinions about it. The clever
chemist Walter Nernst, who was in social contact with him,
thought that this rich man's hobby might be utilized for the
benefit of science while at the same time fulfilling Solvay's de-
sire. He proposed that he call a conference of leading physicists
to discuss the present difficulties in their science, to whom he
could present his ideas on this occasion. The conference became
known as the Solvay Congress. In the opening address Solvay
presented a summary of his ideas, and the conferees then dis-
cussed the new developments in physics. Finally in the conclud-
ing address Solvay thanked the speakers for their interesting
discussions, emphasizing how much pleasure he had derived
from them. Nevertheless, all this had not shaken his faith in
his own theory. All the speakers had avoided entering upon any
criticism of his theory, to prevent any conscientious scruples
arising between their feelings of gratitude and courtesy toward
their host and their scientific convictions. Solvay was imbued
with such sincere interest in the advancement of science that he
subsequently convened similar conferences quite often, and at
these meetings Einstein always played a leading role. A man
like Nernst who has the interests of science at heart and is prac-
tical can utilize such opportunities for the benefit of progress
in scientific research.

The world marveled at the great number of new and aston-
ishing ideas and at the thoroughness with which ithese concepts
were developed, presented, and arranged in a larger chain of
ideas that Einstein had already produced in 1912 after less than
ten years as a physicist. But Einstein himself thought only of
the defects and the gaps in his creations. His new theory of
gravitation, which he had made public in 1911 at Prague, dealt
only with one very special case of the effects of gravity. Only
the case where the force of gravity has the same direction and
intensity throughout the entire space under consideration was
completely clear, and the theory as developed so far was unable
to furnish a complete solution to cases where the force of grav-
ity had different directions at different points in space.

Up to this time Einstein had solved his problems with the

IO2

Einstein at Berlin

simplest mathematical aids and had looked upon every exag-
geration in the use of "higher mathematics" with the suspicion
that it was not due to any desire for clarity, but rather to dumb-
found the reader. Now a new trend appeared in his work. It
has been mentioned that while in Prague Einstein had already
felt that the development of a still more general theory required
more complicated mathematical methods than those he had at
his command. He had discussed this matter with his colleague
Pick, who had called his attention to the new mathematical
theories of the Italians Ricci and Levi-Civita. In Zurich Einstein
found ^among his colleagues his old friend Marcel Grossmann,
and with him he now studied these new mathematical methods.
In collaboration with him Einstein succeeded in preparing a
preliminary sketch of a general theory of gravitation in which
every case of the action of the force of gravity was contained.
This work, published in 1913, still contained many defects,, how-
ever, and they were not removed until the complete theory was
finally published during the World War. We shall discuss it in
detail later.

2. Trip to Vienna

In the fall of 1913, at the Congress of German Sci-
entists and Physicians in Vienna,, Einstein was invited to pre-
sent a summary of his new ideas on the theory of gravitation.
Even then he was regarded as an unusual phenomenon among
the physicists, and it was rumored that he had "thought up" a
general theory of relativity which was "even more incompre-
hensible" than his special theory of 1905 and even further re-
moved from the physics of the laboratory. In consequence a
large audience crowded the room where he was to speak, Ein-
stein, however, took the most obvious and easily understood
ideas as his points of departure and tried step by step to awaken
in his listeners a feeling that radical changes were necessary if
only one tried to see clearly the defects and gaps in the previous
theories.

His explanation was approximately as follows: At first, in-
vestigations of the nature of electricity were concerned only
with electrical charges. The forces involved in the mutual at-
traction and repulsion of these charges were known, and it was
also known that, like the Newtonian gravitational forces, they

103

Einstein: His Life and 'times

decreased with the square of the distance between the charges.
Later, electric currents were discovered, and it was found that
they could be generated by moving magnets, as well as by mov-
ing electric charges. This led to the industrial application of
electricity. Finally, electromagnetic waves were discovered and
utilized in wireless telegraphy and radio. No one had imagined
that all this would develop from the simple attraction of electri-
cal charges. In the theory of gravitation we are still in this first
period where we are acquainted only with the law of attraction
between material bodies. We must create a theory of gravitation
that will be as far removed from the simple Newtonian theory
of attractions as the theory of radio waves is from the views of
Benjamin Franklin.

In his lecture Einstein also mentioned that previous to his
work a young Viennese physicist had already developed some
of the mathematical ideas that he had used in his theory. He
asked whether this man was in the audience, as he did not
know him personally. And in fact a young man rose and Ein-
stein asked him to remain standing so that the entire audience
could see him. This man was Friedrich Kottler, later employed
by the Eastman Kodak Company at Rochester, New York.

Einstein took this opportunity of his stay in Vienna to be-
come personally acquainted with the physicist and philosopher
Ernst Mach, who had had such a profound influence on the
development of Einstein's ideas. (Ch. II) At the University of
Vienna Mach had lectured on the history and theory of the "in-
ductive" sciences that is, sciences such as physics and chemis-
try that advance from individual observations to general laws.
For more than twelve years, however, Mach had suff ered from
a severe paralysis and had retired from his position. He lived in
his apartment in a suburb of Vienna, and occupied himself only
with his studies and receiving occasional visitors. On entering
his room one saw a man with a gray, unkempt beard and a
partly good-natured, partly cunning expression on his face, who
looked like a Slavic peasant and said: "Please speak loudly to
me. In addition to my other unpleasant characteristics I am also
almost stone-deaf." Mach was very much interested in meeting
the originator of the new theory of relativity.

Even though Einstein greatly admired Mach's ideas on the
logical structure of physics, there were many things he could
not accept. According to Einstein's judgment Mach did not give
enough credit to the creative mind of the scientist who imagines
general laws beyond a mere economic description of facts.

104

Einstein at Berlin

Mach's opinion, that the general laws of science are only a means
by which individual facts can be remembered more easily, did
not appear satisfactory to Einstein. To him the phrase "remem-
bered more easily" could in this connection apparently mean
only "remembered with less effort." Mach's economy seemed
to be economy in a psychological sense.

Hence, after conversing awhile with Mach, Einstein raised
the following question: "Let us suppose that by assuming the
existence of atoms in a gas we were able to predict an observable
property of this gas that could not be predicted on the basis of
a non-atomistic theory. Would you then accept such a hypothe-
sis even if the calculations of its consequence required very com-
plicated computations, comprehensible only with great diffi-
culty ? I mean, of course, that from this hypothesis one could
infer the interrelation of several observable properties that with-
out it would remain unrelated. It is then 'economical' to as-
sume the existence of atoms?"

Mach answered: "If with the help of the atomic hypothesis
one could actually establish a connection between several ob-
servable properties which without it would remain isolated, then
I should say that this hypothesis was an 'economical' one; be-
cause with its aid relations between various observations could
be derived from a single assumption. Nor should I have any
objection even if the requisite computations were complicated
and difficult."

Einstein was exceedingly satisfied with this statement and re-
plied: "By 'simple' and 'economical' you mean, then, not a 'psy-
chological economy' but rather a logical economy.' The ob-
servable properties should be derived from as few assumptions
as possible, even though these assumptions appear 'arbitrary'
and the computation of the results might be difficult"

With economy interpreted in this logical sense, there was
no longer any conflict between Mach's standpoint and Einstein's
as to the criteria to be filled by a physical theory. Although
Mach made the concession in conversation, yet Einstein saw
in his writing only a demand for "psychological economy."
Thus for the moment Einstein was satisfied, but he retained a
certain aversion to the "Machist philosophy."

105

Einstein: His Life and Times

3. Invitation to Berlin

Einstein's fame had grown so great by now that many
centers of scientific research desired to secure him as an associate.
For several years efforts had been exerted to develop Berlin not
only as a center of political and economic power but also as a
center of artistic and scientific activity. Emperor Wilhelm II,
who liked to associate with Americans, had learned from them
that in the United States there were, in addition to the universi-
ties, institutions devoted solely to research, to which rich busi-
ness men such as Rockefeller, Carnegie, and Guggenheim
donated large sums of money. The Kaiser was aware that
military and economic power required as a basis an organiza-
tion of scientific research, and he wanted to use his influence
to found similar research institutions in Germany. For his pur-
pose this was particularly important in the fields of physics,
chemistry, and their applications.

To further these aims Wilhelm II founded the Kaiser Wil-
helm Gesellschaft, within which rich industrialists, merchants,
and bankers united to help build research institutes. The mem-
bers received the pompous title of "senator" and the right to
wear a handsome gown, and they were sometimes invited to
breakfast with the Emperor an invitation that cost them each
time a great deal of money. During the course of the conversa-
tion at these breakfasts, the Emperor would mention that money
was requested for a particularly important field of research.

The erection of these institutes had the additional advantage
that scientists whom the government did not want to appoint
as professors in the universities, because of pedagogical, politi-
cal, or other reasons, could still be employed in a way beneficial
to the German Reich. Men of outstanding eminence were
sought for these institutes, and the appointments could be made
solely on the basis of scientific achievement.

Owing to the fact that the Kaiser was interested not only
in physics and chemistry but also in modern Biblical research,
the first president of the Kaiser Wilhelm Gesellschaft was the
liberal Protestant theologian Adolf Harnack. He was persuaded
by Max Planck and Walter Nernst to invite Albert Einstein, the
rising star in physics, to Berlin.

Planck and Nernst, the leaders in German physics at this
time, were to play important roles in Einstein's life. They rep-

106

Einstein at Berlin

resented two very different types of German scientist. Max
Planck was a member of a Prussian family of military officers
and government officials. He was tall, slim, an enthusiastic
mountain-climber, and a lover of classical music. Basically, he
accepted the philosophy of his social class; he believed in the
mission of the Kaiser to make the world happy with his con-
ception of German culture, and in the right of his class to pro-
vide the leaders for Germany and to exclude people of other
origins from such functions. On the other hand, he was an
ardent adherent of Kantian philosophy in the diluted form in
which it had become the common religion of the German aca-
demic and governmental circles. He believed with Kant in the
duty of doing everything that is "qualified to become a general
rule of human conduct." He also believed in the international
mission of science and in non-German co-operation with Ger-
mans in scientific research. But since his immediate emotional
reaction was to respond in terms of the philosophy of the Prus-
sian bureaucracy, an appeal to his reason was necessary to make
him recognize the rights of aliens. As he was conscientious and
an idealist, such an appeal was usually successful.

On the other hand, Walter Nernst, although a great scientist
and scholar, exhibited the mentality characteristic of a member
of the merchant class. He had no national or class prejudice and
was imbued with a type of liberalism that is often peculiar to
business men. He was short, active, witty, and quick of appre-
hension. He occasionally utilized his craftiness in professional
life, and his students jokingly referred to him as the "Kommer*
zienrat" a title conferred in Germany on successful business
men. There was a story about him that he was the only physicist
who had ever signed a contract with an industrial firm in which
the advantage was not on the side of the firm. This contract
concerned his invention of an electric light bulb, widely known
for a time as the Nernst lamp. He earned a good deal of money
from it, but the lamp soon fell into disuse.

Planck and Nernst went to Zurich personally to influence
Einstein in favor of their plan. This was the following: There
was as yet no separate research institute for physics and no hope
that any such institute could be built in the near future. Never-
theless, Einstein was to become the director of the institute that
was being planned, and in the meantime to assist in a consulta-
tive capacity in the physical research being carried on in other
institutes. In addition he was to become a member of the Royal
Prussian Academy of Science. To be a member of this body was

107

Einstein: His Life and Times

considered a great honor; and many outstanding professors at
the University of Berlin never succeeded in achieving it. Al-
though membership in the Academy was only an honorary po-
sition for most of the incumbents., a few were endowed by
foundations which paid a sufficiently large salary. Such a posi-
tion was offered to Einstein. Both in the Academy and in the
Kaiser Wilhelm Institute his main occupation was to be the
organization of research. He was to have the title of professor
at the University of Berlin, but unencumbered by any obliga-
tions or rights, except that of lecturing as much or as little as
he desired. He was to have nothing to do with the administra-
tion of the university or with examinations, or in the appoint-
ment of new professors.

There were great advantages offered by this invitation. Be-
sides the academic honors that the Prussian Academy bestowed
on him, it meant that he would receive a much larger salary
than he did at Zurich. He would also be in a position to devote
himself entirely to research and would have as much of an
opportunity as he desired to come into contact with the many
leading physicists, chemists, and mathematicians who were in
Berlin. Despite his unusual talents he could still expect to be
stimulated by new ideas, since it is always fruitful to receive the
criticism of so many scientists capable of independent thinking,
working in many different fields. In addition it meant that
Einstein would not be obliged to give regular lectures, which
he considered very burdensome.

On the other hand, it was difficult for him to decide to return
to the center of that Germany from which he had fled as a
student. It seemed to him even a kind of betrayal of his con-
victions to become a member of a group with which he did
not harmonize in so many respects, simply because it was con-
nected with a pleasant position for himself. It was for him a
struggle between his personality as a scientific investigator who
could benefit by moving to Berlin, and his feeling as a mem-
ber of a certain social group.

In addition there were also personal factors that entered into
the decision. Einstein had an uncle in Berlin a fairly successful
businessman, whose daughter, Elsa, was now a widow. Ein-
stein remembered that his cousin Elsa as a young girl had
often been in Munich and had impressed him as a friendly,
happy person. The prospects of being able to enjoy the pleas-
ant company of this cousin in Berlin enabled him to think of

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Einstein at Berlin

the Prussian capital somewhat more favorably. And so Einstein
finally decided to accept the offer, and at the end of 1913 he left
Zurich.

4. Einstein's Position in the Academic Life of Berlin

Soon after his arrival in Berlin Einstein separated from his
wif e, Mileva, with whom in many respects he was no longer in
accord, and he now led a bachelor life. When he became a mem-
ber of the Academy he was just thirty-four years old. He was a
young man among men who were in general much older, men
with proud pasts and great authority, and many of them of great
achievements also. The feeling of strangeness that he felt there
from the beginning, however, arose only in a very small part
from the difference in age. Most of these men were, so to speak,
"veterans of university life." Everything that happened in these
circles seemed to them extraordinarily important, and election to
the Academy appeared to be the culmination of their aspira-
tions. All this could not make any great impression on Einstein,
who was already on his way to world fame before he was a
great man in narrower academic circles.

While Einstein was still in Zurich and a long time before the
invitation from Berlin, someone happened to remark in his pres-
ence: "It is really a pity that no one ever enters the Academy
while still a young man, at a time when it would still make him
happy." "If that is the case," Einstein rejoined, "I could be
elected to the Academy immediately, since it would not make
me happy even now."

In an academy there is always much that is comical Einstein
appreciated this as much as he had the comedy in the faculty
meetings at the University of Prague. Moreover, the comical
aspects of such bodies are hardly to be avoided. This is due to
the circumstance that even the greatest scientists of the country
must deal with questions that are often of but slight significance,
but that must be discussed with the same thoroughness and
earnestness as if they were scientific questions of prime impor-
tance. For instance, whether a work to be published by the
Academy is to be done in two or three volumes, whether A
should receive one hundred marks for his work and B one hun-
dred and twenty or vice versa, and many similar questions were

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Einstein: His Life and Times

discussed with considerable acumen and temperament. Also, in
accordance with an old tradition, the papers that were to be
printed in the transactions of the Academy had to be presented,
even if only in summary form when the Academy met. Since
as a rule these papers dealt with very special subjects, they were
completely incomprehensible and uninteresting to most of the
members. One described a rare moss found in a certain part of
Finland, another discussed the solution of a complicated math-
ematical equation, and still another the deciphering of a Baby-
lonian inscription that could be read only with difficulty. In
order to be polite, one had to show a certain interest; actually
the members often had to make an effort not to fall asleep dur-
ing the sessions. This was all very natural, but the contrast be-
tween earnestness and triviality could not but appear comical.
Einstein was well able to appreciate this, and his sense of
humor made it easier for him to endure much that was un-
pleasant

Professor Ladenburg, a German physicist who lived and
worked for a long time with Einstein in Berlin and who is now
at Princeton University, once said to me: "There were two kinds
of physicists in Berlin: on the one hand was Einstein, and on
the other all the rest." This is a very good characterization of
Einstein's position. To all outward appearances he was a mem-
ber of a professional group, but he never belonged to its rank
and file. His aloofness was always noticeable, and his status may
be described aptly by the slang expression: "He was in a class
by himself."

Einstein's contradictory attitude toward co-operation with
others and his aloofness we have so often noted manifested
itself also very definitely in his attitude to his occupation as
professor. He frequently expressed the opinion that a scientist
should earn his living from a "cobbler's job." If he is paid to dis-
cover new theories he must constantly be thinking: "Discoveries
cannot be made on order and if I don't discover anything, I shall
disappoint my employers and receive my pay for nothing." But if
he is active as a technician or a teacher, he is always doing some-
thing useful and hence has a clear conscience. On his own ideas
he should work for pleasure only.

This may be a little exaggerated, since ultimately pure science
has a social value too. But it is certain that Einstein has had a
definite aversion to pure research as a profession. Actually, as
fate would have it, after moving to Berlin he was permanently
what he did not want to be a pure research worker. This

no

Einstein at Berlin

was the situation in Berlin, and he was to obtain a similar posi-
tion later in Princeton.

The contradiction in Einstein's relation to his environment is
also manifested in his aversion to giving regular lectures cov-
ering the entire field of physics, even though probably few
physicists are interested in and familiar with more fields of phys-
ics than he is. Very many, indeed most specialists, in physics as
well as in other sciences, are hardly able to understand any-
thing complicated that does not belong within their narrow
field. Most of them are inclined to exaggerate enormously the
significance of their "subject"; they consider every thought de-
voted to outside matters as a betrayal of pure research and a
concession to dilettantism, Einstein has been the exact opposite
of this type. One may recount to him the most complicated
physical theory; he will listen attentively, and through his ques-
tions show immediately that he has grasped the essence of the
matter. He will almost always make a good critical comment
or a helpful remark. Even when the construction of some ap-
paratus is being discussed, he concerns himself with every sig-
nificant detail and intervenes with his advice.

Obviously Einstein is not a "teacher" if this word is taken in
the sense in which it is current in professional circles. On the
other hand, quite in accord with his divided attitude, which we
have previously noted, he is more interested than most profes-
sors in social matters, such as the position of scientific teaching
and research in the social life of man. He has always tried to
clarify for himself and others the reciprocal relation between
science on the one hand and society, religion, and international
co-operation on the other.

In Berlin, as in many universities, it was customary to have
a physics colloquium every week where recently published re-
searches were discussed. It gave physicists who worked in dif-
ferent institutions an opportunity to exchange opinions and
ideas about every new discovery and theory. During the period
of Einstein's stay, between 1913 and 1933, the Berlin seminar
was an especially interesting gathering, such as hardly existed
anywhere else in the world. Besides Einstein, Planck, and
Nernst, there were Max von Laue, the discoverer of the diffrac-
tion of X-rays by crystals; James Franck and Gustav Hertz,
who discovered that light of specific color can be produced by
the impact of high-velocity electrons; and Lise Meitner, a Vien-
nese girl who had made such great discoveries in the field of
radioactive phenomena that Einstein liked to call her "our

in

Einstein: His Life and Times

Madame Curie/' and in private sometimes expressed the opin-
ion that she was a more talented physicist than Madame Curie
herself. During the latter years of this period there was also
Erwin Schrodinger, another Austrian, who derived the quan-
tum theory of the atom from a wave theory of matter.

The discussions with such outstanding investigators were of
value even to a man with great creative power like Einstein.
At the very least he was spared the necessity of reading much
that would otherwise have taken up a great deal of time, Ein-
stein attended the colloquium quite regularly and took an ac-
tive part in the discussions. He liked to branch out into all
sorts of problems, and his remarks refreshed all who were pres-
ent. His questions alone were sufficient to exert a stimulating
influence. On such occasions there are always many who are
ashamed to ask questions because they do not wish to appear
ignorant, and usually it is just the people who take the longest
to comprehend something who are shy. Since Einstein could
never be suspected of slow comprehending, he did not hesitate to
ask questions that would otherwise be considered as naive. Such
"naive" questions, however, are often very stimulating, because
they frequently deal with fundamental problems that no one
really dares to touch. Most specialists would like to make be-
lieve that they understand the fundamentals and are only seek-
ing to explain secondary matters. Einstein's questions, which
very often threw doubt upon a principle that appeared self-
evident, gave the seminar a special attraction. After Einstein's
departure from Berlin in 1933, the colloquium presented the
appearance of a gathering from which the guest who had en-
dowed it with lustrous brilliancy had departed.

5. Relationship with Colleagues

Einstein's attitude to the teaching profession was also
connected with his concrete relations to his colleagues. There
is no doubt that the immediate impression he made on his col-
leagues was that of a very likable person. He was filled with a
simple natural friendliness toward everyone, no matter what the
individual's position. He was very amicable toward people of
high rank; he had such a feeling of inner security that he did
not have to demonstrate his independence by being short with
people. He never took part in any intrigues such as occur in

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Einstein at Berlin

all corporate bodies and professions, including university fac-
ulties. He was not considered dangerous to anyone, because he
never tried to frustrate anyone's desire. He was ready to con-
verse in a friendly manner about anything and everything; he
liked to crack jokes and to laugh at other people's jokes. He
always avoided putting himself in the foreground and forcing
his will on other people. This would have been easily possible
if he had used his personality and his fame., but he did this very
rarely, and at most to defend himself against unreasonable de-
mands, never in an offensive manner.

He always managed to maintain a certain "free space" around
himself which protected him from all disturbances, a space
large enough to contain a world erected by an artistic and scien-
tific imagination.

There were also certain features in his Berlin environment,
no matter whether one calls them national or cultural peculiar-
ities, that produced in Einstein a feeling of strangeness and lone-
liness. In the eighteenth century, under Frederick the Great,
Frenchmen such as Voltaire and d'Alembert had been the pride
of the Berlin Academy. But since the Bismarck era and the
turning of the German intellectuals to nationalism, an atmos-
phere of voluntary or involuntary submission to the philosophy
of the new German Reich had become more and more prev-
alent, at first under the influence of Bismarck and later under
that of Wilhelm II. This sentiment was also connected with a
certain emphasis on the superiority of the German nation or
race, which, although at that time not yet very conspicuous,
was already quite evident to Einstein.

But what particularly annoyed Einstein from the beginning
was the cold, somewhat mechanical manner of the Prussians
and their imitators, whom Einstein had feared as a student and
from whom he had fled. Einstein sometimes expressed his feel-
ing as follows: "These cool blond people make me feel uneasy;
they have no psychological comprehension of others. Every-
thing must be explained to them very explicitly."

As a result, for a man who came from a somewhat different
environment, and especially for a man like Einstein with a
strong intuitive feeling for the significance of human relation-
ships, life among them was often bound up with conflicts. Ein-
stein experienced this feeling of strangeness even in his rela-
tions with a man like Max Planck, who had done so much for
Einstein's recognition as a scientist, who had supported and
worked for his election to the Academy, and who had a high

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Einstein: His Life and Times

opinion of him as a person. Einstein could never get rid of the
feeling that the emotion and ideas of a man like Planck were
actually opposed to his own and that it was only by means of
rational arguments that Planck forced himself to say or do
something in agreement with Einstein's views or intentions.
Einstein always sensed the existence of a barrier behind which
something hostile lay hidden, and therefore behind which he
preferred not to look; but the conviction that this barrier ex-
isted produced a sense of uneasiness, which, while sometimes
hardly noticeable, was never completely absent.

The degree to which this Prussian reserve and mechanical
thinking weighed upon Einstein became evident when Erwin
Schrodinger, the Austrian, came to Berlin as Planck's successor.
There were no barriers; there was an immediate understanding
between the two men without any long explanations, and an
agreement on the manner in which they would act toward each
other without first having to call upon Kant's categorical im-
perative.

Einstein's solitary position in academic circles was due also
to the fact that he did not like to take part in the problems of
professional daily life; he was unable to take them seriously.
The daily life of a scholar is often a matter of discussing and
becoming excited about the frequency with which his papers are
published, which colleagues have or have not published any-
thing, which colleague has frequently or infrequently cited
which other colleague, or who intentionally or unintentionally
has failed to cite somebody else. There are discussions of the
merits of individual professors, the honors that they have or
have not received from their own or other universities, and the
academies to which they have been elected. Then again the
conversation may turn to the number of students for whom
the professors have been able to obtain positions, the students
and teachers whom they have been able to prevent from ob-
taining positions, whether they have any influence with su-
perior officials, and whether they are able to obtain money for
their department from these authorities.

Taken as a whole, all these problems add up to a tremendous
total of interests and intellectual effort, in which Einstein hardly
participated. It would be very unjust to maintain that all these
conversations are valueless for scientific activity. On the con-
trary, they have their justification in social life. Nevertheless,
too much attention to these details may prevent one from deal-
ing with the actual problems of science. It is perhaps compatible

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Einstein at Berlin

with research in a very specialized field, but it is undoubtedly
a considerable hindrance if one looks upon science as a religion
and a philosophy that influence one's entire life, as Einstein had
done throughout his life. Yet one ought not to overlook the
fact that, in consequence of this withdrawal from the more
trivial details of the daily life of most professors, he often de-
prived himself of opportunities of obtaining concrete influence.
Every social group is so constituted that petty things are inex-
tricably interlinked with important matters, and as a result, by
manifesting an aversion to the petty things, one easily loses the
possibility of exercising an influence on more important mat-
ters. For a man like Einstein, however, such means of exerting
his influence were so disagreeable that he could very rarely de-
cide to make use of them.

This aversion to petty talk was more than compensated for
in unbounded readiness to discuss scientific problems and ques-
tions of general interest with his colleagues. Without the slight-
est trace of pomposity he turned to his colleagues for advice,
even to those younger than he if they were more conversant
with special problems. And all this took place quite informally.

Einstein was always very intent on being a person who did not
require any special consideration. On one occasion he was sup-
posed to pay his respects to a member of the Berlin Academy.
He was not very fond of such formal visits, but he had heard
that Professor Stumpf, a well-known psychologist, was greatly
interested in the problems of space perception. Einstein thought
that he would be able to discuss matters of mutual interest that
might have some connection with the theory of relativity, and
he decided to make this call On the chance that he might find
the professor at home, he went there at eleven in the morning.
When he arrived, the maid told him that the Herr Geheimrat
was not at home. She asked Einstein whether he would like to
leave a message, but he said it was unnecessary. He did not want
to disturb anyone, and would come back later in the day. "In the
meantime," he said, "I'm going to take a walk in the park." At
two in the afternoon Einstein returned. "Oh," said the maid,
"since you were here the Hcrr Geheimrat came home, had his
lunch, and because I did not say that you would come back, he
is taking his afternoon nap," "Never mind," said Einstein, "111
come back later." He went for another walk and came back
again at four. This time he was finally able to see the Geheimrat.
"You see," Einstein said to the maid, "in the end patience and
perseverance are always rewarded."

"5

Einstein: His Life and Times

The Geheimrat and his wife were happy to see the famous
Einstein and assumed that he was now making his formal in-
troductory visit. Einstein, however, immediately began to talk
about his new generalization of the relativity theory and ex-
plained in detail its relation to the problem of space. Professor
Stumpf, who was a psychologist without any extensive mathe-
matical knowledge, understood very little of the discussion and
was hardly able to put a word in edgewise. After Einstein had
talked for about forty minutes, he remembered that he was
actually supposed to be paying an introductory call and that it
had already lasted too long. Remarking that it was quite late
already, he departed. The professor and his wife were dumb-
founded, for they had had no opportunity to ask the customary
questions: "How do you like Berlin?" "How are your wife and
children?" and so on.

6. Relationship with Students

Einstein's chief activity in Berlin was conversing with
colleagues and students about their own work and advising
them about their research programs. He did not have to give
regular courses and he lectured only occasionally, either on his
own special field or on subjects of general interest to lay audi-
ences.

Even among professors whose chief activity was giving regu-
lar courses of lectures, the guidance of students in research was
considered to be an important part of their duties. It was the
pride of the teachers at the German universities to have as many
scientific investigations as possible carried out and published by
students under their direction. Hence many students who other-
wise would never in their life have produced an independent
piece of work published at least a dissertation when they ac-
quired the doctorate. For this purpose a professor had to pro-
vide subjects of research for even untalented students who
lacked ideas of their own, and then push them along until the
studies were completed. In many cases the teacher could have
carried out these investigations better and more rapidly if he
had done the work himself, and so a certain lack of selfish-
ness was required to waste so much effort on incompetent
students.

On the other hand, many professors were themselves not very

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Einstein at Berlin

talented. They divided the subject on which they were working
into innumerable small parts and then let each part be handled
by a student. The student's task under these circumstances was
relatively easy, and was dealt with in great detail so as to create
an impression of being important. In this way there arose what
was known in Germany as the "Betrieb" (mill), where to all
outward appearances no distinction is made between worth-
while ideas and trivialities. Everything produced was a "con-
tribution to the literature/' which had to be cited by every sub-
sequent writer if he wanted to be "scientific." An agreeable
feeling of activity surrounded both teacher and students. They
became so engrossed in this activity and industry that the larger
problem that the partial studies were supposed to elucidate was
often forgotten. The production of dissertations and papers be-
came an end in itself.

Einstein never evinced any interest in this kind of activity.
Above all, he did not like the idea of raising easy questions and
preferred to deal only with problems that naturally arise when
investigating fundamental bases of natural phenomena. Ein-
stein once remarked about a fairly well-known physicist: "He
strikes me as a man who looks for the thinnest spot in a board
and then bores as many holes as possible through it." He
esteemed most highly those who occupied themselves with dif-
ficult problems even if they were able to advance few steps in
this thicket, or even if they themselves could not extend our
knowledge in any positive sense, but were only able to make
clear to the world the magnitude of the difficulties involved.
With this conception of scientific work Einstein was not the
man to have many students working under him. Whatever he
undertook was always so difficult that he alone was able to
carry it through.

There was also a great difference between Einstein's attitude
and that of his colleagues toward the peculiar, pseudo-scientific
questions that university professors often receive by mail from
dilettantes of science. Einstein was remarkably patient in an-
swering them, and in many respects it was easier for him than
for most other scientists. Many professors, even outstanding
ones, are so immersed in their own ideas that it is difficult for
them to comprehend ideas that deviate from the traditional, or
are merely expressed in a way differing from that commonly
used in scientific books. This difficulty frequently manifests it-
self in hatred or contempt for amateurs since the professors are
often actually incapable of refuting the ingenious objections

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Einstein: His Life and Times

made by dilettantes to scientific theories. As a result they give
the impression of incompetence and the falsehood of "academic
science." Einstein, on the other hand, did not regard the differ-
ences between the layman and the professional as being very
great. He liked to deal with every objection and had none of
the reluctance that makes such work so difficult for others; and
this was especially important in his case since laymen frequently
occupied themselves with and discussed the relativity theory.

These characteristic features in his psychological constitution
and in the manner in which he carried on scientific research
brought him into closer contact with students, but here again
not in a way that was characteristic of university professors. His
attitude toward students was characterized chiefly by his friend-
liness and readiness to help them. When a student really had a
problem in which he was profoundly interested, even if it was
a very simple one, Einstein was ready to devote any amount
of time and effort to help him solve it. Also the incredible ease
with which Einstein instituted even difficult scientific reflections
and his almost equally unusual talent for comprehending rap-
idly and thoroughly what was said to him stood him in good
stead in these consultations. As a result he had a good deal of
time, which he lavishly placed at the disposal of his students.

When I came to Prague as his successor, Einstein's students
told me with the greatest admiration and joy that immediately
upon assuming his duties as professor there, he had said to
them: "I shall always be able to receive you. If you have a prob-
lem, come to me with it. You will never disturb me, since I
can interrupt my own work at any moment and resume it
immediately as soon as the interruption is past."

This attitude must be judged in comparison with that of
many professors, who tell their students that they are always oc-
cupied with their research and do not like to be disturbed be-
cause an interruption might possibly imperil the results of their
intensive reflections.

Just as it is the pride of many people never to have any time,
so it has been Einstein's always to have time. I recall a visit I once
paid him on which we decided to visit the astrophysical observa-
tory at Potsdam together. We agreed to meet on a certain bridge
in Potsdam, but since I was a good deal of a stranger in Berlin,
I said I could not promise to be there at the appointed time.
"Oh," said Einstein, "that makes no difference; then I will wait
on the bridge." I suggested that that might waste too much of his
time. "Oh no," was the rejoinder, "the kind of work I do can

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Einstein at Berlin

be done anywhere. Why should I be less capable of reflecting
about my problems on the Potsdam bridge than at home?"

And this was very characteristic of Einstein. His thoughts
flowed like a constant stream. Every conversation that inter-
rupted his thinking was like a small stone thrown in a mighty
river, unable to influence its course.

There was yet another factor that brought Einstein into closer
contact with his students. This was his need to clarify his ideas
for himself by expressing them aloud and explaining them to
others. Thus he often conversed with students about scientific
problems and told them his new ideas. But Einstein did not
really care whether the listener actually understood what was
being explained or not; all that was necessary was that he should
not appear too stupid or uninterested. Einstein once had an as-
sistant who helped him with his administrative duties while at
the same time completing his own studies in physics. Every day
Einstein explained his new ideas to him and it was generally
said that if this young man had had only a slight talent, he could
have become a very great physicist few students had ever re-
ceived such good instruction. But while the student was an
intelligent and industrious man and an ardent admirer of Ein-
stein, he did not become a great physicist. The influence of the
teacher is not so great as some people believe.

7. Outbreak of the World War

Before Einstein had been in Berlin a whole year, the
World War broke out in August 1914. Great enthusiasm swept
Germany, which to a large extent arose from the feeling that
the individual could now merge with the greater whole the
German Empire -and stop living for himself, a feeling that
for many people meant a great sense of relief.

This joy, however, could not be felt by anyone who had any
comprehension of public opinion in the great Slavic centers of
Austria. In Prague Einstein had witnessed the gradual evolution
by which Austrian foreign policy had become an instrument
for the attainment of German aims, and consequently Einstein
could not share the enthusiasm of the crowd in Berlin. He
was placed in a rather unpleasant psychological situation. His
feelings were comparable to those of a person in the midst of
a group that has been stimulated by good wine, but who has

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Einstein: His Life and Times

drunk nothing himself. He felt badly about it, because he rep-
resented for the others a sort of quiet reproach, which they re-
sented. Fortunately, he had a good reason to base his reserve on.
In coming to Berlin, he had retained his Swiss nationality,
and his lack of enthusiasm as a neutral was not taken too much
amiss.

I still remember very clearly the first visit that I paid Einstein
during the war. When I was leaving, he said to me: "You have
no idea how good it is to hear a voice from the outside world,
and to be able to speak freely about everything."

Immediately upon the outbreak of the war there arose behind
the actual battle front an "intellectual front/' where the inteL
lectuals of the hostile camps attacked each other and defended
themselves with "intellectual weapons." The invasion of neutral
Belgium by German troops had shocked the entire world,
which still believed in the validity of "paper" treaties. Further-
more, the suffering of the Belgian people during the fighting
and occupation was utilized to very sound advantage by Al-
lied propaganda. The people of western Europe asked with
astonishment: "How can the German people, whose music we
love and whose science we admire, be capable of such unlawful-
ness and such atrocities ? " Partly for propagandist reasons there
was invented the story of the "two Germanys," the Germany
of Goethe and the Germany of Bismarck.

The creation of this contrast was unpleasant for the German
government, which demanded of the intellectuals that they
publicly proclaim their solidarity with the German military
and diplomatic conduct of the war. In the famous Manifesto of
the Ninety-two German Intellectuals, ninety-two of the out-
standing representatives of German art and science rejected the
distinction between German culture and German militarism.
The manifesto culminated in the assertion: "German culture and
German militarism are identical." What from the German side
was regarded as a disavowal of disunity in the life-struggle of
the nation was considered the height of cynicism by the Allies.

As one might expect, Einstein did not sign the manifesto. But
it illustrates what was expected at that time of every leading
German artist and scientist. Anyone> like Einstein, who refused
to concur was regarded by the great majority of his colleagues
as a renegade who had deserted his people at a difficult time.
Only his Swiss citizenship saved Einstein from being looked
upon as a traitor in the struggle for the existence of the German
people.

I2O

Einstein at Berlin

One can understand how difficult it would have been for Ein-
stein to identify himself publicly with that very militarism to
which he had had the greatest aversion since childhood.

8. German Science in the War

With the outbreak of the war, all of Einstein's col-
leagues became active in one way or another in war service.
Physicists were employed in wireless telegraphy, in constructing
submarine sound detectors, in predicting weather, and various
other important scientific projects. Some served because they
felt it to be their duty, others because such work was less un-
pleasant than service on the battle fronts. On the other hand,
there were some who felt they should share the dangers and
hardships of the soldiers in the trenches instead of working in
a safe laboratory.

Walter Nernst, who has been mentioned several times al-
ready, performed valuable services in the investigation of poison
gases. Fritz Haber, a close scientific friend of Einstein, de-
veloped a process for the manufacture of ammonia utilizing
atmospheric nitrogen, a process of great significance since am-
monia is a chemical necessary for the manufacture of artificial
fertilizers and explosives and since Germany was unable to im-
port natural ammonia compounds because of the English block-
ade. Haber was of Jewish origin, but he was strongly influenced
by such Prussian ideas as high regard for military power and
the subordination of personal feelings to this supreme value. For
their service both Nernst and Haber received the rank of major
in the German army. To Nernst this title was only a minor sat-
isfaction to his vanity, and he did not esteem it very highly, but
for Haber it was a source of great satisfaction and sincere pride.
In the Treaty of Versailles both Nernst and Haber were listed
by the Allies among the "war criminals" whom Germany was
supposed to give up for trial before an international court. No
serious demand for their surrender was ever made, however.

All this work which the scientists performed for the war ef-
fort was only natural at a time of national peril, no matter what
their attitudes were to the government in power. But there was
still another way in which they participated in the war: they
engaged actively in the war on the "intellectual front." There
began a battle of words and of propaganda by which the achieve-

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Einstein: His Life and Times

ments of German scientists were stressed while those of the
workers in the enemy countries were depreciated. A group of
German physicists sent a circular to all their colleagues in
which they urged them not to cite the works of English physi-
cists, or to do so only where this was "unavoidable." They as-
serted that on the whole the work of Englishmen was on a
much lower level and was frequently mentioned only because
of an exaggerated admiration for foreigners,, an attitude that
should now be abandoned.

From a historical point of view it is not so much these hu-
manly understandable attempts to exploit the war spirit for
personal advantages that are of interest, but rather the appar-
ently "scientific" attempts to prove that the entire structure of
German physics differs from that of French or English physics.
It was argued that for this reason one should adopt as little as
possible from them, since otherwise the unity and purity of
German science would be endangered and the minds of Ger-
man students confused. For example, it was frequently asserted
that German science is especially profound and thorough in
contrast to the superficial character of French and Anglo-Amer-
ican science. French superficiality was attributed to the "shal-
low" rationalism that tries to comprehend everything by means
of reason and ignores the mystery of nature; that of the Anglo-
Saxons to the overemphasis on sensory experience, which be-
lieves only in facts and ignores philosophical implications.

Against this the French scientists, in so far as they participated
in the war of words, asserted that the "thoroughness" of Ger-
man science consists in a pedantic collection of unimportant
facts, and its "philosophical" character in the production of a
smoke screen that obscures the true relation between things.
The Anglo-Saxon scientists preferred to point out that German
science emphasizes "idealistic" principles so as to make it easier
to excuse particularly inhuman acts; for if one must commit
atrocities in order to carry out such principles, then they are
"idealistically" justified.

These arguments soon made their appearance in the con-
troversy over the relativity theory. By using arguments of this
kind it could be attacked by the one party as a particularly
"German" theory and by the opposing side as particularly "un-
German," We shall see that in this way Einstein's theories,
which at first sight appear far removed from any political utility,
were soon drawn into the struggles of nations and parties.

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Einstein at Berlin

9. Life in Wartime

During the war the newspapers in Berlin were filled
with the battles and victories of the German army. The people
were filled with joy and occupied themselves with discussions
of such questions as which of the conquered territories should
be kept by Germany after the war, whether Poland should ac-
tually be freed or become a German protectorate, and so forth.
They counted the number of English merchant ships sunk by
their submarines, and many of them kept lists of the amount
of tonnage sent to the bottom of the sea. Every day they copied
the figures from the newspapers and conscientiously added up
the totals like a business man making up his annual accounts.
To their astonishment they soon found that the total exceeded
all the tonnage England ever had, and they began to wonder
that there were still any English ships on the sea.

In private life, however, the pre-eminent interest of every-
body was in obtaining food. Whoever managed a household had
to be as cunning and ingenious as possible to get any of the
food that occasionally appeared on the market; and to prepare
it in a halfway palatable manner, since it was often of an un-
usual nature.

Einstein's health was often poor during the war, and he was
happy to be connected with a family with whom he could eat
home-cooked meals instead of having to depend on restaurant
fare, whose cooking at this time was based on the hygienic in-
structions of the military authorities. Some of Einstein's well-
to-do relatives had previously looked upon him as the black
sheep of the family. His running away from the gymnasium in
Munich, his devotion to studies that could not bring him a good
income, and his marriage to a woman completely outside their
circle had not met their approval. It was therefore with great
astonishment that they had heard of his growing fame. When
Einstein was called to Berlin and made a member of the Royal
Prussian Academy, they felt honored to have him at their homes
and to be mentioned as his relatives. Einstein accepted this situa-
tion good-humoredly.

In his uncle's house Einstein again met his cousin Elsa, with
whom he had been friends as children in Munich. She was now
a widow with two daughters, a woman of friendly, maternal
temperament, fond of amusing conversation, and interested in

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Einstein: His Life and Times

creating a pleasant home and preparing the scanty wartime
meals as best she could. Einstein often went to their house, and
found a new family life there.

Frau Elsa could not study the works of great physicists with
him as Mileva Maritsch had done at Zurich. She had a happy
outlook on life, and not the harsh, self-denying nature of the
Slavic student. Regarding Einstein as a physicist, she knew only
that he had now become a famous man whom the outstanding
scientists of the Prussian Academy, the University of Berlin, and
foreign countries recognized as their equal and often as their
superior. To have such a relative and friend was a source of
pride and joy to her and she wanted to relieve him of the cares
of daily life. Einstein, who valued friendliness, often made him-
self useful in her house by practicing "applied physics."

When I visited Berlin on one occasion during the war, Ein-
stein invited me to his uncle's house for dinner. I declined at
first, saying: "Right now when everything is so scarce no one
likes to have an unexpected guest." Thereupon Einstein replied
in his sincere manner, which sounded like the simplicity of a
child but which could equally well be regarded as acid criticism:
"You need have no scruples. On the contrary, my uncle has
more food than the per capita average of the population. If
you eat at his table you are serving the cause of social justice."
There I met his cousin Elsa for the first time. She said to
me half playfully, half in earnest: "I know very well what a
talented physicist our Albertle is. In these times we have to buy
food in all kinds of cans which no one knows how to open.
Often they are of unfamiliar, foreign make, rusted, bent, and
without the key necessary to open them. But there hasn't been
a single one yet that our Albertle has not been able to open."

While the war was still going on, Einstein married his cousin
Elsa., He, who had always had something of the bohemian in
him, began to lead a middle-class life. Or, to put it more exactly,
Einstein began to live in a household such as was typical of a
well-to-do Berlin family. He lived in a spacious apartment in
the so-called "Bavarian quarter." This section had nothing Ba-
varian about it except that the streets were generally named
after Bavarian cities. He lived in the midst of beautiful furni-
ture, carpets, and pictures; his meals were prepared and eaten at
regular times. Guests were invited. But when one entered this
home, one found that Einstein still remained a "foreigner" in
such a surrounding a bohemian guest in a middle-class home.

Elsa Einstein had many of the characteristics of the people of

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Einstein at Berlin

her native Swabia. She valued greatly what was known in
Germany and especially in Swabia as " GemutTich\eit" It is no
wonder that she was very happy when she saw the esteem and
admiration in which her husband was held and which she
shared as his wife. Nevertheless, there were always two sides to
the job of being the wife of a famous man. The people about
her were always inclined to look very critically at her and, as
a compensation for the respect that they reluctantly paid her
husband, to unload upon her all the reproaches they would
have liked to bring against him.

When Elsa Einstein was discussed in professional circles in
Berlin, one could hear all sorts of criticism of this nature. The
most harmless was probably the assertion that her intellectual
capacities hardly fitted her to be Einstein's wife. But if Einstein
had followed this criticism, what woman could he have mar-
ried ? The question was, rather, could she create tolerable liv-
ing conditions for Einstein in which he could carry on his
work? And in considerable measure she did so. There is no
ideal solution to this problem, and since Einstein believed less
than most men in the possibility of an ideal solution, he did not
feel hurt when his wife did not completely represent this ideal.

Some professors complained that because of her it was diffi-
cult for physicists to gain access to Einstein. She preferred, they
claimed, to have Einstein meet writers, artists, or politicians, be-
cause she understood these people better and considered them
more valuable. Einstein, however, was certainly not the man to
be easily influenced in the choice of his company. He himself
liked to mingle with all kinds of people and did not restrict
himself to professional circles. It may sometimes have happened
that a visitor whom Einstein did not wish to see put the blame
on Einstein's wife because he did not want to admit to himself
that his company was not so interesting for Einstein as he
himself thought it ought to be.

Others complained that Mrs. Einstein placed too much value
on the external symbols of fame and did not really know how
to value her husband's inner greatness. It is obvious, however,
that the wife of a great man can understand most easily the
effect of his activities on public opinion, and that this will con-
sequently interest her more than anything else.

Any woman in Elsa Einstein's position would probably have
acted more or less as she did. The only difference was that the
public is rarely so much interested in the life of a scientist as it
was in Einstein's. On this account his wife was blamed for vari-

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Einstein: His Life and Times

ous things that are actually common occurrences. The married
life of a great man has always been a difficult problem, no mat-
ter how he or his wife is constituted. Nietzsche once said: "A
married philosopher,, is to put it bluntly, a ridiculous figure."

Einstein was protected against various difficulties by the cir-
cumstance that he always kept a certain part of his inner self
from any contact with others, and that he had no desire to share
his inner life completely with anyone. He was very much aware
that every happiness has its shadows, and accepted this fact
without protest.

When in 1932 some women's clubs opposed Einstein's entry
into the United States because in their opinion he spread subver-
sive doctrines, e.g., pacifism, Einstein remarked jokingly to a
representative of the Associated Press : "Why should one admit
a man who is so vulgar as to oppose every war except the inevi-
table one with his own wife ?"

And on another occasion he made a remark based on many
years of experience: "When women are in their homes, they are
attached to their furniture. They run around it all day long and
are always fussing with it. But when I am with a woman on a
journey, I am the only piece of furniture that she has available,
and she cannot refrain from moving around me all day long
and improving something about me."

This lack of any illusion about the possibility of happiness in
life has saved Einstein from the mistake made by many a hus-
band who looks upon all the defects that are characteristic of
life itself as defects in his wife and in consequence plays the
stern judge with her instead of remembering her good qualities
and accepting her bad ones as a necessity of nature.

During this period Einstein's first wife and his two sons lived
in Switzerland. This circumstance caused Einstein a great deal
of financial worry because of the great difficulty in transferring
money from Germany to Switzerland and the rate of exchange,
which became more and more unfavorable as the war pro-
gressed. But since her student days Mileva Maritsch was so at-
tached to her life in Switzerland that on no account would she
live in Germany.

126

VI

THE GENERAL THEORY OF RELATIVITY

i. New Theory of Gravitation

The war and the psychological conditions produced
by it in the world of science did not prevent Einstein from de-
voting himself with the greatest intensity to improving his
theory of gravitation. Working along the line of his ideas that
he had found in Prague and Zurich., he succeeded in 1916 in
developing a completely independent, logically unified theory
of gravitation. Einstein's conception differed fundamentally
from that of Newton, and a real understanding of his theory
requires a wide knowledge of mathematical methods. Without
using any mathematical formulae, I shall here attempt to present
the fundamental ideas in so far as they are necessary for our
understanding of Einstein's personality and the influence of his
theory on his period and environment.

The great difficulty involved in explaining Einstein's new
theory lies in the fact that it does not arise from any slight
modification of Newtonian mechanics. It bursts asunder the
entire framework within which Newton attempted to compre-
hend all phenomena of motion. The familiar concepts of
"force," "acceleration," "absolute space," and so on have no place
in Einstein's theory. Even to the average physicist the principles
composing Newtonian mechanics seem either to be proved by
experience or by reasoning, and it is hardly possible for him to
comprehend any change in a structure that he has come to re-
gard as immutable. This is an illusion that must be destroyed
in order to be able to understand Einstein's theory.

According to Newton's law of inertia, a body not acted on
by any force moves in a straight line with constant velocity.
This is true no matter what is the mass or other physical prop-
erties of the body involved. Hence it may be stated that its mo-
tion can be described "geometrically." On the other hand, if
any force acts on the body, then, according to Newton's law of
force, it experiences acceleration inversely proportional to its
mass. Consequently, particles with different masses perform dif-

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Einstein: His Life and Times

ferent paths under the action of the same force. Motion under
force can only be described by using a non-geometrical term
mass.

We have seen in Section 8 of Chapter IV, however, that
in his gravitational theory of 1911 Einstein had noted that the
force of gravity has the unique property that its influence is
independent of the mass of the body on which it acts. And as
a consequence he had concluded that the presence of a gravita-
tional field of force cannot be distinguished from the result of
accelerated motion of the laboratory. This means that not only
motion under no force, but also motion under gravitational force
alone can be described purely geometrically, if these forces
are parallel and of equal magnitude in the whole region con-
sidered.

| With this foundation, the problem that .now faced Einstein
was this: What is the geometrical form of the path which a
body in a gravitational field describes relative to any laboratory ?

Einstein's solution of this problem is based on a concept that
the laws of geometry in a space where there exists gravitational
field are different from those in a space which is "free of forces"
in the old sense. This was an idea so novel that the physicists
and mathematicians used to nineteenth-century physics were be-
wildered by it. In order to understand what Einstein meant, we
must go back to the positivistic conception of science, and in
particular to the ideas of Henri Poincare described in Section 9
of Chapter II. According to this view, the truth of mathematical
propositions concerning points, straight lines, and so forth can
only be verified in our world of experience when these math-
ematical notions are defined in terms of physical operations. We
must give what P. W. Bridgman calls the "operational defini-
tions" to the geometrical terms. For example, we must define
"straight lines" in terms of certain steel rods prepared according
to a specified method, and if we make a triangle with these rods
we can verify by actual measurement on this triangle whether
the angles add up to two right angles or not.

By means of other experiments we can then investigate
whether these rods actually have all the properties that geometry
postulates about "straight lines." For instance, we can measure
whether such a rod is really the shortest line connecting two
points. Of course in order to be able to carry out this measure-
ment we must also describe a physical operation of measuring
the length of a curved line. It may be found that when a triangle
is formed by joining these points by lines that form the shortest

128

The General Theory of Relativity

distances between these points, the sum of the angles of this
triangle does not equal two right angles. We are then faced
with a dilemma. If we say that the lines forming this triangle
are straight lines, we retain the property of the straight line to be
the shortest distance between any two points, but then the
theorem of the sum of angles is no longer valid. On the other
hand, if we want the theorem to be valid, the property to be the
shortest distance has to be rejected. We are free to decide which
property we retain for the lines we call "straight," but we cannot
have them both as in Euclidean geometry.

Einstein's fundamental assumption can now be re-expressed
in this form: In a space where masses that exert gravitational
forces are present, Euclidean geometry ceases to be valid. In this
theory curves which are the shortest distances between any two
points have special significance, and the angles of a triangle
formed by these lines do not add up to two right angles where
a gravitational field exists.

This distinction between Euclidean space and the "curved"
space of Einstein can be illustrated by considering a similar dis-
tinction between a plane surface and a curved surface. For all
triangles on a plane surface, all of Euclid's theorems hold true;
but what happens for triangles on a curved surface ? Take for ex-
ample the surface of the earth. If we are restricted to only those
points which actually lie on the surface and cannot consider any
point lying above or below it, there are no "straight lines" in the
usual sense. But the curves which form the shortest distance be-
tween two points on the earth's surface are important in naviga-
tion and geodesy; they are called geodesic lines. For the surface of
the sphere, the geodesic lines are arcs of great circles, and con-
sequently all the meridians defining longitude and the equator
are geodesic. If we consider a triangle formed by the North Pole
and two points on the equator it is bounded by geodesic lines.
The equator cuts all the meridians perpendicularly so that the
two angles at the base of the triangle are both right angles, and
hence the sum of the angles is greater than two right angles by
just the value of the polar angle. A similar situation always holds
for any curved surface, and, conversely, if the sum of the angles
of a triangle formed by geodesic lines on a surface does not equal
exactly two right angles, then the surface is curved.

This notion of curvature of a surface is extended to space.
Geodesic lines are defined as curves forming the shortest dis-
tances between any two points in space, and the space is called
"curved" if the angles of a triangle formed by three geodesic

129

Einstein: His Life and Times

lines do not add up to two right angles. According to Ein-
stein's theory, the presence of material bodies produces certain
curvatures in space, and the path of a particle moving in a
gravitational field is determined by this curvature of space.
Einstein found that such paths can be described most simply
by considering the geometry of this curved space rather than
by ascribing its deviation from a straight line to the existence
of forces as Newton had done. Furthermore,, Einstein found that
not only the paths of material particles, but also those of light
rays in a gravitational field can be described simply in terms of
geodesic lines in this curved space; and, conversely, that the
curvature of space can be inferred from observations on the path
of moving bodies and light rays.

We shall see later that many people, even some physicists,
considered it absurd to say that any conclusion about the curva-
ture of space can be drawn from the form of light rays. Some
even considered it completely nonsensical to say that a space is
"curved." To them, a surface or a line may be curved in space,
but to say that space itself is "curved" seemed preposterous and
absurd. This opinion, however, is based on ignorance of the
geometrical mode of expression. As we have seen above, a
"curved space" simply means a space in which the sum of the
angles of a triangle formed by geodesic lines does not equal
two right angles, and this terminology is used because of the
analogous distinction between flat and curved surfaces. It is fu-
tile to try to picture what a curved space "looks" like, except by
describing the measurement of triangles.

2. Role of Four-Dimensional Space

If we wish to describe the motion of a certain particle
completely, it is not sufficient to give the shape of its trajectory,
but it is necessary to add how the position of the particle on
this trajectory varies with the time. For instance, to say that the
motion of a particle uninfluenced by any force in the Newtonian
sense is rectilinear is not complete; we must add that its motion
takes place with constant velocity.

The complete motion can, however, be presented in a ge-
ometrical form by adding a dimension to the number necessary
to describe the trajectory. For example, in the simplest case of
a rectilinear motion, the trajectory is a straight line, and the po-

130

The General Theory of Relativity

sition of the particle describing it can be specified by giving the
distance that the particle is from a certain definite point on the
straight line. We now take a sheet of paper and plot these dis-
tances along one direction, and for each point plot in a direction
perpendicular to the distance the time corresponding to each
position. Then the curve drawn through these points gives the
complete geometrical presentation of the motion. If the mo-
tion takes place with constant velocity as well as being recti-
linear, the curve will be a straight line. Thus motion along a
straight line, or one-dimensional motion, to express it techni-
cally, can be represented completely on a plane that is, in two-
dimensional space. Now, the space of our experience has three
dimensions; to specify the position of a ball in a room, we must
give three numbers, the distances from the two walls and its
height above the floor. Hence we need three dimensions to de-
scribe the trajectory of a general motion, and four dimensions
to give a complete presentation of the motion. The motion of a
particle is specified completely by a curve in a four-dimensional
space.

This notion of four-dimensional space, simple as it is, has given
rise to a great deal of confusion and misunderstanding. Some
writers have maintained that these curves in four-dimensional
space are "only aids for mathematical presentation" and "do
not really exist." The statement "do not really exist," however,
is a pure truism, since the statement "really existing" is used in
daily life to describe only directly observable objects in our three-
dimensional space. In contrast to this, many authors, especially
philosophers and philosophically tinged physicists, have taken
the point of view that only the events in four-dimensional space
are real, and a representation in three-dimensional space is only
a subjective picture of reality. We can readily see that such
a position is equally justified except that the word "real" is used
in a different sense. To clear up this disagreement we have to
use a little semantics.

In his special theory of relativity developed at Bern, Ein-
stein had shown that when mechanical and optical phenomena
are described by means of clocks and measuring rods, the de-
scription depends on the motion of the laboratory in which
these instruments are used. And he had been able to state the
mathematical relations that correlate the various descriptions
of the same physical event. In 1908 Hermann Minkowski, Ein-
stein's former professor of mathematics at Zurich, showed that
this relationship between different descriptions of the same phe-

131

Einstein: His Life and Times

nomena can be represented mathematically in a very simple
manner. He pointed out that these different descriptions o a mo-
tion represented by a curve in four-dimensional space are math-
ematically what are known as "projections of this four-dimen-
sional curve on different three-dimensional spaces." Minkowski
therefore took the view that only the four-dimensional curve
"really" exists, and the different descriptions are merely dif-
ferent pictures of the same reality. This concept is analogous to
saying that a fixed object in three-dimensional space, say a house,
"really exists," but that photographs of this house taken from
various directions 'that is, two-dimensional projections of the
three-dimensional house never represent reality itself, but only
descriptions of it from different points of view.

Obviously the word "real" is not used in the same sense here
as when we say that only the three-dimensional body is "real"
and that the four-dimensional presentation is simply an in-
vented mathematical schema. In Minkowski's speech "real"
means the "simplest theoretical presentation of our experiences,"
while in the other sense it means "our experience expressed as
directly as possible in ordinary, everyday language."

Einstein's theory of gravitation started out from this repre-
sentation of motion as a curve in four-dimensional space. Mo-
tion, if neither gravity nor any other force is acting, is represented
by the simplest curve, the straight line, in flat, four-dimensional
space. If only gravity but no other force is acting, Einstein as-
sumed that the space becomes curved, but the motion is still
represented by the simplest curve in such a space. Since there
are no straight lines in curved space, he took for the simplest
curve in space the curve with the shortest length between any
two points that is, the geodesic line. Hence motion of a
particle under gravity is represented by a geodesic curve in four-
dimensional curved space, and this curvature of space is deter-
mined by the distribution of matter which produces the gravi-
tational field.

Thus Einstein's general theory of relativity consists of two
groups of laws:

First: The field laws which state how the masses present pro-
duce the curvature in space.

Second: The laws of motion both for material particles and
for light rays which state how the geodesic lines can be found
for a space whose curvature is known.

This new theory of Einstein was a fulfillment of the program
of Ernst Mach, From the material bodies present in space it

132

The General Theory of Relativity

enables one to calculate the curvature of space, and from this
the motion of bodies. According to Einstein,, the inertia of bodies
is not due, as Newton has assumed, to their efforts to maintain
their direction of motion in absolute space, but rather to the in-
fluence of the masses about them the fixed stars, as Mach had
suggested.

3. Einstein Suggests Experimental Tests of His Theory

Einstein's new theory, which so boldly and fundamen-
tally changed the tested and successful Newtonian theory, was
originally based on arguments of logical simplicity and gen-
erality. The question naturally arose whether new phenomena
could be deduced from this theory which differed from those
derived from the old, and which could be used as experimental
tests between the two theories. Otherwise Einstein's theory re-
mained only a mathematical-philosophical construction, which
provided a certain degree of mental stimulation and pleasure
but contributed nothing about physical reality. Einstein himself
always recognized a new theory only if it uncovered a new field*
of the physical world.

Einstein showed mathematically that in "weak" gravitational
fields his theory predicted the same results as Newton's. Here
the curvature of our three-dimensional space is negligible, and
the only difference comes from the new mathematical approach
in the addition of the fourth dimension. The calculation of mo-
tionfor example, that of the earth around the sun gives
exactly the same result as that obtained from Newton's law of
force and his theory of gravitation. It is only when the velocity
of a body is comparable to that of light that any difference be-
tween the two theories can be detected.

In order to find phenomena where spatial curvature plays pos-
sibly a role, Einstein searched among the observations of celes-
tial bodies for motions that were inconsistent with the predic-
tions of Newtonian mechanics. He found one case. It had long
been known that Mercury, a planet close to the sun and thus
strongly exposed to its gravitational field, did not move exactly as
predicted by Newton's theory. According to the old theory, all
planets should perform elliptical orbits whose position in space
are fixed in relation to the stars, but, it had been observed that
the elliptical orbit of Mercury rotates around the sun at the very

133

Einstein: His Life and Times

small rate of 43.5 seconds of an arc per century. This discrepancy
had never been given a satisfactory explanation. When Einstein
calculated the motion of Mercury according to his theory, he
found that the orbit should actually rotate as observed. From
the very beginning this achievement has been a strong argument
in favor of Einstein's theory.

The effect of the curvature of space on the path of light rays
is more impressive. While still at Prague Einstein had pointed
out the possibility of bending rays of light as they passed close
to the surface of the sun. He had calculated., on the basis of
Newton's law of force and his own theory of gravitation of
1911, that the deflection should be 0.87 seconds of an arc. Ac-
cording to his new theory of curved space, Einstein found the
deflection is 1.75 seconds, actually twice as great as his former
result.

The third prediction that Einstein made was on the change
in wave length of light emitted by a star. His calculation showed
that light, in leaving the star where it is emitted, has to pass
through its gravitational field, and this passage shifts the wave
length toward the red. Even for the sun the effect turned out
to be hardly observable, but in the case of the very dense com-
panion star to Sirius it seemed to be of observable magnitude.

It is important to note that of these three phenomena pre-
dicted by the theory, only one of them, the motion of Mercury,
was actually known at the time Einstein developed his theory.
The other two were entirely new phenomena, which had never
been observed or even suspected. Both of these predictions re-
ceived unqualified verification some years later, and so gave con-
clusive evidence of the correctness of the theory. It is very re-
markable and a great tribute to Einstein that he was able to
develop a theory which started from few fundamental princi-
ples and using the criterion of logical simplicity and generality
led to amazing results.

4. Cosmologlcal Problems

Even before his new theory had been completely un-
derstood by the great majority of physicists, it was already evi-
dent to Einstein that it was unable to give a correct presentation
of the universe as a whole.
During the nineteenth century the commonest conception of

The General Theory of Relativity

the universe was that there are groups of material bodies like
our Milky Way, and outside this region is "empty" space, which
extends infinitely far. This view had, however, already aroused
doubts among some scientists around the end of the century. For
in this case the stars would behave like a cloud of vapor and
there was nothing to prevent them from dispersing into the sur-
rounding empty space. Since infinite time and space are avail-
able, the whole universe would eventually become completely
empty.

From the standpoint of Einstein's theory, this conception of
the material universe as an island in empty space had additional
difficulty. This is due to the equivalence principle, by which
gravitational and inertial masses are considered identical. It will
be remembered that Ernst Mach first pointed out as a defect of
Newtonian mechanics that in it inertial motion, rectilinear mo-
tion in empty space, is a process uninfluenced by the presence
of other masses. Mach proposed instead the assumption that the
effect of inertia is due to motion relative to the fixed stars. Ein-
stein had introduced this idea in his theory as "Mach's postu-
late" when he assumed that gravitational field, and conse-
quently inertial effects, are determined by the distribution of
matter. If the material bodies formed an island in empty space,
then, according to Einstein, only a finite part of space would be
"curved." This region, however, would be surrounded by a
"flat" space extending to infinity in all directions. In this flat
space, bodies not acted on by any force would move in straight
lines in accordance with Newton's law of inertia, and the in-
ertial force would not be determined by the distribution of mat-
ter. For this reason, the idea of curved "space being enclosed in
an infinite flat space is inconsistent with Mach's postulate.

The next possible assumption then was that matter does not
form an island, but rather that all of space is filled more or less
densely with matter. However, if we further assume that all
these masses act upon each other according to Newton's law,
then we again run into a difficulty. For matter at large distances
exerts individually small eff ects, but the total amount of matter
at large distances increases in such a way that there is an infinite
amount of matter at infinity which exerts an infinitely strong
force. Observations show that stars are not acted on by such
forces, for in this case they would reach high velocities, while
all actually observed velocities of stars are small in comparison
with the speed of light.

Einstein cleared up this difficulty by pointing out that in his

135

Einstein: His Life and Times

theory of curved space uniform distribution of matter does not
necessarily mean that there is an infinite amount of matter.
There is the possibility that., owing to the curvature, space does
not extend to infinity. This does not mean, however, that there
are boundaries in space beyond which is nothing, not even empty
space. The situation may perhaps be illustrated by the same ex-
ample with which I explained the curvature of space. The sur-
face of the earth is a two-dimensional curved surface which has
finite area but has no boundaries. Certain objects, say cities, may
be distributed more or less uniformly on its surface, but the total
number of cities is finite. Furthermore, if one travels in a given
direction along any geodesic (a great circle in this case), one
returns to the original point of departure. In the same way the
space of our experiences may be curved in such a way that it
is finite but unbounded. It becomes meaningful to ask how
much matter is contained in the universe, what is the "radius
of curvature" of our space, and consequently what is the aver-
age density of matter in space.

There is still another possibility, however. Matter may fill "in-
finite" space with approximate uniformity, but the whole uni-
verse may not be at rest, but expanding, so that the density of
matter is decreasing. At present it is not yet possible to say with
certainty which of the two hypotheses concerning the distribu-
tion of matter is correct. Later on, Einstein envisaged also the
possibility that space might be "curved" without the presence of
masses, contrary to Mach's original assumption.

At any rate, the view that matter does not form an island in
infinite empty space is supported by modern astronomy. The
researches of Harlow Shapley and his collaborators have shown
that space, as far as can be seen with present telescopes, seems
to be similar everywhere to the region of our Milky Way. Thus
it is plausible to assume with Einstein that on the average the
entire universe is uniformly filled with matter. Also by count-
ing the number of stars and measuring their distances from us,
Shapley has been able to obtain a rough value for the average
density of matter in the universe. Furthermore, from observa-
tions of the velocity of recession of the distant nebulx and Ein-
stein's law of motion it has been possible to calculate such quan-
tities as the radius of curvature and the volume of space,, and
the total amount of matter in it.

The General Theory of Relativity

5. Expeditions to Test Einstein's Theory

For the mathematician, Einstein's new conception of
gravitation was characterized by beauty and logical simplicity.
For the observational astronomer there still remained the dis-
quieting doubt that all this might be mere fantasy. Newton's
theory had served them well and it would require more than
mathematical elegance to change their views. According to the
astronomers, a solar eclipse was needed for the test.

New theories to use a comparison that Einstein likes to em-
ploy are comparable to beautiful dresses, which when dis-
played in a dressmaker's salon attracts every feminine eye. A cel-
ebrated beauty orders this dress, but will it fit her ? Will it add
to or detract from her beauty ? Not until she has worn it in the
full glare of lights can she tell. Einstein's theory was a kind of
unworn dress that had been in a shop window. The solar eclipse
was the first affair at which it was to be worn.

While the war was still in progress, Einstein's papers on the
general theory of relativity became known in England. The
abstract discussion could be followed only with difficulty, and
the new conceptions about motion in the universe could not
yet be appreciated in all their logical implications. But their
boldness was already admired. For the first time a well-founded
proposal had been advanced to change the laws of the universe
set up by Isaac Newton, England's pride.

For the English, with their tendency toward experimental
verification, one thing was clear. A number of definite experi-
ments had been pointed out to the observer of nature whose re-
sults could give decisive evaluation to the merits of the theory.
And among these it was pre-eminently Einstein's prediction on
the shift in the position of the stellar images during a total solar
eclipse that made it possible to test his two theories, the Prague
theory of 1911 and the Berlin theory of 1916. As early as March
1917 the Astronomer Royal had pointed out that on March 29,
1919 a total solar eclipse would take place that would offer un-
usually favorable conditions for testing Einstein's theories, since
the darkened sun would be situated in the midst of a group of
particularly bright stars, the Hyades.

Although at that time no one knew whether it would be pos-
sible to send expeditions to those regions of the earth where the
observation of the total eclipse would be possible, the Royal So-

137

Einstein: His Life and Times

ciety and the Royal Astronomical Society of London appointed
a committee to make preparations for an expedition. When the
armistice was signed on November n, 1918, the committee im-
mediately set to work and announced the detailed plans for the
expedition on March 27. The committee was headed by Sir
Arthur Eddington, one of the few astronomers who were able
at that time to delve deeply into the theoretical foundations of
Einstein's theories. Eddington, moreover, was a Quaker who
had always attached great importance to the maintenance of
a friendly feeling between the people of "enemy" nations, and
both during and after the war he did not join in the customary
feeling of hate for the enemy. He also regarded all new theories
about the universe as a means of strengthening religious feel-
ing and of directing the attention of people away from indi-
vidual and national egoism.

When the sun is eclipsed by the moon, there is only a certain
zone on the earth's surface where the entire solar disk is dark-
ened. Since there is the chance that the weather may be poor
during the few minutes of darkness and thwart all plans of
observation, the Royal Society sent two expeditions to widely
separated points within the zone of total eclipse. One set out
for Sobral in northern Brazil, while the second sailed for the
isle of Principe in the Gulf of Guinea, West Africa. Eddington
was in personal charge of the second group.

When the expedition arrived in Brazil, it aroused not a little
astonishment and something of a sensation. The war with Ger-
many was hardly over, and the newspapers were still full of
propaganda and counter-propaganda. These had not spared
scientific activities, but yet here was a costly expedition coming
from England to test the theories of a German scientist. A news-
paper in Para, Brazil, wrote: "Instead of trying to establish a
German theory, the members of the expedition, who are well
acquainted with the heavens, should rather try to obtain rain
for the country, which has suffered from a long drought." The
expedition was really in luck, since several days after its arrival
it began to rain in Sobral. The savants had justified the public's
confidence in science.

I shall not describe the observations made in Brazil, but merely
those made by the group on the isle of Principe. The astrono-
mers arrived a month before the date of the eclipse in order to set
up their instruments and to make the necessary preparations.
And then came the few minutes of total eclipse, with the dis-
quieting uncertainty whether it would be possible to photo-

138

The General Theory of Relativity

graph the stars in the neighborhood of the darkened sun, or
the clouds would hide the stars and nullify the months of prep-
aration. Sir Arthur Eddington gave the following description
of these moments:

"On the day of the eclipse the weather was unfavourable. When
totality began, the dark disc of the moon surrounded by the corona
was visible through cloud, much as the moon often appears through
cloud on a night when no stars can be seen. There was nothing for it
but to carry out the arranged programme and hope for the best. One
observer was occupied changing the plates in rapid succession, whilst
the other gave the exposures of the required length with a screen
held in front of the object-glass to avoid shaking the telescope in any
way.

For in and out, above, about, below

'Tis nothing but a Magic Shadow-show

Played in a Box whose candle is the Sun

Round which we Phantom Figures come and go.

"Our shadow box takes up all our attention. There is a marvellous
spectacle above and as the photographs afterwards revealed, a won-
derful prominence flame is poised a hundred thousand miles above
the surface of the sun. We have no time to snatch a glance at it. We
are conscious only of the weird half-light of the landscape and the
hush of nature, broken by the calls of the observers and the beat of
the metronome ticking out the 302 seconds of totality.

"Sixteen photographs were obtained, with exposures ranging from
2 to 20 seconds. The earlier photographs showed no stars . . . but
apparently the cloud lightened somewhat towards the end of totality,
and a few images appeared on the later plates. In many cases one or
the other of the most essential stars was missing through cloud, and
no use could be made of them; but one plate was found showing
fairly good images of five stars, which were suitable for a deter-
mination."

Tense with excitement, Eddington and his collaborators com-
pared the best of the pictures that they had obtained with photo-
graphs of the same stars taken in London, where they were far
removed from the sun and therefore not exposed to its direct
gravitational effect. There actually was a shift of the stellar im-
ages away from the sun corresponding to a deflection of the
light rays approximately as large as that expected on the basis
of Einstein's new theory of 1916 (fig. 3 and 4).

It was quite a few months, however, before the expeditions
had returned to England and the photographic plates were care-
fully measured in the laboratory, taking into consideration all
possible errors. These errors were what actually worried the ex-

139

Einstein: His Life and Times

perts. Around them revolved the discussions in astronomical
circles, while the lay public was interested, and could only be
interested, in the question whether the observations had demon-
strated the "weight of light" or the "curvature of space." The
latter was even more exciting since hardly anyone could imagine
anything very definite under the phrase "curvature of space."

6. Confirmation of the Theory

On November 7, 1919 London was preparing to ob-
serve the first anniversary of the armistice. The headlines in the
London Times were: "The Glorious Dead. Armistice Observ-
ance. All Trains in the Country Stop." On the same day, how-
ever, the Times also contained another headline: "Revolution
in Science. Newtonian Ideas Overthrown." It referred to the
session of the Royal Society on November 6, at which the results
of the solar-eclipse expedition were officially announced.

The Royal Society and the Royal Astronomical Society of
London had convened a combined session for November 6 to
make the formal announcement that the expeditions that had
been dispatched by these societies to Brazil and West Africa
to observe the total solar eclipse had from their observations
reached the conclusion that the rays of light are deflected in the
sun's gravitational field and with just the amount predicted by
Einstein's new theory of gravitation. This remarkable agree-
ment between a creation of the human mind and the astronom-
ical observations gave the session a wonderful and exciting at-
mosphere. We have an eyewitness account of this meeting by
one of the most highly regarded philosophers of our time, Al-
fred North Whitehead. As a mathematician, logician, philoso-
pher, and a man endowed with a fine historical and religious
sense, he was better suited to experience the uniqueness of this
hour than most scientists.

"It was my good fortune," said Whitehead, "to be present at the
meeting of the Royal Society in London when the Astronomer Royal
for England announced that the photographic plates of the famous
eclipse, as measured by his colleagues in Greenwich Observatory, had
verified the prediction of Einstein that rays of light are bent as they
pass in the neighbourhood of the sun. The whole atmosphere of tense
interest was exactly that of the Greek drama. We were the chorus
commentating on the decree of destiny as disclosed in the develop-

140

'o'

FIGURE 3

\

\

- 2

2'

f /

f

2

-I'

d"

1 1

dls

1 1 1 f 1

to

1 1

SCALE OF LIGHT
DEFLECTIONS

FIGURE 4

The observations of the British eclipse expedition of 1919 were repeated with
refined methods by an American expedition in 1922 at Wallal (Western Aus-
tralia) organized by the Lick Observatory, University of California. FIG. 3
shows the original photo of the eclipsed sun, its corona and the brightest stars in
the sun's vicinity. The images of the stars are encircled. FIG. 4 shows the ob-
served deflection of the stars in the gravitational field of the sun. The arrows

Einstein and Charles Proteus Steinmetz

The General Theory of Relativity

ment of a supreme incident. There was dramatic quality in the very
staging the traditional ceremonial, and in the background the
picture of Newton to remind us that the greatest of scientific general-
izations was now, after more than two centuries, to receive its first
modification. Nor was the personal interest wanting; a great adven-
ture in thought had at length come safe to shore.

"The essence of dramatic tragedy is not unhappiness. It resides in
the remorseless working of things. . . . This remorseless inevitable-
ness is what pervades scientific thought. The laws of physics are the
decrees of fate."

At this time the president of the Royal Society was Sir J. J.
Thomson, himself a great research physicist. He opened the
.session with an address in which he celebrated Einstein's theory
as "one of the greatest achievements in the history of human
thought" Continuing, he said: "It is not the discovery of an
outlying island but of a whole continent of new scientific ideas.
It is the greatest discovery in connection with gravitation since
Newton enunciated his principles."

Then the Astronomer Royal reported in a few words that the
observations of the two expeditions gave the value 1.64 seconds
of an arc for the deflection of light, as compared with the value
1.75 seconds predicted by Einstein. "It is concluded/' he an-
nounced briefly and dispassionately, "that the sun's gravitational
field gives the deflection predicted by Einstein's generalized
theory of relativity."

Sir Oliver Lodge, the famous physicist, who is widely known
as an exponent of extra-sensory perception and other "parapsy-
chological" phenomena, was always a convinced adherent of
the existence of an "ether" that filled all space, and therefore
hoped that the observations would decide against Einstein's
theory. Nevertheless, after the session he said: "It was a dramatic
triumph."

The scientists of the Royal Society were now ready to recog-
nize that a direct observation of nature had corroborated the
theory of the "curvature of space" and the invalidity of Euclid-
ean geometry in gravitational field. Nevertheless, it was omi-
nous of coming developments that during the formal session the
president of the Royal Society himself said: "I have to confess
that no one has yet succeeded in stating in clear language what
the theory of Einstein really is." He persisted in his assertion
that many scientists were themselves forced to admit their in-
ability to express simply the actual meaning of Einstein's theory.
It really meant that they were unable to grasp the meaning of

141

Einstein: His Life and Times

the theory itself; all they could understand were its conse-
quences within their special field. This situation subsequently
contributed a good deal to the confusion of the lay public re-
garding Einstein's theory.

7. Attitude of the Public

The significance of the new theory was soon appre-
ciated by men who were themselves creatively active in the de-
velopment of science, but many of the so-called "educated"
people were annoyed that the traditional knowledge acquired
with great effort in the schools had been overthrown. Since such
people were themselves convinced of their lack of understand-
ing of astronomy, mathematics,, and physics, they attacked the
new theory in the fields of philosophy and politics, in which
they felt themselves qualified.

Thus an editorial writer in a reputable American newspaper
wrote of the session of the Royal Society described above: "These
gentlemen may be great astronomers, but they are sad logicians.
Critical laymen have already objected that scientists who pro-
claim that space comes to an end somewhere are under some
obligation to tell what lies behind it."

We recall that the statement: "Space is finite" has nothing to
do with an "end" of space. It means rather that light rays travel-
ing through the world space return along a closed curve to their
origin. The editorial writers of daily newspapers like to repre-
sent the standpoint of the "man in the street," who is more often
influenced by a medieval philosophical tradition than by the
progress of science.

The editorial continues:

"This fails to explain why our astronomers appear to think that
logic and ontology depend on the shifting views of astronomers.
Speculative thought was highly advanced long before astronomy. A
sense of proportion ought to be useful to mathematicians and physi-
cists, but it is to be feared that British astronomers have regarded
their own field as of somewhat greater consequence than it really is."

The same tendency to play off common sense that is, in
this case, the knowledge acquired in elementary schools
against the progress of science is also evident in another editorial
that appeared in the same reputable paper about this time:

142

The General Theory of Relativity

"It would take the president of at least two Royal Societies to give
plausibility or even thinkability to the declaration that as light has
weight space has limits. It just doesn't, by definition, and that's the
end of that for common folks, however it may be for higher
mathematicians."

Since in the opinion of the man in the street the two Royal
Societies were affected by delusions which made them in-
capable of understanding things that were clear to anyone with
an average school education, he began to inquire why such a
thing had happened. An explanation was soon found, which,
was very illuminating for the man in the street.

One week after the famous London meeting, a professor of
celestial mechanics at Columbia University, New York, wrote:

"For some years past the entire world has been in a state of unrest,
mental as well as physical. It may well be that the war, the Bolshevist
uprising, are the visible objects of some deep mental disturbance. This
unrest is evidenced by the desire to throw aside the well-tested meth-
ods of government in favor of radical and untried experiments. This
same spirit of unrest has invaded science. There are many who would
have us throw aside the well-tested theories upon which have been
built the entire structure of modern scientific and mechanical develop-
ment in favor of methodological speculation and phantastic dreams
about the Universe."

The writer then pointed out that the situation was analogous
to the period of the French Revolution, when as a result of
similar revolutionary mental diseases doubts were expressed
concerning the Newtonian theory, though these objections later
proved to be incorrect.

While various individuals were vexed by these innovations
which disturbed their pride in their education, others received
the matter in a more friendly manner. Einstein's predictions of
the stellar shifts had shown, so these men thought, that physical
phenomena could be predicted by means of pure thought, by
pure mathematical speculation about the geometry of universal
space. The view of the "wicked" empiricists and materialists
that all science rests on experience, a view that caused so many
conflicts with religion and ethics, had now been dropped by sci-
ence itself. In an editorial dealing with the session of the Rqyal
Society the London Times said: "Observational science has in
fact led back to the purest subjective idealism." And "idealism"
for the educated Englishman who received his education from
his school, his church, and the Times was the diametrical op-
posite of "materialistic" Bolshevism.

143

Einstein: His Life and Times

The psychological situation in Europe at this time increased
the interest of the general public in Einstein's theory. English
newspapers tried to efface every connection between Germany
and the man whom they were honoring. Einstein himself was
averse to any tactics of this kind, not because he placed any
value in being regarded as a representative of German science,
but because he hated every manifestation of narrow-minded
nationalism. He also believed that he could advance the cause of
international conciliation if he utilized his fame for this pur-
pose. When the Times requested him to describe the results of
his theory for the London public, he did so on November 28
and used this opportunity to express his opinion in a friendly,
humorous way. He wrote:

"The description of me and my circumstances in the Times shows
an amusing flare of imagination oa the part of the writer. By an
application o the theory of relativity to the taste of the reader, today
in Germany I am called a German man of science and in England
I am represented as a Swiss Jew. If I come to be regarded as a 'bete
noire' the description will be reversed, and I shall become a Swiss Jew
for the German and a German for the English."

At that time Einstein did not anticipate how soon this joke
would come true. The editor of the Times was slightly annoyed
by the characterization of the way in which regard was taken of
the prejudice of the middle-class British, and likewise answered
in a semi-humorous vein: "We concede him his little joke. But
we note that in accordance with the general tenor of his theory
Dr. Einstein does not supply any absolute description of him-
self." The Times was also somewhat uneasy over the fact that
Einstein did not have any feeling of belonging completely to
a definite nation or race.

In Germany itself the news of the events in London acted
like a spark that caused the explosion of pent-up emotion. It was
a double satisfaction. The achievement of a scientist from a de-
feated and humiliated country had been recognized by the
proudest of the victor nations. Furthermore, the discovery was
not based on any collection of empirical researches but arose
rather from a creative imagination which by its power had
guessed the secret of the universe as it actually is, and the cor-
rectness of the solution of the puzzle had been confirmed by
the precise astronomical observations of the cool-headed Eng-
lishmen.

The situation contained still another peculiarity in that the

144

The General Theory of Relativity

discoverer was a descendant of the Jewish people who had often
been insulted and slighted by the defeated nation. The mem-
bers of the Jewish community had often been compelled to hear
and to read that while their race possessed a certain craftiness
in business pursuits, in science it could only repeat and illumi-
nate the work of others, and that truly creative talents were
denied them. That this unique, ancient people had again pro-
duced a leader in the intellectual world not only seemed excit-
ing for the Jews themselves, but also was a kind of consolation
and stimulus for all the vanquished and humiliated people of
the world.

A Russian observer gave this description of the remarkable
psychological situation in defeated Germany at that time:

"With the growing social misery there appeared among the intel-
lectuals pessimistic currents of thought, ideas about the decline of
Western culture, and, with the violence of a hurricane, religious move-
ments. The extent of these movements must seem remarkable even
to one who is acquainted with German intellectual life. The number
of independent religious groups in Germany grew endless. World
War invalids, merchants, officers, students, artists, all were seized by
the desire to create a metaphysical basis for their view of the world."

This flight from tragic reality into a dream world also in-
creased the enthusiasm for Einstein's theory, which occupied a
special place because it appeared to the public that here a por-
tion of the reality of the universe had been discovered by dreams.

In Soviet Russia people at this time were in the process of
constructing a new social order on principles that were con-
sciously opposed to the pessimistic ideas of the "declining" West.
They renounced all idealistic dreams or at least believed that
they were doing so. They wanted to dissociate themselves as
completely as possible from the attitudes prevalent both in the
defeated and in the victorious countries. Everywhere they looked
for signs of "decline " It was thought that such symptoms like-
wise evidenced themselves in the development of physical sci-
ence. As early as 1922 A. Maximov, a leading exponent of Soviet
Russian political philosophy who occupied himself especially
with the physical sciences, wrote in the official philosophical
journal of Soviet Russia in conjunction with the above descrip-
tion of German life;

"This idealistic atmosphere has surrounded and still surrounds the
relativity theory. It is only natural, therefore, that the announcement
of 'general relativity' by Einstein was received with delight by the

145

Einstein: His Life and Times

bourgeois intelligentsia. The impossibility within the limits of bour-
geois society for the intellectuals to withdraw from these influences
led to the circumstance that the relativity principle served exclusively
religious and metaphysical tendencies."

Here we note something of the feeling against Einstein that
was to develop in some groups of the Soviet Union.

In this connection, however, it should not be forgotten that
at the same time in Germany opinions were expressed char-
acterizing Einstein's theory as "Bolshevism in physics/' similar
to those of the aforementioned American scientist. The rejection
of Einstein's theories by some prominent Soviet spokesmen did
nothing to change these opinions. And since the Bolsheviks and
the Jews were commonly regarded as somehow related, we are
not surprised to find that the relativity theory soon began to be re-
garded as "Jewish" an d capable of harming the German people.
This hostile attitude toward Einstein emanated in Germany
from those circles which ascribed the loss of the war to the "stab
in the back" and not to the failure of the ruling classes.

For Einstein himself this intrusion of politics and nationalism
into the judgment of his theories was completely astonishing
indeed, hardly comprehensible. For a long time he had hardly
paid any attention to these things and had not even noticed
many such attacks. But gradually complete absorption in the
regularities of the universe began to be difficult for him. More
and more the anarchy of the human world pushed into the
foreground. With brutal force it slowly but surely laid claim
to a greater or lesser part of his intellectual energy.

146

VII
EINSTEIN AS A PUBLIC FIGURE

i. Einstein's Political Attitude

With the intense public interest aroused by the con-
firmation of his theory, Einstein ceased to be a man in whom
only scientists were interested. Like a famous statesman, a vic-
torious general, or a popular actor, he became a public figure.
Einstein realized that the great fame that he had acquired placed
a great responsibility upon him. He considered that it would
be egoistic and conceited if he simply accepted the fact of his
recognition and continued to work on his researches. He saw
that the world was full of suffering, and he thought he knew
some causes. He also saw that there were many people who
pointed out these causes, but were not heeded because they were
not prominent figures. Einstein realized that he himself was now
a person whom the world listened, and consequently he felt
it his duty to call attention to those sore spots and so help eradi-
cate them. He did not think of working out a definite pro-
gram, however, he did not feel within himself the calling to
become a political, social, or religious reformer. He knew no
more about such things than any other educated person. The
advantage he possessed was that he could command public at-
tention, and he was a man who was not afraid, if necessary, to
stake his great reputation.

It was always clear to him that anyone venturing to express
his opinion about political or social questions must emerge from
the cloistered halls of science into the turmoil of the market
place, and he must expect to be opposed with all the weapons
common to the market place. Einstein accepted this situation
as self-evident and included in the bargain. He also realized that
many of his political opponents would also become his scientific
opponents.

In the years immediately following the World War it was
only natural that the main problem of all political reformers was
the prevention of another such catastrophe. The obvious means
to this goal were the cultivation of international conciliation,

147

Einstein: His Life and Times

struggle against economic need, for disarmament, and the em-
phatic rejection of all attempts to cultivate the militaristic spirit.
The surest and indeed an infallible method of obtaining the
desired end seemed to be the refusal of military service by the
individual, the organization of "conscientious objectors" on a
large scale. All these ideas appeared as obvious to Einstein as
they did to so many others. Only he had more courage and
more opportunity than others to advocate them. Einstein did not
have the self-complacency with which scholars, especially in
Germany, liked to retire into the ivory tower of science. But the
means toward the goal appeared to him at that time, as to many
thousands, much simpler and more certain than was later found
to be the case.

Einstein's political position, like that of all the intellectuals in
the world, changed during the twenty years of armistice be-
tween the two World Wars, but he was never a member of
any political party. Parties made use of his authority where they
could do so, but he was never active in any group. This was due
fundamentally to the fact that Einstein was never really inter-
ested in politics.

Only to very superficial judges does Einstein appear to be
a genius so buried in his researches that he finds all his happiness
in them without being influenced by the outside world. There
are many more unresolved contradictions in Einstein's character
than one would believe at first glance, and these, as I have men-
tioned already, are due to the contrast between his intense so-
cial consciousness on the one hand and the aversion to entering
into too intimate relations with his fellow men on the other.

This trait manifests itself above all in his attitude toward po-
litical groups, with which he has co-operated at times because
he sympathized with some of their aims. There were always
moments when it was extremely vexatious for him to be forced
into actions and expressions of which he did not approve, and
the moment always recurred when he developed antipathies to
the representatives of the groups with which he sympathized.
Moreover, he did not like to claim any special role for himself
and so he sometimes participated in things that were actually
not very much to his liking. When something of this sort hap-
pened, naturally he did not become any fonder of the people
who had caused him to do so. As a result he impressed many
people as a vacillatory supporter. He always stood first for what
seemed valuable to him, but he was not ready to let himself be

148

Einstein as a Public Figure

influenced too much by party stereotypes and slogans. This was
his attitude in his co-operation with the Zionists, pacifists, and
socialists.

Einstein realized very well that everything has several aspects
and that by supporting a good cause one must often help one
that is less worthy. Many people who are essentially hypocrites
seize upon such situations and refuse to participate in any good
cause because of "moral scruples." Such behavior was not Ein-
stein's way of acting. If the basic cause was good he was occa-
sionally ready to take into the bargain a less worthy, secondary
tendency. He was much too realistic and critical a thinker to be-
lieve that any movement conducted by human beings to attain
human aims could be perfect.

He helped the Zionist movement, for instance, because he be-
lieved that it was of value in creating a feeling of self-respect
among the Jews as a group and in providing a refuge for home-
less Jews. He was well aware, however, that at the same time he
was helping occasionally the development of nationalism and
religious orthodoxy, both of which he disliked. He saw that at
present no other instrument than a kind of nationalism was
available to produce a feeling of self-respect in the rank and file
of the Jewish community.

There were times, however, when the prospect of having his
remarks interpreted falsely appeared so unpleasant to Einstein
that he did not permit himself to be placed in a position where
such a situation could develop. Einstein received repeated in-
vitations to visit and lecture in Soviet Russia, especially during
the early years of the development of her science, but he de-
clined. Einstein realized that any friendly remark he might
make to the country would be interpreted by the outside world
as a sign that he was a Communist, and any critical remark
would be taken by the Communists as a part of a capitalistic
crusade against Russia.

2. Anti-Semitism in Postwar Germany

After the war, when Germany's defeat led to a collapse
of the rule of the generals and the junkers, who had generally
been regarded as the source of all prejudice, many people
thought that the period of discrimination against the Jews was

149

Einstein: His Life and Times

now past. But actually the loss of power aroused a deep-seatea
feeling of anger in these classes. A human being is inconsolable
over a catastrophe only so long as he believes its cause was due
to his own inferiority. Consequently he tries to put the blame
on someone else. Thus the supporters of the overthrown rulers
spread the idea that the defeat had been caused not by military
weakness, but by an internal revolt led by the Jews. The spread
of this view caused a feeling of extreme hatred against the Jews
in Germany. Such sentiments were very widespread even among
the educated class, and they were all the more dangerous for the
Jews because they were completely irrational. The Jews could
not refute them by any arguments or escape the enmity by any
change in their conduct.

Many of the Jews in Germany, however, did not understand
this situation, and they made efforts to divert attention from
themselves through various kinds of mimicry. In the mildest
form, they tried to shift the blame for the defeat by putting it
on the lack of patriotism among the Socialists. Many went even
further, emphasized a division among the Jews, and accused the
"bad" group. The Jews who had been long resident in Germany
ascribed all the inferior characteristics to the Jews who had
immigrated from eastern Europe. Among them were included,
depending on preference and momentary need, Jews from Po-
land, Russia, Rumania, Hungary, and sometimes even of Aus-
tria. When Hitler, who, as is well known, came from Austria,
began his persecutions of the Jews, a Jewish professor at a Ger-
man university said: "One cannot blame Hitler for his views
about the Jews. He comes from Austria and he is right as far
as the Jews there are concerned. If he had known the German
Jews well, he would never have acquired such a poor opinion
of us." Such statements characterize in drastic fashion the feel-
ing of some German Jews. This feeling was so bitterly resented
by the eastern Jews that when Hitler began to persecute the
German Jews, the reaction was not a united front of all Jews
but often one regional group tried to put the blame for Hitler
on other Jewish groups.

This lack of self-respect in the behavior of some German Jews
made a mortifying impression on Einstein. Until then he had
taken little interest in the condition of the Jews and had hardly
realized the grave problems in their situation, but now he de-
veloped a deep sympathy for their position. Although Einstein
had a certain aversion to Jewish orthodoxy, he looked upon the
Jewish community as a group that was the bearer of a very valu-

150

Einstein as a Public Figure

able tradition and that regarded intellectual values very highly.
Hence, he saw with bitter feeling the Jewish community not
only attacked by external enemies but also disintegrating in-
wardly. Einstein saw the Jews move deeper and deeper into a
distorted psychological situation that could only produce a per-
verted mentality.

This profound sympathy aroused in him an ever increasing
feeling of responsibility. As his fame grew, he gave the entire
Jewish community the certainty that it was capable of producing
a man with the creative intellectual power to formulate a theory
of the universe recognized by the whole world as one of the
greatest achievements of our time. Here was a refutation of the
widespread opinion that truly creative intellectual powers are re-
stricted to the Nordic-Aryan race.

3. The Zionist Movement

During the World War, when the British government
declared its willingness to support the development of a national
home for the Jews in Palestine, the Zionist movement experi-
enced a powerful revival in all countries. Its goal was to establish
a Jewish state in the ancient historical homeland of the Jews in
order to give the Jews of the entire world a national and cul-
tural center. In the British promise they saw the first step toward
this goal. It was hoped that the co-operation of all the Jews in
the world would enable them to throw off the humiliating feel-
ing that they alone among all people had no national home
and were everywhere tolerated only as guests.

From the beginning Einstein had various doubts about the
Zionist aims. He was not sympathetic to the strong nationalistic
emphasis, and he saw no advantage in substituting a Jewish for
German nationalism. He also realized the difficulties inherent
in the Palestine plan. He thought the country was too small to
receive all the Jewish immigrants who might want to settle in
a national home, and he foresaw the clash between Jewish and
Arab nationalism. Zionists often have tried to minimize the mag-
nitude of these problems, but Einstein considered this due to
wishful thinking.

But in spite of all these doubts and scruples, Einstein saw
many reasons in favor of Zionism. He saw in it the only active
movement among the Jews that appeared capable of arousing

151

Einstein; His Life and Times

in them the sense of dignity, the absence of which he deplored so
much. He did not much care to have this educational process
put into effect by an emphasis on nationalism, yet he felt that
the Jewish psyche, and in particular that of the German Jews,
was in such a pathological state that he recommended every
educational means that tended to alleviate and remedy this
situation.

He therefore decided in 1921 to appear publicly as a sup-
porter of Zionism. He was well aware that this action would
produce an astounding impression within German Jewry, since
almost all the Jews in Germany who were active in public life
as scholars and writers considered the Zionist movement as a
mortal enemy of the development that they sought the grad-
ual complete assimilation of the Jews among their fellow citi-
zens. When a man like Einstein, certainly the greatest of the
Jewish scientists in Germany and a man of world reputation,
stepped forth in this manner and thwarted their efforts, it was
obvious that by many German Jews his action would be re-
garded as a "stab in the back." But Einstein was not the man
to be afraid of any such reaction. He even felt that this antag-
onism was already the beginning of the educational process at
which he was aiming. Also, since Einstein had taken upon him-
self to say so much that other people did not dare express, self-
expression became easier and inhibitions were abated.

Thenceforth Einstein has been regarded by many people as
a "black sheep" among the German scholars of Jewish origin.
Attempts were made to explain his conduct on the basis of all
sorts of causes, such as his misunderstanding of the German
character, his wife, the propaganda of skillful journalists, or
even his being, allegedly, a "Russian draft-dodger." They did
not realize that Einstein was utilizing the credit he had ob-
tained through his scientific achievements to educate the Jew-
ish community.

Einstein's participation in the work of the Zionists, how-
ever, was due not only to the primary aim of this movement,
but as well to a secondary plan that struck a responsive chord in
his innermost being. This was the plan to establish a Jewish
university in Jerusalem.

It had always been very painful for Einstein to see many
Jewish youths who wished to acquire a higher education pre-
vented from doing so on account of the discrimination against
them. Most universities in eastern Europe were averse to ad-
mitting a large number of Jewish students. In central Europe,

152

Einstein as a Public Figure

again, this attitude prevailed against the admission of Jewish
students barred from the eastern universities. To Einstein it ap-
peared as a special form of brutality indeed, a paradoxical
brutality that just these people who had always had a special
respect and love for intellectual pursuits should be thwarted in
their ambitions. Although the Jewish students were often among
the most interested and industrious, every admission of an East-
ern Jew to a Germanic university was regarded as a special act
of tolerance. Thus even the few fortunate ones who were ad-
mitted were not fully regarded by the others as fellow students
and friends, and they never felt really at ease. The same preju-
dice was also felt by quite a few Jewish teachers. For this rea-
son Einstein felt that it was necessary to found a university that
would belong to the Jews and where students and professors
would be free of the tension that arises through constant contact
with an unfriendly environment.

It was through this plan for a university that Einstein came
into contact with Chaim Weizmann, the recognized leader of
the Zionist movement. Like Einstein, Weizmann was a scientist,
but he was more interested in the application of science to tech-
nical problems. He was a professor of chemistry at the Univers-
ity of Manchester in England, and his work in the war research
had been of great service to the British government during the
World War. As a result he had become associated with influential
English circles and had thus been able to propagate the Zionist
plan. Einstein certainly intended to collaborate with the party
led by Weizmann for a definite purpose, and the plan for the
establishment of a university in Jerusalem rendered this col-
laboration easier. Weizmann himself characterized the aims of
the university in a far-sighted way that Einstein must also have
found sympathetic. He said: "The Hebrew University should
further self-expression and shall play a part as interpreter be-
tween the Eastern and Western world."

4. Einstein as a Pacifist

From his childhood Einstein had been terribly de-
pressed at the sight of people being trained to become autom-
atons, whether they were soldiers marching through the streets
or students learning Latin at the gymnasium. Aversion to me-
chanical drill was combined in him with an extreme abhorrence

Einstein: His Life and Times

of all violence, and he saw in war the culmination of all that was
hateful mechanized brutality.

Einstein placed this aversion above and apart from any po-
litical conviction. On one occasion, speaking to a group of Amer-
icans who visited him in Berlin in 1920, he said:

"My pacifism is an instinctive feeling, a feeling that possesses me
because the murder o men is disgusting. My attitude is not derived
from any intellectual theory but is based on my deepest antipathy
to every kind of cruelty and hatred. I might go on to rationalize this
reaction, but that would really be a posteriori thinking."

Because Einstein's attitude to war was based on general hu-
man grounds rather than on political ones, it was very difficult
for him to work together with institutions that also considered
themselves to be working for world peace. In 1922 Einstein
was appointed to the "Commission pour la Cooperation Intellec-
tuelle" of the League of Nations. The purpose of this body was
to make intellectuals acquainted with the aims of the League
and to induce them to use their knowledge and talents for
the achievement of these aims. The commission never got be-
yond certain vague beginnings. At first, however, Einstein be-
lieved that he ought not to refuse to co-operate, and in his letter
of acceptance he wrote as follows: "Even though I must admit
that I am not at all clear as to the character of the work to be
done by the commission, I consider it my duty to obey its sum-
mons since nobody in these times should refuse assistance to
efforts toward the realization of international co-operation."

But after one year Einstein recognized that the League did
not prevent the use of force by great powers and sought only for
means to induce weak nations to submit without resistance to
the demands of the strong ones.

Consequently he resigned from the commission, giving the
following reason for his action: "I have become convinced that
the League possesses neither the strength nor the good will
necessary to accomplish its task. As a convinced pacifist it does
not seem well to me to have any relation whatever with the
League."

In a letter to a pacifistic magazine he presented an even
sharper formulation of this step:

"I did so because the activities of the League of Nations had con-
vinced me that there appeared to be no action, no matter how brutal,
committed by the present power groups against which the League
could take a stand. I withdrew because the League of Nations, as it

154

Einstein as a Public Figure

functions at present, not only does not embody the ideal of an inter-
national organization, but actually discredits such an ideal.*'

Tlie correctness of his judgment was shown already in the
fall of that year (1923) when in the conflict between Greece and
Italy the League endeavored only to make Greece, the weaker
party, yield. It did not wish to hurt the feelings of Italy, which
was then celebrating the honeymoon of Fascism.

Soon, however, Einstein realized that the matter had an-
other aspect. He noticed that his resignation from the commis-
sion was greeted with glee by the German nationalist groups.
Thereupon, as on so many other occasions, he reflected that even
though one sees many mistakes in a movement, yet it is not right
to refuse to support it if its essential principle is a good one.
In 1924 he therefore rejoined the commission. On the occasion
of the tenth anniversary of the League (1930) he expressed the
essence of his opinion as follows: "I am rarely enthusiastic about
what the League has done or has not done, but I am always
thankful that it exists." He always emphasized, however, that
without the collaboration of the United States the League would
never become a factor for international justice.

Einstein always thought that scientists have a special part to
play in advancing the cause of international understanding. The
nature of their work is not restricted by national boundaries as
is the case, -for instance, with history and economics, and their
judgments of merit tend to be objective. It is therefore particu-
larly easy for scientists of different countries to find a common
ground. As he once put it:

"The representatives of the natural sciences are inclined, by the
universal character of the subject dealt with and by the necessity of
internationally organized co-operation, toward an international men-
tality predisposing them to favor pacifistic objectives. . . . The tra-
dition of science as a force in cultural training would open a much
more comprehensive view before the mind and would be a powerful
influence because its outlook is world-wide in drawing men a
little way from senseless nationalism. You cannot drive out nation-
alism unless you put something in its place. And science gives this
wide something which men could hang on to."

Here Einstein also saw a task for the Jewish people. For cen-
turies the Jews had formed such a small minority among their
neighbors that they had been unable to defend themselves by
physical force. They had shown how in the face of physical
violence it is possible to survive by intellectual means. In an
address at a Jewish meeting in Berlin in 1929 Einstein said;

155

Einstein: His Life and Times

"Jewry has proved that the intellect is the best weapon in history.
Oppressed by violence, Jewry has mocked her enemies by rejecting
war and at the same time has taught peace. ... It is the duty of us
Jews to put at the disposal of the world our several-thousand-years-old
sorrowful experience and, true to the ethical traditions of our fore-
fathers, become soldiers in the fight for peace, united with the noblest
elements in all cultural and religious circles."

Einstein's attitude to pacifism must always be kept in mind
if one wants to understand his political position. As the prob-
lem of social reorganization became more and more complicated
and it was no longer certain which groups represented progress
toward this goal, Einstein refused definitely to link the fight
against war with the cause of socialism. The American Socialist
leader Norman Thomas once asked him whether lie did not
consider the realization of a socialist society a necessary prereq-
uisite to guarantee general peace. Einstein replied:

"It is easier to win over people to pacifism than to socialism. Social
and economic problems have become much more difficult today, and
it is necessary that men and women reach the point where they believe
in pacific solutions. Then you can expect them to approach economic
and political problems in a spirit of co-operation. I would say that we
should not work for socialism first, but for pacifism."

Just as Einstein was aware that social problems cannot be
solved by a simple declaration of faith in socialism, but that very
complicated and often antithetical interests must be reconciled,
so he had likewise long been cognizant of the paradox in the
ideal of democracy. The people should rule, yet freedom can
never be realized by means of a formula, but only if the system
is headed by men worthy of the confidence placed in them.
Democracy necessarily leads to the formation of parties; but
mechanical party rule often leads in turn to the suppression of
oppositional groups. Thus he wrote in 1930:

"My political ideal is democracy. . . . However, well do I know
that in order to attain any definite goal it is imperative that one person
should do the thinking and commanding and carry most of the respon-
sibility. But those who are led should not be driven, and they should
be allowed to choose their leader. It seems to me that the distinctions
separating the social classes are false; in the last analysis they rest on
force. I am convinced that degeneracy follows every autocratic system
of violence, for violence inevitably attracts moral inferiors. Time has
proved that illustrious tyrants are succeeded by scoundrels."

Einstein as a Public Figure

Einstein never considered the essence of democracy to be the
observance of certain formal rules; it lay chiefly, rather, in the
absence of any spirit of violence directed against certain sections
of the nation. Even before Germany became a dictatorship, he
had already recognized the shady sides of this system, as well
as those of the still prevailing formal democracy. He once said:

"For this reason I have always been passionately opposed to such
regimes as exist in Russia and Italy today. The thing that has dis-
credited the European forms of democracy is not the basic theory of
democracy itself, which some say is at fault, but the instability of our
political leadership, as well as the impersonal character of party
alignments."

At that time Einstein already regarded the American system
of government as a form of democracy superior to the German
or even the French republic. It was based not so much on par-
liamentary deliberations and votes as on the leadership of an
elected president. "I believe," Einstein told an American journal
in 1930, "that you in the United States have hit upon the right
idea. You choose a president for a reasonable length of time
and give him enough power to acquit himself properly of his
responsibilities."

Similarly, during the discussions over Roosevelt's third term
Einstein was unable to agree with the view that the number of
terms to which a president is elected is important for democ-
racy, because he felt that the spirit in which the president exer-
cised the powers of his office was much more significant.

But while the question of democracy or socialism always
seemed complicated to him and incapable of solution by a
formula, yet at that time the problem of his attitude to military
service and war still seemed simple because his aversion was not
based on any political convictions.

It is even possible to find statements by Einstein that sound
"undemocratic" and almost like an espousal of the doctrine of
elite, as, for instance: "What is truly valuable in our bustle of
life is not the nation, I should say, but the creative and impres-
sionable individuality, the personality he who produces the
noble and sublime while the common herd remains dull in
thought and insensible in feeling." And he hated all military
institutions because they cultivated and developed this very herd
spirit:

"This subject brings me to the vilest offspring of the herd mind
the odious militia. The man who enjoys marching in line and file to

157

Einstein: His Life and Times

the strains of music falls below my contempt: he received his great
brain by mistake, the spinal cord would have been amply sufficient.
This heroism at command, this senseless violence, this accurate bom-
bast of patriotism how intensely I despise them! 5 *

Einstein was not opposed to a dictatorship because it recog-
nized the existence of an elite, but because it tried to develop
a herd mind among the majority of the people.

This goal the avoidance of war and military service
seemed so desirable that in this case he believed the most primi-
tive and most radical means to be the most eff ective that is,
the refusal of the individual to perform military service, as
practiced by certain religious groups such as the Quakers or
Jehovah's Witnesses. In 1929, when he was asked what he would
do in case of a new war, he replied in a magazine: "I would
unconditionally refuse to do war service, direct or indirect, and
would try to persuade my friends to take the same stand, re-
gardless of how the cause of the war should be judged." In
1931 he placed his reputation and his personal co-operation at
the disposal of the War Resisters International and issued an
appeal in which he said:

"I appeal to all men and women, whether they be 'eminent or
humble, to declare that they will refuse to give any further assistance
to war or the preparation of war. I ask them to tell their governments
this in writing and to register this decision by informing me that
they have done so. ... I have authorized the establishment of the
'Einstein War Resisters International Fund/ "

When I visited the House of Friends in London, the head-
quarters of the Quakers, I saw the pictures of three men in the
secretary's office: Gandhi, Albert Schweitzer, and Einstein. I
was rather surprised at this combination and asked the secretary
what it was that these three persons had in common. Amazed
at my ignorance, he informed me: "All three are pacifists.'*

5. Campaigns against Einstein

The German intellectuals who had blindly followed
the ruling military class into the first World War were bewil-
dered when their trust was broken by the loss of the war. The
professors in the years immediately following the armistice felt
like sheep without a shepherd. When Einstein ventured forth

158

Einstein as a Public Figure

into this confused atmosphere by entering into public affairs in
support of Zionism and pacifism, strong opposition began to
be organized against him.

For the ardent nationalists., the Jews and the pacifists were
the scapegoats to be blamed for the defeat in the war by a "stab
in the back," and any supporter of their movements was the
object of their violent anger. Even those who agreed with Ein-
stein's ideas were shocked by his blunt way of speaking in face
of the opposing sentiment, and he began to be looked upon as
a kind of enfant terrible. Einstein was not familiar with politi-
cal machinations and had no interest in them, and so his state-
ments were considered either childish or cynical With the suc-
cess of his theory acclaimed by the English solar expedition and
the rise of his fame, his enemies set out to depreciate this success
as far as possible.

There suddenly appeared an organization whose only pur-
pose was to fight Einstein and his theories. The leader was a
certain Paul Weyland, whose past, education, and occupation
were unknown. The organization had at its disposal large sums
of money of unknown origin. It offered relatively large fees to
people who would write against Einstein or oppose him at
meetings. It organized meetings by means of large posters, such
as were used to announce the greatest virtuosi.

The people who spoke for and represented this movement
may be divided into three groups. The first group comprised
the political agents of the "revolution from the Right." They
knew absolutely nothing about Einstein and his theories except
that he was a Jew, a "pacifist," that he was highly regarded in
England, and that he also seemed to be trying to gain a hold
on the German public. These people spoke loudest and with the
greatest assurance. As professional propagandists usually do,
they accused Einstein and his supporters of making too much
propaganda. They did not enter into any objective discussions,
and they intimated in a more or less veiled fashion that the
spread of Einstein's theory was due to the same conspirators
who were to blame for the German defeat. Since it is character-
istic of the mode of thought of this group, I wish to quote
from an article that appeared in the magazine Der Turmer, a
literary monthly that was highly regarded in German national-
istic circles. Under the title "Bolshevistic Physics" Einstein's
theory is directly related to the political situation. In the opin-
ion of many, the German defeat was due to the circumstance
that President Woodrow Wilson had promised the Germans

159

Einstein: His Life and Times

a just peace, and had thus led them to conclude an armistice,
as they were not compelled to do by the military situation. The
article continues:

"Hardly had it become clear to the horrified German people that
they had been frightfully duped by the lofty politics of Professor
Wilson and swindled with the aid of the professorial nimbus, when
a new professorial achievement was again being commended to the
simple Germans with the greatest enthusiasm and ecstasy as the pin-
nacle of scientific research. And unfortunately even highly educated
people fell for this all the more so since Professor Einstein, the
alleged new Copernicus, numbers university teachers among his ad-
mirers. Yet, without mincing words, we are dealing here with an
infamous scientific scandal that fits very appropriately into the picture
presented by this most tragic of all political periods. In the last analysis
one cannot blame workers for being taken in by Marx, when German
professors allow themselves to be misled by Einstein."

A second group in this movement directed against Einstein
was composed of several physicists who had acquired a reputa-
tion in professional circles as a result of precise experiments,
and who now wondered that someone could become world-
famous because of the constructions of his creative imagination.
They lacked the comprehensive vision to realize the necessity
for such far-reaching generalizations as those of Einstein; on
the whole they were inclined to see only that honest hard-work-
ing physicists were being slighted in favor of a frivolous in-
ventor of fantastic hypotheses. Here there was already some-
thing of the idea that the ability to observe nature faithfully was
a characteristic of the "Nordic" race, which Einstein conse-
quently lacked.

The third group was composed of philosophers who advo-
cated certain philosophical systems that were inconsistent with
the theory of relativity. Or, to put it more precisely, they did
not understand the exact physical meaning of the relativity
theory, and so they attributed to it a metaphysical interpretation
that it actually did not contain. Then they denounced this phi-
losophy that they themselves had invented. Here, too, there is
already something of the conception that the Nordic-Aryan phi-
losopher probes the true profundity of nature itself while other
races are satisfied with a discussion of how nature may be de-
scribed from different points of view.

But since physicists as well as philosophers are often very
naive or, to put it more plainly, are very thoughtless in matters
of individual and political psychology, the latter two groups

1 60

Einstein as a Public Figure

were frequently not even aware that they were acting in the
service of a specific political propaganda.

When Paul Weyland organized Ms first meeting in the Berlin
Philharmonic, he even made great efforts to secure speakers
who were of Jewish origin so as to create a kind of smoke
screen. At this first meeting Weyland, whose speech was more
political than scientific, was followed by E. Gehrcke, a com-
petent experimental physicist of Berlin, who criticized the theory
from the point of view of a man who, while making no mis-
takes in his experiments, simply lacks the acute understanding
and flight of imagination to pass from individual facts to a
synthesis. Such people are usually ready to accept old hypotheses
because through habit they have forgotten that they are not facts,
but they like to stamp new theories as "absurd 51 and "opposed
to the spirit of empirical science." An invitation had also been
extended to a representative of philosophy who was to prove
that Einstein's theory was not "truth," but only a "fiction." He
was of Jewish descent and was intended to be the climax of
the meeting. Despite his political innocence and urgent tele-
grams, he declined at the last moment because some friends had
explained the purpose of the meeting to him. As a result the
first attack took place without the blessing of philosophy.

Einstein attended this meeting as a spectator and even ap-
plauded the attacks in a friendly spirit. He always liked to re-
gard events in the world around him as if he were a spectator
in a theater. The meetings of this group were just as amusing
as the sessions of the university faculty in Prague, or of the
Prussian Academy of Science.

Other meetings of this group took place, and in this year the
"Einstein case" became a constant subject of discussion in the
press. Einstein was besieged with requests to express publicly
his opinion of these attacks. But it was repugnant to him to act as
if he thought that he was dealing with scientific discussions. He
had no desire to discuss publicly questions that for most people
were incomprehensible and that played no part whatsoever in
these meetings. Finally, in order to terminate the entire affair,
he wrote in a Berlin newspaper that it would be senseless to
answer in a scientific manner arguments that were not meant
scientifically. The public would not be able to judge who was
right. Therefore he said simply: "If I were a German nationalist
with or without a swastika, instead of being a Jew with liberal,
international opinions, then . . " This was more understand-
able to everyone than scientific arguments would have been,

161

Einstein: His Life and Times

Now Einstein's opponents were more furious than ever and
asserted that Einstein was turning a scientific discussion into a
political one. Actually, he had once again been the enfant ter-
rible and had simply called the thing by its right name. Even
many of his friends would have preferred it had he acted as if
he did not understand the motives of his opponents.

At this time he began to feel uneasy in Berlin and there was
a great deal of talk that he would leave Germany. He was also
offered a professorship at the Dutch University of Leiden. When
he was asked whether he actually wanted to leave Berlin, he
said: "Would such a decision be so amazing? My situation is like
that of a man who is lying in a beautiful bed, where he is being
tortured by bedbugs. Nevertheless, let us wait and see things
develop."

The movement against Einstein acquired a certain respecta-
bility as soon as a physicist who was generally regarded as an
outstanding member of his profession put himself at its head. I
have already spoken of Philipp Lenard on several occasions. In
1905 Einstein had based his new conception of light on the ob-
servations of Lenard. For these and other experiments carried
out with the greatest ingenuity, Lenard had received the Nobel
prize. He was less skilled, however, in deriving general laws
from his observations. When he tried to do so, he involved him-
self in such complicated hypotheses that they could not con-
tribute to any clarification. He therefore achieved no recogni-
tion as a theoretician.

He was one of the physicists who during the World War had
become extreme nationalists and particularly embittered en-
emies of England. He regarded the defeat, which came quite
unexpectedly for him as well as for the others who held the
same political views, as the work of international powers:
namely, the Socialists and pacifists. He was one of those who
began to accuse the Jews of being the actual wire-pullers in the
background. Lenard soon joined the Hitler groups and was a
very old member of the National Socialist Party.

He was astonished that Einstein had such great success after
the war. In the first place, this man was not an experimenter;
secondly, he was the inventor of an "absurd" theory that con-
tradicted sound common sense as embodied in mechanistic phys-
ics; and thirdly, in addition to all this he was a Jew and a paci-
fist. For Lenard this was more than he could stand, and he put
his reputation and prestige as a physicist at the service of Ein-
stein's opponents. In him were united the motives of all three

162

Einstein as a Public Figure

groups that opposed Einstein: the agents of the revolution from
the Right, the pure "empiricists/' and the advocates of a certain
philosophy.

Lenard's nationalistic fanaticism was revealed by many inci-
dents. On one occasion the well-known Russian physicist A. F.
Joffe was traveling through Germany after the war in order to
resume contact with German colleagues. He went to Heidel-
berg and wanted to visit Lenard to discuss scientific subjects
with him. He requested the porter at the institute to announce
him to Lenard. The porter returned and said to Joffe: "Herr
Geheimrat Lenard wishes me to say that he has something more
important to do than to converse with the enemies of his fa-
therland."

As is well known throughout the entire world the unit of
intensity of an electrical current is called an ampere, after the
French physicist and mathematician Andre M. Ampere. Lenard,
however, ordered that in his laboratory the electrical unit must
change its French name and assume the name of a German
physicist, Weber. This change was made on all the instruments
in the Heidelberg laboratory.

Every year in September there was a meeting of German-
speaking scientists and teachers of sciences. Usually several thou-
sand persons came together. In 1920 this meeting was to take
place at the well-known spa Bad Nauheim. Several papers deal-
ing with the relativity theory were also on the program. Lenard
decided to take this opportunity to attack Einstein's theories
before the assembled scientists and to demonstrate their ab-
surdity.

This became generally known and the session was awaited
as if it were a sensational and decisive meeting of a parliament.
Max Planck presided. This great scientist and distinguished
man detested any kind of sensation. He endeavored to arrange
the session in such a way so as to keep the debate on the level
on which scientists usually discuss matters and to prevent non-
scientific points of view from being brought into it. He ar-
ranged it so that the greatest part of the available time was
filled with papers that were purely mathematical and techni-
cal. Not much time remained for Lenard's attack and the debate
that would ensue. The entire arrangement was made to prevent
any dramatic effects.

Questions of principle were not touched upon in the long re-
ports, which were full of mathematical formulae. Then Lenard
took the floor for a short talk in which he attacked Einstein's

163

Einstein: His Life and Times

theory, but without Introducing any emotional coloring. His
argument was neither that the theory was inconsistent with ex-
perimental results, nor that it contained logical contradictions,
but actually only that it was incompatible with the manner in
which ordinary "common sense" conceived things. Fundamen-
tally it was only a criticism of a language that was not that of
mechanistic physics.

Einstein replied very briefly and then two others spoke still
more briefly for and against Einstein. With this the session came
to an end. Planck was able to heave a sigh of relief that the meet-
ing had passed without any major conflict. The armed police-
men who had watched the building were withdrawn. Planck
was in such good humor that he ended the session with one of
the trivial jokes that have been current among non-physicists:
"Since the relativity theory unfortunately has not yet made it
possible to extend the absolute time interval that is available for
the meeting, our session must be adjourned."

To a certain degree the lack of understanding of the philo-
sophical significance of Einstein's theory among most profes-
sional physicists stood in the way of a real debate in which it
would have been possible to explain the true content of the
theory to its well-meaning opponents. As a result, however, the
impression was created that while the Einstein theory might
have a meaning for mathematicians, yet for a more philosophi-
cally thinking mind it contained various absurdities.

Thus Lenard himself received the impression that not enough
attention was paid to his arguments, and the mass of physicists
and mathematicians had no opportunity to take part in a truly
fundamental discussion on a grand scale. For the moment the
physicists probably felt relieved that nothing worse had hap-
pened; nevertheless, the opportunity had been permitted to pass
without organizing a real explanation for the great mass of
scientists and educated persons.

The opposition of Lenard and his supporters to Einstein's
theory was checked by one fact. Even though the foundations
of the theory could be characterized as "absurd" and "mud-
dled/' yet it was undeniable that inferences could be drawn
from this "absurd" theory that every scientist had to admit were
usable and important Even the most vigorous opponent, if he
was a physicist or chemist, had to reckon with the formula that
represented the relation between mass and energy. If the energy
E is given off, this is equivalent to a loss of mass E/c* f where c
is the velocity of light (see Chapter III). Even the most zealous

164

t Einstein as a Public Figure

adherent of the "revolution from the Right" had to use this
formula E = me 2 if he wanted to penetrate the nucleus of the
atom. Consequently Lenard and his group endeavored to sepa-
rate this law from its connection with Einstein's theory and to
prove that it had already been known before Einstein, having
been advanced by a physicist of whose racial origin and senti-
ments they approved.

In the writings of those who want to avoid the name of Ein-
stein at any price, the law of the transformation of mass into
energy is often to be found as the "principle of HasenohrL" It
is interesting, perhaps, for an understanding of the entire milieu
in which Einstein worked to describe how this deliberate re-
moval of Einstein's name occurred.

It had long been known that light falling on a surface exerts
a pressure on it as if particles were being hurled against the sur-
face. In 1904 the Austrian physicist Hasenohrl had concluded
from this knowledge: if light radiation is enclosed in a vessel,
it will exert a pressure on the walls. Even if the vessel itself does
not have any material mass, yet because of the pressure of the
enclosed radiation it would under the impact of a force behave
like a body with material mass. And this "apparent" mass is
proportional to the enclosed energy. When the vessel radiates
energy E the "apparent" mass m will decrease, according to
E = mc 2 .

This principle is obviously a special case of Einstein's law. If
radiation is already contained in a body, its mass will decrease
when the radiation is given off. Einstein's law, however, is much
more general. He says that the mass of a body, no matter what
its nature, decreases if the body loses energy in any manner
whatsoever.

Lenard and his group, however, were seeking a substitute for
the name Einstein. There were several external factors that fa-
vored the choice of Hasenohrl's name. During the World War
he had fought in the Austrian army that is, on Germany's
side and was killed in battle at the age of forty. He thus ap-
peared to be an ideal figure in the view of Einstein's enemies, a
hero and model for German youth who was the very antithesis
of the abstract speculator and international pacifist Einstein.
Actually, Hasenohrl was a honest and competent scientist and a
sincere admirer of Einstein.

The legend originated with Lenard's book Great Men of
Science. The author presented a series of biographies of great
men, such as Galileo, Kepler, Newton, Faraday, and others,

165

Einstein: His Life and Times

and he concluded with one of Hasenohrl. In order to link
him with the preceding heroes Lenard said of him: "He loved
music and his violin as Galileo his lute: he was very fond of his
family and as extremely modest as Kepler." Further on he
says about HasenohrPs conclusions: "The applications of this
idea have already progressed very far today, although almost
entirely in the names of other people." "Other people" appar-
ently means Einstein.

166

VIII

TRAVELS THROUGH EUROPE, AMERICA,
AND ASIA

i. Holland

The vicious attacks on Einstein resulted in arousing
interest in Ms theories among all classes of people in every coun-
try. Theories that were of no great significance to the masses
and at that almost incomprehensible to them became the center
of political controversies. At a time when political ideals had
been shattered by the war and new philosophies and political
systems were being sought, the public was puzzled and myste-
riously attracted by the connection between Einstein's scientific
work and politics. The public interest was further increased by
the appearance of articles by philosophers published in daily
newspapers stating that Einstein's theories might perhaps be of
some importance in physics, but were certainly untrue philo-
sophically.

The public wondered what sort of man was this Einstein, and
they wanted to see and hear this famous scientist in person.
From every country Einstein began to receive invitations to
come and give lectures. He was amazed, but happy to comply
with the people's wishes. He enjoyed leaving the narrow circle
of his professional colleagues and coming into contact with new
people. It was also refreshing for him to leave Berlin and Ger-
many, to go away from this tormented and harrowing atmos-
phere, and to see new countries.

These journeys and public appearances, however, added an-
other cause for attacks on Einstein. Even some German scientists
became annoyed, and one of them, a hard-working observer in
the laboratory, wrote a brochure entitled The Mass Suggestion
of the Relativity Theory. In it he gave aa interpretation of Ein-
stein's travels from his own point of view. He wrote: "As soon
as the erroneous character of the relativity theory became evi-
dent in scientific circles, Einstein turned more and more to

167

Einstein: His Life and Times

the masses and exhibited himself and his theory as publicly as
possible."

The first instance of this "unscientific" publicity was Ein-
stein's lecture at the ancient and honorable University of Leiden
in Holland. There he lectured before fourteen hundred students
of this famous center of physical science on "Ether and the Rela-
tivity Theory." This lecture led to many misinterpretations.
Einstein, who had previously suggested that the term "ether" be
dropped so as to prevent the rise of any idea that one is dealing
with a material medium, discussed another proposal : namely,
the word "ether" be used for "curved space," or what amounts
to the same thing, for the gravitational field present in space,

Einstein's new proposal irritated some physicists and made
others happy. Quite a few were unable to differentiate between
a proposal to use a word in a certain sense and an assertion of
a physical fact. They said: "For a long time efforts were made
to convince us of the sensational fact that the ether had been
got rid of, and now Einstein himself reintroduces it; this
man is not to be taken seriously, he contradicts himself con-
stantly."

Einstein, however, was happy to be in the quiet, pleasant city
of Leiden, among good friends and remote from the contro-
versies of Berlin. He loved to carry on discussions with a physi-
cist of this city, Paul Ehrenfest, a Viennese by birth who was
married to a Russian physicist. Husband and wife were inde-
fatigably ready to discuss with Einstein the most subtle ques-
tions regarding the logical relations of physical propositions.

Einstein was also appointed professor at Leiden, but he was
required to lecture there only a few weeks throughout the year.
It was a pleasant thought to look forward to this period of rest
every year. And in Berlin there were constant speculations as
to whether Einstein would move permanently to Holland. His
opponents tried everything possible to make it unpleasant for
him to remain in Berlin. Many Germans thought that they must
be thankful to Einstein because by means of his great popularity
abroad he was acting to increase Germany's prestige after the
lost war. His enemies, however, began a campaign against him,
asserting that he was making propaganda abroad only for his
own reputation, not for Germany.

Hanisch, the Prussian Minister of Education and a member
of the Social Democratic Party, wrote an anxious letter to Ein-
stein entreating him not to let himself be disturbed by these
attacks and to remain in Germany. The government of the Ger-

168

Travels through Europe, America, and Asia

man Republic was very well aware how valuable he was for
German culture and for its prestige throughout the world. The
German government was even sorry that the great new theory
of a German scientist had been studied and confirmed by Eng-
lish astronomers so that a large part of the ensuing fame had
been lost to the Germans. The Minister requested Einstein to
make use of the assistance of German observers and promised
him governmental assistance.

Einstein, who appreciated greatly the significance of Berlin
as a center of science and research, also understood very well
that it was now important for all progressively minded elements
to do everything possible to increase the prestige of the Ger-
man Republic. He wrote a letter to the Minister in which he
said: "Berlin is the place to which I am bound by the closest
human and scientific ties." He promised if possible to remain
in. Berlin and even applied for German citizenship, something
that he had not wanted to accept from the Imperial government.
He thus became a German citizen, a circumstance that later en-
tailed only troubles for him.

2. Czechoslovakia

In Prague, which was now the capital of the new
Czechoslovak Republic, a Urania society had been organized to
arrange lectures for the German-speaking population, and in
particular to acquaint them with the great personalities of the
new republican Germany. The president of Urania, Dr. O.
Frankel, also endeavored to induce Einstein to lecture in Prague.
Einstein, who was fond of recalling the quiet times he had en-
joyed when he was working in Prague, seized the opportunity
to revisit his old university and friends. He was also interested
in becoming acquainted with the new democratic state that had
arisen under the leadership of President Masaryk on the ruins of
the Habsburg monarchy. The psychological status of the Ger-
man minority in Prague and in Czechoslovakia in general was
approximately like that of the population of the defeated Ger-
man Reich within Europe. Einstein's visit increased the self-
esteem of the Germans in Czechoslovakia, who were later called
"Sudeten Germans/' and played a fateful role in the crisis
that led to the second World War. When Einstein's visit was
announced, one of the papers of this minority wrote: "The

169

Einstein: His Life and Times

whole world will now see that a race that has produced a man
like Einstein, the Sudeten German race, will never be sup-
pressed." This was characteristic of the nationalistic thinking.
On the one hand every effort was made to keep the race free
of all foreign admixtures; on the other hand, when someone
was needed, even one who had not spent two years among this
race was counted as a member of the group.

Early in 1921 Einstein returned to Prague, where I was
then teaching as his successor. I had not seen him for years.
I remembered only the great physicist, the man with an artistic
and often jesting outlook on the world, who at that time had
already enjoyed a great reputation among scientists. But during
the years that had passed since then, he had become an inter-
national celebrity, a man whom everyone recognized from his
photographs in the newspapers, whose opinions on politics and
art were sought by every reporter, and whose autograph was
wanted by every collector; in short, a man whose life no longer
belonged entirely to himself. As so often happens in such cases,
he had ceased to be an individual person in many respects; he
had now become a symbol or banner upon which the gaze of
masses of people was directed.

I was therefore very curious to meet him again, and was some-
what worried about how I could make it possible for him to
live a halfway quiet life in Prague and prevent him from being
overburdened by his obligations as a famous man. When I met
him at the station, he had changed very little and still looked
like an itinerant violin virtuoso, with the combination of child-
likeness and self-assurance that attracted people to him, but that
sometimes also offended them. I had been married only a short
time then, and during this period shortly after the war it was
so difficult to find an apartment that I lived with my wife in
my office at the Physics Laboratory. It was the same room, with
the many large windows looking out on the garden of the
mental hospital, that had formerly been Einstein's office. Since
Einstein would have been exposed to curiosity-seekers in a hotel,
I suggested that he spend the night in this room on a sofa. This
was probably not good enough for such a famous man, but it
suited his liking for simple living habits and situations that con-
travened social conventions. We told no one about this arrange-
ment, and no journalist or anyone else knew where Einstein
spent the night. My wife and I spent the night in another room.
In the morning I came to Einstein and asked him how he had

170

Travels through Europe, America, and Asia

slept. He replied: "I felt as if I were in a church. It is a remark-
able feeling to awake in such a peaceful room."

We went first to police headquarters, where, as was common
during the postwar period, every stranger had to report. Then
we visited the Physics Laboratory of the Czech University. The
professors there were pleasantly surprised by seeing Einstein,
whose picture hung on the wall, appear in person in their room.
By this visit Einstein wanted to express his sympathy for the new
Czechoslovak Republic and its democratic policy under Ma-
saryk's leadership.

In Prague, as in all the cities that had belonged to the Austro-
Hungarian monarchy, a large part of the social life took place
in the cafes. There people read newspapers and magazines, met
with friends and acquaintances, and discussed business prob-
lems and scientific, artistic, or political questions. New political
parties, literary circles, or large business firms were founded in
cafes. Often, however, people sat alone, studying books or doing
their own writing. Many students prepared for their examina-
tions there, because their rooms were too cold, too dark, or
simply too dreary. Einstein wanted to visit such places and he
said to me: "We ought to visit several cafes and look in to see
what the various places frequented by different social classes
look like." Thus we paid rapid visits to several cafes; in one we
saw Czech nationalists, in another German nationalists; here
were Jews, there Communists, actors, university professors, and
so forth.

On the way home Einstein said to me: "Now we must buy
something for lunch so that your wife won't have too much
bother." At that time my wife and I cooked our meals on a gas
burner such as is used for experiments in chemical or physical
laboratories, a so-called Bunsen burner. This took place^in the
same large room in which we lived and where Einstein had
also slept. We came home bringing some calf's liver that we had
purchased. While my wife began to cook the liver on the gas
burner, I sat with Einstein talking about all sorts of things. Sud-
denly Einstein looked apprehensively at the liver and jumped at
my wife: "What are you doing there? Are you boiling the liver
in water? You certainly know that the boiling-point of water is
too low to be able to fry liver in it. You must use a substance
with a higher boiling-point such as butter or fat." My wife had
been a college student until then and knew little about cooking.
But Einstein's advice saved the lunch; and we got a source of

171

Einstein: His Life and Times

amusement for all our married life, because whenever "Ein-
stein's theory" was mentioned, my wife remembered his theory
about frying calf's liver.

That evening he lectured before the Urania association. It
was Einstein's first popular lecture that I had heard. The hall
was dangerously overcrowded since everyone wanted to see the
world-famous man who had overthrown the laws of the uni-
verse and proved the "curvature" of space. The ordinary public
did not really know whether it was all a colossal humbug or
a scientific achievement. Nevertheless, it was ready to marvel at
both. As we were going in to the lecture, a very influential man
in public life who had himself done a great deal to organize
the meeting pushed through the crowd and said to me: "Please
tell me quickly in one word, is there any truth in this Einstein
or is this all bunk?" Einstein spoke as simply and clearly as
possible. But the public was much too excited to understand the
meaning of the lecture. There was less desire to understand,
than to experience an exciting event

After the lecture the chairman of the Urania gathered to-
gether a number of guests to spend the evening with Einstein.
Several speeches were made. When Einstein's turn came to an-
swer, he said: "It will perhaps be pleasanter and more under-
standable if instead of making a speech I play a piece for you
on the violin." It was easier for him to express his feelings in this
way. He played a sonata by Mozart in his simple, precise, and
therefore doubly moving manner. His playing indicated some-
thing of his intense feeling for the complexity of the universe
and simultaneously of the intellectual joy over the possibility of
expressing it in simple formulas,

Einstein remained in Prague another evening to participate
in a discussion of his theories that was to take place in the Urania
before a large audience. Einstein's main opponent was a philos-
opher of the Prague University, Oskar Kraus, an acute thinker
in the philosophy of law, whose conception of scientific discus-
sions, however, was more like that of a counsel at a trial He
made no attempt to explore the truth, but instead wanted
only to refute his opponent by finding passages that were con-
tradictory in the writings of Einstein's supporters. In this he
was successful. Anyone who wants to present a complex subject
popularly must introduce some simplifications. But every author
introduces them at different places according to his own taste
or his opinion of his reader's tastes. If every statement by a
popularizer is then taken literally, contradictions must neces-

172

Travels through Europe,, America, and Asia

sarily arise. But this has nothing to do with the correctness o!
Einstein's theory.

Professor Kraus was a typical proponent of the idea that one
can learn various things about the geometrical and physical be-
havior of bodies through simple "intuition." Anything that con-
tradicted this intuition he considered absurd. Among these ab-
surdities he included Einstein's assertion that Euclid's geometry,
which we all learned in school, might not be strictly correct.
Since in Kraus's opinion the truths of ordinary geometry must
be clear to every normal person, it was a puzzle to him how a
person like Einstein could believe the opposite. His wife re-
minded me not to speak to him about Einstein's theory. She
said that he often spoke about it in his sleep and he got excited
over the idea that there were people who could "believe what
is absurd." It was tormenting for him to think that such a thing
was possible.

This philosopher was the chief speaker against Einstein. I
presided at this discussion and endeavored to direct it in half-
way quiet paths. A number of people now appeared who wanted
to take advantage of an opportunity that would probably never
present itself to them again. They could now fling the opinions
that they had formed privately directly at the famous Einstein;
he was compelled to listen to them. As a result several comical
things occurred. Thus a professor of mechanical engineering
at the Institute of Technology made some remarks that were
false, but sounded rather reasonable. After the lecture Einstein
said to me: "That laborer spoke naively, but not in an entirely
foolish way." When I replied that he was not a laborer, but
a professor of engineering he said: "In that case it was too
naive."

On the following day Einstein was to depart, but by early
forenoon the news had already spread that Einstein was staying
at the Physics Laboratory and many people hurried to speak to
him. I had great difficulty in arranging a relatively quiet depar-
ture. For instance, a young man had brought a large manuscript.
On the basis of Einstein's equation E = me 2 he wanted to use the
energy contained within the atom for the production of fright-
ful explosives, and he had invented a kind of machine that could
not possibly function. He told me that he had awaited this
moment for years and in any case wanted to speak to Einstein
personally. I finally prevailed upon Einstein to receive him.
There was but little time left and Einstein said to him: "Calm
yourself. You haven't lost anything if I don't discuss your work

Einstein: His Life and Times

with you in detail Its foolishness is evident at first glance. You
cannot learn any more from a longer discussion." Einstein had
already read about a hundred such "inventions." But twenty-
five years later, in 19455 *he " rea ^ thing" exploded at Hiroshima.

3. Austria

From Prague Einstein went to Vienna, where he also
had to give a lecture. The Vienna of this postwar period was
completely different from the city that Einstein had visited in
1913. It was now no longer the capital of a great empire, but
only that of a little republic.

Among Einstein's acquaintances, too, changes were notice-
able. His friend Friedrich Adler had become a public figure.
During the war, when the Austrian government had refused to
convene the parliament and to submit its course of action to the
judgment of the people's representatives, Friedrich Adler, im-
bued with a fanatical desire to achieve what he considered just,
had shot the head of the government during a dinner in a
fashionable hotel.

Adler was arrested and condemned to death, but the Emperor
commuted his sentence to life imprisonment, since Adler's fa-
ther, although leader of the Socialists, was a man highly regarded
in government circles. The hypothesis was set up that Friedrich
Adler was not in his right mind when he committed the assas-
sination. This assumption made it easier to commute his sen-
tence, but the investigation of his mental state was remarkable.
While in prison, Adler had written a work on Einstein's theory
of relativity; he believed that he was able to present cogent
arguments against it This manuscript was sent by the court to
expert psychiatrists and physicists. They were to determine
whether any conclusion could be drawn from it that the author
was mentally deranged. In this way I received a copy of the
manuscript. The experts, especially the physicists, were placed
in a very difficult situation. Adler's father and family desired
that this work should be made the basis for the opinion that
Adler was mentally deranged. But this would necessarily be
highly insulting to the author, since he believed that he had
accomplished an excellent scientific achievement. Moreover,
speaking objectively, there was nothing in any way abnormal

Travels through Europe, America, and Asia

about It except that his arguments were wrong. I imagine, how-
ever, that he owed the commutation of his sentence rather to
the prestige of his father and the inclination of the Imperial
government to compromises than to the madness of his argu-
ments against the theory of relativity.

In Vienna Einstein lived with the well-known physicist Felix
Ehrenhaf t, who in his entire mode of working was the diametri-
cal opposite of Einstein, but whom Einstein occasionally found
congenial for this very reason. Einstein was always interested in
determining how much could be deduced from a few funda-
mental principles. The greater the extent to which natural phe-
nomena could be fitted into a simple pattern, the more interest-
ing they were for him. Ehrenhaft, however, was a man of the
direct experiment. He believed only what he saw, and constantly
found isolated phenomena that did not fit into the grand
scheme. For this reason he was frequently regarded with dis-
dain, especially by persons who accepted the general scheme
as an article of faith. A man like Einstein, who had himself
brought these general principles to life, always felt mysteriously
attracted whenever he heard of irregularities. Even though he
did not believe that they existed, yet he suspected that there
might be the germs of new knowledge in these observations.

Ehrenhaft's wife was a remarkable figure among the women
of Vienna. She was herself a physicist and an outstanding or-
ganizer of education for girls in Austria. She was astonished
when Einstein arrived with only one white collar. She asked
him: "Perhaps you have forgotten something at home?" He
replied: "By no means; this is all that I need." As a good house-
wife she sent one of the two pair of trousers that he had brought
with him to be pressed by a tailor. But to her consternation she
noticed at the lecture that he had put on the unpressed pair.
Mrs. Ehrenhaft also thought that he had left his bedroom slip-
pers at home and bought him a new pair. When she met him
in the hall before breakfast, she noticed that he was barefooted.
She inquired whether he had not seen the slippers in his room.
"They are entirely unnecessary ballast," was his reply. He did
not like shoes at all, and at home when he really wanted to re-
lax he could often be seen in his stocking feet, sometimes even
when he had visitors who were not very formal.

During his stay Einstein also came in contact with the two
intellectual currents of Vienna that have most strongly influ-
enced the intellectual life of our time: Siegmund Freud's psy-

Einstein: His Life and Times

choanalysis, and the positivistic tradition of Ernst Mach. Ein-
stein called on Josef Breuer, a doctor who together with Freud
had published the first paper on the psychological causes of hys-
terical paralyses, and the engineer and writer Popper-Lynkeus,
the nearest friend of Ernst Mach, who once remarked that at
first Popper-Lynkeus had been the only one to understand his
ideas. At this time Popper-Lynkeus was already eighty years
old and confined to his sofa, but intellectually he was still very
alert and always eager to meet new and interesting people. He
had worked out a project for the abolition of economic misery in
Germany through the introduction of a general labor service*
This plan was put into practice later in a distorted way by Adolf
Hitler. It was a great occasion for Popper when he met Einstein
who had become the true heir of Mach's ideas in the field of
physics.

Einstein's lecture, which was given in an enormous concert
hall before an audience of some three thousand people, was
probably the first lecture of this kind that he had given. Even
more than in Prague the public was in a remarkably excited
state, the kind of mental state in which it no longer matters
what one understands so long as one is in the immediate neigh-
borhood of a place where miracles are happening.

4. Invitation to the United States

After Einstein's return to Berlin he was more than ever
a center of general attention. Just as formerly the German pro-
fessor who forgets his umbrella, the hunter who buys a hare at
the butcher's shop, or the old maid looking for a man had ap-
peared repeatedly in the German comic journals, now the name
Einstein became a generic name for anyone who writes some-
thing incomprehensible and is admired on this account. Espe-
cially the word "relative" stimulated people to the most trivial
jokes. In part they were malicious, trying in some way to con-
nect Einstein's theory with the efforts of victorious France to
squeeze as large reparations as possible out of Germany. The
German government always tried to show that the country was
completely impoverished, while the French doubted this. Thus
a German comic journal represented Einstein in conversation
with the French President Millerand, who was a vigorous advo-
cate of the "Make Germany pay" policy- Millerand says to Ein-

176

Travels through Europe, America, and Asia

stein: "Can't you persuade die simple-minded Boctie that even
with an absolute deficit of 67,000,000,000 marks he is still rclar
lively well off?"

Einstein, however, paid as little attention as possible to all
these political and personal vexations and endeavored rather to
dispel scientific and philosophical misunderstandings of his the-
ories. Many people considered particularly absurd the assertions
of Einstein's theory that Euclidean geometry is invalid in a
gravitational field, that space is curved, and perhaps even finite.
This was because everyone had learned in school that the postu-
lates of geometry are absolutely correct, since they are not based
on experience, which is fallible, but rather on infallible pure
thought or on still more infallible "intuitive perception."

In a lecture delivered at the Prussian Academy in January
1921 Einstein clarified the relation between "Geometry and Ex-
perience," He said there: "In so far as geometry is certain, it
says nothing about the actual world, and in so far as it says
something about our experience, it is uncertain." He made a
sharp distinction: On the one side is mathematical geometry,
which deals only with the conclusions that can be drawn from
certain assumptions without discussing the truth of these as-
sumptions. In it everything is certain. Alongside it is a physical
geometry, which Einstein used in his theory of gravitation. It
deals with the results of measurements on physical bodies and is
a part of physics, like mechanics. Similarly it is just as certain
or uncertain as the former. This lecture through its clear formu-
lations brought order into a field where confusion often pre-
vailed, and in some instances still prevails even among mathe-
maticians and physicists. Since then Einstein's formulations
have been cited as the clearest and best, even by philosophers.

But while Einstein was working on this lecture, thoughts of
another kind were also passing through his head. A short time
before, he had received an invitation from Weizmann, the
leader of the Zionist movement, to accompany him on a trip to
the United States,

At a time when but few German scientists and very few Ger-
man Jews had any intimation of the coming Nazi revolution
in Germany, it was already fairly evident to Einstein that con-
ditions were developing there that could become very unpleas-
ant for him. He sensed the activities of the group growing
beneath the surface that were later to come to power as the Na-
tional Socialist Party. Indeed, Einstein was one of the first to
feel the impact of this movement. When Einstein gave his lec-

177

Einstein: His Life and Times

ture in Prague, he spoke to me about these apprehensions. At
that time he thought that he would not like to remain in Ger-
many longer than another ten years. It was then 1921. His
estimate was too conservative by only two years.

The purpose of the trip that Weizmann planned was to ob-
tain help in America for the establishment of a Jewish national
home in Palestine, and in particular for the Hebrew University
to be founded there. Since the American Jews were considered
the wealthiest in the world, these aims could be accomplished
only with their financial assistance. Weizmann laid great value
on this teamwork. He hoped that Einstein's scientific fame
would encourage American Jews to contribute to a noble cause.
Einstein was now in a position to place his prestige at the dis-
posal of the Zionist movement for these purposes, which he
considered as having a very great educational significance for
the Jews. After considering the matter for only a few days Ein-
stein accepted the invitation.

He was motivated chiefly by the desire not only to be active
as a pure scientist, but also to contribute something to the wel-
fare of persecuted human beings. He was also impelled by the
desire to see America with his own eyes and to become ac-
quainted with the life in this new world. He felt that it would
be worth while for him to know something about the great
country on the other side of the Atlantic whose tradition of
democracy and tolerance had always struck a sympathetic chord
within him.

5. Reception by the American People

The arrival of Einstein and his wife in New York
Harbor was accompanied by demonstrations of enthusiasm such
as had probably never before been seen at the arrival of a sci-
entist, especially not of a scientist whose field is mathematical
physics. Reporters and cameramen in large numbers rushed
aboard ship to photograph him or to ask him various questions.
Facing the cameras was the easiest of these ordeals. After it
was over, Einstein said: "I feel like a prima donna." He also
replied with a fine sense of humor to the questions that the re-
porters put to him. As a matter of fact, he was used to strange
questions and had already 'developed a certain technique for an-
swering such questions as cannot be answered rationally. On

Travels through Europe, America, and Asia

such occasions he usually said something that was not a direct
answer to the question, but was still rather interesting, and
which when printed conveyed to the reader a reasonable idea
or at least gave him something to laugh about. Einstein was
never a killjoy.

The interrogators were chiefly interested in three things. The
first question was the most difficult: "How could one explain
the content of the relativity theory in a few sentences?" It was
probably impossible to answer this question, but it had already
been put to Einstein so many times that he had prepared an
answer in advance. He said: "If you will not take the answer too
seriously and consider it only as a kind of joke, then I can ex-
plain it as follows. It was formerly believed that if all material
things disappeared out of the universe, time and space would be
left. According to the relativity theory, however, time and space
disappear together with the things."

The second question was very "urgent": "Is it true that only
twelve people in the world understand the theory of relativity ?"
Einstein denied that he had ever made such an assertion. He
thought that every physicist who studied the theory could read-
ily understand it, and that his students in Berlin all understood
it. Nevertheless, this last assertion of Einstein's was certainly
too optimistic.

The third question, on the other hand, was a very delicate
one: the reporters asked Enstein to explain the existence of
such mass enthusiasm for an abstract theory that is so hard to
understand. Einstein answered with a joke. He suggested that
it was a problem for psychopathological investigation to de-
termine why people who are otherwise quite uninterested in
scientific problems should suddenly become madly enthusiastic
over the relativity theory and want to greet Einstein on his ar-
rival. One of the reporters asked him whether it might not be
due to the circumstance that the theory has something to do
with the universe, and the universe in turn with religion. Ein-
stein replied that it was quite possible. But in his endeavor not
to permit the rise of any exaggerated opinions regarding the
general significance of his theory for the great majority, he said:
"But it will not change the concept of the man in the street"
He explained that the only significance of the theory was that
it derived from simple principles certain natural phenomena
that were formerly derived from complicated principles. This
is naturally important for philosophers, but hardly for the man
in the street.

179

Einstein: His Life and Times

After this rather abstract discussion the desire to ask ques-
tions subsided somewhat and Einstein was able to close with the
words: "Well, gentlemen, I hope I have passed my examina-
tion." Then, to get an element of human interest, Mrs.^ Einstein
was asked whether she also understood the theory. "Oh no,"
she answered in a friendly but somewhat amazed tone, "al-
though he has explained it to me so many times; but it is not
necessary for my happiness."

Finally Mr. and Mrs. Einstein could go ashore. Einstein passed
through the enormous crowd of onlookers, a brier pipe in one
hand, a violin case in the other. Now he no longer appeared to
the crowd as a mythical harbinger of a new system of ^the uni-
verse, as the man who had revolutionized space and time, but
rather as a friendly musician who arrived for a concert in New
York smoking his pipe.

The enthusiasm manifested by the general public on Ein-
stein's arrival in New York is an event in the cultural history
of the twentieth century. There was no single cause for this
phenomenon. First of all, there was the general interest ^in the
theory of relativity, which in itself was something astonishing.
A second factor was the recognition that Einstein had received
in England two years earlier, after the observation of the solar
eclipse had confirmed his theory. Finally, there was something
romantic about his present trip. He came not only as a scientist,
but also to fulfill a political mission that was not a matter of
ordinary politics but was itself surrounded with an aura of
romanticism. His visit to America was his contribution to the
movement whose purpose it was to enable the Jewish people to
return to its homeland after having wandered over the world
for two thousand years. For the Jews who felt that to a greater
or lesser degree they were strangers everywhere in the world,
these were happy tidings; and to every person in America it re-
called the Holy Land and the legend of the Wandering Jew,
thus striking a strongly responsive chord and evoking profound
sympathies in many Christians.

Einstein took the whole matter very calmly. Nevertheless, he
was amazed that so many people could be interested in things
about which he had pondered in silence and which he had
thought would probably always remain limited to a small
group. Einstein's enemies often claimed that this enthusiasm
had been manufactured by the press. This assertion, however,
is as trivial as it is erroneous. Newspapers are constantly pub-
licizing all sorts of things; they succeed in arousing enthusiasm

1 80

Travels through Europe, America, and Asia

for football games and movie stars; but no newspaper publicity
could ever produce such enthusiasm for a mathematical physi-
cist, even though all kinds of scientists have been publicized
by the press. The reasons for this success must already have been
present in the situation Itself, in the unique coincidence of Ein-
stein's achievements, his personality, and the intellectual needs
of his age at the moment. When I once asked Einstein what
emotions were aroused in him when he saw himself honored
in this way, he replied: "The impression cannot be very ele-
vating when I remember that a victorious boxer Is received with
still greater enthusiasm."

He himself was always inclined to see the causes of this phe-
nomenon rather in the disposition of the public than in his own
person. Thus he sometimes jokingly remarked: "The ladies in
New York want to have a new style every year this year the
fashion is relativity."

Nevertheless, if one considers the matter realistically and dis-
passionately, one must ask with amazement: how was it that a
mathematical physicist became as popular as a boxer ? Seen ob-
jectively, this was indeed a good indication of popular taste in
New York. It may have been simply a desire for sensation, but
if so, why was this popular interest centered on Einstein ?

Some persons regarded it as an indication of the high cultural
level of the American people. This was the view of the editor
of the best popular scientific journal: "No European populace
would welcome a distinguished scientist with such enthusiasm.
America doesn't boast a leisure class that takes conventional
interest in science and philosophy. But the figures of reading and
educational efforts justify the belief that Einstein should have
taken the honors bestowed upon him at their face value, as evi-
dence of a profound popular interest in the field where he has
so few peers."

Perhaps it will seem strange to some people, but the truth is
that Einstein never worried his brain very much regarding the
reasons for this interest. His attitude toward the world around
him was always to some extent that of an onlooker at a per-
formance. He was accustomed to believe that many things are
incomprehensible, and human behavior was not one of the
things in which he was most interested. As a normal, natural
person he was happy when he was received with friendliness
and goodwill, without inquiring too much into the reasons for
such kindliness. He was never inclined to have too high an
opinion of the goodwill of the public or to make any conces-

181

Einstein: His Life and Times

sions to it. His utterances were never calculated to evoke cheap
applause. In later years he was well aware that many persons
paid a great deal of attention to everything he said,, and that it
was important to utilize this power over people for educational
purposes. For this reason in interviews with newspapermen he
often said things that were not very pleasant or very compre-
hensible to the readers of these newspapers. His idea was that
when an opportunity presents itself, good seed should be sown.
Somewhere some of it will sprout.

Einstein had put himself at the disposal of the Zionist leaders
with the idea that his presence would help their propaganda for
the Jewish National Fund and especially the collection of con-
tributions for the university in Jerusalem. At the meetings that
were organized for these purposes in many places throughout
the United States, he sat near Weizmann, generally in silence,
sometimes speaking a few words in support of him. He sin-
cerely wanted to be a faithful member of the movement for the
rebirth of the Jewish people. At one meeting he spoke after
Weizmann, quite as if he was a member of the rank and file
who wanted no personal prominence but wished only to serve
the cause. He said: "Your leader Dr. Weizmann has spoken and
he has spoken very well for us all. Follow him and you will
do well. That is all I have to say." This sounds almost as if it
was spoken in the spirit of the leadership principle. In some
respects it was probably a relief for Einstein, who always stood
alone, to feel himself a member of a popular movement rooted
in the broad masses. But this feeling was always of only short
duration. Inevitably there soon reappeared his aversion to every-
thing that ties him to a party, even though in certain respects
it may have been congenial to him.

Einstein and Weizmann were regarded by all official person-
alities in America as authorized representatives of the Jewish
people and greeted as such. President Harding wrote in a letter
to a meeting at which Einstein and Weizmann spoke: "Repre-
senting as they do leadership in two different realms their visit
must remind people of the great services that the Jewish race
has rendered to humanity."

Similarly Mayor Hylan of New York in welcoming them at
the City Hall addressed them as the representatives of their peo-
ple, saying: "May I say that in New York we point with pride
to the courage and fidelity of our Jewish population demon-
strated in the World War."

The Jewish population of America itself regarded Einstein's

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Travels through Europe, America, and Asia

visit as the visit of a spiritual leader, which filled them with
pride and joy. The Jews felt that their prestige among their
fellow citizens was raised by the fact that a man of Einstein's
generally recognized intellectual greatness publicly acknowl-
edged his membership in the Jewish community and made their
interests his own. When Einstein arrived with Weizmann in
Cleveland, all the Jewish businessmen closed their establish-
ments so as to be able to march in the parade that accompanied
Einstein from the Station to the City Hall When Einstein and
Weizmann addressed Zionist meetings, it seemed almost as if
the political and spiritual heads of the Jewish people were ap-
pearing together.

These appearances in the service of the organization that rep-
resented some of his political and cultural aims were inter-
spersed with lectures on his scientific theories. Sometimes he
appeared in a most informal manner. Thus he visited Professor
Kasner's class at Columbia University just as he was explain-
ing the theory of relativity to his students. Einstein congratu-
lated Kasner on the comprehensible manner in which he did
this, and then spoke to the students himself for about twenty
minutes.

Later he addressed the students and faculty of Columbia Uni-
versity and was greeted by the outstanding physicist Professor
Michael Pupin. This remarkable man, once a Serbian shepherd,
had become one of the leading inventors and scientists in the
world, and through his understanding of electrical phenomena
the first transatlantic telephone cable had been made possible.
He regarded all theories with the dispassionateness of a labora-
tory worker, but, unlike so many others, greeted Einstein not as
a person who invented absurd and sensational things but as
the "discoverer of a theory which is an evolution and not a
revolution of the science of dynamics."

At this time Einstein always lectured in German, because he
did not yet have full mastery of English. On May 9 he received
an honorary degree from Princeton University. President Hib-
ben of the university lauded him in a German address: "We
salute the new Columbus of science voyaging through the
strange seas of thought alone." Later Einstein gave several lec-
tures at Princeton, in which he presented a comprehensive sur-
vey of the theory of relativity.

Einstein was regarded, however, not only as a representative
of the Jewish people. Since he had left his work at the Berlin
Academy to come to America, and because he spoke German

183

Einstein: His Life and Times

everywhere, he was also considered a representative of German
science. In view of the fact that it was not long after the war,
this aroused hostile reactions in some quarters.

Sometimes semi-comical occurrences took place when politi-
cal attacks were directed against him and no one knew whether
he was attacked as a Jew or as a German. An episode of this
kind occurred when Fiorello H. La Guardia, then president of
the Board of Aldermen of New York City, proposed that Ein-
stein be given the "freedom of the City of New York." All the
aldermen were in favor of this resolution but one, who declared
"that until yesterday he had never heard of Einstein." He asked
to be enlightened,, but nobody offered to explain the theory of
relativity. But the Jews and the Germans did not believe in the
naivete of Einstein's opponent. He was accused of partly anti-
Semitic, partly anti-German opinions. He defended his action
on patriotic grounds: he wanted to spare his beloved native city
from the possibility of becoming a scientific and national laugh-
ing stock. He. said at the session: "In 1909 the key of the city
was unfortunately given to Dr. Cook, who pretended to have
discovered the North Pole." Perhaps, he suggested, Einstein had
not really discovered the theory of relativity. Besides, he con-
tinued, "I have been assured that Professor Einstein was born
in Germany and was taken to Switzerland but returned to
Germany prior to the war. He is consequently a citizen of Ger-
many, of an enemy country, and might be regarded as an
enemy alien."

Everyone was so interested in Einstein's theory and its mean-
ing that Congressman J. J. Kindred of New York requested the
Speaker of the House of Representatives for permission to pub-
lish a popular presentation of the relativity theory in the Con-
gressional Record. Representative David Walsh of Massachu-
setts had his doubts about permitting anything to appear in
the Record that had nothing to do with the activities of Con-
gress and that in addition seemed to be incomprehensible.

"Well, Mr. Speaker," said Representative Walsh, "ordinarily
we confine matters that care to appear in the Congressional
Record to things that one of average intelligence can under-
stand. Does the gentleman from New York expect to get the
subject in such shape that we can understand the theory?"
Kindred answered: "I have been earnestly busy with this theory
for three weeks and am beginning to see some light." But then
Representative Walsh asked him: "What legislation will it bear
upon?" To this Representative Kindred could only reply: "It

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Travels through Europe, America, and Asia

may bear upon the legislation of the future as to general rela-
tions with the cosmos/ 5

At the time when Einstein was in the United States, a state-
ment by the great inventor Thomas Edison created quite a
furore throughout the country. He denied the value of college
education and asserted that education should be directed toward
learning relevant facts. He worked out a questionnaire contain-
ing questions that he thought were relevant for practical peo-
ple, and suggested that tests be made, which would show that
most college graduates were unable to answer these questions.

While Einstein was in Boston, staying at the Hotel Copley
Plaza, he was given a copy of Edison's questionnaire to see
whether he could answer the questions. As soon as he read the
question: "What is the speed of sound ?" he said: "I don't know.
I don't burden my memory with such facts that I can easily find
in any textbook," Nor did he agree with Edison's opinion on
the uselessness of college education. He remarked: "It is not
so very important for a person to learn facts. For that he does
not really need a college. He can learn them from books. The
value of an education in a liberal arts college is not the learning
of many facts but the training of the mind to think something
that cannot be learned from textbooks." For this reason, ac-
cording to Einstein, there can be no doubt of the value of a gen-
eral college education even in our time.

Einstein was often mentioned together with Edison, both be-
ing honored as the outstanding representatives of physical sci-
ence. Edison was to the technical application of physics what
Einstein was to its theoretical foundation.

Einstein also visited the physics laboratories of the oldest uni-
versity in the United States, Harvard University. Professor Theo-
dore Lyman, famous for his optical investigations, informed him
about the work that was being done there. Lyman had the feel-
ing that after the many meetings at which Einstein had been
used as an instrument of political propaganda, even though for
a purpose with which he was entirely in sympathy, he now
could breathe freely, being again in the atmosphere of a physics
laboratory and able to immerse himself in the problems of nature.
Most visitors to a laboratory rapidly pass by the experimental ar-
rangements and listen only half-heartedly to the explanations of
the students. Einstein, however, did not remain satisfied with a
superficial "That is very interesting," or some similar polite re-
mark; instead, he allowed several students to give him detailed
explanations of the problems on which they were working. Fur-

Einstein: His Life and Times

thermore, lie actually thought about these problems, and some
students received advice from him that was helpful in their
research. Such absorption during a strenuous journey is only pos-
sible for a man possessing two qualities that are rarely found to-
gether: first, an unusual ability to familiarize himself rapidly
with an unfamiliar problem; and secondly, the capacity to enjoy
helping someone who is doing scientific research.

There is no doubt that Einstein made his first trip to America
not only in the service of science and of the future university
in Jerusalem,, but also because he was particularly interested in
becoming acquainted with life on this continent, which was new
to him. This first trip, however, was not very favorable for the
achievement of this purpose. The entire journey proceeded at
a whirlwind pace, leaving him no time for any quiet reflection.
As a result the impressions that Einstein received on his first
visit to the United States could only be very superficial ones that
struck one at first glance. In the first place he was impressed
by American youth, with its fresh energetic urge to acquire
knowledge and to do research. He once said: "Much is to be ex-
pected from American youth: a pipe as yet unsmoked, young
and fresh." Then there was the impression of the many peoples
that had settled America, which despite their different origins
lived together in peace under a tolerant democratic regime. He
remarked in particular about New York City: "I like the res-
taurants with the color of the nations in the air. Each has its own
atmosphere. It is like a zoological garden of nationalities, where
you go from one to another." He was also struck by the role
of women in American life, observing that it was much greater
than the part played by women in European life.

Efforts were made to enlist Einstein's interest in campaigns
to restrict the use of tobacco and Sunday amusements. In such
matters, however, Einstein did not favor any excessive restric-
tions on individual liberty. He was much too natural a person
not to have recognized the importance of the innocent pleas-
ures of daily life. He did not have any faith in cut and dried
schemes for making people happy by dictating to them what
they are to regard as work and what as play. Replying to a man
who had requested his opinion on the matter of Sunday rest,
he said: "Men must have rest, yes. But what is rest? You can-
not make a law and tell people how to do it. Some people have
rest when they lie down and go to sleep. Others have rest when
they are wide awake and are stimulated. Some must work or
write or go to amusements to find rest. If you pass a law to show

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Travels through Europe, America, and Asia

all people how to rest, that means you make everybody alike.
But everybody is not alike."

Einstein, who devoted his entire life to the discovery of physi-
cal laws that could be derived from a few general principles,,
was not of the opinion that life could be regulated according to
a few abstract principles. He was always more inclined to rely
on the natural instincts. As a passionate smoker he also re-
marked on that occasion: "If you take tobacco and everything
else away, what have you left ? Ill stick to my pipe."

He often had experiences that made it difficult for him to
maintain his equanimity. His naive joy in simple pleasures
such as smoking certainly helped him in these situations. Ascetic
instincts were foreign to him.

6. England

The report of the English astronomers to the Royal
Society in London in 1919 had laid the foundation for Einstein's
world fame. But Einstein himself had not yet been in London.
In 1919, in the postwar atmosphere of hostility to Germany, it
had indeed been possible to recognize the theory of a German,
but not to honor a German personally. Lord Haldane, who
had always worked for the improvement of Anglo-German re-
lations, had been in Berlin shortly before Einstein's arrival there,
but had received a cool reception from the Kaiser. Immediately
after the war and Germany's defeat, however, Haldane again
began to build up new cultural relations with Germany. Einstein
seemed to him to be a person who could serve as the thin
end of a wedge with which one could penetrate the mass of hos-
tility and prejudice. Many favorable factors seemed to be pres-
ent: the great acclaim that Einstein's prediction of the result of
the solar eclipse expeditions had produced; the opportunity for a
great achievement that had thus been presented to English sci-
ence; and finally, also, the favorable circumstance that Einstein
did not belong to the hated kind of German; indeed, if one so
desired, he could be regarded as a non-German. It thus seemed
almost as if Einstein had been specially created to act as an inter-
mediary. In addition, for Lord Haldane there was a very im-
portant personal factor. He was one of those English states-
men whose hobby was science combined with philosophical
speculation* Haldane had set himself the problem of how, de-

187

Einstein: His Life and Times

spite the skepticism that had become prevalent in religion, mor-
als, politics, and even science as a result of the disappointments
of the postwar period, one could still retain an objective con-
ception of truth. In his book The Reign of Relativity, published
in 19215 he pointed out that the views that skeptics regard as
different are actually only different aspects of the same truth
and that therefore a single objective truth exists. Or, in Hal-
dane's own words:

"The test of truth may have to be adequacy in a fuller form, a form
which is concerned not only with the result of measurement with the
balance or rule, but with value, that cannot be so measured and that
depends on other orders of thinking. What is truth from one stand-
point may not of necessity stand for truth from another. Relativity,
depending on the standard used, may intrude itself in varying forms.
... It may, therefore, be stated generally that an idea is true when
it is adequate, and only completely adequate when it is from every
point of view true. Each form of test that is applicable must be satis-
fied in the conception of perfect adequacy; for otherwise we can
have only truth that is relative to particular standpoints."

This philosophy found its practical application in a training
for tolerance toward one's fellow man and in the struggle against
the overestimation of political doctrines. In Einstein's theory
Haldane saw a special example of his own philosophy. He be-
lieved that the physical theory of relativity would invest his
philosophy of relativity with greater certainty and an increased
brilliance. Consequently Haldane endeavored to induce Einstein
to stop over in England for several days on his return from
America, to give several lectures there, and personally to meet
scientists and people in public life.

Not only were there political difficulties in the way of such
personal contacts, but the entire mental attitude of the English
physicists was not such as to make them very enthusiastic about
a theory like that of relativity. English science was always much
more intent upon the direct connection between experiment
and theory. A connection that consisted in such long chains of
thought as in Einstein's theory often appeared to the English
physicist to be a philosophical phantasm too much theory for
so few facts. In England philosophers, astronomers, mathemati-
cians, even theologians and politicians were passionately inter-
ested in the theory, but the physicists themselves were still rather
cool to "Relativity" as a basic concept.

Lord Haldane presided at Einstein's lecture at King's College.

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Travels through Europe., America, and Asia

He introduced the lecture by saying that it had been an ex-
tremely moving moment for him when Einstein laid a wreath
on Newton's grave in Westminster Abbey. "For," Haldane told
the audience, "what Newton was to the eighteenth century, Ein-
stein is for the twentieth."

In Haldane's house, where Einstein lived, he met many
famous Englishmen, like Lloyd George, Bernard Shaw and
A. N. Whitehead, the mathematician and philosopher, who had
so vividly sensed the historic significance of the session of the
Royal Society at which the result of the solar eclipse had been
announced. Whitehead had long discussions with Einstein and
repeatedly attempted to convince him that on metaphysical
grounds the attempt must be made to get along without the as-
sumption of a curvature of space. Einstein, however, was not in-
clined to give up a theory, against which neither logical nor
experimental reasons could be cited, nor considerations of sim-
plicity and beauty. Whitehead's metaphysics did not seem quite
plausible to him.

The Archbishop of Canterbury, the head of the Anglican
Church, was especially desirous of meeting Einstein. Lord Hal-
dane, who called attention everywhere to the philosophical sig-
nificance of the relativity theory, had told him that this theory
also has important consequences for theology and that as head
of the Anglican Church it was his duty to become acquainted
with it. Shortly thereafter, at the Athenaeum Club, a friend of
the Archbiship met J. J. Thomson, the physicist and president
of the Royal Society, and requested his help in a very important
matter. "The Archbishop, who is the most conscientious of men,
has procured several books on the subject of relativity and has
been trying to read them and they have driven him to what, it
is not too much to say, is a state of intellectual desperation. I
have read several of these myself and have drawn up a memo-
randum which I thought might be of service to him."

Thomson was surprised by these difficulties and said he did
not think that the relativity theory was so closely connected with
religion that the Archbishop had to know something about it.
Nevertheless, the conscientious head of the church was not satis-
fied, and when Einstein came to London and Lord Haldane ar-
ranged a dinner the Archbishop asked for an invitation. He was
placed as Einstein's neighbour and was able to hear whether
Haldane was right in his assertion that the theory of relativ-
ity is important for theology, or Thomson, who disputed it.
At dinner the Archbishop asked bluntly "what effect relativity

189

Einstein: His Life and Times

would have on religion." Einstein replied briefly and to the
point: "None. Relativity is a purely scientific matter and has
nothing to do with religion."

7, Einstein Tower and the Rathenau Murder

In June 1921, after visiting the United States and Eng-
land, Einstein returned to Berlin. The honors that he had re-
ceived abroad had their effect in Germany. Well-meaning per-
sons who were not really interested in science tried in every
possible way to learn about Einstein's theories without having to
exert themselves mentally. As a result some people profited from
this boom by convincing others that they could teach the rela-
tivity theory. At this time, for instance, a so-called "Einstein
film" was shown in movie theaters that was supposed to teach
the theory painlessly. First it showed a student listening to a
boring lecture by a dull professor and sighing: "How much
longer will this lecture last? Still another quarter of an hour?"
Then it showed the same student sitting on a bench in a garden
with a pretty girl, complaining: "I can only stay fifteen min-
utes more." This was supposed to teach the "relativity of time"
to the public. As we have seen, this has nothing to do with Ein-
stein's theory. Such popularizations, which distorted and made
the theory trivial, vexed Einstein more than the attacks on him.

In Berlin people also amused themselves with anecdotes from
England. For instance, an imaginary conversation between Ein-
stein and Bernard Shaw was described in which the skeptical
author asks: "Tell me, my dear Einstein, do you really under-
stand what you wrote?" And Einstein, smiling at him, replies:
"As much as you understand your things, dear Bernard."

At this time the desire for a short, easily comprehensible pres-
entation of the theory of relativity led an American who was
living in Paris and who had been impressed by the London re-
ports on the solar eclipse expeditions to offer a prize of five thou-
sand dollars for the best essay on Einstein's theory in not more
than three thousand words. Attracted by the remuneration of
five dollars for three words, many entered the contest, and, in-
deed, it was rather difficult to find judges, since everyone ac-
quainted with the subject preferred to enter the contest. Einstein
remarked playfully: "I am the only one in my entire circle of
friends who is not participating, I don't believe I have the ability

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to accomplish the task." On June 21, 1921, out of the three hun-
dred essays submitted, the prize was awarded to a sixty-one-year-
old Irishman, a native of Dublin, who like Einstein had been
employed in a patent office for a long time (in London), and
who was a dilettante in physics. It can hardly be said that his
essay was better than those of his competitors, nor did it have
any further influence in spreading an understanding of the rel-
ativity theory. The public remembered only the fact that some-
one had been able to earn five thousand dollars by means of it,
and concluded that it must therefore be worth the effort of
studying it.

In the fall of 1921 an important step was taken to investigate
another of the astronomical conclusions of Einstein's theory.
Dr. Bosch, the director of I. G. Farben, the greatest chemical
concern in Germany, that was outstanding in the production of
synthetic dyes, medicaments, and explosives, donated a large
sum of money for the erection at Potsdam of an institute to be
connected with the Astrophysical Observatory, where the color
composition of solar rays could be investigated with great pre-
cision. It will be recalled that from his theory of gravitation Ein-
stein had predicted that the color of light coming to us from
the stars depends on the intensity of the gravitational field
through which the rays pass. This prediction was to be verified
by exact observations.

The astronomer Erwin Finlay-Freundlich was appointed di-
rector of this institute. The laboratory was built in the form of
a tower and the architectural design was in the characteristic
modern Berlin style of that period, so that the result was a cross
between a New York skyscraper and an Egyptian pyramid. The
tower became generally known as the Einstein Tower. Its ap-
pearance alone was enough to excite the ire of the nationalistic
groups who preferred a style more reminiscent of German me-
dieval models or at least of classical antiquity.

Through a strange concatenation of circumstances, the Ein-
stein Tower was under the control of Friedrich Wilhelm Luden-
dorff, a brother of the famous general Ludendorff who for a
long time collaborated with Adolf Hitler. At that time the
astronomer Ludendorff still permitted the investigation of
solar light on the basis of Einstein's theory. He satisfied his
nationalistic sentiments by endeavoring to prove that Coperni-
cus was a German and not a Pole, even though his monument
stood in Warsaw.

On June 24, 1922 Walther Rathenau, then minister of foreign

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Einstein: His Life and Times

affairs, was murdered by several fanatical students. This murder
revealed the preparations for the revolution from the Right, and
even those who consciously or unconsciously ignored the back-
ground of this crime were compelled to take a more serious view
of the matter. The effect on Einstein was more intense than on
the general masses because through his insight and instinctive
perception it had become clear to him that sincere allegiance to
the German Republic was confined to a small group; beneath
it yawned a hate-filled abyss.

Einstein had been acquainted with Rathenau and had liked
this man whose breadth of vision was so rare among German
politicians. Rathenau, a descendant of a rich Jewish family in
Berlin, had been the motive force behind the planned economy
in Germany during the war. After the proclamation of the Re-
public, Rathenau had played an important part as an economic
adviser to the government, and through his international repu-
tation he had been able to perform various services in aid of its
foreign policy. During the government of the Catholic Chancel-
lor Wirth, Rathenau had accepted the position of Foreign Min-
ister and by concluding the Treaty of Rapallo had entered into
friendly relations with Soviet Russia. This treaty served to stamp
him as a "Bolshevik," and moreover, being a Jew, he had be-
come extremely unpopular with the monarchists and the advo-
cates of the "revolution from the Right."

The republican government ordered the day of Rathenau's
burial to be observed as a day of mourning and ordered all
schools and theaters to remain closed. At the universities lec-
tures were canceled, but Philipp Lenard, the Heidelburg physi-
cist who has already been mentioned as an opponent of Einstein,
refused to obey the order. While the Socialist workers marched
through the city and organized protest meetings against the
murderers and their reactionary supporters, Lenard demon-
stratively gave his regular lecture. A number of students who
sympathized with the assassins listened to him with enthusiasm.
A group of workers passing by the building saw the lecture
going on and, regarding this as a demonstration in favor of the
murderers, entered the building and dragged Lenard out with
them. As they passed over the Neckar River some of them at-
tempted to throw Lenard into the water, but the moderates pre-
vented them and turned him over to the police, who immedi-
ately released him.

In the eyes of all Germany these events linked the fight against
Einstein's theory with the struggle against the republican re-

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gime. Rumors began to spread that in the search for Rathenau's
murderers a list had been found containing the names of other
persons who were to be the future victims of the same group,
and the list was supposed to contain Einstein's name. The police
denied the rumors, but a feeling of uneasiness concerning Ein-
stein's person began to spread. Einstein himself, with his belief
in the inevitable in the universe, had no inclination for super-
stitious presentiments and fears and was not affected. But the
reaction on those about him was all the greater.
^ Every year the annual meeting of German scientists and phy-
sicians took place in September. This year a special celebration
was planned, as it was the centennial meeting. It was to be held
in Leipzig. Because during the past few years he had contributed
most to increase the prestige of German science throughout the
world, Einstein was invited as keynote speaker to emphasize
the special character of the occasion. He would have liked to
accept the invitation, but in the troubled and uneasy atmosphere
that prevailed after the Rathenau murder he did not wish to
make any public appearances and declined to participate. Nev-
ertheless, the executive committee of the society insisted on pre-
senting lectures by other scientists on the significance of Ein-
stein's theory, one by the physicist Max von Laue, the other by
the philosopher Moritz Schlick.

Because of the spreading sentiment in favor of violence, and
as a result of his own adventure as well, Lenard felt himself
compelled and encouraged to protest against the meeting of the
German scientists in Leipzig. In his opinion, by arranging for
lectures on Einstein's work, the society of German scientists was
carrying on propaganda against the revolutionists of the Right
and on behalf of the group to which the "justly" murdered
Rathenau belonged. Lenard assembled a group of people who
drew up a protest against the meeting of the German scientists,
which was sent to all the newspapers and distributed in Leipzig
at the doors of the lecture halls.

Lenard did not succeed, however, in inducing any of the
creative German physicists to sign his protest. Once again it was
only the same three types of persons who had taken part in the
meetings at the Berlin Philharmonic.

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Einstein: His Life and Times

8. France

Einstein's travels had contributed somewhat to im-
prove the relations between the scientists of Germany and those
of America and England. This was agreeable to the government
of the German Republic and to the German scientists, but was
very annoying to all those groups that endeavored to maintain
the idea that in western Europe the Germans were looked down
upon as an inferior nation and there was a desire to destroy their
culture. The effect of this "atrocity propaganda" was disturbed
by the reports of the friendly reception granted to Einstein. It
had long been discussed whether Einstein would now be bold
enough to visit Paris, the capital of Germany's "mortal enemy."
It had been rumored that scientific groups in France were try-
ing to induce Einstein to make such a visit, so as to be able to
discuss the new theories with him personally. They had also
been greatly admired in France, but many persons had found
it very difficult to understand them. Thus the French mathe-
matician Paul Painleve, who as Minister of War during the
World War, and later as Premier and President of the French
Chamber of Deputies, played a leading role in French politics,
was much interested in Einstein's work, but misinterpreted it
at many points and attacked it because of this misunderstand-
ing. Later he withdrew all his objections. The great French
physicist Paul Langevin, who immediately grasped the meaning
of the Einsteinian theories, once remarked to me: "Painleve
studied Einstein's work very closely, but unfortunately not until
after he had written about it. Perhaps he is used to this sequence
from politics."

Langevin was not only a sagacious scientist but also an active
participant in every enterprise intended to advance international
conciliation. At the College de France, the highest scientific
school in France, he presented a resolution to invite Einstein
to come to Paris. For this purpose he proposed to use the income
of an endowment that had been employed to invite other out-
standing foreign scientists to lecture at this institution. The
resolution was warmly supported by Painleve. There was some
opposition, however. The nationalists did not want the recep-
tion of a German scientist to arouse an impression that any
diminution of their hatred was possible. With all sorts of threats
they tried to induce Langevin and his friends not to extend the

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invitation, just as the analogous groups in Germany attempted
to force Einstein to reject it. At that time, however, neither of
these two groups was yet strong enough to achieve its aim. Ein-
stein accepted die invitation extended by the College de France,
and toward the end of March 1922 he went to Paris.

Langevin, the physicist, and the astronomer Charles Nord-
mann went ahead to Jeumont on the Belgian border to meet
Einstein and traveled with him to Paris. During the trip they
discussed the scientific and political questions connected with
this visit. In the course of this conversation they asked Einstein
for his opinion on the aims and influence of the Left in German
political and cultural life. 'Well," replied Einstein, "what is
superficially called the Left is actually a multidimensional struc-
ture." Einstein already felt that the roads to the Right and to
the Left might occasionally lead to the same end.

Throughout the entire trip Langevin was rather worried. Be-
fore his departure from Paris it had been rumored that groups
of the "Patriotic Youth" and other nationalistic groups would
gather at the station and give Einstein an unfriendly reception.
Both Langevin and the French officials did not want any dis-
turbances of this kind to spoil Einstein's visit. While on their
way, Langevin asked for information about the situation in
Paris. He received a telegram from the Paris police informing
him that groups of excited young people were gathering at the
Gare du Nord, where the trains from Belgium arrived. Since
it was believed that they were the "patriots," Langevin was ad-
vised to leave the train with Einstein on a sidetrack where no
one expected him. They did so, and Einstein was quite happy to
be able to slip away from the train through a side entrance of
the station into the street without being bothered by reporters
or cameramen^ and to ride in the subway to his hotel unnoticed
by anyone.

At the Gare du Nord, however, a crowd of students who had
gathered under the leadership of Langevin's son to give Ein-
stein an enthusiastic reception and to prevent possible hostile
demonstrations by the "patriots," waited in vain for his arrival.
It was these admirers of Einstein whom the police had regarded
as a hostile crowd, and it was from them that Einstein had fled.

On March 31 Einstein gave his first lecture at the College de
France. Only people with tickets were admitted, the tickets hav-
ing been given only to persons who were known to have an
actual interest in the subject and who would not attend simply
to organize a hostile demonstration. Former Premier Painleve

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Einstein: His Life and Times

stood at the door himself and watched to check that only people
with invitations were admitted.

Einstein spoke in the hall where great philosophers such as
Ernst Renan and Henri Bergson had lectured before large audi-
ences. Here it was easier than in England and America for him
to come into contact with his audience, since he spoke French
fluently and confidently, but with a slowness to which the
French were unaccustomed and which together with his slight
foreign accent gave his speech a certain charm and attractive-
ness the charm of pensiveness combined with a trace of mys-
tery. This slight trace of mystery contrasted with the evident
effort to present everything as logically and clearly as possible,
using as few technical expressions and as many metaphorical
comparisons as possible. Many internationally known scholars
and persons in public life attended the lecture, among them
Madame Curie, the discoverer of radium, the great philosopher
Henri Bergson, Prince Roland Bonaparte, and many others.

Besides this public lecture there were sessions of the philo-
sophical and mathematical society for scientists who wanted a de-
tailed discussion where everyone could put questions to Einstein
and raise all kinds of objections. Einstein answered every ques-
tion thoroughly and many misunderstandings were cleared up.

It was very strange that the Society of French Physicists did
not take part officially in any of these arrangements even though
many of its members naturally met Einstein. This attitude was
determined chiefly by its nationalistic tendencies, which, it
seems, are stronger among physicists and technicians, than
among the more abstractly thinking mathematicians, astron-
omers, and scientific philosophers.

As in Germany, a certain resistance among the "pure" experi-
mental physicists may also have been involved. In France there
were also "pure empiricists," the kind of physicists about whom
Einstein often remarked: "Everything that they learned up to
the age of eighteen is believed to be experience. Whatever they
hear about later is theory and speculation."

The famous Academy, which had been attacked and ridiculed
for years in French literature as a center of all kinds of preju-
dices, likewise maintained its reputation on the occasion of Ein-
stein's visit. There were long discussions whether Einstein
should or could be invited to give a lecture. Some members
maintained that it was impossible because Germany was not a
member of the League of Nations, Others, in turn, thought that
such an invitation would give rise to a difficult question of

196

Travels through Europe, America, and Asia

etiquette. Since Einstein was not a member of the Academy, lie
could not sit among the members, but would have to sit in the
audience. Such an unhonorable seat, however, could not be of-
fered to so famous a man. Finally thirty members of the Acad-
emy stated very bluntly, without any subtle phraseology, that if
Einstein entered the room, they would immediately leave. In
order to spare his French friends any unpleasantness and annoy-
ance, Einstein himself declined to participate in a session of the
Academy.

On this occasion a Paris newspaper inquired derisively: "If a
German were to discover a remedy for cancer or tuberculosis,
would these thirty academicians have to wait for the application
of the remedy until Germany joined the League?"

The reception in Paris had shown that the need for an under-
standing of the modes of thought and methods of work of dif-
ferent peoples and individuals existed among scientists in all
countries, and could be satisfied if there were a few courageous
men. It also became clear that everywhere the forces of ultra-
nationalism waited only for a suitable occasion in order to ap-
pear on the surface. In order to be able to judge these events
correctly one circumstance must not be forgotten. Exactly the
same groups that protested violently against the reception of
Einstein because he was a German became the most zealous
proponents of a policy of "collaboration" with Germany after
the Nazis had seized the power there. These French "patriots"
prepared the French defeat of 1940 and the German domination
of the Continent.

In France just as in Germany it was evident that the atti-
tudes of people to Einstein depended greatly on their political
sympathies, since most of them made no serious effort to form
an opinion about his theories. A famous historian at the Sor-
bonne put it as follows: "I don't understand Einstein's equa-
tions. All I know is that the Dreyfus adherents claim that he
is a genius, while the Dreyfus opponents say he is an ass."
Dreyfus was a captain in the French army who in 1894 had
been accused of treason by anti-Jewish propagandists. The
affair developed into a struggle between the Republic and its
enemies, and the entire country was divided into two camps,
the defenders of Dreyfus and their opponents. "And the re-
markable thing," added this historian, "is that although the
Dreyfus affair has long been forgotten, the same groups line
up and face each other at the slightest provocation."

In Germany the republican government was attacked because

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Einstein: His Life and Times

it had allowed Einstein to go to Paris and "overtures" to be
made to the French; and in France the mathematicians and
philosophers were attacked because they wanted to listen to one
"whose people killed our sons." And when Einstein returned
to Berlin and attended the first session of the Prussian Academy
again, quite a few of the seats around him were empty.

9. China, Japan, Palestine, and Spain

After these journeys to England and France, where his
stay was always bound up with political tensions and where
it was really impossible to enjoy the new experiences, it was a
relief for Einstein to travel to the countries of the Far East, to
experience the varied impressions made upon him, and like a
child at play to enjoy the variety of the world without having
to consider constantly whether or not national sensibilities at
home or abroad were being insulted.

Einstein arrived in Shanghai on November 15, 1922 and in
Kobe, Japan, on November 20. He remained in Japan until
February, when he sailed for Europe.

He was honored everywhere not only as a scientist, but also
as a representative of Germany. In Shanghai he was greeted at
the pier by the teachers and pupils of the German school, who
sang Deutschland, Deutschland uber dies. In Japan he was re-
ceived personally by the Empress, who conversed with him in
French.

When I once asked Einstein whether he had not experienced
many strange things in his travels through these picturesque
and exotic countries, he replied: "I have seen strange things
only in my homeland for instance, at the sessions of the Prus-
sian Academy of Science."

The Orientals the Hindus, the Chinese, the Japanese
with their calmness, meditativeness, and politeness, enchanted
Einstein. Their liking for moderation and beauty was for him
a true relaxation after the exaggerated glorifications and ani-
mosities he had experienced in his own country and its imme-
diate neighbors.

With his preference for the music of Mozart, Bach, and the
old Italian masters, Oriental music necessarily appeared very
strange to him. He was unable to discover anything enjoyable
in it. He was impressed, however, by the love for art, that makes

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Travels through Europe, America, and Asm

Japanese families often spend a good part of the day in the
theater listening to the music, bringing their food with them
and not stirring from the spot.

In certain respects it was a similar attitude when hundreds
of Japanese listened patiently to Einstein's lectures without un-
derstanding even the language in which he spoke, let alone the
content. One time Einstein observed that his lecture, together
with the added Japanese translation, lasted more than four
hours. He was shocked by this fact, because he pitied the people
who listened so long and patiently to him, most of them with-
out understanding much of what he said. When he gave his
next lecture he shortened it so that it lasted only two and a half
hours. While riding in the train to the next city, he noticed
that his Japanese companions were whispering to each other in
Japanese, looking at him, and then whispering again. Einstein
began to feel uneasy, because such behavior was quite unusual
in view of the politeness of the Japanese. Finally Einstein said
to one of his companions: "Please tell me quite frankly if there
is something amiss." Thereupon the polite Japanese answered
with embarrassment: "We did not dare to say anything to you
about it, but the persons who arranged the second lecture were
insulted because it did not last four hours like the first one.
They considered it as a slight."

On his way back, Einstein visited Palestine. For him this land
was in a different category from China or Japan. Here he was
unable to be simply an unparticipating observer, viewing the
varied scenery as a pleasant relaxation from his work. Here he
was to experience tensions that were both pleasant and un-
pleasant, because Einstein himself had carried on propaganda
for the development of a Jewish national home in Palestine and
to a certain degree felt himself responsible for it. Naturally,
however, many things were not carried out as he would have
desired, with the result that many people held him responsible
for things with which he himself was not in sympathy. Ein-
stein's collaboration in the development of Palestine was always
directed only toward the advancement of the main goal, which
he regarded as desirable. Of the concrete details of this develop-
ment, only very few could be attributed to his suggestions. Con-
sequently he was curious to see the actual appearance of what
until then had been only a more or less vague dream.

As one of the most prominent advocates of Jewish coloniza-
tion and as one of the outstanding personalities among the Jews
throughout the world, he was received in Palestine, even more

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Einstein: His Life and Times

than in other countries, as a public figure. He was invited by
the Governor of Palestine to live at his house. The Governor
at this time was Viscount Herbert Samuel, a man who had al-
ready acquired a reputation in English domestic politics. He
was himself a Jew, a fact that the English government appar-
ently considered a particularly appropriate manifestation of its
friendly attitude toward the development of the Jewish national
home. In practice, however, things did not work out so well.
The position of a Jewish governor was particularly difficult in
the face of the growing controversies between the Jews and
Arabs. Daily he had to prove the absolute impartiality of the
English government in this conflict. Since he himself was a
Jew, it was only natural to attribute to him a certain bias in
favor of the Jews, so that he had to compensate for this by
leaning over backward in favor of the Arabs, with the result
that in the end he discriminated against the Jews. He could not
help making himself generally unpopular.

Like Lord Haldane, Viscount Herbert Samuel was one of
those English statesmen whose hobby was to occupy themselves
with science, especially with the philosophy of science. Like
Haldane he too had a strong personal interest in the relativity
theory. As regards its philosophical interpretation, Herbert Sam-
uel's views were opposed to those of Einstein and were more
along the lines of traditional philosophy.

In the land, which was regarded more or less as a colony, an
English governor had to present an imposing front in order to
keep the "natives," including both Jews and Arabs, obedient and
respectful. When he left his palatial residence a cannon was
fired, and when he rode through the city he was accompanied
by mounted troops. Within his residence there prevailed a cere-
monial formality reminiscent of the ceremonial practices at the
English court* It was necessary to arouse in the "natives" a
sense of awe in the presence of the direct representative of the
King. Einstein did not pay too much attention to all this. He
was as simple and natural as anywhere else. Mrs. Einstein, how-
ever, felt rather uneasy. She said later: "I am a simple German
housewife; I like things to be cozy and comfortable and I feel
unhappy in such a formal atmosphere. For my husband it is a
different matter; he is a famous man. When he commits a breach
of etiquette, it is said that he does so because he is a man of gen-
ius. In my case, however, it is attributed to a lack of culture."
Sometimes, to avoid the difficulties of etiquette and ceremonial,
she went to bed.

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Travels through Europe, America, and Asia

Einstein studied with, the greatest interest the work of the
Jews in developing an independent national life. He saw the
new Jewish city of Tel-Aviv. In Europe the Jews usually be-
longed to only one particular class of the population; they were
often persecuted by other classes, who represented the work
performed by the Jews as being especially easy or particularly
obnoxious. Tel-Aviv, however, was a city in which all work was
done by Jews. Here they could not so easily acquire the feeling
of occupying an abnormal position as an ethnic and economic
group.

Nevertheless, Einstein also saw the difficulties of the Jewish
situation above all, the unsatisfactory relations with the Arabs.
He was not enough of a national partisan to do what so many
others did that is, simply put the blame on the ingratitude of
the Arabs and the insufficient support of the Jews by England.
He demanded on the part of the Jews an effort to understand
the cultural life of the Arabs and to make friends with them.

For this reason not all the Zionist groups welcomed Einstein.
The extreme nationalists looked upon him just as suspiciously
as the adherents of Jewish religious orthodoxy. The latter took
it a little amiss that he did not consider the observance of the an-
cient rites important and that occasionally he even ventured a
joke.

In March 1923 Einstein returned from Palestine by boat to
Marseille. Thence he traveled to Spain, whose landscape and
art were always a source of joy to him. Just as he had conversed
with the Empress of Japan, so Einstein also had a conversation
with King Alfonso XIII of Spain. Thus he not only saw strange
lands and cities, but also obtained a personal impression of a
class of people that usually remains unknown to scientists. Ein-
stein, who always retained something of the curiosity of an in-
telligent child gathered new strength for his creative work from
all these experiences. Everything seemed to him like a dream,
and he sometimes remarked to his wife: "Let us enjoy every-
thing, before we awake,"

10. Nobel Prize, Alleged Trip to Russia

On November 10, 1922, while Einstein was on his trip
to the Orient, the committee of the Swedish Academy of Sci-
ence awarded him the Nobel prize for physics. Although he had

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Einstein: His Life and Times

long been recognized as one of the greatest physicists of his
time, it had taken rather a long while for the committee to de-
cide to award him the prize. In establishing the endowments,
Alfred Nobel had stipulated that the prize should be awarded
for a recent discovery in physics from which mankind had de-
rived a great use. No one was sure whether Einstein's theory of
relativity was a "discovery." Originally, it did not assert new
phenomena, but was rather a principle from which many facts
could be derived more simply than formerly. Furthermore,
whether this discovery was of any great use to mankind was
naturally a matter of personal opinion. After Einstein's theory
became an object of so many attacks and was even linked to
political controversies, the Swedish Academy thought that it
should be cautious and not award the prize to Einstein for a
while. After the explosion of the atomic bomb in 1945, the
Academy apparently recognized the great use to mankind of
Einstein's theory of relativity, as it quickly awarded the prize
to O. Hahn, the discoverer of the uranium fission.

Toward the end of 1922, however, the Academy thought of
a clever expedient by which it could award the prize to Einstein
without having to take a stand on his relativity theory. It
awarded the prize to Einstein for his work in "quantum theory"
(see Chapters III and IV). This work had not been so hotly de-
bated as the theory of relativity. But in it "facts were discovered"
'that is, statements were advanced from which observable
phenomena could be deduced by means of few conclusions. In
the case of the theory of relativity this train of reasoning was
much longer. This subtle distinction, however, authorized the
Academy in the case of the photoelectric and photochemical law
to speak of a "discovered fact," while it would not do so in the
case of the relativity theory. By this expedient the Academy suc-
ceeded to avoid the expression of any opinion about the contro-
versial theory of relativity. The statement of the award was
couched in very general terms: "The prize is awarded to Ein-
stein for the photoelectric law and his work in the field of theo-
retical physics."

As soon as Einstein's enemies heard of this, they began to as-
sert with greater vehemence than ever before that there was
something peculiar about the entire business. Einstein, they said,
received the prize for a discovery that was not important enough
to justify such a reward. Early in 1923 his old enemy Lenard
wrote a letter to the Swedish Academy in which he branded the

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Travels through Europe, America, and Asia

entire action as an attempt "to restore Einstein's lost prestige
without compromising the Academy itself."

In July 1923, when he received the award, Einstein lectured
at a meeting of Scandinavian scientists at Goteborg, which was
attended by the King of Sweden.

Since the public, especially in Germany, carefully followed
everything that Einstein did, some with enthusiasm, others with
suspicion and hatred, the following report, which appeared on
September 15 in the Deutsche Allgemeine Zeitung, a paper for
the more educated and wealthier nationalistic groups, could not
but arouse great excitement, and in some people even anger and
indignation:

"From Moscow we learn that Professor Einstein is expected there
at the end of September. He will speak there on the theory of rela-
tivity. Russian scientists are looking forward to the lecture with great
interest. In 1920 Einstein's writings were brought to Russia by plane,
immediately translated, and appeared among the first works of the
Bolshevist state press."

It must be kept in mind that in Germany Einstein's relativity
theory had been characterized as "Bolshevism in physics," that
many people believed in a Jewish conspiracy in which Einstein
and Rathenau had participated, and finally that Rathenau had
concluded the treaty of friendship with Soviet Russia. At that
time the alliance with Soviet Russia was not yet regarded by the
German nationalists as a particularly shrewd move in foreign
policy intended to serve the national interests of Germany, but
rather as a betrayal of the German people. Hence it is not sur-
prising that many persons saw Einstein's reported trip as an in-
dication of his participation in a Bolshevist conspiracy against
Germany, and spread all kinds of rumors about it.

On October 6 the democratic Berliner Tageblatt reported:
"Professor Einstein has left for Moscow. ... In Moscow prep-
arations are being made to give the famous German scientist
an imposing welcome."

On October 27 the nationalistic Berliner Eorsenzeitung re-
ported: "The Soviet Russian press reports that Einstein is arriv-
ing in Petersburg on October 28 and will speak on the relativity
theory to a group of scientifically trained workers."

On November 2 the Kieler Zeitung reported: "Einstein is
staying in Petersburg for three days."

In the middle of November, when it was believed that Ein-

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Einstein: His Life and Times

stein had returned from Russia, he received many threatening
letters in which nationalistic fanatics threatened that he would
be "executed" like Rathenau, if he continued his conspiracies
with the Bolsheviks. The remarkable thing about all this, how-
ever, is that Einstein has never been in Russia, either then or
at any other time in his life. His journeys to France and Eng-
land had frequently been taken amiss and had produced a great
deal of unpleasantness for him in Germany. Evidently it was of
no avail even to avoid such unpopular trips if one once had be-
come the target of hate-filled agitators.

For Einstein the end of 1923 was the end of a period of jour-
neys throughout the world as a messenger of international un-
derstanding and as a symbol of an omnipresent interest in the
most general questions regarding the nature of the universe. In
1925 he made a trip to South America, but in general he spent
the following years in Berlin.

204

IX

DEVELOPMENT OF ATOMIC PHYSICS

i. Einstein as a Teacher in Berlin

In 1924, after Ms many journeys, Einstein settled down
again in Berlin. The transition from lecturing in different coun-
tries in different languages to people with various intellectual
training back to regular teaching of physics was not entirely a
smooth one. Since he was not required to give a regular course
of lectures., he preferred to give lectures of two extremely di-
vergent types. On the one hand, he liked to speak before an
audience of educated laymen to which he could explain the gen-
eral scientific principles as simply and clearly as possible, seeking
to give his listeners a vivid picture of the general trends in the
development of scientific thought. On the other hand, he also
liked to give highly technical lectures on the problems with
which he was concerned at the moment, before an audience of
very advanced students.

Then, too, his world fame attracted many foreigners visiting
Berlin. Their lists of sights to be seen there included, together
with the Brandenburg Gate with its goddess of victory, the
Siegesallee with its statues of Prussian princes, and the theatri-
cal productions of Reinhardt, the famous Einstein. Many who
did not even know whether he was a physicist, mathematician,
philosopher, or dreamer came to listen to his lectures. On occa-
sions when these sightseers were unusually numerous, Einstein
would say: "Now I shall stop for a few minutes so that all those
who have no further interest can leave." Usually only eight or
ten students would remain, and then Einstein was happy to be
able to talk about the things closest to his heart without being
disturbed by the sight of faces devoid of any understanding.

Such lectures were not easy to follow even for students in-
tending to become physicists. Even the brighter ones generally
expected that Einstein would drum into their heads in a form
adapted for students the famous discoveries that he had pre-
sented in his writings and about which everyone spoke. Ein-
stein, however, was not much interested any longer in researches

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Einstein: His Life and Times

that had been concluded and published. He was always looking
for the solutions o new problems, and students who were will-
ing and able to think about these difficult problems independ-
ently were few and far between even in such a large center of
learning as Berlin.

As I already mentioned, Einstein was at first skeptical about
the use of very advanced mathematics in developing physical
theories. When in 1908 Minkowski showed that Einstein's spe-
cial theory of relativity could be formulated very simply in the
language of four-dimensional geometry, Einstein had regarded
this as the introduction of an involved formalism by which it
became rather more difficult to grasp the actual physical content
of the theory. When Max von Laue, in the first comprehensive
book on Einstein's relativity theory, presented it in a very elegant
mathematical form, Einstein remarked at that time jokingly: "I
myself can hardly understand Laue's book."

The center of German mathematical teaching and research
during this period was the University of Gottingen. Minkowski
taught there, and the mathematical formulation of the relativity
theory had begun there. Einstein once remarked playfully: "The
people in Gottingen sometimes strike me, not as if they wanted
to help one formulate something clearly, but instead as if they
wanted only to show us physicists how much brighter they are
than we." Nevertheless, the greatest mathematician in Got-
tingen, David Hilbert, realized that while Einstein did not care
for superfluous formal difficulties in mathematics., he did know
how to use mathematics where it was indicated. Hilbert once
said : "Every boy in the streets of our mathematical Gottingen
understands more about four-dimensional geometry than Ein-
stein. Yet, despite that, Einstein did the work and not the math-
ematicians." And he once asked a gathering of mathematicians:
"Do you know why Einstein said the most original and pro-
found things about space and time that have been said in our
generation ? Because he had learned nothing about all the phi-
losophy and mathematics of time and space."

In his general theory of relativity, however, Einstein had had
to resort to the use of a branch of advanced mathematics called
"tensor analysis" in order to give an adequate description of
physical phenomena in four dimensional non-Euclidean space.
With the complication in the calculations that this entailed, Ein-
stein began to find the need for an assistant who was well
trained in mathematics. For this purpose Einstein preferred
young people who had a scientific education and ambition, but

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Development of Atomic Physics

who because of external circumstances were unable to get a
job at a public institution. Thus one of his first assistants In
Berlin was a Russian Jew who suffered from a pathological en-
largement of his bones (leontiasis) and as a result made such
a repulsive impression on people that no one wanted to engage
him as an assistant., let alone as a teacher. In time the young
man understandably wanted to advance to an independent po-
sition. He expected Einstein to get him a position as teacher in
a school although it was obvious that with his unfortunate ap-
pearance no school would hire him. Nevertheless he blamed
Einstein for not trying hard enough and finally quarreled with
him.

It was not easy for Einstein to find a suitable assistant. This
may appear strange, but there were reasons for it. Students who
wanted to study physics could wish for no better opportunity
than to watch and help a man like Einstein at his creative work,
and to this was added the pleasure of being in contact with a
man with a very interesting personality, who was extremely
friendly and adept In the art of conversation* But in large meas-
ure Einstein's trouble was due to the fact that he did not carry
on any ordinary teaching in Berlin. The students at the uni-
versity who were working toward the doctorate or to pass
examinations as physics teachers were busy enough trying to sat-
isfy all the demands made on them. They studied with the pro-
fessors at the university who gave the examinations, and re-
ceived from them the subjects for their doctoral dissertations.
Only rarely did one of them come into personal contact with
Einstein. As a result Einstein usually had as assistants students
from outside Germany. These foreigners did not come to Berlin
to pass examinations or to find positions, but to learn from the
outstanding scientists there. They immediately turned to men
like Planck, Nernst, or Einstein. In this way Einstein had as
collaborators first the aforementioned Russian and later the
Hungarian Cornelius Lanczos and the Austrian Walter Mayer.
The last two were of great help to Einstein, and published val-
uable contributions to the general theory of relativity. They are
now both teaching in American institutions.

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Einstein: His Life and Times

2. Structure of the Atom

The world believed that Einstein's theory of relativity
was the oddest and the most radical change in physics that had
occurred for a long time. Actually new conceptions of matter
even more baffling and far-reaching In their effects were being
developed simultaneously.

In 1905, while still at Bern, Einstein had made outstanding
contributions to the structure of light, as described in Section 10
of Chapter III. Since then he had turned his attention to his
theories of relativity and gravitation, which dealt mainly with
large objects such as stars and planets and not with the ultimate
particle of nature the atom. He had considered properties of
light rays in gravitational fields, but in these cases it had made
no difference whether light was simply a wave phenomenon or
consisted of a stream of photons.

Einstein himself had realized in 1905 when he proposed the
idea of light quanta (photons) that it was only a provisional
hypothesis. Numerous difficulties had remained unsolved. For
instance, the theory of the photon had had amazing success in
explaining properties of heat radiation and the photoelectric
effect, but it could not explain the whole set of phenomena
dealing with the interference and diffraction of light. On the
other hand, the wave theory, which could cope with these latter
properties, was useless for those phenomena for which the pho-
ton theory was successful

In conversation Einstein expressed this dual character of light
as follows: "Somewhere in the continuous light waves there
are certain 'peas,' the light quanta." The amplitude of the
waves determines how many "peas" are present at any spot,
but only as a statistical average. One can never know whether
such a "pea 55 will be present at a particular point at a specific
instant of time. From the beginning Einstein thought that
this could not be the ultimate truth. "I shall never believe,"
he once said, "that God plays dice with the world." Neverthe-
less, "God's dice" penetrated into physics at several points. For
instance, in the disintegration of radioactive substances a cer-
tain percentage of the atoms present disintegrate every second,
but there is no way by which we can tell which particular atom
will disintegrate in the next second.

But Einstein's early suggestion of "photons (light quanta) in

208

Development of Atomic Physics

every light ray" had fallen on fertile soil. The "heuristic point
of view" turned out to stimulate actually new discoveries. In
1913 the Danish physicist Niels Bohr attempted to correlate
the structure of atoms with the light emitted by them. Ruther-
ford in England had shown in 1911 that the atom consists of
a central nucleus with positive charge and a number of nega-
tively charged electrons around it Also it had been known for
a long time that free atoms, unlike glowing solid bodies that
emit light with continuous distribution of different color s, emit
light of only certain definite frequencies which are characteristic
of the atom. In trying to explain this unique character of light
emitted by free atoms Bohr found that it was completely impos-
sible if he assumed that the electrons circulate around the nu-
cleus according to Newton's laws of motion in the same way
that the planets revolve around the sun. He was thus led to
setting up a separate hypothesis, with which he modified New-
ton's laws in much the same way that Planck had done in ex-
plaining properties of heat radiation. Bohr assumed that only
certain discrete sets of circular orbits (preferred orbits) were al-
lowed for the electrons moving around the nucleus. Electrons
in different orbits had different energies, and when an electron
jumped from one of higher to one of lower energy, the differ-
ence in energy was emitted in the form of a light quantum
(photon). This concept of emission of photons may be consid-
ered as a sort of inversion of Einstein's photoelectric law, in
which a photon is absorbed and an electron liberated. But here
again, as in the case of radioactive atoms, only the average be-
havior of the atoms, and nothing of individual cases, could be
predicted. At first this deficiency did not cause much concern.
It was thought that the behavior of the atoms was not unlike the
mortality statistics of life-insurance companies, from which the
average life expectancy of man can be predicted accurately, but
not that of individuals. Nevertheless every single death has its
cause. The physicists believed then that similarily causes exist
for the behavior of the individual atoms, but that they are as yet
unknown.

3. Mechanics of the Atom

The feeling that God did not play dice for the fate of
the world began to be shaken about the time Einstein settled

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Einstein: His Life and Times

down in Berlin after his trips. In 1924 Prince Louis de Broglie,
a graduate student in Paris, submitted a doctoral thesis to Pro-
fessor Langevin in which he proposed even greater changes in
Newtonian mechanics than Einstein had done in his theory of
relativity. Langevin, who was well known as a radical in poli-
tics,, was staggered by the boldness of the new proposals. De
Broglie's work seemed fairly absurd to him, but considering that
the idea of Bohr's "preferred" orbits was also very baffling, he
thought there might be something in his student's thesis.

De Broglie had noted that Einstein's "heuristic point of view"
in optics had been helpful by attributing to light properties that
are usually ascribed to material particles; namely, energy and
momentum of photons. De Broglie took his cue from Einstein
and introduced an analogous "heuristic viewpoint" into mechan-
ics. To resolve the difficulties in the description of the motion
of subatomic particles (particles within the atom) de Brog-
lie suggested that certain wave properties be attributed to parti-
cles. He assumed that, just as the motion of photons in a light
ray is determined by the electromagnetic field that constitutes
the light wave, so the motion of particles is guided or "steered"
by a new type of waves, called "matter waves" by de Broglie
and < de Broglie waves" by other physicists. According to this
view, the "preferred" orbits of Bohr are orbits along which the
de Broglie waves are built up by interference, while along all
other orbits the waves are annihilated by interference. This
phenomenon is exactly analogous to the interference patterns of
light passing a small hole where there are light and dark regions
depending on whether light falling on the regions from differ-
ent directions builds up or interferes. De Broglie waves, how-
ever, have wave lengths inversely proportional to the momen-
tum of the particles, and manifest themselves only in the case of
very small masses, in particular in the case of subatomic parti-
cles. For any ordinary body like a billiard ball, the wave length
is so small that it has no observable wave property.

Two years later Erwin Schrodinger, an Austrian, developed
on the basis of de Broglie's idea a new mechanics of the atom ac-
cording to which the motion of atomic particles could be calcu-
lated for any field of force. In Bohr's theory of the atom New-
tonian laws and arbitrary assumptions (preferred orbits) are
mixed to give satisfactory results. Schrodinger, however, ob-
tained the same results by means of a coherent theory.

Originally de Broglie and Schrodinger had assumed that the
connection between the particles and the "steering" waves by

210

A recent portrait of Einstein

Development of Atomic Physics

which the motion of these particles was directed was a strictly
"causal" connection. But in 1926 the German physicists Max
Born and P. Jordan interpreted the intensity of de Broglie waves
as the average number of particles situated in a unit volume of
space. The relation between the intensity of matter waves and
the number of particles is thus exactly the same as that between
the intensity of light and the number of Einstein's photons.

This theory, developed by de Broglie, Schrodinger, and Born,
by means of which not the position itself but only the average
position of atomic particles could be calculated, began to be
known as wave mechanics, so named appropriately since it
laid stress on the wave property of material particles. By this
theory future observable events cannot be predicted precisely,
but only statistically. For example, we cannot predict the exact
point where a particle or photon will hit a screen, but only what
percentage of incoming protons or particles will hit within any
given region of the screen. If science could not advance beyond
this stage, "God would/* as Einstein said, "play dice indeed."

The idea that there are waves associated with material parti-
cles received a striking experimental verification. In 1927 two
Americans, Clinton J. Davisson and L. H. Germer, proved that
a beam of electrons is diffracted by a metal crystal in exactly the
same way that light is diffracted by a grating, and X-rays by
crystals. This confirmation is all the more amazing since diffrac-
tion is a phenomenon that is purely characteristic of waves, and
nobody had ever even dreamed that it could be caused by ma-
terial particles such as the electron until de Broglie suggested
and Davisson and Germer actually observed it. Moreover, the
wave length associated with the electrons, which could be cal-
culated from the size of the diffraction pattern, agreed exactly
with the value predicted by de Broglie.

At about the same time, W. Heisenberg, a young German,
approached the interaction between subatomic particles and
radiation from another direction. He broke away completely
from the fundamental notion in Newtonian mechanics that
a particle changes its location continuously and can thus be
pursued.

Einstein in his general theory of relativity started from
"Mach's requirement" that a physical theory should lead eventu-
ally to relations between quantities that can actually be meas-
ured. Accordingly, "absolute motion" was replaced by "motion
relative to material bodies." Heisenberg started similarly. He
abandoned the computation of the exact motions of electrons in

211

Einstein: His Life and Times

an atom. For the laws of nature are such that it is impossible to
determine the path of electrons by any measurement. The only
properties of an atom that are accessible to actual measurement
are the intensity and frequency of the emitted radiation. There-
fore Heisenberg suggested to formulate the basic laws govern-
ing subatomic phenomena in terms of intensity and frequency
of radiation. This suggestion implies a radical break with mech-
anistic physics, which uses "position and velocity of particles"
as the basic concepts occurring in the fundamental laws of
nature.

If we accept Heisenberg's suggestion, subatomic particles
(like electrons or photons) are no longer "full-fledged particles"
in the Newtonian sense, as their behavior cannot be described
in the Newtonian way. But they are physical objects possessing
some of the properties of particles.

This aproach to the theory of atoms has come to be known as
quantum mechanics. It received a logically more satisfying form
when Heisenberg went to Copenhagen and collaborated with
Niels Bohr.

4. Bohr's Complementarity Principle

According to Bohr, it was not advisable to throw over-
board completely the motion of particles as the basis of a descrip-
tion of subatomic phenomena. The presentation in terms of the
observable intensity and frequency of radiation, as originally
suggested by Heisenberg, should be replaced by a restricted or
qualified use of the "moving particle" as the principal means
of description. Heisenberg had certainly proved his point that
the motion of atomic particles cannot be described in the New-
tonian sense. According to Newton, once the forces that act on
a particle and its initial position and momentum are given, its
subsequent position and momentum at any instant can be cal-
culated with any desired precision. Heisenberg discovered that
this is not true of subatomic particles. There are no laws which
connect the position and the momentum of such a particle in
one instant of time with the values of these quantities at a future
instant. The laws have in this domain a different character. If
the initial position and momentum of a particle of very small
mass (a subatomic particle) are known within a certain margin,
the position at a future instant can be computed within a cer-

212

Development of Atomic Physics

tain margin. By making the initial margin sufficiently narrow,
however, we cannot achieve, as in Newton's mechanics, a final
margin as narrow as we desire. In other words, if we want to
hit a definite point of a target, we cannot be sure to achieve the
desired result even if we aim very accurately. If we want to hit
our target point at least within a reasonable margin, we have to
consider that according to Heisenberg there is a definite relation
between the initial margins of position and momentum: the
product of these two margins has to equal a definite quantity,
which is, roughly speaking, Planck's constant h. This relation
has become famous under the name of "Heisenberg's relation of
indeterminacy."

Soon afterward Bohr gave a more satisfactory interpretation
of this strange behavior of atomic particles. He pointed out that
"position" and "momentum" are two different aspects of a small
mass (e.g., an electron) in much the same way that the particle
properties and wave properties are two aspects of the photon. To
say that a particle is located in a certain limited region of space is
exactly analogous to the statement that light-energy is concen-
trated in a photon, and to define the momentum of a particle is
analogous to the emphasis on the wave aspect of light. Both ma-
terial particles and light have the dual characteristics of particles
and waves, but their behavior is neither contradictory nor hap-
hazard. Bohr emphasized again "Mach's requirement" that we
should make only such statements as can be tested by definite
physical experiments. According to him, it depends solely on the
specific arrangement of apparatus used whether the emission
of light and of electrons has to be described as a wave or as a
beam of moving particles. According to this view, the two types
of properties exhibited are "complementary" features of the
same physical object. What we observe depends on what observ-
able reaction of our subatomic phenomena we bring to a test.
This conception has been called Bohr's theory of complemen-
tarity.

Bohr's point of view is therefore even more different from
Newtonian mechanics than Einstein's theory of relativity. In
Bohr's conception, we cannot describe what "actually" occurs in
space while, say, light is emitted by the sun before it hits the
earth. We can describe only what we observe when a measur-
ing apparatus is hit by light. We can, for example, describe
whether or not the light from the sun hits a certain spot on a
screen. Or, to express it more precisely: We cannot describe
"physical reality" by describing the path that a particle traverses

213

Einstein: His Life and Times

in space, but we can and must describe only the observations
made on various physical instruments arranged at different
points in space and time. Physical laws link together these ob~
servations, but not the positions or paths of the particles or pho-
tons. This viewpoint was interpreted as being in agreement
with positivistic philosophy which asserts that science cannot
discover what actually happens in the world, but can only de-
scribe and combine the results of different observations.

Since the beginning of the twentieth century more and more
emphasis has been placed on the conflict between the above
view that science can only describe and systematize the results
of observations and the view that it can and must investigate
the real world. This controversy became particularly acute
among the physicists in central Europe. Max Planck was the
spokesman for the latter view, which he called^the "metaphysi-
cal" view, and he directed his sharpest polemics against those
who seemed to him to be the most radical representatives of
the opposite side. In particular he attacked Mach's positivistic
conception of science, which agrees with Bohr's view.

About this time a reformulation of positivism started in Vienna
and Prague. The new movement was closely related to "Mach's
requirement." The core of the movement was the Wiener Kreis
(Vienna Circle), Moritz Schlick, R. Carnap, O. Neurath, and
others. In this country it was described as logical positivism and
established contact with related established tendencies such as
pragmatism and operationism. In England a similar movement
is headed by Bertrand Russell.

5. Einstein's Philosophy of Science

Since the positivistic conception of physics had been
stimulated strongly by Einstein's pioneer work in the theory of
relativity and in atomic physics, many persons regarded Einstein
as a kind of patron saint of positivism. To the positivists he
seemed to bring the blessing of science, and to their opponents he
was the evil spirit. Actually his attitude to positivism and meta-
physics was by no means so simple. The contradictions in his
personality that we have observed in his conduct as a teacher and
in his attitude to political questions also manifested themselves
in his philosophy.

Einstein recognized wholeheartedly the great success of

214

Development of Atomic Physics

Bohr's theory in explaining the many phenomena of atomic
physics, but from a more philosophical standpoint he was not
ready to admit that one must abandon the goal of describing
physical reality and remain content only with the combination
of observations. He was aware that it was not possible, as New-
ton had thought, to predict all future motions of all particles
from the initial conditions and the laws of motion. But perhaps,
thought Einstein, physical events could be described in terms of
a new theory as yet unknown. It would consist in a system
of field equations so general that they would contain the laws of
motion of particles and of photons as special cases.

I must admit that over a long time I myself believed that Ein-
stein was an adherent of the positivistic interpretation of Bohr's
theory. In 1929, at a congress of German physicists in Prague,
I delivered an address in which I attacked the metaphysical posi-
tion of the German physicists and defended the positivistic
ideas of Mach. After my address a well-known German physi-
cist with whose philosophical views I was not acquainted rose
and said: "I hold to the views of the man who for me is not
only the greatest physicist of our time, but also the greatest phi-
losopher: namely, Albert Einstein." Thereupon I felt a sense of
relief and expected the speaker to support me against my oppo-
nents, but I was mistaken. The speaker declared that Einstein
rejected the positivistic theories of Mach and his supporters and
that he regarded physical laws as being more than combinations
of observations. He added that Einstein was entirely in accord
with Planck's view that physical laws describe a reality in space
and time that is independent of ourselves.

At that time this presentation of Einstein's views took me
very much by surprise. It was oversimplified, indeed, but I soon
realized that Einstein's partly antagonistic attitude toward the
positivistic position was connected with his attitude toward
Bohr's conception of atomic physics. Shortly afterward I saw a
paper by Lanczos, one of Einstein's closest collaborators, in
which he contrasted the theory of relativity with. Bohr's theory
in the following manner: Einstein's general theory of relativity
is the physics corresponding to the metaphysical conception of
science; Bohr's theory, on the other hand, is in accord with the
radical positivistic conception. I was quite astonished to find the
theory of relativity characterized in this manner, since I had
been accustomed to regarding it as a realization of Mach's
program.

Not long afterward I believe it was in 1932 I was visiting

215

Einstein: His Life and Times

Einstein in Berlin. It had been a long time since we had con-
versed personally, and consequently I knew little of his stand
on questions about which he had not published anything. We
discussed the new physics of Bohr and his school, and Einstein
said, partly as a joke, something like this: "A new fashion has
now arisen in physics. By means of ingeniously formulated
theoretical experiments it is proved that certain physical magni-
tudes cannot be measured, or, to put it more precisely, that ac-
cording to accepted natural laws the investigated bodies behave
in such a way as to baffle all attempts at measurement. From
this the conclusion is drawn that it is completely meaningless to
retain these magnitudes in the language of physics. To speak
about them is pure metaphysics." In this statement, among other
things, he apparently referred to magnitudes such as the "posi-
tion" and "momentum" of an atomic particle.

Hearing Einstein talk in this way reminded me of many other
discussions to which his theory of relativity had given rise. Re-
peatedly the objection had been raised: if magnitudes such as
the "absolute temporal interval between two events" cannot be
measured, one should not conclude that consequently it is com-
pletely meaningless to speak of this interval and that "absolute
simultaneity" is simply a meaningless conglomeration of words.
Einstein's reply to this argument had always been that physics
can speak only about magnitudes capable of being measured
by experimental methods. Furthermore, Professor P. W. Bridg-
man regarded Einstein's theory of simultaneity as the best illus-
tration of the fruitfulness of his "positivistic" requirement that
only magnitudes having an "operational definition" should be
introduced into physics. Consequently I said to Einstein: "But
the fashion you speak of was invented by you in 1905 ?" At first
he replied humorously: "A good joke should not be repeated
too often." Then in a more serious vein he explained to me
that he did not see any description of a metaphysical reality
in the theory of relativity, but that he did regard an electro-
magnetic or gravitational field as a physical reality, in the same
sense that matter had formerly been considered so. The theory
of relativity teaches us the connection between different descrip-
tions of one and the same reality.

Actually Einstein has been a positivist and empiricist since he
has never been willing to accept any perennial framework for
physics. In the name of progress in physics he claims the right to
create any system of formulations and laws that would be in
agreement with new observations. For the older positivism the

216

Development of Atomic Physics

general laws of physics were summaries of individual observa-
tions. For Einstein the basic theoretical laws are a free creation
of the imagination, the product of the activity of an inventor
who is restricted in his speculation by two principles: an empiri-
cal one, that the conclusions drawn from the theory must be
confirmed by experience, and a half-logical, half aesthetic prin-
ciple, that the fundamental laws should be as few in number as
possible and logically compatible- This conception hardly dif-
fers from that of "logical positivism," according to which the
general laws are statements from which our observations can be
logically derived.

In the twentieth century, when Einstein created his special
theory of relativity, and even more so when he produced his gen-
eral theory, it became evident that physical theories were to an
ever increasing degree no longer simple summaries of observa-
tional results, and that the path between the basic principles of
the theory and the observational consequences was more in-
volved than had formerly been thought. The development of
physics from the eighteenth century to Einstein was accom-
panied by a correspondent development of philosophy. The
conception of general laws as summaries of observations gave
way more and more to the conception that laws are creations of
the imagination, which are to be tested by observation. Mack's
Positivism was replaced by Logical Positivism.

In the Herbert Spencer Lecture which he gave at Oxford in
the summer of 1933 shortly before he left Europe forever, Ein-
stein presented the finest formulation of his views on the nature
of a physical theory. He spoke first about the physics of the
eighteenth and nineteenth centuries that is, the period of
mechanistic physics:

"The scientists o those times were for the most part convinced that
the basic concepts and laws of physics were not in a logical sense free
inventions of the human mind, but rather they were derivable by
abstraction that is, by a logical process from experiment. It was the
general theory of relativity that showed in a convincing manner the
incorrectness of this view."

After Einstein had emphasized that the fundamental physi-
cal concepts were products of invention or fictions, he continued :

"The conception here outlined of the purely fictitious character of
the basic principles of physical theory was in the eighteenth and nine-
teenth centuries far from being the prevailing one. But it continues
to gain more and more ground because of the ever widening gap be-
tween the basic concepts and laws on the one side and the conse-

217

Einstein; His Life and Times

quences to be correlated with our experience on the other a gap
which widens progressively with the developing unification of the
logical structure that is a with the reduction of the number of the
logically independent conceptual elements required for the basis of
the whole system."

As in so many aspects of his life and thought, we also note a
certain internal conflict in Einstein's attitude toward the posi-
tivistic conception of science. On the one hand, he felt an urge
to achieve a logical clarity in physics such as had not previously
been attained, an urge to carry through the consequences of an
assumption with extreme radicalism, and was unwilling to
accept any laws that could not be tested by observation. On the
other hand, however, he felt that even Logical Positivism did
not give sufficient credit to the role of imagination in science and
did not account for the feeling that the "definitive theory" was
hidden somewhere and that all one had to do was to look for it
with sufficient intensity. As a result Einstein's philosophy of
science often made a "metaphysical" impression on persons who
are unacquainted with Einstein's positivistic requirement that
the only "confirmation" of a theory is its agreement with observ-
able facts.

6. Unified Field Theory

In his general theory of relativity Einstein had treated
the force of gravity as due to a gravitational field. Matter gave
rise to a gravitational field, which in turn acted on other ma-
terial bodies to cause forces to act. Einstein had taken this force
into account by means of curvature in space. A similar situa-
tion existed for electrically charged particles. Forces act between
them, and they could be taken into account by considering the
electric charges to give rise to an electromagnetic field, which
in turn produced forces on other charged particles. Thus matter
and gravitational field were exactly analogous to electric charge
and electromagnetic field. Consequently Einstein sought to
build a theory of "unified field" which would be a generaliza-
tion of his gravitational theory and would include all electro-
magnetic phenomena. He also thought that in this way he
might be able to obtain a more satisfactory theory of light quanta
(photons) than Bohr's, and derive laws about "physical reality"
instead of only laws about observational results,

218

Development of Atomic Physics

The great success of the geometrical method in the general
theory of relativity naturally suggested to him the idea of de-
veloping the new theory in the structure of four-dimensional
space. In this case it must have still other characteristics besides
the curvature which takes care of gravitational effects.

The news that Einstein was working on a unified field theory
became particularly widespread in 1929, the year of Einstein's
fiftieth birthday. To the public at large it seemed to be an espe-
cially attractive idea that on the very day on which he attained
fifty years, a man should also find the magic formula by which
all the puzzles of nature would finally be solved. Einstein re-
ceived telegrams from newspapers and publishers in all parts of
the world requesting that he acquaint them in a few words with
the contents of his new theory. Hundreds of reporters beseiged
his house. When some reporters were finally able to get hold of
him, Einstein said with astonishment: "I really don't need any
publicity," But everyone expected some new sensation that
would surpass the wonder produced by his previous theories.
They learned that a communication dealing with the new theory
would be published in the transactions of the Prussian Academy
of Science, and efforts were made by newspapers to secure
galley proofs from the printer, but without success. There was
nothing to do but to await the publication of the article, and in
order not to be too late, an American newspaper arranged to
have it sent immediately by phototelegraphy.

The article was only a few pages long, but it consisted for
the most part of mathematical formulae that were completely
unintelligible to the public. The emotion with which it was re-
ceived by the layman may be compared to that experienced at
the sight of an Assyrian cuneiform inscription. For an under-
standing of the paper a considerable capacity for abstract ge-
ometrical thinking was required. To those who possessed this
quality it revealed that general laws for a unified field could be
derived from a certain hypothesis regarding the structure of
four-dimensional space. It could also be shown that these laws
included the known laws of the electromagnetic field as well
as Einstein's law of gravitation as special cases. Nevertheless,
as yet no result capable of experimental verification could be
derived from them. Thus for the public at large the new theory
was even more incomprehensible than the previous theories.
For the expert it was an accomplishment of great logical and
aesthetic perfection.

219

X -
POLITICAL TURMOIL IN GERMANY

I, Einstein's Fiftieth Birthday

As the month of March in 1929 approached, Einstein
and his family began to fear that the sensationalism of the news-
papers would be so great on the date of his fiftieth birthday
that it would only be disagreeable for Einstein. Many news-
papers had undertaken to secure Einstein's own remarks on
more or less personal matters and to publish them. Moreover,
the visits and congratulations of his true admirers and friends
threatened to assume such proportions that Einstein decided
to avoid everything and to leave his apartment for several days.
Immediately all sorts of rumors appeared: Einstein has gone to
France, to Holland, to England, or even to America. But it was
all greatly exaggerated. He spent the day peacefully near Berlin
at the country estate of a shoe-polish manufacturer, who some-
times put at Einstein's disposal a pavilion in his garden, situated
very close to a beautiful lake. Here he was able to play the organ
or to sail on the lake.

From their apartment in Berlin Mrs. Einstein had brought
along the dinner that had been prepared. Einstein's immediate
family that is, his wife, her two daughters, and their hus-
bands were present. Einstein was very comfortable and un-
ceremonious, dressed in the garb he usually wore in the country,
or even in the city when no strangers were present. This con-
sisted of a pair of old trousers and a sweater, but no jacket, and
very often also without shoes or stockings. From their city apart-
ment Mrs. Einstein also brought along some of the congratula-
tory letters and presents that had arrived in large numbers.

Einstein was connected with many different activities, so that
he received letters and gifts from all sorts of people; naturally,
from physicists and philosophers, but also from pacifists and
Zionists. There were even some from very simple people who
were admirers of great discoveries and wanted to express this
admiration. Among these was a gift from an unemployed man,
consisting of a small package of pipe tobacco. It had become

220

Political Turmoil in Germany

generally known that Einstein was rarely to be found without a
pipe. Alluding to the relativity theory and the field theory, the
man wrote: "There is relatively little tobacco, but it is from a
good field."

Several of his friends had combined to present him with a
new and very modern sailboat. Einstein loved to sail the beau-
tiful lakes and rivers around Berlin, and to daydream while the
boat flew before the wind. The handling of the sails was a
pleasant activity. It was a very simple application of the rules
of mechanics, and it gave him a great deal of pleasure to apply
the physical laws that are closest to direct experience instead of
those that are most abstract. He also wrote a popular article in
which he explained to the lay public the physical laws that en-
able one to travel in a certain direction by placing the sails in
a certain position and to reach a particular goal by means of a
zigzag motion that is, by successive tacks.

A group of Zionists in America bought a plot of land in
Palestine and planted it with trees on his birthday. They made
provision that for all time to come the woods that grew there
were to be known as the Einstein Grove.

The most beautiful and interesting present, however, was to
come from the municipal administration of the city of Berlin,
where Einstein had lived since 1913, and which, to mention only
a very trivial matter, he had helped to make a center of attrac-
tion for all foreigners. Since it was generally known that Ein-
stein was fond of sailing on the Havel River and on the many
lakes into which this remarkable stream expands, the municipal
council of Berlin decided to present Einstein with a small coun-
try house situated on the bank of the Havel close to the point
where it enters the Wannsee. The house was located on a plot
belonging to the city of Berlin. This resolution on the part of
the municipal council was well received by the entire popula-
tion a sentiment arising from a combination of love of sci-
ence, respect for an illustrious fellow citizen, and a fondness
for aquatic sports and sailing. In all the illustrated magazines
appeared pictures of the idyllic "Einstein house."

When Mrs. Einstein wanted to see the house, she noticed
to her amazement that people were living in it. The latter, in
turn, were astonished to find someone wanting to take posses-
sion of their home, even though it was the famous Einstein.
It turned out that when the city of Berlin had acquired this
property, it had guaranteed to the inhabitants of the house the
right to keep on living there. The municipal council seemed

221

Einstein; His Life and Times

to have forgotten this when it gave its birthday present to Ein-
stein. How can one explain such an occurrence in Berlin, the
capital of Prussia, famous for its orderliness ?

At first it seemed to indicate a considerable confusion in the
registry of landed property. When the leaders of the municipal
council heard about this mistake, they wanted to correct it as
soon as possible. The park in which the frustrated "Einstein
house" stood was large and filled with beautiful trees, and
there was enough room in it for several houses. The council
therefore chose another part of the park, very close to the water,
and offered it to Einstein as a birthday present. The house, how-
ever, was to be built at his own expense. Einstein and his wife
were very happy about it and agreed to this arrangement. But
on closer investigation it was found that this was also impos-
sible. When the owner of the "Einstein house" received the
right to live in it, he had also been assured that no other house
would be built in the park that might in any way disturb his
enjoyment of nature and his view over the lake.

Finally the entire matter began to become unpleasant for
both Einstein and the municipal council. A gift that came into
being in this way could no longer give pleasure to anyone.
Thus it became more and more of a mystery what was actually
occurring in the famous model city of Berlin.

But the matter was not yet at an end. After considerable re-
flection the municipal council hit upon a third piece of land
near the water. It was not nearly so well situated nor was it
actually near the water. The neighbors, however, permitted at
least a passage from the piece of land in question to the water.
The gift became poorer and poorer. When it was finally dis-
covered that the city had no right to dispose of this third plot
of land, all Berlin burst out laughing. The laughter aimed at
the municipal administration was justified, but Einstein was
involved in the matter through no fault of his own.

Now the council finally became aware that there was no land
whatever at its disposal along the water. But since the mag-
nificent gesture of presenting a gift to the Berlin scientist had
already become public knowledge, the members of the council
felt ashamed to let the entire matter turn into a fiasco. A delegate
came to Einstein and said: "In order to be sure that the land
we will present to you really belongs to us, please pick out a plot
of land that suits you and is for sale. We will buy it." Einstein
agreed. But since he did not like to occupy himself with choos-
ing a piece of land, he let his wife go out to look. Finally she

222

political l urmoil in Germany

found a beautiful place in the village of Caputh, near Potsdam.
The council agreed to the selection, and at the next session of
the council a motion for the purchase of the land was presented.
Thereupon the entire matter began to develop into a political
dispute. A representative of the nationalist parties began to dis-
cuss whether Einstein actually deserved such a gift. The subject
was postponed to the next session.

Then Einstein finally lost patience. The gift from his adopted
city presented in the name of all the citizens had become an
object of political strife, and under the most favorable circum-
stances it would result from a political bargain. Einstein wrote
a letter to the Mayor of Berlin, who later occupied a prominent
place in the public eye when it became known that he had ac-
cepted a gift of a fur coat for his wife from persons to whom
he had given municipal contracts. Einstein wrote approximately
as follows: "My dear Mr. Mayor: Human life is very short,
while the authorities work very slowly. I feel therefore that
my life is too short for me to adapt myself to your methods.
I thank you for your friendly intentions. Now, however, my
birthday is already past and I decline the gift."

The result of the entire matter was that Einstein not only
built the house at his own expense, but also had to buy the
land with his own money. Some time after these events I was
in Berlin and Mrs. Einstein said to me: "In this way, without
wanting it, we have acquired a beautiful home of our own situ-
ated in the woods near the water. But we have also spent most
of our savings. Now we have no money, but we have our land
and property. This gives one a much greater sense of security."

This feeling was to be proved wrong, because hardly three
years later Einstein and his wife had to leave the land and
their beautiful villa with its new furnishings. This, however,
is more a private matter. Much more interesting is the question
of how this entire comedy of errors was possible in the orderly
city of Berlin. The answer to this question is the answer to the
whole problem of the German Republic. The city of Berlin was
apparently headed by men who represented culture and who
wished to express this position by honoring Einstein. The de-
cisive power, however, lay in the hands of persons who sabo-
taged the work of the apparent rulers. The officials of the city
of Berlin carried out the orders of the municipal council in
such a way as to result in failure and to make the republican
administration look ridiculous.

The situation was similar throughout the German Republic.

223

Einstein: His Life and Times

The Chancellor and the government showed their admiration
for art and science; but even at that time the real power already
lay in the hands of the underworld.

2. Visiting Professor at Pasadena

In the following year, 1930, Einstein received an in-
vitation to spend the winter in Pasadena, California, as visiting
professor at the California Institute of Technology. Conse-
quently in December he sailed for America. At this time his
entire political interest was concentrated on pacifism, and he
felt that this was also the great mission of the United States.
While still on shipboard he broadcasted a message to America
in which he said:

"Greetings to America. This morning, after an absence of ten years,
when I am once more about to set foot on the soil o the United States,
the thought uppermost in my mind is this: This country has through
hard labor achieved the position of undisputed pre-eminence among
the nations of the world. ... It is in your country, my friends, that
those latent forces which eventually will kill any serious monster of
professional militarism will be able to make themselves felt more
clearly and definitely. Your political and economic condition today
is such that you will be able to destroy entirely the dreadful tradition
of military violence. ... It is along these lines of endeavor that your
mission lies at the present moment. . . ."

Einstein was not of the opinion, however, that the United
States could accomplish this mission by a policy of isolation. On
March 29, 1931 he wrote: "In this country the conviction must
grow that her citizens bear a great responsibility in the field of
international politics. The role of passive spectator is not worthy
of this country." Moreover, he always regarded America's in-
tervention in world politics as an intervention in favor of peace.
He quoted Benjamin Franklin, who had said: "There never was
a bad peace or a good war."

This time Einstein did not have to make such troublesome and
disturbing trips throughout the entire country. Instead he was
invited to take part in the scientific research that was being car-
ried on at the California Institute of Technology and the Mount
Wilson Observatory. Both institutions are situated near Pasa-
dena, a quiet suburb of Los Angeles. Through the efforts of
R. A. Millikan, the California Institute of Technology had be-

224

Political Turmoil in Germany

come a center of physical research. Millikan, a recipient of the
Nobel prize, was originally a student of Michelson, and was
consequently acquainted with the entire trend of Einstein's re-
search from its experimental aspect. He has been a man possess-
ing not only scientific, but also administrative ability, and he
has always been a realist. Einstein's enthusiasm for pacifism al-
ways appeared to him as something not suited to our world,
and this opinion was to be proved correct only too soon. Milli-
kan was in accord with Einstein on one point, however: neither
of them denied the important role of religious communities in
the advancement of human co-operation. But neither Millikan
nor Einstein recognized any control over science by religious
dogmas.

In the spring of 1931 Einstein returned to Berlin and in the
fall went back again to Pasadena to spend another winter there.
When he again returned to Berlin in the spring of 1932, he ar-
rived just in time to witness the principal act in the death agony
of the German Republic.

In March 1932 a presidential election was to take place. The
Imperial field marshal, the octogenarian Hindenburg, was the
candidate of the Democrats and Socialists ; his chief opponent
was Adolf Hitler, the leader of the Right-radical revolutionaries.
Thanks to the propaganda of Reich Chancellor Briining, Hin-
denburg won the election. The Republicans and Democrats
were jubilant, but the truth was that now the power was in
the hands of an adherent of the former German monarchy. Un-
der the influence of his immediate environment, he used the
power to overthrow the Republic.

Hindenburg's first act after his election in May was to compel
Briining, his most faithful champion and the man who had
brought about his election, to resign as Chancellor. In his place
he appointed Papen, a man who was resolved to rule with the
support of bayonets and to eradicate every trace of republican-
ism and democracy. He announced to the Reichstag that a
"fundamentally new regime" was beginning, now that the pe-
riod of "materialism" was at an end. With the aid of the Reichs-
wehr, he deposed the Prussian government.

Many scientists were happy at these developments. They be-
lieved that now the reins were in the hands of the military. Since
the time of Bismarck they had been accustomed to the belief
that for Germany as a state and people, the rule of the "profes-
sors" could only be harmful. The fall of the "intellectuals and
democrats" would enable Germany to become great.

225

Einstein: His Life and Times

I can still recall very well a conversation that I had with Ein-
stein in the summer of 1932. We were at his country home in
Caputh. It was a log house, constructed of sturdy beams, and
we looked out through enormous windows on the idyllic forest
landscape. When a professor who was present expressed the hope
that a military regime might curb the Nazis, Einstein remarked:
"I am convinced that a military regime will not prevent the im-
minent National Socialist revolution. The military dictatorship
will suppress the popular will and the people will seek protec-
tion against the rule of the junkers and the officers in a Right-
radical revolution. 3 '

Someone asked Einstein for his opinion of Schleicher, the
"social general" who would perhaps soon seize power. "He will
produce the same result as the present military dictatorship/'
Einstein replied.

During this summer Abraham Flexner, the famous American
educator, came to Caputh to interest Einstein in his new research
institute at Princeton. "For the time being," said Einstein, "I
am still under obligation to spend the coining winter in Pasa-
dena. Later, however, I shall be ready to work with you."

When Einstein set out with his wife for California in the
fall of 1932, and as they left the beautiful villa in idyllic Caputh,
Einstein said to her: "Before you leave our villa this time, take
a good look at it."

"Why?" she asked.

"You will never see it again," Einstein replied quietly. His
wife thought he was being rather foolish.

In December, Schleicher became Chancellor. He wanted to
form a new government based on the working class, but the
power of President Hindenburg was exerted against him.
Schleicher was only a transitional phase. At the end of January
1933, while Einstein was still in sunny California discussing
with the astronomers of Mount Wilson Observatory the dis-
tribution of matter in space and similar problems of the uni-
verse, Schleicher resigned and President Hindenburg appointed
Adolf Hitler, his opponent at the last presidential election, as
Chancellor of the German Reich.

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Political Turmoil in Germany

3. Racial Purging in German Universities

Heretofore no aspect of Marxism had been so repug-
nant to the German professors as the assertion that the evolu-
tion of scientific knowledge is influenced by political power.
Their highest ideal was always the complete independence of
science from politics and the sharp separation of the two. But
now the political power had come into the hands of Chancellor
Hitler and his party whose foremost principle was the primacy of
politics over all fields of human life; over science just as much
as over economic life, art, and religion.

The standpoint of the new government is understandable if
one remembers that the new state not only appeared as a new
political organization, but also claimed to represent a new phi-
losophy and a new orientation in all fields of life. The new
orientation was that every effort was to be directed toward the
goal of serving the German people and the German race. This
was the ultimate aim of science just as it was of any other
activity.

This conviction that an entirely new Weltanschauung had
to be taught at the universities led the government to put pres-
sure on the university teachers. But since the freedom of science
was one of the most favored slogans in the professorial world,
the new government sought to introduce its goal by compul-
sion while retaining the old mode of expression as far as pos-
sible. The fine-sounding word "freedom" continued to be used,
but it received a new meaning. The equivocal use of this word
in earlier German philosophy had already prepared the ground
for the National Socialist use. In an essay on "German Free-
dom" written under the influence of the first World War, the
American philosopher George Santayanahad already said:

"Freedom in the mouth of German philosophy has a very special
meaning. It does not refer to any possibility of choice nor any private
initiative. German freedom is like the freedom of the angels in heaven
who see the face of God and cannot sin. It lies in such a deep under-
standing of what is actually established that you would not have it
otherwise; you appropriate and bless it all and feel it to be the provi-
dential expression of your own spirit. You are merged by sympathy
with your work, your country and the universe, until you are no
longer conscious of the least distinction between the Creator, the state
and yourself. Your compulsory service then becomes perfect freedom."

227

Einstein: His Life and Times

A clear presentation of the practical application of this pro-
found metaphysical theory was given by E. Krieck, German
pedagogical leader at this period:

"It is not science that must be restricted, hut rather the scientific in-
vestigators and teachers; only scientifically talented men who have
pledged their entire personality to the nation, to the racial conception
of the world, and to the German mission will teach and carry on
research at the German universities."

Thus a philosophical foundation was provided for the "cleans-
ing" of the faculties of the German universities.

The first application of the new theories was in the eradica-
tion of all teachers at institutions of higher learning who on the
basis of their racial origin were not considered fit to train the
youth in the spirit of the new philosophy. In this group were
all those who did not belong to the Germanic or Nordic, or,
as it was frequently called, the Aryan race. This grouping of
non-German or non-Aryans was meant specifically for the Jews,
since it was believed that because of their history and education
they formed a group that would tend to hinder the training in
the spirit of the new rulers. The term "Jews" included not only
those who professed the Jewish religion. The new government
assumed a standpoint of neutrality toward religion as such,
What the National Socialists meant was the Jews as a race; but
in this case there was no clear criterion by which to determine
a racial Jew. Since such a definition was difficult to make and
had to be arbitrary -in some degree, the conscientious and
thorough German professors believed that no racial "cleans-
ing" could take place. Without a neat and tidy definition the
German government would be unable to do anything.

But they were still unacquainted with the "pragmatic" spirit
of the new philosophy. The definitions that were needed were
produced with the greatest speed, even though they did not
satisfy the requirements of the German professors with respect
to anthropological, ethnological, or philological accuracy, or
even logical consistency. From the very beginning it was obvious
that there was no scientific definition of an "Aryan/' except
that he was a person who spoke a language belonging to the
"Aryan linguistic family." Such a definition, however, was im-
possible; otherwise everyone who spoke Yiddish, which is bas-
ically a German dialect, would be an Aryan. Thus from the
beginning it was not the "Aryan," but rather the "non- Aryan"

228

Political Turmoil in Germany

who was defined. The definition of a non-Aryan included ev-
eryone who had at least one non-Aryan grandparent. The grand-
parents, however, were defined as non-Aryan if they professed
the Jewish religion; they were defined, that is, in terms of a
criterion that has nothing to do with race in the ethnological
sense. It was simply taken for granted that two generations
earlier there were no persons of Jewish origin who professed
the Christian religion.

This cunning combination of definitions on the basis of origin
and religion achieved the intended political purpose: namely,
to exclude an entire group of people that it was feared could
exert a dangerous political or ideological influence on the stu-
dents. The definition, however, was not characterized by the
scientific clarity and precision that the professors required. Quite
a few would have been ready to co-operate in carrying out a polit-
ical purge of the universities, but it would have to be done in a
scientifically unobjectionable manner.

The attempt to exclude the Jews everywhere, but to talk only
of non-Aryans, gave rise to many difficulties. According to the
customary meaning and usage of the word "Aryan" prior to
the advent of the Nazis, there were other non-Aryans besides the
Jews. At first rather unpleasant sensations were aroused by the
idea that such peoples as Hungarians and Finns, who were very
popular with the National Socialists, were to be branded as non-
Aryans. On the other hand, one could not very well call a Hun-
garian an Aryan. Consequently, it was decided that a non- Aryan
status is determined by means of the official definition using the
religion of the grandparents. Nevertheless, even if anyone a
Hungarian, for instance can prove that he is not a non-Aryan,
it does not follow that he is an Aryan, Thus one of the funda-
mental rules of ordinary logic was dropped: namely, the prin-
ciple of the excluded middle, which says that a thing either has
or does not have a certain characteristic; there is no other pos-
sibility. According to the new official mode of expression, how-
ever, a Hungarian was neither a non- Aryan nor an Aryan.

As the new regime achieved political successes the number of
people who were neither Aryans nor non-Aryans grew ever
greater. The Japanese were soon the outstanding members of
this group. Finally, however, when their anti-British policy led
the National Socialists to seek the friendship of the "Semitic"
Arabs, the latter were also included among the "non-non-Ary-
ans." Previously the Jews had been opposed because, it was said,

229

Einstein: His Life and Times

they belonged to the "Semitic" race. Now, however, with the
inclusion of this race among the noble races, it was asserted that
the Jews did not belong to any race at all, but instead formed a
mongrel "anti-race."

But since a criterion of race that was not based on a religious
confession was still wanted, it was finally decided to consider
as related to the German race every other race that lived in
"compact settlements" and not, like the Jews, scattered in sep-
arate cities and commercial centers.

The definition that had been so anxiously awaited was thus
successful, and the universities were thoroughly purged accord-
ing to this pattern. At first there were still several exceptions.
All those professors were retained who had been appointed by
the Imperial German government and not by the Republic, be-
cause it was assumed that the latter had favored the Jews. Fur-
thermore, all those were allowed to remain who had fought
for Germany or her allies in the World War of 1914-18.

In time, however, all these exceptions were dropped and the
purge became more rigorous. Soon a further step was taken,
and all teachers were dismissed whose wives were non-Aryans
according to the official definition.

The "racial" purge was accompanied by a simultaneous po-
litical purge. But the principles upon which it was based were
much less distinct. The professors who were dismissed included
all those who had taken an active part in the work of the Social
Democratic and Communist parties, or who had belonged to the
Freemasons or to a pacifist organization. All other principles
were vague. This purge was even more baffling than the racial
one, since in the latter case the individual's fate was predestined
and he could do little to improve it. On the other hand, by
means of good behavior anyone could hope to make good any
previous political sins. Thus many professors who were formerly
known as "democrats" now began to express in a very obtrusive
manner their sympathy with the racial purge and with other
catchwords of the ruling party. Or one saw such democratic
sinners engaged in studying the application of the race theory
to such fields as mathematics, chemistry, and so forth. On the
other hand, many former supporters of the old nationalist and
monarchist groups assumed an attitude of reserve toward the
new masters. Actually some of those who had been victims of
the first political purge were later reinstated after they had
shown signs of "improvement."

In order to make the change even more thorough, advantage

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Political Turmoil in Germany

was taken of this opportunity to pension off, because of age,
many older professors who were not suspect on either racial or
political grounds. It was believed that they would be unable to
adapt themselves to the new regime. As a result of all these
measures it was possible to appoint many new teachers whom
the government considered reliable and who it was believed
would teach in the light of the new philosophy.

4. Hostility toward Einstein

When the purge began, Einstein was fortunately not
in Germany. It was immediately evident, however, that the
hostility of the new rulers to certain scientific groups was con-
centrated to an astonishing and even frightening degree against
Einstein. Just as the general enthusiasm for Einstein's theory is
an amazing phenomenon in the history of science, so the perse-
cution of a man who advanced such abstract theories is likewise
very puzzling.

His opponents may have said: "He is a Jew and became
world-renowned as a creator of new ideas. This is not in accord
with the views of the new rulers on the intellectual sterility of
the Jewish race. He is a pacifist and sympathizes with the ef-
forts for international co-operation." Nevertheless, this does not
suffice to explain the intensity of the antagonism to Einstein.
Here as well as in the growth of his fame a process of crystalliza-
tion was involved. Hate is added to hate, and fame to fame, just
as new crystals arise by forming around already existing crystals.

This development finally reached a point where the National
Socialists believed that Einstein was the chief of a secret move-
ment, sometimes described as "communistic," sometimes as the
"Jewish International/' which was working against the new
government.

Actually Einstein has always steered clear of actual politics.
The National Socialists, however, not only set about to attack
Einstein's purely theoretical remarks on politics, which were in
general academic, but they also tried to show that there was
something "Bolshevistic" and "Jewish" about his theories.

As we have seen, the modest beginnings of these attacks were
already evident at the end of the war in 1918. Now, however,
the leaders of the campaign against Einstein felt that their time
had come. Now they could come out into the open with their

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Einstein: His Life and Times

sincere opinions, while Einstein's defenders were no longer al-
lowed to reply to them. Thus in May 1933 Lenard, Einstein's
old enemy, published an article in the Volfysche Beobachter, the
chief organ of the National Socialist Party. Here Lenard could
finally speak without having to restrain himself in any way:

"The most important example of the dangerous influence of Jew-
ish circles on the study of nature has been provided by Herr Einstein
with his mathematically botched-up theories consisting of some an-
cient knowledge and a few arbitrary additions. This theory now
gradually falls to pieces, as is the fate of all products that are estranged
from nature. Even scientists who have otherwise done solid work
cannot escape the reproach that they allowed the relativity theory to
get a foothold in Germany, because they did not see, or did not want
to see, how wrong it is, outside the field of science also, to regard this
Jew as a good German. 5 '

Two years later this same Lenard delivered an inaugural ad-
dress at the opening of a new physics institute in which he said:

"I hope that the institute may stand as a battle flag against the
Asiatic spirit in science. Our Fiihrer has eliminated this same spirit
in politics and national economy, where it is known as Marxism. In
natural science, however, with the overemphasis on Einstein, it still
holds sway. We must recognize that it is unworthy of a German to
be the intellectual follower of a Jew. Natural science, properly so
called, is of completely Aryan origin, and Germans must today also
find their own way out into the unknown. Heil Hitler! 3

Proof that Einstein's research was characteristically "Jewish"
was obtained by producing a definition of "Jewish physics" that
contained all the characteristic features of Einsteinian physics.
Thus it was regarded as particularly "Jewish" if a theory was
very "abstract"; that is, if it was connected with the imme-
diate sensory observations only by long trains of thought and
did not lead to immediate technical applications. All this was
now considered "Jewish." It had been completely forgotten that
innumerable adherents of the Nordic doctrine had proved that
the Aryan spirit hovers in the heaven of speculation, while the
"non-Aryan" is at home in the material world which is the only
one that he comprehends with his "inferior mind."

The demand that science occupy itself with immediate prac-
tical necessities is not uncommon in a new regime that must
develop the resources of a country as rapidly as possible, whether
it be for a policy of conquest or reconstruction. We find similar
features at the beginning of the Soviet regime in Russia.

In 1934 Hermann Goring, the second leading Nazi, said:

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Political Turmoil in Germany

"We honor and respect science; but it must not become an end in
itself and degenerate into intellectual arrogance. Right now our
scientists have a fertile field. They should find out how this or that
raw material that we must import from abroad can be replaced equally
well at home."

And the Minister of Education Bernhard Rust said briefly and
succinctly: "National Socialism is not an enemy of science, but
only of theories."

Herewith not only Einstein himself, but actually an entire
science, theoretical physics, was condemned. At about this time
an outstanding representative of this science in Germany who
had been spared in the purge remarked to me jokingly: "You
must know that Einstein has compromised our entire science."

Only a few years previously the German physicist Wilhelm
Wien, who was rather sympathetic toward German nationalism,
in a conversation with the great English physicist Ernest Ruth-
erford, had said: "The relativity theory is something that you
Anglo-Saxons will never understand, because it requires a gen-
uine German feeling for abstract speculation." And the national-
istic French physicist Bouasse said: "The French spirit with its
desire for Latin lucidity will never understand the theory of
relativity. It is a product of the Teutonic tendency to mystical
speculation."

As I have said, when the great purge began, Einstein was
still in America. Upon learning of the events in Germany he
went to New York and communicated with the German consul.
In accordance with his official duty the latter told Einstein that
he need have no fear to return to Germany. A "national" gov-
ernment was now in power there, which would do justice to
all. If he was innocent, nothing would happen to him. Ein-
stein had decided, however, not to return to Germany so long
as the existing regime remained in power ; and he said so quite
openly at the consulate. After the official conversation was at
an end, the consul's deputy said to him privately: "Herr Profes-
sor, now that we are speaking as man to man, I can only tell
you that you are doing the right thing."

Numerous reporters wanted to hear Einstein's opinion on the
recent events in Germany. But he repeated what he had always
said: he had no desire to live in a state where freedom of ex-
pression did not exist and in which racial and religious intoler-
ance prevailed. He did not enter into any concrete discussions,
however.

He sailed for Europe, and in the spring of 1933 took up his

233

Einstein: His Life and Times

residence in the Belgian sea resort Le Cocque, not far from Os-
tend. From the beginning he knew that his connection with the
Prussian Academy must cease. The only question was whether
he should resign of his own accord or wait until the Academy
expelled him. The leading person in the Academy at this time
was Max Planck, the man who had first "discovered" Einstein,
who had declared him to be the Copernicus of the twentieth
century, and who, despite all conflicts, had supported him all
the time that he was in Berlin. One can imagine that this man
did not want to exclude Einstein from the Academy. And in
turn, Einstein wanted to spare him this unpleasant step. He
wrote briefly and to the point that under the present government
he could no longer serve the Prussian state and therefore resigned
his position.

At first the Academy beat about the bush, and there were
great discussions about what should be done. On one hand was
the desire to retain the reputation of the Academy as an im-
partial scientific body, on the other the desire to avow the idea
of the national government. Nernst, who was always some-
thing of a liberal, said at one session: "Why should one demand
of a member of the Academy, who is a great mathematician, that
he should also be a nationally minded German? Were not
d'Alembert, Maupertuis, and Voltaire members of our Acad-
emy, of whom we are proud even today? And these men, more-
over, were Frenchmen." He repeated over and over again, when
he met an academician: "How will posterity judge our Acad-
emy? Won't we be regarded as cowards who yielded to force?"

But since the newspapers of the ruling party were already full
of attacks against Einstein and accused him of agitating against
his own country abroad, the Academy finally decided to publish
a statement, characterized by a certain dolefulness, in which
they denied having any connection with Einstein. "We have
no reason to regret Einstein's resignation," it said. "The Acad-
emy is aghast at his agitational activities abroad. Its members
have always felt in themselves a profound loyalty to the Prussian
state. Even though they have kept apart from all party politics,
yet they have always emphasized their loyalty to the national
idea."

Einstein who was unaware that he had been actively en-
gaged in agitation abroad, answered the Academy in a letter
on April 5:

"I am not aware that I have spread so-called 'atrocity stories* about
Germany abroad. And, to be honest, I have not ever noticed that any

234

Political Turmoil in Germany

'atrocity reports' were being circulated. What I have noticed is that
the statements made by members of the new German government
have been repeated and commented upon, especially the program
for the destruction of the German Jews. ... I hope that the Academy
will transmit this letter to its members and will also do its part to
spread it among the German public; because I have been libeled in
the press, and the Academy by its communications to the newspapers
has assisted this libel."

Since the Academy could no longer assert that Einstein had
invented "atrocity stories" and spread them abroad, it retreated
to the statement that while Einstein had not invented any stories,
yet he had made no effort to oppose energetically those that
were in circulation and to defend his fatherland.

On April 7 the Academy wrote to Einstein approximately as
follows:

"We have awaited with confidence for a man like you, who was
for so long a member of our Academy., to range himself at the side
of our nation and without regard for his political sympathies to
oppose the flood of lies that has been let loose against us. In these days
when filth is hurled at the German nation, partly in a common, partly
in a ridiculous manner, a kind word for Germany from the mouth
of such a famous man as you would have had a great effect abroad.

"Instead, your remarks were still another instrument for the ene-
mies not only of the present German government, but also of the
entire German people. This was a bitter disappointment to us. It
would have led to a parting of our ways under any circumstances,
even if we had not received your resignation."

Einstein now saw that a continuation of the correspondence
would have no further purpose. On April 12 lie wrote a fare-
well letter to the Academy, with which he was linked by so
much work in common. In it he said:

"You write that a kind word on my part concerning the German
people would have had a great effect abroad. To this I must reply
that such a 'kind word' would have been a denial of every concept
of justice and freedom for which I have fought all my life. Such
testimony would not have been, as you put it, a 'kind word' for the
German people. On the contrary, such a statement would only have
helped to undermine the ideas and principles by means of which the
German people have acquired an honorable place in the civilized
world. By such a testimony I would have contributed, even though
indirectly, to the barbarization of morals and the destruction of cul-
tural values.

"Your letter shows me only how right I was to resign my position
at the Academy."

235

Einstein: His Life and Times

Einstein had voluntarily resigned from his position at the
Academy in order to spare a man like Max Planck the painful
and shameful act of expelling from the Academy at the behest
of a political party a man whom he himself regarded as one of
its most valuable members. Max Planck was one of the German
professors who repeatedly asserted that the new rulers were
pursuing a great and noble aim. We scientists, who do not under-
stand politics, ought not to make any difficulties for them. It is
our task to see to it that as far as is possible individual scientists
suffer as few hardships as possible., and above all we should do
everything in our power to maintain the high level of science in
Germany. At least envious foreigners should not notice that a
lowering of the level is taking place anywhere in our country.

The idea that the many brutalities practiced upon individuals
and institutions were only temporary attendant phenomena of
the "revolution from the Right" was widespread among men of
Planck's type. One of the outstanding scientists of the University
of Berlin approached Planck and told him that he would like to
leave Berlin immediately and look about for a place to work
abroad. He felt that one day he would become a victim of a later
purge. To this Planck replied: "But, my dear colleague, what
strange ideas you have! If you do not find present conditions at
the universities congenial, why don't you take a leave of absence
for a year? Take a pleasant trip abroad and carry on some
studies. And when you return all the unpleasant features of our
present government will have disappeared."

At the Kaiser Wilhelm Institute, of which he was president,
Planck likewise endeavored to retain non-Aryan scientists in
their positions. He believed that in this way he would be able
to prevent those people whom he valued from suffering hard-
ships. As a result the research work of the institute and the fame
of German science would, he hoped, remain undamaged.

He was helped by the circumstance that non-Aryans were
tolerated somewhat longer in the field of research than in the
teaching profession. Thus Planck succeeded in retaining sev-
eral of these research workers even after the general purge in
Berlin. But when the purge finally did hit them, they were in
a particularly poor situation. It was more difficult for them to
leave Germany and to find positions abroad.

Planck once tried by personal intervention to convince Adolf
Hitler that the mechanical application of his "non-Aryan de-
finition" to the organization of education and research would

Political Turmoil in Germany

have an unfavorable effect. Planck's meeting with Hitler was
the subject of much discussion in Berlin university circles at
this time. Planck had but little opportunity to present his argu-
ments. The Fiihrer spoke to him in an argumentative manner
as if he were spreading agitational propaganda at a mass meet-
ing, and not as one speaks to a single visitor in an office. Among
other things, Hitler said that he would give the Jews some op-
portunity to work if they were not all Bolsheviks. When Planck
timidly objected that this certainly did not apply to a man like
Haber, Hitler said: "Believe me. Those that are not Bolsheviks
openly are so in secret." Furthermore said the Fiihrer decisively:
"Do not think that I have such weak nerves as to let myself be
diverted from my great goal by such petty considerations. Ev-
erything will be carried out to the last letter."

As we have seen, Einstein had spared the Prussian Academy
the embarrassment of having to throw him out, but he did re-
ceive an official letter from the Bavarian Academy of Science
informing him that he was expelled from its ranks.

Einstein's villa at Caputh was searched by the political police.
It was believed that the Communist Party had hidden stores of
arms there. Such accusations were a result of the fantastic ideas
regarding Einstein's role as a political leader or conspirator.

Einstein's possessions, his villa as well as his bank account,
were all confiscated by the state. In the announcement of this
act that he received from the political police the reason given
was: "The property was obviously going to be used to finance a
Communist revolt." The "gift" of the city of Berlin had led him
to use the greatest part of his savings to build his villa, which was
now confiscated, and Einstein had but little left of all his prop-
erty. Simultaneously it became evident that by adopting Ger-
man citizenship as a sign of sympathy for the German Repub-
lic he had acted to his own disadvantage, since as a foreigner
(Swiss) he would have been protected against the confiscation
of his property.

Einstein's writings on the relativity theory were burned pub-
licly in the square before the State Opera House in Berlin, to-
gether with other books, some of which were regarded as ob-
scene, others as Bolshevistic. For some time there was even a
regulation according to which all books written by Jews were
to be marked "translated from the Hebrew." This was intended
to express that they were only apparently written in German. At
that time there was still an occasional professor of physics in

237

Einstein: His Life and Times

Germany who while lecturing on the relativity theory permitted
himself the joking remark: "It is a mistake to believe that Ein-
stein's original paper was translated from the Hebrew."

As was to be expected, some of Einstein's scientific opponents
took advantage of the new regime's hostility toward him to
prevent as far as possible the teaching of Einstein's theories at
the German universities. Among these opponents, in addition to
the aforementioned Lenard, was another well-known physicist
named Johannes Stark. He had made some outstanding experi-
mental discoveries, for which, like Lenard, he had received the
Nobel prize. But he was just as incapable as Lenard of com-
prehending a complex theoretical structure. Like Lenard he
advocated the view that there was something "un-German" in
the predominance of theory over sensory observation and it
must therefore be eradicated from the teaching in the German
schools. Stark also found an explanation for the fact that so
many German physicists accepted the relativity theory even
though it was repugnant to the German spirit. He explained it
as resulting from the circumstance that so many physicists had
Jewish wives.

This use of political power to compel the acceptance of one
view in the field of science aroused great concern among the
German physicists. One of the leading physicists said to me at
that time: "It is fortunate for us that Lenard and Stark are no
longer young. If they still had their youthful Man they would
command what should be taught as physics. 55

Nevertheless, not everything was carried out as radically as
Einstein's opponents wanted it. The National Socialist Party
even adopted a resolution stating that no physical theory could
claim to be "genuinely National Socialistic." Thus Einstein's
theory was not completely eradicated in the German univer-
sities. It depended on the courage of the individual teacher.
Some taught the theory without mentioning Einstein's name,
others dropped the name "relativity theory." Others went still
further; they taught the individual facts that followed from this
theory as facts of experience, but they omitted completely the
logical connection of these points by the theory. No physicist
could dispense with these important facts, such as the relation
between mass and energy or between mass and velocity.

Most of the German physicists were at their wits' end think-
ing up ways of protecting themselves from the continual inter-
ference in their science by the political physicists such as Lenard,
and some of them hit upon an idea that despite the seriousness

Political Turmoil in Germany

of the situation had something comical about it They thought
that there was only one way to shake Lenard's prestige with
the new authorities, and that was to prove that he was a non-
Aryan. This seemed a plausible possibility, as Lenard's father
had conducted a brokerage business in Pressburg (Bratislava),
the capital of modern Slovakia. Since many of the inhabitants of
this city were Jewish and the brokerage business was regarded
as a Jewish occupation, there was some hope that this might be
true. As I was then teaching in Czechoslovakia, to which Press-
burg belonged at that time, I repeatedly received direct requests
from some of the outstanding German physicists to institute
inquiries in^ Pressburg regarding Lenard's four grandparents.
I must admit that my interests did not lie in the field of gene-
alogical research. I turned the Investigation over to a friend in
Pressburg, but he too was not very zealous. The researches did
not go beyond Lenard's parents. It was possible to determine
that they did not profess the Jewish religion.

Nevertheless, the zeal with which the German physicists had
to pursue such problems in the interest of their science is a sign
of this peculiar period.

5. Last Wee\s in Europe

Einstein passed the last weeks of his European resi-
dence in a villa that lay hidden among the great sand dunes of
Le Cocque sur Mer, a beautiful bathing resort in Belgium. Round
about, children built large castles of sand and women prome-
naded in attractive Parisian-model bathing suits. Einstein was
in a peculiar situation. He had not returned to Germany, and
his friends there warned him that he would certainly be ar-
rested or perhaps murdered if he showed up in that country.

Le Cocque, however, was not very far from Germany. Many
feared that fanatics would be able to slip across the border and
"liquidate" him. If they fled to Germany after committing such
an act, they would not have to fear any punishment, since the
deed would have been committed "with the best of intentions."
There were several precedents for such actions. It was even
rumored that a high price had been set on Einstein's head;
but it is manifestly difficult to check the correctness of such
talk.

Einstein had good friends in Belgium. The Abbe Lemaitre,

239

Einstein: His Life and Times

a Catholic priest, had found that Einstein's equations of the
gravitational field in universal space were also consistent with
a distribution of matter in the universe which did not always
remain the same on the average. Hence, the Abbe could as-
sume that the various galaxies move farther and farther away
from one another. He thus founded the theory of the expand-
ing universe, which had been adumbrated in connection with
Einstein's theories by Friedmann, a Soviet Russian mathema-
tician more than a decade earlier. It first received attention
through Lemaitre and still more through Eddington, and was
supported by astronomical observations. As Abbe Lemaitre was
one of the glories of Belgian science, the Queen of Belgium
likewise became interested in Einstein's theories and on various
occasions took pleasure in conversing with him.

The Belgian royal family and the Belgian government were
very much concerned about the rumors that assassins might
come to Belgium and threaten Einstein. It was therefore ar-
ranged for two bodyguards to watch Einstein day and night.
Naturally this was rather annoying for him. In the first place
it was unpleasant for a kind-hearted person like Einstein to
keep his two shadows too busy, and secondly, for a bohemian
like Einstein it was very annoying to be under constant "police
supervision." The Belgian government, however, had no desire
to be responsible for any accidents.

In the summer of 1933, while passing through Ostend in the
course of a trip from London to the Continent, I remembered
that Einstein was living near by and decided to try to find him
there. I did not know his address, but I took a chance and went
to Le Cocque, where I inquired of the inhabitants whether they
knew where Einstein was living. As I later learned, the author-
ities had given strict orders to the inhabitants not to give any
information to anyone about Einstein's residence. Since I knew
nothing of all these precautions, I asked very naively and in
time received with equal naivete all the information that I
wanted.

Finally, I came to a villa in the midst of the dunes and saw
Mrs. Einstein sitting on the veranda, whereupon I knew I had
reached my goal. From the distance I saw two rather robust
men in a very excited conversation with Mrs. Einstein, I was
rather surprised at these visitors, as one was accustomed to see-
ing only scientists, writers, and artists with the Einsteins. I ap-
proached closer to the villa. As soon as the two men saw me,
they threw themselves at me and seized me. Mrs. Einstein

240

Political Tunnoil in Germany

jumped up, her face frightened and chalky white. Finally she
recognized me and said: "They suspected you of being the ru-
mored assassin," She reassured the detectives and led me into
the house.

After a while Einstein himself came downstairs. In the mean-
time Mrs. Einstein had asked me how I had found the house*
I replied that the people in the neighborhood had pointed it
out to me. But that was strictly prohibited, she said. Einstein
himself laughed heartily at the failure of the measures taken by
the police for his protection.

At this time his mind was still much occupied by his cor-
respondence with the Academy in Berlin. He showed me all
the letters and commented on the parts played by the various
persons concerned in the matter. He spoke at some length about
the personality of Max Planck. "And finally," he said, "to get rid
of my annoyance I composed several humorous verses. I put
all the letters in a folder and on top of them the verses. They
began with these lines :

Thank you for your note so tender ;
'Tis typically German, like its sender."

There was something genuinely artistic in Einstein's nature.
It recalled to mind the passage in Goethe's autobiography where
he relates that he rid himself of every mental vexation by re-
enacting it artistically. Einstein in such cases played a short but
vigorous composition on the violin or composed a few humor-
ous verses. Even though they did not attain the classical level
of Goethe's Faust, yet psychologically they fulfilled the same
function equally well

On this occasion Einstein repeatedly emphasized that in get-
ting rid of his Berlin environment he also experienced in a cer-
tain respect a psychological liberation. Mrs. Einstein, who was
present at this conversation, was not very much in sympathy
with such statements. Emotionally she had a strong feeling of
attachment to Germany. She said: "But you should not be so un-
just. You had many happy hours in Berlin, too. For instance^
you often said to me after coming home from the physics
colloquium that such a gathering of outstanding physicists is not
to be found anywhere else in the world at the present day."

"Yes," said Einstein, "from a purely scientific point of view
life in Berlin was often really very nice. Nevertheless, I always
had a feeling as if something was pressing on me, and I always
had a presentiment that the end would not be good."

241

Einstein: His Life and Times

We then spoke about the prediction that he had made to me
in Prague about eleven years previously, before his first trip to
America. The catastrophe in Germany had actually occurred at
approximately the time that he had anticipated.

"Do you know/' said Einstein, "I have recently had a very
remarkable experience. You probably remember my friend and
colleague Fritz Haber, the famous chemist." The reader will
recall that he belonged to Einstein's intimate circle in Berlin.
He had always urged Einstein to adapt himself to the thought
of German nationalists, and himself had advanced rather far
in this direction. "I recently received a letter from Fritz Haber,"
related Einstein, "in which he informs me of his intention to
apply for a position at the Hebrew University in Jerusalem.
There you have it, the whole world is topsyturvy."

We talked a great deal about this university to whose found-
ing Einstein had contributed so much. Now that Einstein had
become available, the university in Jerusalem made every ef-
fort to obtain his services. But he was not much inclined to ac-
cept. He did not like the idea that in this period which was so
critical for the Jewish people, the university endeavored chiefly
to obtain certain professors who were already famous, in order
to increase its prestige. At a time when the future of so many
young Jewish scholars was endangered, he felt that this uni-
versity should rather pick out the most capable of these younger
men and enable them to teach and to carry on research. For
these reasons Einstein also advised the famous Haber not to go
to Jerusalem.

We discussed the fantastic ideas regarding Einstein as a poli-
tician that were current among the ruling circles in Germany.
Mrs. Einstein related an incident that had occurred recently.
They had received a German letter from an unknown man in
which he urgently demanded that Einstein receive him. Since
no unknown person was permitted to come near him for fear
of an assassination, Mrs. Einstein refused. Upon repeated in-
sistence that the matter was very important, Mrs. Einstein fi-
nally declared herself ready to see this man in the absence of
her husband. The man actually came and related that he had
been a member of the Nazi Storm Troops (S.A.). He had fallen
out with the party and was now opposed to it. He knew all
the secrets of the party and wanted to sell them to its opponents
for fifty thousand francs. He wanted to find out whether Ein-
stein would spend the money for this information. "Why do
you assume/' asked Mrs. Einstein, "that Professor Einstein is

242

Political Tmmoil in Ger?nmy

Interested in the secrets of your former party ?" "Oh," replied the
ex-S.A. man, "we all know very well that Professor Einstein
is the leader of the opposing party throughout the entire world,
and that such a purchase would therefore be very important for
him." Mrs. Einstein explained to the man that he was mistaken
and that Einstein was not interested in these secrets,, no matter
whether they were genuine or spurious.

Nevertheless, the occurrence left a very uncomfortable feel-
ing. It was now definitely known that the National Socialist
Party, which at that time was already one of the most powerful
factors in the world, regarded Einstein as a leader of its op-
ponents. All sorts of unpleasant surprises had to be expected.

6, Einstein's Views on Military Service

Germany's revolution from the Right made it evident
to the small neighboring states that the time had come when
Germany would break the bonds of the Versailles Treaty, if
necessary by force. To any intelligent person acquainted with
the lessons of history it was obvious that Germany would not
stop with the eradication of the "injustice of Versailles," but
would take advantage of the opportunity to obtain something
more for herself in order to realize her old dream of a "living
space." The war of 1914-18 had made it evident to the Belgians
that the German politicians included Belgium within this liv-
ing space. As early as 1933, at about the time that Einstein came
to Belgium, this realization aroused a feeling of insecurity in
many persons.

On the other hand, in Belgium as elsewhere at this time, espe-
cially among the youth, the view was firmly rooted that all wars
are organized by the capitalist class to suppress the workers.
Therefore every socially minded and progressive young person
should refrain from supporting war in any way. But even then
it was already evident to many Belgians that absolute opposi-
tion to every war would make the country an easy prey for its
neighbors, who preached that war is the most important instru-
ment of politics. Thus radically minded youth was faced by
this problem: should the propaganda against military service
and military preparedness be continue^, thus rendering easier
an invasion by warlike neighbors, or should one take part in
the defense of the fatherland, thereby following a slogan that

243

Einstein: His Life and Times

had previously been regarded as a pretext of the exploiters In
their fight against their own workers ? A group of representa-
tives of Belgian pacifist youth turned to Einstein for his opin-
ion in this matter of conscience, since he was widely known as
a radical champion of the movement against war and military
service. As late as the spring of 1931 he had greeted with de-
light and affirmation a manifesto issued by American clergymen
in which they announced that they would take no part in any
future wars, even though their own government claimed that
it was for the defense of their country. Einstein had written as
follows, referring to this statement:

"It is a gratifying revelation of the temper of the American clergy
that fifty-four per cent o those who answered the questionnaire
should have indicated their purpose not to participate in any future
war. Only such a radical position can be of help to the world, since
the government of each nation is bound to present every war as a war
of defense."

But when the young Belgians turned to Einstein with the
question whether they should refuse to co-operate if Belgium
became involved in a war against its big neighbors, Einstein
did not let himself be confused for a moment. From the very
first he knew that he had to answer in such a way as to en-
courage the course of action that he considered advisable under
the given circumstances. He did not allow himself to be con-
fused by the vain idea of standing forth as one who sticks to
his principles under all circumstances. Such a person would in-
sist on his principles even though they should lead to actions
and results with which he was not in sympathy. Einstein was
aware that the purpose of principles In both public and private
life is only to encourage actions that produce results which one
would approve. Principles, however, are not to be considered
as ends in themselves. He answered briefly and concisely: in this
case everyone should fight as best he can for the freedom of
his fatherland, Belgium.

This answer created a sensation at the time. Many persons
even doubted its genuineness. Many said: "Surely a principle
does not become false because in a single case it leads to con-
sequences that are repugnant, as for instance in this case to a
triumph of National Socialism."

The people who expected that Einstein would stick to his
principles without any consideration of the consequences did
not understand the fundamentally positivistic, pragmatic char-

244

Political Turmoil in Germany

acter of his thought. Basically he thought in politics just as he
did in physics. When he actually came to grips with a concrete
problem, the positivistic basis of his thinking became evident.
He did not believe that principles have any meaning except
their consequences, which we can test on the basis of our ex-
periences. Occasionally, he liked to think about the emotional
effect brought about by the wording of the principles. As a re-
sult his language in physics as well as in politics in some cases
acquired a metaphysical touch. But this was only a more or less
poetical way of speaking, which furnished a point of contact
with human feeling.

Basically his position was always clear: he would never sup-
port principles because of their beautiful sound, if they led to
consequences which he could not approve.

For this reason the attacks on Einstein by those who opposed
war on principle were of the same character as those of some
of his opponents in physics who attacked him with the reproach
that he had first advanced the principle of the constancy of the
velocity of light in the special relativity theory of 1905, and had
then abandoned it in his theory of gravitation, since according to
the latter the velocity with which light is propagated depends
on the intensity of the gravitational field. Some of Einstein's op-
ponents accused him of being inconsistent and of trying to hide
this inconsistency. This description, however, is somewhat mis-
leading. The constancy of the velocity of light is true only under
very specific conditions namely, when strong gravitational
fields are not present. By enumerating the restrictions under
which a certain principle is valid, one is not being inconsistent,
but only adding to our knowledge of the world.

The same is true of Einstein's attitude to the question of mili-
tary service. At that time I had no opportunity to discuss this
matter personally with him, but soon after Einstein's arrival in
America the same question became acute there. The radical
youth movement, as represented by the American Youth Con-
gress, at first wanted to uphold the principle of absolute op-
position to war, even in the case of a war of the democratic
states against fascism, because such a war for them was in prin-
ciple an imperialist war. Einstein, however, did not let himself
be confused by such arguments, and saw that here as in Belgium
these "opponents of war" were only working for the victory
of the greatest military power. As a result they would achieve
the very opposite of what they thought they were working for,
Einstein thought that the principle of absolute non-participation

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Einstein: His Life and Times

in war made sense only when a victory of the different powers
did not lead to very different consequences for the population.
In Europe after 1918 one might have said: It does not make
much difference whether one is ruled by the French or the
German Republic, by the United States or Great Britain. This
difference does not justify war. But this standpoint can no
longer be maintained when there are states whose principles
of government differ as radically from each other as do those of
Nazi Germany from those of the states around it. Under these
conditions no one can remain indifferent to who will be the
victor. Just as the principle of the constancy of the velocity of
light is valid only if no great differences of gravitational po-
tential and therefore no great forces are present, so the principle
of absolute refusal to perform military service is valid only
when there are no extreme differences between the govern-
mental principles of opposing states.

In U.S A. opponents of military service such as Bertrand Rus-
sell and Archibald MacLeish drew the same consequences from
the situation. Various metaphysically thinking authors charac-
terized such men as "inconsistent" and wondered that logicians
such as Russell could be so illogical. Einstein's case, however,
would already have shown them that consistency in a metaphysi-
cal sense that is, to hold fast to the letter of a principle is
not consistency in a scientific sense which means to hold fast to
the desirable consequences of a principle. Thus, because of his
direct and honest thinking, Einstein once again became an ob-
ject of attacks, even before he had actually departed from Eu-
rope, and this time the attacks came from "progressive" and
"radical" circles.

At this time Einstein was most immediately concerned with
the many hundreds and soon thousands of scholars and sci-
entists, both young and old, who were expelled from their po-
sitions by the purge in Germany. English scientists tried to give
the refugees some opportunity to continue their work under
more favorable conditions. The great English physicist Ruther-
ford put himself at the head of this movement and organized
the Academic Assistance Council in London. At its first meet-
ing Einstein was to be presented to the public as a symbol of the
victims, and with his great prestige was to make an appeal for
this cause. One can very well imagine that this was not very
pleasant for Einstein. He did not like to appear publicly in any
matter where he was personally involved. Nevertheless, the seri-
ousness of the situation and the importance of the relief measures

246

Political Turmoil in Germany

induced Mm to go to London and deliver an address on the sub-
ject "Science and Liberty." At the meeting he sat next to Lord
Rutherford, who presided. Immediately after his introductory
words Rutherford pointed to his neighbor with an energetic
gesture and presented him proudly: "Ladies and gentlemen, my
old friend and colleague Professor Einstein."

Einstein spoke with great reserve. He tried to point out the
need for relief measures, while avoiding all political attacks.
Strong words were superfluous, the cause spoke for itself. Ein-
stein said : "It cannot be my task to act as judge of the conduct of a
nation which for many years has considered me as her son. Per-
haps it is an idle task to judge in times when action counts."

Soon after this meeting, which took place early in October
1933, Einstein was waiting at Southampton for a passenger ves-
sel of moderate size that was coming from Antwerp and was
to bring him to New York.

But before I describe Einstein's new life in America, we will
remain awhile yet in Europe to see the remarkable manner in
which Einstein's abstract theories were utilized by political and
religious groups for their purposes.

247

XI

EINSTEIN'S THEORIES AS POLITICAL
WEAPONS AND TARGETS

i. Scientific Theories and Political Ideologies

To a physicist or mathematician who actually under-
stands, or believes that he understands, Einstein's theories, it
must seem strange and frivolous when people whose under-
standing of this matter is much more limited argue whether
his theory is a product of the Bolshevization of Europe or per-
haps a stage in the development of Europe from liberalism to
fascism; whether it is a support for religion in its fight against
materialism or whether it helps to breed disbelief in everything
that traditional religion teaches about the universe. The profes-
sional physicist will not find any trace of these ideas in Einstein's
theories. He believes that their validity depends only on the
correctness of certain computations, and on whether certain
delicate experiments are carried out with the necessary care.
Consequently he must feel that these disputes over Einstein's
theories have been simply a result of ignorance and madness.

But whoever investigates the fate of other radically new theo-
ries about the universe for example, the fate of the Coper-
nican system, the Newtonian theory, the laws of energy will
find that all these theories led to discussions that from the stand-
point of the physicist or mathematician appeared to be either
superfluous or even foolish.

The transition from science to political ideology occurs
by means of philosophy. The generalizations of science are ex-
pressed in philosophical language, in which terms such as "ideal-
ism," "materialism," "force," "energy," and others play a part.
The same words also appear in the philosophical doctrines that
tell men how to act in private as well as in political life. In this
way the generalizations of science are gradually transformed
into principles of moral and political philosophy.

On this point Viscount Samuel, a man who is conversant with

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Einstein's Theories as Political Weapons and Targets

science, philosophy and politics, and who in addition has been
connected with Einstein in a number of ways, said:

"Philosophy of some kind moves the nations. Every land resounds
with the tramp of armies, behind the armies are the dictators and the
parliaments, behind them are the political creeds Communism,
National Socialism, Fascism, Democracy and behind the creeds are
the philosophers Marx, Engels, Hegel, Nietzsche, Sorel, Mill, and
others."

Philosophical systems like to make use of the newest scientific
theories in order to have "exact" foundations. But the help that
philosophy gets in this way does not lead to unambiguous re-
sults. One and the same scientific theory can be used to support
different political creeds. Bertrand Russell gave a very good
characterization of this ambiguity:

"There has been a tendency, not uncommon in the case of a new
scientific theory, for every philosopher to interpret the work of Ein-
stein in accordance with his own metaphysical system and to suggest
that the outcome is a great accession of strength to the views which
the philosopher in question previously held,"

This ambiguity arises from the fact that it is not the physical
content of a theory that is responsible for its philosophical in-
terpretations. Frequently it is rather the language in which the
theory is formulated, its images and analogies that are inter-
preted.

The interpretation of Einstein's Relativity is usually connected
with two characteristics of the language in which he and his
followers clothed his theory. The first characteristic is the aban-
donment of mechanical analogies. There is no mention of any
mechanism in the sense in which this word is used in daily life;
for instance, there is no mechanism for the shortening of a body
by rapid motion. Instead, a logical-empirical mode of expression
is employed; that is, a system of mathematical formulae is given
and the operations are described by which the magnitudes in
these formulae can be measured empirically. The second charac-
teristic is the use of the expression "relative to a certain body."
The use of this mode of expression gives rise to a comparison
with the language of so-called "relativism"; for example, ethical
relativism, which asserts that any human action can be called
good or bad only "relative to a certain ethnical group and histori-
cal period," and so forth.

By abandoning the mechanical analogy Einstein's theory har-

249

Einstein: His Life and Times

monized to a certain extent with all the currents of thought
that opposed the mechanistic conception of the world and the
materialistic philosophy connected with it. The second char-
acteristic of his mode of expression brought him close to those
who were called ethical skeptics and who were frequently linked
to a materialistic philosophy.

Thus Einstein's theories could be used equally well as prop-
aganda for materialism or against it. And since words such as
"materialism/' "idealism/' "relativism/' and so forth, are fre-
quently used as the catchwords of political ideologies, we can
understand that Einstein's theories were very often used as a
weapon in the struggle of political parties.

2. Pro-Fascist Interpretation

The fascist groups always have asserted that the Com-
munist philosophy is materialistic, while theirs is anti-material-
istic, or idealistic. Consequently Einstein's theories could be used
as weapons for fascism if they were interpreted as arguments
against materialism and for idealism.

As early as 1927 that is, before the seizure of power by the
Nazis Joseph Goebbels had shown how the language of Ger-
man idealistic philosophy could be employed in the service of
his party. First of all he presented an interpretation of the
Kantian expression "thing-in-itself" (Ding an sich}, the char-
acteristic concept of German idealism. Goebbels said: "The folk
is a constituent of humanity. Humanity is not a thing-in-itself,
nor is the individual a thing-in-itself. The folk is the thing-
in-itself. . . ."

"The materialist/' Goebbels continued, "regards the folk only
as an instrument and does not want to concede that it is an in-
dependent objective reality. For him the folk is an intermediate
thing between man and humanity, and mankind is for him the
ultimate. . . . Therefore the materialist is necessarily a demo-
crat. The idealist sees in the word 'humanity' only a concept.
Humanity is only something imagined, not a fact. . . ."

By emphasizing its anti-mechanistic aspects it was, indeed,
possible to employ Einstein's relativity theory as a weapon in the
fight against "materialistic" democracy, German physicists who
considered it desirable to teach Einstein's theories even in Na-
tional Socialist Germany occasionally made use of this possi-

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Einstein's Theories as Political Weapons and Targets

bility. Pascual Jordan, for instance, in his book The Physics of
the Twentieth Century, recommended Einstein's theory of rel-
ativity to National Socialists as a weapon in the fight against
materialistic philosophy. Jordan said that the eradication of this
philosophy is an "integral aspect of the unfolding new world
of the twentieth century that has already begun, especially in
Italy and Germany." The "new world" is that of Fascism and
National Socialism.

Since many opponents of Einstein's theories wanted to make
use of the political power of the National Socialist Party in their
fight against Einstein, they were very much upset by efforts
such as that of Jordan. Thus, for instance, Hugo Dingier, who
had already agitated against Einstein without any great success
long before National Socialism, remarked with indignation
about Jordan's book: "To hang this destructive Einstein phi-
losophy on the skirts of the national movements in Germany
and Italy is really a little too much."

With the adjective "destructive" Dingier touched directly
upon the other feature in the language of the theory of rela-
tivity, the use of the expression "relative." He connected Ein-
stein's theories with the English philosophy of enlightenment
of David Hume, which according to popular conception is only
a variant of materialism, and which the National Socialist Party
felt obliged to oppose.

If the theory of relativity had been advanced by someone other
than Einstein, it is entirely possible that it would not have been
unanimously condemned by the National Socialist Party. The
relativity theory would very possibly have remained a constant
object of controversy in these circles like various other philos-
ophies. Einstein's Jewish ancestry, however, and his political
attitude as a pacifist made the condemnation of his theory
inevitable.

3. Einstein's Theories Attached as Expressions of
Jewish Mentality

In general, National Socialist writers regarded two
groups of characteristics as typical of Jewish thinking. In the first
place, it was said, the Jew prefers pure speculation to experimen-
tal observations of nature. Secondly, it was asserted that the Jew
does not recognize purely mental concepts, but believes only in

251

Einstein: His Life and Times

truths that can be discovered by sensory experience of material
things. Obviously it is not difficult to find one of these char-
acteristics in any physicist-

Among those who attacked Einstein on the ground that his
theories were purely speculative, the most ardent was Philipp
Lenard, who has been mentioned several times already. In his
book German Physics he said:

"Jewish physics can best and most justly be characterized by recall-
ing the activity of one who is probably its most prominent repre-
sentative, the pure-blooded Jew Albert Einstein. His relativity theory
was to transform and dominate all physics; but when faced with
reality, it no longer has a leg to stand on. Nor was it intended to be
true. In contrast to the equally Intractable and solicitous desire for
truth of the Aryan scientist, the Jew lacks to a striking degree any
comprehension of truth that is, of anything more than an apparent
agreement with a reality that occurs independently of human
thought,"

In a lecture delivered at Munich in 1937 before the associa-
tion of provincial teachers and students (Gaudozentenbund
und Gaustudentenbund), the origin and development of this
"Jewish" way of looking at nature was related to political condi-
tions after the first World War. It was said:

"The entire development of natural science is a communal effort
of Aryan scientists, among whom the Germans are numerically fore-
most. The period of Heinrich Hertz coincides with the gradual de-
velopment of a Jewish natural science, which took advantage of the
obscure situation in the physics of the ether and branched off from
the course of development of Aryan physics. By systematically filling
academic positions with Jews and by assuming an increasingly dic-
tatorial attitude, this Jewish natural science tried to deprive Aryan
physics of its foundations, to dogmatize, and to oppress all thinking
about nature. Ultimately it replaced these foundations by a deceptive
imaginary structure known as the relativity theory, above which it
simultaneously inscribed the typically Jewish taboo that is, 'not
to be touched.' This development was temporarily and causally coin-
cident with the victory of Jewry in other fields during the postwar
period/*

In 1938 the Zeitschrift fur die gesamte Naturwissenschaft
(Journal for General Science} was founded for the specific pur-
pose of propagating the National Socialist conception in sci-
ence. In an article: "Racial Dependence of Mathematics and
Physics/' we read the following:

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Einstein's Theories as Political Weapons and Targets

"The influence of the Jews on the development of natural science
is due first of all to a difference in their attitude toward the funda-
mental relation between experiment and theory in favor of the latter.
Theories were constructed without regard for the forms of human
thought and perception and without any rigorous methodology of
reasoning. . . . Einstein's theory of relativity offers us the clearest
example of a dogmatic Jewish type of theory. It is headed by a dogma,
the principle of the constancy of the velocity of light. In a vacuum
the velocity of light is supposed to have constant magnitude inde-
pendent of the state of motion of the light sources and the observer.
It is falsely asserted that this is a fact of experience."

Actually Einstein's principle of the constancy of the velocity
of light is just as much and just as little a fact of experience
and a dogma as any other of the basic hypotheses of a physical
theory. It is only because of erroneous and defective presenta-
tions of Einstein's theory that many persons believe the relation
between theory and experience to be different here from, what
it was in the older theories.

This alleged preference of the Jews for theoretical delibera-
tions was contrasted with the striving of the Aryan German
for concrete action. The same contrast was seen in politics: the
eternal pondering and indecision of the democratic states; and
the firm action of National Socialist Germany.

But by the average spokesmen of Nazi philosophy Einstein's
theories were branded as materialistic and thus linked with
Marxism. In 1936 a lecture was given at the camp of the Natural
Scientific Professional Group of the National Socialist Student
Association, in which it was said:

"Einstein's theories could only have been greeted so joyfully by a
generation that had already been raised and trained in materialistic
modes of thought. On this account it would likewise have been unable
to flourish in this way anywhere else but in the soil of Marxism, of
which it is the scientific expression, just as this is true of cubism in
the plastic arts and of the melodic and rhythmic barrenness of music
in recent years."

The speaker summarized his views in the statement: "The
formulation of general relativity as a principle of nature cannot
be anything but the expression of a thoroughly materialistic
mental and spiritual attitude."

Comparisons can certainly be drawn between the expressions
of a period in different fields. But that Einstein's theories had
developed on the basis of Marxism has certainly not been evi-
dent to the Marxists, as we shall soon see.

253

Einstein: His Life and Times -

The same speaker later (1937) commented on his remarks,
saying:

"Under the influence of the philosophy of enlightenment the nine-
teenth century was a period that was excessively attached to the
surface of things and valued material things beyond all measure.
Hence, the majority of scientists were unable to grasp and to develop
the concept of the ether which by its very nature obeys other laws
than those of matter. Only a few, among them Philipp Lenard, had
the breadth of soul and mind that was necessary for such a step. The
others fell into the hand of the Jew, who instinctively grasped and
exploited the situation."

In order to be able to judge these arguments, one must re-
member that the ether was introduced into physics only to
explain phenomena by analogy with mechanics. Einstein was
the first to recognize the impossibility of a mechanical explana-
tion of optical phenomena, and therefore got rid of the ether.
This was the consistent action of a man who recognized the
untenableness of the mechanistic conception of nature. The sci-
entific supporters of the National Socialist Party did not want to
take this step. They did not want to give up the mechanistic
conception of physics, since it somehow fitted into their philos-
ophy of unsophisticated approach to nature. But as they were
simultaneously opposed to materialism, their position became
a rather difficult one. They introduced an ether that was not
material, and thus had none of the properties for the sake of
which it was introduced.

Later Lenard also proposed this compromise solution. Since
the seizure of power by the Nazis, he attacked Einstein from a
new standpoint. Previously he had opposed Einstein because
the latter had given up mechanistic explanations in physics; now
he accused Einstein of materialism and failing to recognize an
immaterial ether. Einstein, however, introduced no mechanical
basis whatever for optical phenomena and was farther removed
than Lenard from materialism in this mechanistic sense.

Another reason for the opposition to Einstein came from the
circumstance that the word "force" is a term that was used with
particular favor by the National Socialists. They considered it
a great misfortune that this word should disappear from physics.
The fight for this word reveals very clearly the manner in which
physics and politics are connected.

The Austrian Ernst Mach and the German Gustav Kirchhoff
were the first among the physici v sts to construct a system of

254

Einstein's Theories as Political Weapons and Targets

mechanics in which the word "force 5 * did not occur in the laws
of motion. This word was introduced only as an auxiliary con-
cept to abbreviate the mode of expression. Since the National
Socialists characterized everything that they did not like as "Jew-
ish," they regarded the elimination of the word "force" as the
work of the Jews, even though, as we have seen, it was undoubt-
edly first carried out by German physicists. In his Mechanics
Heinrich Hertz, the discoverer of electrical waves, followed
Mach and Kirchhoff in seeking a new way to eliminate the
word "force" from the fundamental laws of motion. National
Socialist authors ascribed this striving to Hertz's Jewish blood.
One of them writes: "If we recall that the Jewish physicist
Einstein also wanted to remove the concept of force from physics,
we must raise the question at this point whether an inner, racially
determined relationship does not appear here." In Einstein's
theory of gravitation the concept of force does not appear as a
basic concept. Bodies move in paths that are represented by the
"shortest" possible curves.

This elimination of force as a fundamental concept is re-
garded as characteristic of the Jewish type of thinking. In an
article in the Zeitschrijt fur die gesamte 'Naturwissenschajt we
read:

"The concept of force, which was introduced by Aryan scientists
for the causal interpretation of changes in velocity, obviously arises
from the personal experience of human labor, of manual creation,
which has been and is the essential content of the life of Aryan man.
The picture of the world that thus arose possessed in every detail the
quality of visual clarity, from which arises the happy impression that
it produces on related minds. All this changed fundamentally when
the Jew seized the reins in natural science to an ever increasing degree.
. . . The Jew would not be himself if the characteristic feature of his
attitude, just as everywhere else in science, were not the disintegration
and destruction of Aryan construction."

The author links "Jewish Physics" with a favorite Nazi target,
the Talmud:

"The mode of thought that finds its expression in Einstein's theory
is known, when applied to other ordinary things, as 'Talmudic think-
ing.' The task of the Talmud is to fulfill the precepts of the Tora, the
Biblical law, by circumventing them. This is accomplished by means
of suitable definitions of the concepts occurring in the law and by a
purely formalistic mode of interpreting and applying them. Consider
the Talmud Jew who places a food receptacle under his seat in a rail-
way car, thus turning it formally into his residence, and in this man-

255

Einstein: His Life and Times

ner formally obeying the law that on the Sabbath one should not
travel more than a mile from his residence. It is this formal fulfill-
ment that is important for the Jews,

"This formalistic Talmudic thinking likewise manifests itself in
Jewish physics. Within the theory of relativity the principle of the
constancy of the velocity of light and the principle of the general
relativity of natural phenomena represent the 'Tora/ which must be
fulfilled under all circumstances. For this fulfillment an extensive
mathematical apparatus is necessary; and just as previously the con-
cept of 'residence' and 'carrying' were rendered lifeless and given a
more expedient definition, so in the Jewish relativity theory the con-
cepts of space and time are deprived of all spirit and defined in an
expedient, purely intellectual way."

The characterization of the Einsteinian definitions of
"length/' "temporal duration/' and so on, as "lifeless" in con-
trast to the definitions of traditional physics has only the fol-
lowing justification. At every stage of scientific development
concepts are introduced by means of such definitions as cor-
respond to the particular stage; that is, they are as practical as
possible for the presentation of available knowledge. When
such a stage has lasted for a long time, the words that are used
in science gradually become words of daily life; they acquire
an emotional overtone and become filled with life. Every in-
troduction of new definitions appears to us to create "lifeless"
concepts.

I once met on a train a Japanese diplomat who was just com-
ing from the Wagner festival at Bayreuth. I asked him how he
liked Wagnerian music. He replied: "Technically it is highly
developed and ingenious. But in comparison with Japanese
music it lacks a soul." For one who has grown up with the
sound of Japanese music in his ears Wagnerian music sounds
just as "lifeless" and "intellectualistic" as the definitions of Ein-
stein's theory do to one who has been accustomed all his life to
Newtonian mechanics.

4. Attitude of the Soviet Philosophy toward Einstein

The Soviet government publishes the great Soviet En-
cyclopaedia that presents the entire knowledge of our time from
the point of view of Soviet doctrines. This article on "Einstein"
begins with the words; "Einstein is the greatest physicist of our

256

Einstein's Theories as Political Weapons and Targets

time." Among the Soviet philosophers he is regarded as a great
physicist who was prevented by the economic circumstances
under which he grew up from drawing the correct philosophical
conclusions from his theory. Regarding Einstein's philosophical
views the Encyclopedia reads: "Einstein's philosophical position
is not consistent. Materialistic and dialectical elements are inter-
woven with Machist assertions, which predominate in almost
all of Einstein's remarks."

In order to understand these comments, it must be remem-
bered that dialectical materialism has been the official philosophy
of Soviet Russia, and that Machism, the teaching of Ernst Mach,
has been the main target of its attack.

On consulting the article on "Ether" in the same Encyclo-
pedia, we find there:

"In physics we often find a completely erroneous contrast between
ether and matter. Since the physicists regard only gravity and inertia
as criteria of materiality, they were inclined to deny the materiality
of the ether. Here we have the same confusion of the physical and
philosophical concepts of matter that was analyzed by Lenin in his
consideration of the crisis in natural science at the beginning of the
twentieth century. . . . The ether is a kind of matter and has the
same objective reality as other kinds. . . . The antithesis of ether
and matter is senseless and leads to agnostic and idealistic arguments.
. . . The theory of relativity has recourse to a mathematical descrip-
tion, it abandons the answering of the question concerning the objec-
tive nature of physical phenomena; that is, in the question of the ether
it takes the standpoint of Mach."

By studying events in Russia since the seizure of power by
Lenin, we can see that no attempt was ever made to exert political
influences on physical theories proper, and when individuals
did attempt to do this, it was not approved by the authorities.
On the other hand, the philosophical interpretation of theories
has been a political matter; the intervention of the party and its
organs, as for example, the Communist Academy of Science in
Moscow, has been regarded as a matter of course. Naturally, the
boundary between a physical theory and its philosophical in-
terpretation cannot always be drawn so distinctly, and on various
occasions border trespassing has taken place. Lenin had already
said on one occasion: "Not a single professor among those who
are able to make the most valuable contributions to the special
domains of chemistry, history, or physics, can be trusted even so
far as a single word when it comes to philosophy."

The official conception of the reciprocal relations between

257

Einstein: His Life and Times

physics, philosophy, and politics is very clearly set forth in an
address delivered by A. F. Joffe, the leading physicist of the
Soviet Union, in 1934 at a memorial session of the Philosophi-
cal Institute of the Communist Party. This session was held to
commemorate the publication twenty-five years previously of
Lenin's chief philosophical work, Materialism and Empirio-
criticism, which contains Lenin's views on the misinterpreta-
tions of modern physics and his attacks on "Machism." In his
address Joffe said:

"When physicists such as Bohr, Schrodinger, and Heisenberg ex-
press their opinions in popular works regarding the philosophical
generalizations of their work in physics, their philosophy is sometimes
a product of the social conditions under which they live and of the
social tasks that they carry out, either consciously or unconsciously.
Thus Heisenberg's physical theory is a materialistic theory; that is,
it is the closest approximation to reality possible at present. Lenin, too,
did not criticize Mach's scientific researches, but only his philosophy."

The philosophers of the Roman Church made, already, a clear
distinction between the astronomical theories of Copernicus and
Galileo's philosophical interpretation of these theories.

In 1938 A. Maximov, one of the best-known Soviet writers
on the philosophy of physics, said in an article on the significance
of Lenin's book mentioned above:

"No physical theory has produced such a stream of idealistic
fantasies as Einstein's theory of relativity. Mystics, clerics, idealists of
all shades, among them also a number of serious scientists, snatched
at the philosophical consequences of the theory of relativity. The ideal-
ists directed all their efforts to the refutation of materialism. Somehow
it had proved the philosophical relativity of time and space. Then
came the general theory of relativity, together with the theory of the
curvature and finiteness of space."

By the phrase "refutation of materialism" is here meant the
proof that departures from Newtonian mechanics and the ether
theory of light are necessary. Maximov then referred explicitly
to the political causes of the idealistic tendencies manifested by
the scientists. He said:

"In our time the bourgeoisie in a number of countries has aban-
doned the veiled forms of capitalistic dictatorship for the open dic-
tatorship of ax and bludgeon. As a result of the persecutions of the
scientific Weltanschauung in the capitalistic countries, which was con-
nected with this transition, many scientists joined the camp of re-

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Einstein's Theories as Political Weapons and Targets

action. This change of loyalties manifests itself among scientists by
the appearance of avowals of idealism and metaphysics. During the
last ten to fifteen years a retrograde trend has manifested itself in all
fields of natural science in the capitalistic countries. Opposition to
Darwinism and to the Kant-Laplace theories in physics, and attacks
on the law of the conservation and transformation of energy, have
become the fashion."

^ It is certainly true that idealistic "interpretations" of the rela-
tivity theory have been frequently used to bolster up Fascist
philosophy.

Soon after the general theory of relativity achieved world
fame, in 1928, this same Maximov described it as a plant that
had sprouted in the mystically inclined soil of die postwar pe-
riod. After describing the postwar years in Germany, he said:

"This idealistic atmosphere surrounded the theory of relativity and
still surrounds it at the present day. It is therefore only natural that
the announcement of general relativity by Einstein was received with
delight by the bourgeois intellectuals. The inability of scholars to
withdraw from this influence within the boundaries of bourgeois
society led to the result that the relativity principle served exclusively
religious and metaphysical sentiments.

"What should be our relation to the theory of relativity ? We should
accept all the empirical material as well as all the conclusions and
generalizations that follow logically from it. ... But in place of the
idealistic presentation of the theory of relativity favored by bourgeois
society we must develop a dialectical presentation of the theory. We
need young capable scientists who are thoroughly imbued with the
proletarian ideology."

In order to understand correctly the Soviet attitude toward
Relativity we have to distinguish two periods. During the first
years of the Soviet regime there prevailed among the official
philosophers the opinions that the relativity theory contradicted
materialism because it did not regard optical phenomena as
phenomena of motion occurring in a material body. This view
was supported by the Moscow physicist A. K. Timiryasev, who
judged all physicists on the basis of their agreement or nonagree-
ment with Newton's mechanistic science.

It will be recalled that Lenard, the leading Nazi physicist in
Germany, had also rejected Einstein's theory because it could
not present a mechanical model of optical events. Soon after its
publication in 1922, Lenard's book was translated into Russian
and published with an introduction by Timiryasev. In the same

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Einstein: His Life and Times

year Maximov wrote a review of Lenard's book for the leading
philosophical journal of the Soviet Union, Under the banner of
Marxism, in which he said :

"While Einstein, the idealist, ascribes an absolute value to the crea-
tions of the mind and puts the world of events on an equal footing
with the world of experiences, Lenard takes a diametrically opposed
point of view. From the standpoint of common sense, which is more
inclined to stick to the experiences of the material world than to the
need of philosophy, Lenard prefers to retain the mechanical picture
of the world. Starting from a standpoint that is in general purely
materialistic, Lenard clearly recognizes the contradiction to which
one is led by the theory of relativity."

On the other hand we have seen that spokesmen of Nazi phi-
losophy frequently asserted that Einstein's theory could have
flowered only in the soil of materialism and that it appears to-
gether with Marxism. Now we see that the authorized inter-
preters of Marxism were apparently not of this opinion. We
also see that the description of a physical theory as "material-
istic" or "idealistic" depends only upon its philosophical interpre-
tation.

The attacks of the earlier Soviet philosophers upon Mach and
Einstein coincided at many points with those of the National
Socialist writers. We need only consider the criticisms that Ein-
stein's theories only "describe" nature, but do not "explain" it,
that they reject everything that cannot be an object of sensory
experience, that they lead to general skepticism and to the de-
struction of all objective knowledge of nature, and so forth.

Later on confusion of materialism with "mechanistic physics"
has been denounced by the "Soviet Institute of Philosophy" as
a "reactionary" doctrine that is not compatible with modern
science. By "materialism" one should not mean that all natural
phenomena could be reduced to motions following Newton's
law. This "mechanistic materialism," as a matter of fact, had
been denounced already by Marx and Engels. But it enjoyed a
comeback, as some physicists used it as a weapon against Ein-
stein's theory as Nazi physicists like Lenard had done in Ger-
many, In stressing dialectical materialism in the sense of Marx,
Engels, and Lenin, "materialism" means that science has to do
with objective facts that are independent of human conscious-
ness; but these facts do not need to be merely motions of material
particles.

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Einstein's Theories as Political Weapons and Targets

In the second period of Soviet philosophy, after the abandon-
ment of "mechanistic" materialism, a leading Russian physicist,
Vavilov, demonstrated that the theory of relativity is quite in
agreement with materialism if this word is interpreted in the
sense of Marx, Engels, and Lenin. In an article that appeared in
1939 Vavilov said clearly:

"Objective real space devoid of material properties, motion divorced
from matter, are metaphysical phantoms that sooner or later have to
be expelled from the physical picture of the world. . . . The historic
service rendered by Einstein was the criticism of the old metaphysical
conceptions of space and time. ... In Einstein's theory space-time
is an inseparable property of matter itself. Such is the basic idea of
Einstein's general theory of relativity. The idealistic conception of
space-time as a category of thought is swept away. . . . Before us is
the first outline, still far from perfect, of the dialectical materialistic
understanding of space and time. Once again dialectical materialism
has triumphed."

More recently, the danger of a "pure philosophy" separated
from science has been more and more recognized in the Soviet
Union. A close co-operation between scientists and philosophers
has been more and more required as the only basis of progressive
thought. Discussions between physicists and philosophers re-
moved the most harmful misunderstandings, and in 1942, after
"twenty-five years of philosophy in the U.S.S.R." the leading
Soviet philosopher, the Academician M. Mitin, gave an address
in the Russian Academy of Science at the twenty-fifth anni-
versary of the Soviet Union in which he celebrated as an im-
portant achievement of these twenty-five years of philosophy
the fact that the attacks against Einstein's theory had ceased and
its compatibility with a sound brand of materialism had been
established.

"As a result," says Mitin, "of the tremendous work that our
philosophers and physicists had carried out, as a result of many im-
passioned discussions ... it may be now said that our philosophical
conclusions concerning this theory have been firmly established. The
theory of relativity does not deny that time and space, matter and
movement, are absolute in the sense of their objective existence out-
side human consciousness. . . . The theory of relativity establishes
only the relativity of the results of measuring time and space by ob-
servers who are moving relatively to one another."

And then Mitin proceeds to characterize Einstein's theory in
almost the same words that Einstein himself had used to sum-

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Einstein: His Life and Times

marize the gist of his theory in one sentence to the newspaper-
men who interviewed him at his first arrival in New York
Harbor.
Mitinsays:

"Time and space are indivisible from the moving body and must be
regarded relative to that movement. In this respect time and space
are relative. ... In place o the old metaphysical conception of pure
time and space having only geometrical qualities, we obtain a new
theory of time and space inseparable, bound up with bodies and
movement."

5. Einstein's Theories as Arguments for Religion

We have seen how Einstein's theories were linked to
expressions such as "materialism" and "idealism" in a fairly am-
biguous manner and in this way used to support political creeds.
It is not surprising therefore that they were used in a similar
fashion in the battle over religious ideas.

It will be remembered how (ch. VIII, sect. 6) the Archbishop
of Canterbury had gone to a great deal of trouble to study the
theory of relativity, and how he had felt reassured by Einstein's
statement that this theory had nothing to do with religion.
Nevertheless, a man like Sir Arthur Eddington, who not only
was an outstanding astronomer and thoroughly conversant with
the theory of relativity, but had also achieved a great reputation
in the field of the philosophy of science, did not agree at all with
Einstein's remark. In his book The Philosophy of Physical Sci-
ence, published in 1939, he said that Einstein's answer to the
Archbishop was not very conclusive.

Consequently I wish to describe some attempts that have been
made to establish a connection between Einstein's theories and
religion. Once again the course taken was by way of philosophy,
and here too the starting-point was the question: Is Einstein's
theory idealistic or materialistic ?

Several years ago in an address to Catholic students Cardinal
O'Connell, Archbishop of Boston, said:

"Remembering the tremendous excitement over the Darwinian
theory of evolution during my boyhood and the furore created less
than ten years ago by Einstein's theory of relativity I tell you that those
theories became outmoded because they were mainly materialistic
and therefore unable to stand the test of time."

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Einstein's Theories as Political Weapons and Targets

Nevertheless, Catholic philosophers were themselves not
agreed whether Einstein's theory is actually materialistic. The
Irish philosopher A. O'Rahilly, who is also thoroughly conver-
sant with theoretical physics, disagrees with Einstein's theory of
relativity because it is based on "subjective idealism."

Thomistic philosophy, which is at present generally regarded
as the scientific foundation of Catholic theology, rejects both
idealism and materialism. Consequently, to the Catholic who
takes his stand on the basis of Scholasticism, either philosophical
interpretation of Einstein's theory is a weapon that can be turned
against him. If, however, the scholastic foundations of religion
are not considered and one consults simply one's feeling, then a
religious person will regard any theory that can be interpreted as
an argument for idealism as supporting his faith. On the occasion
of Einstein's visit to London the conservative Times had stated
triumphantly in an editorial: "Observational science has, in fact,
led back to the purest subjective idealism."

What the journalist stated briefly and concisely for the public
at large was soon demonstrated professionally by the British phi-
losopher Wildon Carr in a book for philosophers and theolo-
gians. In it he said:

"The adoption of the principle of relativity means that the subjec-
tive factor, inseparable from knowledge in the very concept of it, must
enter positively into physical science. . . . Hitherto the scientific
problem has been to find a place for mind in the objective system of
nature and the philosophical problem to validate the obstinate
objectivity of nature. . . . Now when the reality is taken in the
concrete, as the general principle of relativity requires us to take it,
we do not separate the observer from what he observes, the mind
from its object, and then dispute as to the primacy of the one over the
other."

According to this, the achievement of the relativity theory
for religion is simply that it provided a place for mind in nature,
which during the period of mechanistic physics had been re-
garded as completely "material and mindless."

If the reader will recall Einstein's physical theories, he will
easily see that this interpretation is more closely related to the
wording than to the content of these theories. This is even more
obvious in the case of authors who use the four-dimensional rep-
resentation of the theory of relativity as an argument for tradi-
tional religion. As a typical example I wish to quote from an
article written by the director of the Department of Theology

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Einstein: His Life and Times

of an English college abroad, which appeared in the Hibbert
Journal in 1939. He said there:

"If the idea of time as a fourth dimension is valid, then the difference
between this mortal life and the 'other life' is not a difference in the
time nor in the quality of the life. It is only a difference in our view
of it our ability to see it whole. While we are limited to three-
dimensional understanding, it is mortal life. Where we perceive it
in four dimensions, it is eternal life."

This is obviously an interpretation of the words used in the
theory of relativity and has hardly anything to do with its factual
content. Einstein's own attitude to religion, however, has never
been determined by his particular physical theories, but rather by
his general judgment about the role of science and faith in
human life. The numerous attempts to make the theory of
relativity a springboard for excursions into the field of theology
have never been encouraged by Einstein.

264

I.

XII
EINSTEIN IN THE UNITED STATES

The Institute for Advanced Study

As the racial and political purging proceeded in the
German universities, it soon became evident throughout the
entire world that a large number o capable and often famous
men were looking for positions outside Germany. It thus became
possible for institutions abroad to acquire many outstanding
scholars cheaply. One of the greatest German scientists, whom
I visited at his Berlin laboratory in the summer of 1933, showed
me a long list of men who were available and said haltjokingly :
"What we are now doing in Germany is organizing a bargain
sale of good merchandise at reduced prices. Shrewd persons will
certainly seize this opportunity to buy something from us."

The scholars who had been dismissed in Germany could ac-
tually be compared in this way to merchandise that had to be
sold at reduced prices as "irregulars." Even such a slight defect
as the ancestry of a scientist's wife made the sale necessary. And
of these bargains which appeared on the market at that time,,
Einstein naturally created the most sensation. It was as if a great
museum were suddenly to offer for sale Rembrandt's most valu-
able paintings at a very low price simply because the new direc-
tors of the museum did not like to have pictures of a certain style.

Einstein, of course, did not have any troubles in finding a
new position. Many universities offered him posts. The Uni-
versities of Madrid and Jerusalem, among others, invited him,
and one of the oldest and most esteemed institutions of Europe,
the venerable Sorbonne in Paris, actually appointed Einstein a
professor though he never really occupied this position. Ein-
stein wanted to leave Europe because he did not expect any
change for the better in the immediate future. His friends also
cautioned him against settling anywhere near Germany since,
in view of the fantastic ideas regarding Einstein's political in-
fluence and activity held by the ruling party, the danger was
always present that some fanatic might order Einstein to be
"liquidated."

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Einstein: His Life and Times

Einstein had no difficult decision to make, since he had been
offered already and had accepted an ideal position in the United
States. The offer had been made in the summer of 1932, and at
that time it was for him an unexpected sign from heaven to pre-
pare for emigration from Europe.

In 1930 Mr. Louis Bamberger and Mrs. Felix Fuld, on the
advice of Abraham Flexner, who had done so much for the
reform of American education, donated a sum of five million
dollars for the founding of an entirely novel institution for re-
search and teaching. They had asked Dr. Flexner how in his
opinion they could most usefully employ their money, and he
had replied that there were already in the United States many
universities where students could work for the degree of Doctor
of Philosophy, but he felt the lack of another type of institu-
tion. He had recognized the important need for promising
young scholars who had completed the work for the doctorate
to continue their training and research in daily informal inter-
course with the leaders in their fields. Flexner felt that this in-
formal contact between outstanding scholars and students had
been the great achievement of the German universities during
their golden era. In his opinion the American universities were
still not yet adequately organized for this purpose, with the
courses only serving to prepare students for certain academic
degrees and the professors too greatly overburdened to main-
tain any contact with students who had completed their studies.

This institute, which was named the Institute for Advanced
Study, and whose direction Dr. Flexner was asked to assume,
was to be an institution in which a small group of professors
served as the nucleus of a larger, temporary group of mature,
though generally younger scholars. The choice of the staff and
admission of students were to be based entirely on ability, and
no consideration of a social or political nature, which must
necessarily enter into any appointment at collegiate institutions,
was to be made. The founders of the institute made this clear
in a letter addressed to the trustees, as follows :

"It is our hope that the staff of the institution will consist exclu-
sively of men and women of the highest standing in their respective
fields of learning, attracted to the institution through its appeal as an
opportunity for the serious pursuit of advanced study and because
of the detachment it is hoped to secure from outside distraction.

"It is fundamental in our purpose, and our express desire, that in
the appointments to the staff and faculty, as well as in the admission
of workers and students, no account shall be taken, directly or in-

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Einstein in the United States

directly, p race, religion, or sex. We feel strongly that the spirit
characteristic of America at its noblest, above all, the pursuit of higher
learning, cannot admit of any conditions as to personnel other than
those designed to promote the objects for which this institution is
established, and particularly with no regard whatever to accidents of
race, creed, or sex."

It was also intended to free the faculty of this institute as far
as possible from all administrative and pedagogical duties, so
that they could concentrate on their academic work. In the letter
the founders also said:

"It is^our desire that those who are assembled in the faculty of the
institution may enjoy the most favorable opportunities for continu-
ing research in their particular field and that the utmost liberty of
action shall be afforded to the said faculty to this end."

In his address at the organizing meeting Flexner emphasized
particularly that the members of the institute were to have bet-
ter living conditions than in most universities. He said:

"The sacrifices required of an American professor and his family
are to a high degree deterrent. The conditions provided are rarely
favorable to severe prolonged and fundamental thinking. Poor sala-
ries frighten off the able and more vigorous and compel the university
instructor to eke out his inadequate income by writing unnecessary
textbooks or engaging in other forms of hackwork. ... It is there-
fore of utmost importance that we should set a new standard."

It thus became the policy of the institute to have a faculty
consisting of a few excellent but well-paid members.

At first no decision was made as to which subjects would be
cultivated at the institute, but if the principles laid down by the
founders and Dr. Flexner were to be realized, the limited means
that were available made it necessary that the institute restrict
its activities at first to a certain special field. After a good deal
of reflection and consultation Flexner decided to devote the
institute first to mathematical sciences. He was led to this choice
by three reasons. Firstly, mathematics is fundamental; secondly,
it requires the least investment in equipment and books; and
thirdly, it became obvious to Flexner that he could secure greater
agreement upon those who were considered the outstanding
leaders in the field of mathematics than in any other field.

Until the institute could have its own building, President
Hibben of Princeton University turned over to Flexner a part of
Fine Hall, the mathematics building on the Princeton campus.
The beautiful campus with the shady trees and the buildings

267

Einstein: His Life and Times

in the Gothic style of the English universities presented a stim-
ulating environment. Also, the institute obtained a certain point
of departure for its activities by collaborating with the mathe-
maticians of the university. It was expected that as time went
on, outstanding men from the entire world who had already
obtained the doctorate in mathematics would come to Fine Hall.
From the very beginning it had been the idea of the found-
ers that it should somehow have a cloistered character. As Flex-
ner once expressed it: "It should be a haven where scholars and
scientists may regard the world and its phenomena as their lab-
oratory without being carried off in the maelstrom of the im-
mediate." This seclusion of the institute was increased in 1940
when it moved away from Fine Hall and the Princeton campus
to its own building, situated a few miles outside of the town
of Princeton.

2. Einstein's Decision to Join the Institute

Flexner first set out to look for the great masters who
were to form the basis of his institute. He traveled through
America and Europe looking for men of such rank who were
available. In the course of these journeys he came to Pasadena in
the winter of 1932. There he discussed the matter with R. A.
Millikan, the famous physicist, who said to him: "You know
that Einstein is a guest here at present. Why don't you tell him
about your plan and hear his opinion?" At first Flexner was
rather hesitant about discussing such questions concerning
teaching and administration with a man who had already be-
come a legend. He was afraid to approach Einstein because he
was "a too much lionized man." Millikan told him, however,
that Einstein was a man who was interested in all projects for
improving the training of young scholars and who liked every-
thing that was new and bold. "I will tell him about you imme-
diately. Look him up at the Athenaeum." This is the faculty
club of the California Institute of Technology, situated in the
midst of a beautiful palm garden, where foreign scholars stayed
as guests.
Flexner described this visit as follows:

"I drove over to the Athenaeum where he and Mrs. Einstein were
staying and met him for the first time. I was fascinated by his noble
bearing, his simply charming manner and his genuine humility. We

268

Einstein in the United States

walked up and down the corridor of the Athenaeum for upwards of
an hour, I explaining, he questioning. Shortly after twelve, Mrs. Ein-
stein appeared to remind him that he had a luncheon engagement.
'Very well/ he said in his kindly way, c we have time for that. Let us
talk a little longer.' "

At this time Flexner did not yet consider Einstein himself
for this institute. He wanted only to hear his opinion about the
plan. They agreed to meet again early the next summer at
Oxford, where Einstein was to lecture.

As they had planned, Einstein actually met Flexner on the
beautiful lawn of the quadrangle of Christ Church College at
Oxford, where Einstein was staying. Flexner describes the
meeting:

"It happened to be a superbly beautiful day and we walked up and
down, coming to closer and closer grips with the problem. As it
dawned on me during our conversation that perhaps he might be
interested in attaching himself to an institute of the proposed kind,
before we parted I said to him: Trofessor Einstein, I would not pre-
sume to offer you a post in this new Institute, but if on reflection you
decide that it would afford you the opportunity which you value you
would be welcome on your own terms.' "

They agreed that during the summer Flexner would come to
Berlin to continue the talks. It was the summer of Papen's in-
terim government in Germany, the summer when the German
Republic was already dead and led only a ghostly existence. Ein-
stein saw the future with complete clarity and had decided to
keep the road to America open for himself.

When Flexner came to Berlin, Einstein was already living
in his country home at Caputh near Potsdam. It was the same
summer and the same house of which I have already spoken
in Chapter X. Flexner arrived at Einstein's country house on a
Saturday at three in the afternoon. He describes his visit as
follows:

"It was a cold day. I was still wearing my winter clothes and heavy
overcoat. Arriving at Einstein's country home, beautiful and com-
modious, I found him seated on the veranda wearing summer flan-
nels. He asked me to sit down. I asked whether I might wear my
overcoat. 'Oh yes/ he replied. 'Aren't you chilly?' I asked, surveying
his costume. 'No,' he replied, 'my dress is according to the season,
not according to the weather, it is summer.'

"We sat then on the veranda and talked until evening, when Ein-

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Einstein: His Life and Times

stein invited me to stay to supper. After supper we talked until almost
eleven. By that time it was perfectly clear that Einstein and his wife
were prepared to come to America. I told him to name his own terms
and he promised me to write to me within a few days."

As was his custom, Einstein, wearing a sweater and no hat,
accompanied his visitor through the rain to the bus station. The
last thing he said on bidding Flexner farewell was: "I am full
of enthusiasm about it."

Einstein soon communicated the conditions under which he
would take the new position in a letter to Flexner, who found
them much too modest for such an institute and for a man like
Einstein. He requested that the negotiations be left to himself
and to Mrs. Einstein. The contract was concluded at this time.
Einstein pointed out that he was obliged to spend the winter
of 1932-3 in Pasadena and could not go to Princeton until the
fall of 1933. At that time he still had intentions of spending a
part of every year in Berlin, for he preferred not to be unfaithful
to his friends in the world of physics there. But he was very
much aware of coming events. When the Nazi revolution took
place early in 1933, the way had already been prepared for his
emigration to America, and in the winter of 1933 Einstein en-
tered upon his new position at the Institute for Advanced Study,
which Flexner had founded at Princeton. Now there was nat-
urally no further mention of spending a part of the year in
Berlin. Einstein moved to Princeton to become a permanent resi-
dent and citizen of the United States. There were still, however,
a number of stages through which he had to pass in order to
achieve this.,goal. He had entered the country only as a visitor
and for the present had no legal right to remain here perma-
nently, to say nothing of becoming a citizen.

3, Einstein's Activities at the Institute

The institute that Einstein joined was in some respects
similar to the Kaiser Wilhelm Institute to which he had be-
longed in Berlin. Thus he once again occupied a position that
in a certain respect had always appeared distasteful to him. As
I have already mentioned, he always regarded it as an uncom-
fortable situation for anyone to be paid only for his research
work. One does not always have really valuable ideas, so that
there is a temptation to publish papers of no special value. Thus

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Einstein in the United States

the scientist is subject to a painful coercion. But when one Is a
teacher with a moderate load one has every day the consoling
feeling of having done a job that is useful to the society. In such
a situation it is satisfying to carry on research for one's own pleas-
ure during the leisure hours, without compulsion.

On the other hand, however, a man of creative ideas like Ein-
stein chafed under the daily routine of teaching. He found the
idea of teaching very noble, but when he was actually offered
a position where he would be able to devote himself entirely to
research, he was unable to refuse it. At the new Institute he was
able to guide talented students who had already acquired the
doctorate in carrying on their researches. In consequence, how-
ever, his contact with students was restricted to a very small
group. Einstein often vacillated between a feeling of satisfaction
at being spared any routine work and a certain feeling of lone-
liness due to his isolation from the great mass of students.

This divided attitude was quite in accord with his divided at-
titude toward contact with his fellow men in general, which
has already been mentioned repeatedly. This division, which
has played a large part in his entire life, manifested itself also
in his attitude to his environment in Princeton. It would have
been simple enough for him to give lectures or to organize a
seminar, which many of the students might have attended.
Einstein, however, felt that it would not be fair for him, a man
with an international reputation, to enter into a contest with
the professors of the university, some of whom were still quite
young. They could with some justification regard it as "unfair
competition." At any rate Einstein very punctiliously avoided
any such competition for students. It is possible, however, that he
exaggerated in his mind the touchiness and ambition of his col-
leagues, since many would gladly have taken advantage of the
presence of such an outstanding scientist in Princeton to learn
from him themselves. As things were, his presence there has not
been utilized so much as it might have been. No one, perhaps not
even Einstein himself, can say to what degree this situation is
due to his consideration for others and his aversion toward more
intimate contact with people.

By and large, at Princeton Einstein took up his researches
where he had left off in Berlin; this is true both of the prob-
lems themselves and of the way in which he dealt with them.
It was always very characteristic of him to be independent of
his environment. Just as at the time of our meeting in Berlin
twenty-five years before it had been a matter of indifference to

271

Einstein: His Life and Times

him whether he was working at his problems in his study or on
a bridge in Potsdam, so now it made no difference to him that
he had moved his office from the western suburb of Berlin to
the distinguished American university town of Princeton be-
yond the ocean.

Three groups of problems occupied Einstein during this pe-
riod. In the first place there was the desire to develop his special
and general relativity theories of 1905, 1912, and 1916 into an
ever more logically connected structure. In one important point
Einstein succeeded in making a great advance at Princeton. It
will be recalled that Einstein regarded the gravitational field as
a geometrical property of space, which can be called in a word
the "curvature." This curvature is determined by the presence of
matter in space and can be computed from the distribution of
matter. If the curvature of space, or, in other words, the gravita-
tional field, is known, then one also knows how a 'body that
is present in this space will move. This is given by the "equa-
tions of motion/' which can be stated briefly as follows: A body
moves in such a manner that the representation of the path in
a four-dimensional space-time continuum is a geodesic (short-
est) line. This would be entirely satisfactory if one assumed that
matter and force field were two completely different entities.
But one is driven closer and closer to the conception that the
mass of a particle is actually nothing but a field of force that
is very strong at this point. Consequently "motion of mass" is
nothing but a change of the force field in space. The laws for
this change are the "field equations" that is, the laws that
determine the force field. But if the motion of the body is al-
ready determined by the field equations, then there is no more
room for special laws of motion. One cannot make a supple-
mentary assumption, in addition to the field equations, that
masses move along geodesic lines. Instead these equations of
motion must already be contained in the field equations.

C. Lanczos, Einstein's co-worker in Berlin, had sketched the
idea of deriving the laws of motion mathematically from the
field equations. His derivation, however, did not appear satis-
factory to Einstein, and in Princeton he succeeded in showing
in a completely convincing way that only the field laws need
be known in order to be able to derive the laws of motion from
them. This is regarded as a confirmation of the idea that matter
is nothing but a concentration of the field at certain points.

I have already mentioned that Einstein liked to have the assist-
ance of young physicists or mathematicians,, especially when he

272

Einstein in the United States

dealt with involved mathematical computations. From Berlin he
had brought with him the Viennese mathematician Walter
Mayer, who soon obtained an independent position at the In-
stitute of Advanced Study and no longer collaborated with
Einstein, During the first few years of Einstein's residence a
very talented Polish physicist, Leopold Inf eld, came to Prince-
ton, where he remained several years and with whom Einstein
worked out the aforementioned proof of the "unity of field and

matter."

Einstein liked to discuss with Infeld all kinds of problems,
including the fundamental problems of physics and their de-
velopment. These conversations gave rise to the book by Ein-
stein and Infeld, Evolution of Physics, which has achieved a
wide circulation. It is certainly one of the best presentations of
the fundamental ideas of physics for the public at large.

Infeld wrote also an autobiography entitled Quest: The Maf^-
ing of a Scientist. This book contains much about Einstein's life
at Princeton as seen by a keen observer and competent collabo-
rator.

A second group of problems with which Einstein was in-
tensely occupied at this time is the criticism of the development
of the quantum theory, which has been described in Ch. IX.
Einstein felt impelled to show by concrete examples that the
quantum theory, in the "Copenhagen" form in which it had
been formulated by Niels Bohr, did not describe a "physical
reality," such as a field, but only the interaction of the field
with a measuring instrument. A paper that Einstein published
together with N. Rosen and B. Podolsky, two young physicists,
was particularly important in this discussion. This paper shows
by a simple example that the way in which the quantum theory
describes the physical condition in a certain spatial area cannot
be called a complete description of physical reality in this area.

This work stimulated Niels Bohr to formulate more clearly
than he had previously done his standpoint on the question of
physical reality. Bohr now rejected definitely all the "mystical"
interpretations to which his theory had been subjected. Among
these was the conception that the "real state" in a spatial area
is "destroyed" by observation, and similar ideas. He now stated
clearly that the quantum theory did not describe any property of
a field, but an interaction between field and measuring instru-
ment. It is plain that one could not decide between the concep-
tions of Einstein and Bohr by general logical considerations, since
they were not opposed assertions, but rather opposed proposals.

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Einstein: His Life and Times

Einstein proposed to retain tentatively a kind of description of
the physical state in an area of space which was not too far from
the way in which the language of daily life describes reality.
This means that he proposed to describe the physical state in an
area in such a manner that the description itself need not state
with which measuring instrument it was obtained. Einstein has
been well aware that it would not be absurd to abandon this kind
of description where the laws of physics are formulated in terms
of a "field"; but he would abandon it only if it became necessary
beyond any doubt.

The third and most exciting problem was his attempt to find
the actual physical field that permits a formulation of physical
laws for the subatomic phenomena in a form that is a generaliza-
tion of the equations of the electromagnetic and gravitational
fields. Einstein has collaborated in this task with two young men,
one called Bergmann, the other Bargmann, a similarity that gave
rise to many jokes.

Every forenoon Einstein went regularly to his office at the
Institute for Advanced Study, where he met either Peter Berg-
mann or Valentin Bargmann or both of them. Einstein sug-
gested to them various ways of conceiving the structure of space,
not only as four-dimensional, but sometimes also as five-dimen-
sional, so that the magnitudes that describe this geometrical
structure could also furnish a description of the unified physical
field of force. The real force field would then be found, if one
could find relations between the described magnitudes, from
which the actual laws of observable phenomena can be derived
in all domains of physics, including atomic and nuclear physics.

The difficulties of this task proved to be even greater than had
been supposed. At present it seems that all the paths that have
previously been tried do not lead to the goal Recently, Einstein
has probed new field equations and he has by no means aban-
doned the hope that electrons and protons will turn out to be
just particular fields. Despite the tremendous range of experi-
mental confirmation of Bohr's "positivistic" Theory it remains,
according to Einstein, still an open question, whether it is not
possible to derive the same observable facts from a field theory
and to save the historic conception of a physical reality inde-
pendent of the devices of observation and measurement.

Besides the regular work connected with the Institute, Ein-
stein had to occupy a part of his time as an adviser of young men
with interest or ambition in science. It had often been Einstein's
fate to be judged not only as an individual, but as a type in-

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deed, even more, as the symbol of a certain group of people. This
fate was all the more painful for him as there was nothing that
he liked less than to be classified as a member of a party or a
group. As he had come out courageously for the cause of the
Jewish people he has been expected to play the part of a leader
or at least of a representative of his people both by the enemies of
the Jews and by the Jews themselves. The life of Einstein has
been regarded as symbolizing the fate of a people, often talented,
but often attacked and driven into isolation. Therefore among
the people who looked for Einstein's advice there were many
young Jews who wrote letters to him appealing for his help. In
some degree he has played the role among the Jews that Tolstoy
at one time had played among Russian youth. Poor young Jews
looked upon Einstein as one of their people who had made good
and who was so world-renowned that boundless power and
wealth were ascribed to him. This was, I dare say, a great mis-
take. Neither his fortune nor his influence has corresponded
even remotely to his fame.

Very often young people of any background turned to him for
advice about beginning an academic career for which they felt
they were equipped instead of turning to some mechanical work
in an office or a shop. Einstein was always ready to advise what he
considered proper and was interested in each one's personal
situation. However, as we have learnt, Einstein also believed that
it was a good thing to earn a living by means of a " cobbler's
trade " and to devote one's spare time to study.

Einstein never liked to speak about the material and moral
help he provided for distressed people. I recall several cases,
however, that I was able to observe myself. Einstein remained
interested in students whom he had helped to enter a university,
and continued to watch them as they progressed with their
studies. He advised them with which teachers to study, which
books to read, and even sent them books himself. I remember
one such case very clearly.

It concerned a student from one of the Balkan countries. Upon
Einstein's advice he had applied to the university in Prague,
where he was admitted. Einstein asked me to take an interest in
him and so he consulted me when he had trouble. The student
lived on a stipend that he received from a big manufacturer in his
native land. But this money, which barely sufficed for himself,
the student used to enable his brothers and sisters to study as well.
The fact that one of the greatest men of our time was watching
his studies was the great event of his life and filled even the

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Einstein: His Lije and Times

minutest experience with a remarkable splendor. When the
young man first turned to Einstein, the latter was still in Berlin,
but when the young man arrived in Prague Einstein was already
in America. The student wrote to Einstein telling him about
every phase, even the most trivial, of his studies; and frequently
he received answers from America that gave him extremely de-
tailed advice. When the student met with difficulties in his rela-
tions with teachers or fellow students, he asked Einstein's advice
as to how he should behave. Einstein usually advised him to be
conciliatory. This was certainly very good advice for this young
man, as he became involved in various conflicts in the unfamiliar
environment. He was naturally filled with pride because he was
distinguished from all the other students of physics by the fact
that he corresponded personally with the greatest physicist of our
time.

There is little wonder that occasionally a student in this situa-
tion imagined himself as Einstein's representative to such a de-
gree that he regarded all insults to him as insults to Einstein. He
would even feel that he was a martyr, happy at being permitted
to suffer for Einstein, and finally even came to believe that by
being connected with Einstein he was making a sacrifice and
getting himself into trouble.

4. Refugee Scholars

As the persecution of the Jews increased in Germany
and her satellite countries, the number of scientists, writers,
artists, teachers, and others who wished to find haven in the
United States grew larger and larger. As when a large quantity
of good merchandise is thrown on the market at reduced prices,
economic repercussions occur, even inflation, so when these refu-
gee scholars offered themselves, great difficulties were encoun-
tered.

The new immigration began while the United States was
still in the midst of the great economic crisis. This was, of
course, not an accidental coincidence since without the world-
wide depression the Nazi revolution in Germany would not
have occurred. As the number of immigrants increased, fan-
tastic rumors began to be spread about them. It was frequently
said that the refugees were not pioneers; they did not per-
form any constructive work as the earlier immigrants had done,

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Einstein in the United States

but they wanted only to get rich without working or to live
on charity. Many regarded and feared them as professional
competitors, many simply used them as scapegoats whom they
could blame for various ills. Skillful agitators were even able
to convince people that enormous numbers of such immigrants
would soon change the national and racial composition of the
people of the United States.

When Bertrand Russell, the English mathematician and phi-
losopher, because of his critical attitude to traditional views on
marriage and religion, was prevented from being appointed as
professor of philosophy at the College of the City of New York,
Einstein backed him. He felt that it was harmful for the develop-
ment of science when attacks of personal and political opponents
could prevent the appointment of a scientifically outstanding
professor. Russell's enemies, however, used Einstein's support
for their own aims. They wrote letters to newspapers contain-
ing such statements as: "How dare the 'nudist' Russell and the
'refugee' Einstein interfere in the family life of the United
States!" The use of the words "nudist" and "refugee" as equally
disparaging characteristics is noteworthy.

Every institution that wanted to appoint one of the refugee
scholars was in a dilemma. On the one hand, the American uni-
versities were quite ready to help the victims of political persecu-
tions and were glad to have the opportunity of acquiring men
of great ability, but, on the other hand, they had a responsibility
to their own graduates who were looking for academic posi-
tions. It would have been a severe disappointment for them to
have positions unexpectedly filled by scholars from Europe who
were naturally older and had greater reputation.

This situation also placed those refugee scholars who had al-
ready obtained a position in a difficulty. They felt morally ob-
ligated to help their countrymen and fellow sufferers who had
been less fortunate, but they also felt obliged to look after the
interests of their students primarily. Some of them even went so
far as to say that it was the duty of every refugee scholar who had
a position to see to it that no other refugee obtained one at the
same institution.

For Einstein the situation was even more difficult. Here again
he came to be regarded as the symbol and leader of the entire
group of refugee scholars. The friends of the refugees upheld
Einstein as an example of the outstanding men who were com-
ing to the United States, while their opponents felt themselves
compelled to disparage him in order to oppose the refugee

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group. The refugees themselves looked upon Einstein as their
natural leader. They felt that with his fame he would some-
how be able to help them, and they turned to him for help.

Einstein received hundreds of letters from scholars in Europe
who wanted to emigrate and who asked his aid in getting them
a position or an "affidavit of support/' required under the Amer-
ican immigration regulations. Einstein tried hard to help them,
and he even made out such affidavits himself for many. Others
immediately turned to Einstein on their arrival in America. He
did the best he could, but naturally the number of persons
whom he was actually able to help was very small in comparison
with the enormous number who appealed to him.

In recommending foreign scholars for positions, Einstein as
always had only two considerations in mind: the immediate
feeling of sympathy for every suffering person, and the convic-
tion that the pursuit of science should be assisted wherever pos-
sible. He was always ready to write recommendations for these
people. He thought that if a foreign scientist was needed, his
recommendation would be of some help, and if this were not
the case, it would not hurt either the person recommended or
the institution.

Einstein might have done more for the refugees if he had un-
dertaken to study the situation at various universities and to
take advantage of the personal, economic, and political factors
involved, but such an action was not possible for him. The peo-
ple who are the most outstanding intellectually and also the
kindest are not always very practical. This explains the con-
tradictory opinions about Einstein. Some people felt that he was
kind and devoted, others that he cared little for the fate of in-
dividuals.

While co-operating sincerely in charitable social and political
organization Einstein will suddenly tell you: "Sincerely speak-
ing I have never been much interested in people but only in
things." And if you ask him what he meant by "things" he
would say: "physical phenomena and methods to handle them."

The psychological situation of these new refugees also had
its difficulties. Many came from Germany, which they had al-
ways considered their native land and with whose intellectual
and cultural life they felt themselves united. They had been
driven out, but that did not mean that they had therefore lost
all connection with it. They came to a foreign country that gave
them a friendly reception and made it possible for them to
start a new life, which was sometimes even better than the life

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Einstein in the United States

in their former country. If they laid too great an emphasis on
their connection with German culture, they could easily arouse
a feeling of antagonism to themselves in the new country.

On the other hand, owing to the circumstances leading to
their emigration, they were strongly opposed, both politically
and culturally, to the ruling circles in Germany. As a result,
they were accused on the one hand of propaganda in favor of
German culture, and on the other hand of carrying on hate
propaganda that might create enmity between the United States
and Germany or even involve them in war. Remarkably enough,
these contradictory accusations were often made at the same
rime.

Einstein himself was often surprised that the new immigrants
from Germany still remained so much attached to their old
country. It was a special puzzle to him why the Jewish refugees,
who had suffered so much in Germany, still had such a strong
yearning for that country. As Erika and Klaus Mann reported,
Einstein on one occasion told this story:

"I met a young German lawyer who is living in New York, a so-
called Aryan, and asked him whether he was homesick. 'Homesick?'
he said. 1 ? What for? I am not a Jew.'

"Isn't that a good one?" Einstein added. "Isn't that typical? Isn't
the nationalism of the Jews sentimental and lachrymose, a sullen and
morose love for a country such as is to be found only among people
who do not feel sure which country is theirs?"

"I am also a Jew," continued Einstein, "but yet everything seems to
me so fine in America that I am not homesick for any country, to say
nothing of Herr Hitler's Germany."

We know Einstein's aversion against the inhuman mechanical
attitude of the German ruling caste under the Kaiser, let alone
under Hitler. Equally strong, however, is his love for the Ger-
man music of Bach and Mozart. In certain respects, perhaps, he
even shares the tastes of the German nationalists in art. He dis-
likes "modern" music and finds it rather repugnant. Generally,
he likes everything German that derives from the spirit of the
pre-Bismarckian and pre-Wilhelminian period. He has been
happy with visitors imbued with the spirit of classical German
music and literature. He is even quite sympathetic to the Kan-
tian philosophy, partly perhaps because of its emotional relation-
ship with that period of the German spirit. He has this sympa-
thetic feeling for it although on purely scientific grounds he has
rejected it in all essential points.

I have been struck by the fact that despite his emphasized hos-

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Einstein: His Life and Times

tility to the spirit of a Germany ruled by Prussian militarists, he
has always been fond of conversing with men for instance,
German- American ministers, in whom the older German spirit
had somehow been preserved.

In America Einstein had often been regarded officially as a
leader of the Jewish people. When the World's Fair was opened
in New York in 1939-40, Palestine was represented by a pa-
vilion. Since it was customary, at the opening of a pavilion, for
the ambassador of the particular country to deliver an address,
the question arose who should deliver such an address at the
opening of the Palestinian pavilion. The choice did not fall
upon a political leader of the Zionists, nor on a rabbi, but instead
on Einstein, who was thus officially recognized as a kind of
spiritual leader of the Jews.

5. Einstein's Attitude toward Religion

To understand Einstein in its attitude to the Jewish peo-
ple, one must understand his attitude to traditional Biblical re-
ligion and to religion in general. Would not a man like Ein-
stein, whose unsparing criticism had removed the last remnants
of medieval semi-theological conceptions from physics, assume
a purely critical attitude to the religion of the Bible ? Ever since
his arrival in America this aspect of his personality has been
much in the limelight. In this country people are more interested
than in Europe in the problem of the relation between science
and religion, and they feel more strongly the need for a mutual
understanding between them.

Einstein's attitude toward traditional religion is related in
turn to his divided attitude to social relations in general
When I first became acquainted with Einstein, around 1910, I
had the impression that he was not sympathetic to any kind of
traditional religion. At the time of his appointment to Prague
he had again joined the Jewish religious community, but he
looked at this act rather as at a formality. At this time, too, his
children were about to enter elementary school, where they
would receive religious instruction. This was a rather difficult
problem as he belonged to the Jewish religion and his wife to
Greek Orthodox. "Anyway," said Einstein, "I dislike very much
that my children should be taught something that is contrary to
all scientific thinking." And he recalled jokingly the manner

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Einstein in the United States

In which school children are told about God. "Eventually the
children believe that God is some kind of gaseous vertebrate/'
This was an allusion to a saying of the German scientist and
philosopher Ernst Haeckel that was then current.

At that time a superficial observer would easily have settled
the question of Einstein's attitude to religion with the word
"sceptical" Perhaps characteristic of this attitude is a remark that
Einstein made to an orthodox Jew whom he once met at a
police station in Prague, where I had gone with him to obtain a
visa for a passport. The man asked Einstein if he knew a restau-
rant in Prague where the food was strictly kosher that is,
prepared according to the ritualistic precepts, Einstein men-
tioned the name of a hotel that was known to be kosher. The
man asked Einstein: "Is this hotel really strictly kosher?" This
annoyed Einstein somewhat and he said seriously: "Actually
only an ox eats strictly kosher." The pious man was hurt and
looked indignantly at Einstein. The latter, however, explained
that his statement was not offensive at all but quite objective
and innocent: "An ox eats grass, and that is the only strictly
kosher food because nothing has been done to it."

Einstein's attitude reflects often the immediate response of a
genius which is similar to that of an intelligent child. The world
is not judged in the traditional way, but as reason suggests. If
this judgment is expressed without any of the traditional eu-
phemisms, it is often called "cynical"; but it should be called
rather "sincere with a sense of humor."

Einstein was once told that a physicist, whose intellectual ca-
pacities were rather mediocre, had been run over by a bus and
killed. He remarked sympathetically: "Too bad about his body."

On another occasion Einstein was invited by a committee
organized to honor a well-known scholar to take part in the cele-
bration of his seventieth birthday and to address the gathering.
Einstein replied to this committee: "I hold the man whom you
are honoring in high esteem and I like him very much. For this
reason I will arrange a dinner in his honor all alone at my home
on his birthday. Since no audience will be present, I will simply
keep the speech to myself. Wouldn't it be more convenient for
you and the scholar whom you are honoring if you did the
same?"

His manner of speech is often an expression of the urge to
make the serious things in the world tolerable by means of a
playful disguise, a form of behavior that is ultimately the basis
of all artistic activity. The use of such caustic words was for

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Einstein: His Life and Times

Einstein an artistic way of coming to terms with the world, like
the playing of a Mozart sonata, which also represents the evil
of the world in a playful manner. In a certain sense all of Mo-
zart's music might be called "cynical." It does not take our tragic
world very seriously and reflects it in gay, youthful rhythms.

To understand Einstein's views on religion seriously it is good
to start from his conception of physical science and of science in
general As I have already repeatedly emphasized, the general
laws of science, according to Einstein, are not products of induc-
tion or generalization but rather products of free imagination
which have to be tested by physical observations. In his Oxford
address Einstein asks:

"If it is the case that the axiomatic basis of theoretical physics can-
not be an inference from experience, but must be free invention, have
we any right to hope that we shall find the correct way ? Still more
does this correct approach exist at all save in our imagination?'*

To Einstein the physical theory is a product of human in-
ventiveness, the correctness of which can be judged only on the
basis of its logical simplicity and the agreement of its observable
consequences with experience. This is exactly the description of
a theory and the criterion of its validity which has been advocated
by the Logical fositlmsts. To them the belief in the "existence of
a correct theory" means the "hope to make a certain invention."
The expression "the correct form of a theory" has no more mean-
ing than "the correct form of an airplane" what is obviously a
meaningless expression.

But here Einstein deviates definitely from the conception of
Logical Positivism. In his Oxford lecture he replied to the ques-
tion whether there is a "correct way" as follows:

"To this I answer with complete assurance that in my opinion there
is the correct path and, moreover, that it is in our power to find it.
Our experience up to date justifies us in feeling sure that in nature
is actualized the idea of mathematical simplicity.

"It is my conviction that pure mathematical construction enables us
to discover the concepts and the laws connecting them, which give us
the key to the understanding of the phenomena of nature. Experi-
ence can, of course, guide us in our choice of serviceable mathematical
concepts; it cannot possibly be the source from which they are derived.

"In a certain sense, therefore, I hold it to be true that pure thought
is competent to comprehend the real as the ancients dreamed."

Here Einstein even goes so far as to use the language of ideal-
istic philosophy, of the advocates of an aprioristic knowledge

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Einstein in the United States

that is, knowledge independent of experience although he
has been a decided opponent of this philosophy. Nevertheless,
in order to emphasize as strongly as possible his opposition to
some oversimplifications current under the name of "positivism"
he employs a mode of expression that can easily be misunder-
stood by those who have only a superficial knowledge of Ein-
stein's views.

The difference between Einstein's views and those "dreams of
the ancients" to whom he felt related is the following: Accord-
ing to the views of the ancient philosophers the power of intui-
tion suffices to advance propositions that do not need to be tested
by experience. But this is not what Einstein actually means. He
means that the inventive faculty presents us with various pos-
sibilities for the construction of mathematical theories, among
which only experience can decide.

The conviction of which Einstein spoke, and for which, nat-
urally, no cogent reasons can be given, is the following: among
the theories there will some day be one which in its logical
simplicity as well as in its simple representation of observation
will be so greatly superior to all rival theories that everyone will
recognize it as the best in every respect. This conviction is noth-
ing but an expression of scientific optimism. It is an expression
of belief in a certain constitution of observable nature, which has
been often called a "belief in the rationality of nature."

The existence of such logical pictures of nature is a character-
istic that is not self-evident, but which we recognize by experi-
ence and which we may call the "rationality of nature," if we
prefer to employ the terminology of traditional philosophy.
This terminology is usually employed when one wishes to ex-
press one's sympathy with certain feelings that are customarily
expressed with great beauty in the language of that philosophy.
Amazement at this rational aspect of nature turns into admira-
tion; and this admiration is, in Einstein's opinion, one of the
strongest roots of religious feeling.

When we speak of the existence of a logical system that cor-
responds to natural processes, the term "existence" means in
everyday language only that there are thinking beings similar
to men which can imagine such a system. If we speak of the
"existence" of such a system without relating it to a thinking
being, it is an obscure mode of expression. If we do connect it
with a thinking being, we imagine more or less vaguely a being
similar to man with superior intellectual capacities. Conse-
quently, to speak of the "rationality" of the world always means

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Einstein: His Life and Times

to think vaguely of a spirit superior to man and yet similar to
Mm. In this way Einstein's conception of nature is related to
what is usually called a "religious" conception of the world.
Einstein knows very well that this is not a statement about
nature that is in any way scientific, but that it expresses a feeling
aroused by the contemplation of nature. In this connection he
once said:

"The most beautiful emotion we can experience is the mystical.
It is the sower of all true art and science. He to whom this emotion is
a stranger,, who can no longer wonder and stand rapt in awe, is as
good as dead. To know that what is impenetrable to us really exists,
manifesting itself as the highest wisdom and the most radiant beauty,
which our dull faculties can comprehend only in their most primitive
forms this knowledge, this feeling, is at the center of true re-
ligiousness. In this sense, and in this sense only, I belong to the ranks
of devoutly religious men."

According to Einstein's conception, it is particularly the sci-
entist in the field of natural science, and especially in the field
of mathematical physics, who has this mystical experience. Here
is the root of what Einstein calls "cosmic religion." He once said:

"The cosmic religious experience is the strongest and the noblest,
deriving from behind scientific research. No one who does not ap-
preciate the terrific exertions, the devotion, without which pioneer
creation in scientific thought cannot come into being can judge the
strength of the feeling out of which alone such work, turned away
as it is from immediate practical life, can grow.

"What deep faith in the rationality of the structure of the world,
what a longing to understand even a small glimpse of the reason
revealed in the world, there must have been in Kepler and Newton!"

In recent years the view has frequently been put forth that the
physical theories of the twentieth century, especially Einstein's
theory of relativity and the quantum structure of energy, have a
great significance for the mitigation of the conflict between
religion and science. Since Einstein has spoken of a "cosmic reli-
gion" based on science he has been often quoted as an advocate
of that view. This, however, is a great misunderstanding. With
his clear insight into the logical structure of a scientific theory, he
has never encouraged the religious interpretation of recent phys-
ics which became current by the popular books of such scientists,
as Jeans and Eddington.

For Einstein religion is both a mystical feeling toward the laws

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Einstein in the United States

of the universe and a feeling of moral obligation toward his fel-
low men as well. Nevertheless, the strictly logical-empirical char-
acter of his thought prevents him from assuming a scientific
or apparently scientific link between these two feelings. We may
feel a hint of it in music, which expresses what cannot be formu-
lated in words.

This feeling, however, has been misunderstood by some peo-
ple, since Einstein has never placed any importance on the formal
aspects of religion. It was striking how readily Einstein used the
word "God" as a figurative expression, even in physics. It will
be recalled that he had repeatedly expressed his rejection of the
statistical conception of physics with the statement: "I cannot
believe that God plays dice with the world." It is certain that
the word "God" is used here only as a figure of speech and not
in a theological sense. Other physicists, however, do not em-
ploy this figure of speech with equal readiness. One of Einstein's
finest remarks, which is recorded on a wall in the Institute of
Advanced Study at Princeton, expresses his conception of the
nature of physical science by means of the same figure of speech.
Einstein wants to say that from a mathematical standpoint the
system of physical laws is very complex, and that to under-
stand it very great mathematical capacities are required. Never-
theless, he has hope that nature actually obeys a system of mathe-
matical laws, and that the human mind can find these laws if
it allows itself to be led by its scientific judgment. All this is
expressed by the aforementioned remark:
"God is sophisticated, but he is not malicious."
In the fall of 1940 a conference was held in New York to
discuss what contributions science, philosophy, and religion
could make to the cause of American democracy. Einstein was
among those asked to address the conference. At first he did
not want to write anything, as he disliked to attract public
attention to himself, especially in political matters. Nevertheless,
as the aim of the conference appealed to him, he allowed him-
self, even though he would not appear and speak in person, to
be induced to send a written contribution, entitled "Science and
Religion." In it he said:

"The main source of the present-day conflicts between the spheres
of religion and of science lies in the concept of a personal God. It is
the aim of science to establish general rules which determine the
reciprocal conceptions of objects in time and space. ... It is mainly
a program, and faith in the possibility of its accomplishment in prin-
ciple is only founded on partial success. But hardly anyone could be

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Einstein: His Life and Times

found who would deny these partial successes and ascribe them to
human self-deception. . . .

"The more a man is imbued with the ordered regularity of all
events, the firmer becomes his conviction that there is no room left
by the side of this ordered regularity for causes of a different nature.
For him neither the rule of human nor the rule of divine will exists
as an independent cause of natural events. To be sure the doctrine
of a personal God interfering with natural events could never be
refuted, in the real sense, by science, for this doctrine can always take
refuge in those domains in which scientific knowledge has not yet
been established. . . .

"To the sphere of religion belongs the faith that the regulations
valid for the world of existence are rational, that it is comprehensible
to reason, I cannot conceive of a genuine scientist without that pro-
found faith. The situation may be expressed by an image: science
without religion is lame, religion without science is blind."

There is apparently nothing sensational or shocking in these
sentences. Those scientists who were willing to concede to re-
ligion an important place in human life have generally found
that Einstein formulated just what they thought. On the other
hand, there are certainly many scientists who take it much amiss
that Einstein even mentions religion and spirituality in the
same breath with science.

Suddenly, however, a number of people appeared with the
cry: "Einstein wants to deprive us of our personal God." "It is
this very personal element in God," they said, "that is most
precious to man." Einstein received innumerable letters, many
containing vehement accusations to the effect that he wanted to
rob people of such a beneficial faith. Letters to the editor ap-
peared in newspapers, in which the writers protested against
permitting a "refugee" to meddle with the belief in God.

There were Christian clergymen who asserted that the ex-
pression "personal God" was characteristic of the Christian God
in contradistinction to the Jewish God, and that Einstein was
carrying on a polemic against the Christian conception of God.
Actually Einstein knew nothing of these subtleties of Christian
and Jewish theology. On the contrary he wanted to emphasize
the common ground of liberal Judaism and liberal Christianity
in their conception of God. But here again, as in so many in-
stances, his well-meant intentions involved him in odious and
malicious polemics, which he could not have foreseen.

As in most other points, Einstein advocated practically posi-
tivistic views concerning the relations of the exact sciences and of
science in general to human conduct. To the question whether

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Einstein in the United States

the goal of human life could be derived from science only, Ein-
stein, like positivism, replied with a decided "No." Like logical
positivism, Einstein is of the opinion that no matter what degree
of mathematical simplicity and beauty the laws of nature
exhibit, no matter how well they reflect observation, they can
never tell us what man's aims in life should be. From natural
laws we learn only how nature behaves, how we can utilize
these forces to realize human aims, not what these aims should
be.

These aims man can learn only by example and indoctrina-
tion. It is this indoctrination that Einstein believes to be the
task of the church, not the preaching of a certain conception of
nature.

Because Einstein is profoundly convinced that science, even
when most highly developed, cannot present man with a goal,
he is far from disputing the usefulness of church organizations.
He does not care for religious ritual, but he realizes the value
of churches and religious services as means of education; and
in so far as the ritual increases the effect of indoctrination, he has
learned to appreciate the value of religious ceremony.

Einstein's views on the responsibility of the church for moral
education may be seen, perhaps, in an address that he delivered
in the summer of 1939 in the theological seminar at Princeton
before an audience of clergymen and students of theology. The
title of the lecture was "The Goal. 5 ' Among other things he
said:

"It is certainly true that principles cannot be more securely founded
than on experience and consciously clear thinking. In this one will
have to agree absolutely with the extreme rationalists. The weak point
of the conception, however, lies in the fact that those principles which
are decisive and necessary for our actions and judgments of value
cannot be obtained only in this scientific way. The scientific method
cannot teach us anything but the conceptual comprehension of the
reciprocal relations among facts. The endeavor to obtain such ob-
jective knowledge is one of the loftiest aspirations of which man is
capable, and you will certainly not suspect me of underrating the
heroic efforts and achievements of the human mind in this field. On
the other hand, however, it is clear that no path leads from a knowl-
edge of that which is to that which should be. No matter how clear
and perfect our knowledge of present existence, no goal for our
human aspirations can be inferred from it. ... No matter how
splendid the knowledge of truth as such may be, as a guide it is 30
impotent that it is not even able to establish the justification and the
value of this very striving for a knowledge of the truth. . . .

287

Einstein: His Life and Times

"Reason apprises us of the interdependence of aims and values,
What thought alone cannot give us are the ultimate and most funda-
mental goals, in terms of which the more secondary ones are oriented.
The setting up of the most fundamental goals and valuations and
their establishment in the life of the individual seem to me to be the
most important function of religion in the social life of man. If one
should ask whence these fundamental goals receive their authority,
since they are not set up by reason and cannot be founded upon it,
one can only answer that they do not come into existence as a result
of argument and proof, but instead by revelation, and through the
actions of strong personalities. One should not attempt to prove
them, but rather to recognize their essence as clearly and purely as
possible.

"The most fundamental principles of our aspirations and valua-
tions are given to us in the Judeo-Christian religious tradition. It is a
lofty goal. . . . When one divests this goal of its religious form and
regards only this purely human side, it may be expressed as follows:

"Free and self-responsible development of the individual so that
he will freely and joyfully put his energies at the service of the com-
munity of man. If attention is paid to the content and not to the
form, the same words may be considered as the expression of the
fundamental democratic principle. The true democrat deifies his
nation just as little as the religious person in our sense does."

Einstein's conception of the relation between religion and sci-
ence is very similar to that prevailing in the liberal Protestant
churches of America. As an example one need only cite the
views of an outstanding representative of American science
such as Robert Millikan. According to this conception, science
can never be criticized or directed by religion, since it deals with
very different aspects of human life. Millikan once said:

"Let me show why in the nature of things there can be no conflict.
This appears as soon as one attempts to define what is the place of
religion in human life. The purpose of science is to develop without
prejudice a knowledge of the facts and the laws of nature. The even
more important task of religion, on the other hand, is to develop the
conscience, the ideals and the aspirations of mankind."

This conception of religion abandons completely any demand
for belief in any specific scientific or historical facts, and regards
religion as a social institution, the purpose of which is to promote
a certain attitude toward life and a certain type of behavior in
our daily living. Einstein's conception of religion fits in very
well with this general attitude. Consequently we can under-
stand why English and American clergymen in particular have
been so much interested in Einstein.

288

Einstein in the United States

6. Beginning of the Atomic Age

The dramatic climax with which the second World
War was brought to an end by the atomic bomb again brought
Einstein's name to public attention. The result that he had de-
rived from his special theory o relativity in 1905 namely,
that mass and energy are equivalent was demonstrated to
the world with almost incredible force of destruction.

As was mentioned in Section 7 of Chapter III, there are nu-
clear transformations in which a part of the mass of the atomic
nucleus is transformed into energy. Numerous such reactions
were discovered by scientists, but in all cases the energy required
to perform the transformation was much greater than that ob-
tained from the reaction. Hence the practical use of nuclear
transformations as a source of power did not seem feasible.

The whole picture changed, however, with the discovery by
Otto Hahn and Lise Meitner of the fission of uranium. These
scientists at the Kaiser Wilhelm Institute in Berlin found that
when uranium is bombarded with neutrons, its nucleus some-
times breaks up into two more or less equal parts with the lib-
eration of a tremendous quantity of energy. When this news
was communicated to other laboratories, the startling result was
immediately confirmed. Furthermore, Enrico Fermi, an Italian
physicist who had fled to the United States from the Fascist
regime, pointed out the possibility, which was soon found to
be true, that this breaking up of the uranium nucleus is ac-
companied by the production of several neutrons. The impor-
tant significance of this last discovery lies in the fact that this
process, named the "fission" of uranium, may be made self-
sustaining. Once the process is started, the neutrons produced
by the fission of one uranium nucleus can cause others to break
up, and the neutrons from these can, in turn, cause other fis-
sions. Thus a self-perpetuating nuclear "chain reaction," in
which a large number of nuclei breaks up with the consequent
liberation of a tremendous amount of energy, became a pos-
sibility. Calculations showed that as much energy would be re-
leased by the fission of a pound of uranium as by the burning
of thousands of tons of coal

It soon became evident to many scientists that this liberation
of energy may be made to take place almost instantaneously,
and that consequently uranium bombs with millions of times

289

Einstein: His Life and Times

the destructive power of ordinary explosives could be produced.
It was also evident to them that if such an instrument came into
the hands of the fascist nations, they would use it in their war
of aggression, and civilization would then be doomed. Such
apprehensions were felt especially strongly by those scientists
who had fled from the persecutions in their native countries.
Two physicists at Columbia University, a Hungarian named
Leo Szilard, who had fled from the University of Berlin, and
the aforementioned Fermi, became convinced that the military
authorities in the United States ought to be informed about
this possibility. Moreover, Szilard realized that unless this prob-
lem was taken to a government official in a very high position,
their words would not be heeded. He had been acquainted with
Einstein in Berlin and it seemed to Szilard that Einstein's great
reputation and world-wide recognition as a physicist could be
used to convince the authorities of the importance of this prob-
lem. He therefore got in contact with Eugene Wigner, another
Hungarian physicist, then teaching at Princeton University, and
in July 1939 they conferred with Einstein.

At that time the average engineer, civilian or military, re-
garded the theory of relativity as something very bookish, which
only impractical college professors talked about and which
would never have any industrial application. And as for nuclear
physics, he had not even heard of it. It was therefore obvious
that the problem of interesting the government in the prac-
tical use of atomic energy and of obtaining funds for its de-
velopment was a difficult one. To these scientists it seemed that
if anybody would respond to such a suggestion, it was Presi-
dent Roosevelt. He had been aware of the Nazi policy of ag-
gression from the very beginning, and he was fully cognizant
of the threat to the future security of this country. Moreover,
he was not as firmly convinced of the foolishness of college pro-
fessors as most politicians are.

In view of these circumstances, Szilard and Fermi suggested
to Einstein that he make a direct appeal to the President.

As we have already seen, Einstein disliked becoming involved
in public affairs, and he felt a special reluctance to give advice
on military affairs and to encourage the development of the
most devastating weapon yet discovered by man. On the other
hand, he was convinced that the Nazis would be in possession
of atomic power in the near future and would use it to subdue
the rest of the world. With the responsibility that he felt in his

290

Einstein in the United States

exceptional position as the most famous scientist in this country,
he realized what his duty was.

On August 2, 1939 Einstein addressed a letter to President
Roosevelt, which began:

"Some recent work by E. Fermi and L. Szilard which has been
communicated to me in manuscript leads me to expect that the ele-
ment Uranium may be turned into a new and important source of
energy in the immediate future. ... A single bomb of this type . . .
exploded in a port . . . might very well destroy the whole port, to-
gether with the surrounding territory. . . ."

Furthermore, Einstein advised the President of the probability
that research in this field might be far advanced in Germany,
and stressed the great danger that the United States would incur
if the Nazis got hold of such a bomb. Einstein suggested that a
special organization with a staff of scientists who had devoted
themselves to nuclear research should be created to carry on the
investigations on the practical use of uranium.

The result of this project which was so dramatically made
public and the subsequent publicity concerning the organiza-
tion and development of the Manhattan Project, as it was later
called, are too well known by now to need reiteration here.

The immediate reaction of the American people to the an-
nouncement of the atomic bomb and the Japanese surrender,
which soon followed, was the feeling of relief that the war was
over and of pride that the United States had proved to be in
the lead in science.

The scientists who had worked on the development of the
atomic bomb, however, saw in it a political implication that
gave them cause for alarm. The war had been brought to an
end with a brilliant victory for the democracies, but the estab-
lishment of peace seemed to lead to an impasse. An atmosphere
of distrust had arisen among the Allies which could easily sow
the seed for another war. Moreover, the atomic bomb now made
it possible for an aggressor nation to make a surprise attack that
would practically annihilate its opponent within a few minutes.
The scientists felt the full weight of the responsibility that they
had created, and they began to take action in educating the Con-
gress and the public in general. They wanted the whole nation
to realize the full gravity of the situation. The "secret" of the
atomic bomb would be shortlived and there is no adequate de-
fense agaiast it.

291

Einstein: His Life and Times

For Einstein, who had been instrumental both in the develop-
ment of the basic theory and in the approach to President Roose-
velt, the responsibility weighed doubly hard. He agreed whole-
heartedly with the scientists like Oppenheimer and Shapley who
tried their best to explain the full implications of the new
weapon to the politicians and the military authorities. Ein-
stein, however, has always disliked getting involved in politics
and he was never willing to compromise his views with the
troubles of the next day. He is in full agreement with the view
expressed by Emery Reves in his book The Anatomy of Peace,
in which we read: "We must grasp the fact that it is necessary
to limit the sovereignty of nations and to establish a world gov-
ernment which will regulate the relations between nations by
law, as the United States, for example, now regulates the rela-
tions between states." For this reason Einstein is not satisfied
with the suggestion to hand over the secret of the atomic bomb
to the principal members of the United Nations or even to the
United Nations organization itself.

Since no world government exists at present, however, Ein-
stein's view seems to suggest that the secret should remain for
the time being with the original manufacturers, the United
States, Great Britain, and Canada. Hence, he was accused by
some people of being idealistic and impractical and by others of
being reactionary and taking sides with the "brass hats."

When I discussed with Einstein recently his views on the
international aspects of the atomic bomb he protested vehe-
mently against these interpretations of his views. He realizes
exactly that the "control of atomic energy" is primarily not a
technical but a political problem which cannot be solved except
in the form of a peace settlement between the big nations. Every
"control" requires an international agreement that entrusts
agents with the supervision of the war research and industry of
all nations. Such an agreement presupposes a high degree of
mutual trust, and if such a trust exists, there will be no danger
of war, bomb or no bomb.

Einstein realizes that this vicious circle cannot be broken
by singling out the "control of atomic energy" but only by a
comprehensive territorial and economic agreement. He hopes
that the fear of atomic warfare may become so great that govern-
ments and people will be prepared to sacrifice their sovereignty
to a greater degree than they would without this threat,

292

Einstein in the United States

7. Life in Princeton

Einstein's wife Elsa died in 1936. She had been strongly at-
tached emotionally to her German homeland., and after losing
her, Einstein became even more strongly linked to his new
country. His first wife never left Switzerland, but their eldest
son, who had been born in Bern at the time of Einstein's first
great discoveries, is now also active in the United States as an
engineer. Of Einstein's two stepdaughters, one died after leav-
ing Germany; the other, Mar got, a talented scupltress, was di-
vorced from her husband and now lives mostly with Einstein in
Princeton.

In 1939 Einstein's only sister Maja moved from Florence, Italy,
to Princeton. She is married to the son of that teacher Winteler
of the cantonal school of Aarau, to whom Einstein had been
strongly attracted. She had felt uneasy because of the increasing
Nazi influences in Italy. Her husband returned to Switzerland
temporarily, while she visited her brother. Her manner of speak-
ing and the sound of her voice, as well as the childlike and yet
skeptical formulation of every statement, are unusually similar
to her brother's mode of expression. It is amazing to listen to her ;
it arouses a sense of uneasiness to find a replica of even the minor
traits of a genius. Nevertheless, there is also a certain feeling of
reassurance at seeing even the greatest genius as a link in a chain
of ordinary natural events.

Since 1928 Einstein's secretary and later his housekeeper is
Miss Helen Dukas. She is trim, intelligent, and energetic. She is
a native of Einstein's Swabian homeland,, and comes from the
same small place as Elsa Einstein. These three women now form
Einstein's immediate environment.

In 1933 when Einstein came to the United States he had only
a visitor's visa. Under the American immigration law there is
no place within the country where one can obtain permission
to become a permanent resident of the United States. Such per-
mission can be given only by an American consul, and these
officers are only to be found in foreign countries. Consequently
Einstein went to the English colony of Bermuda in order to
apply to the American consul there. Einstein's visit to the island
was a gala occasion. The consul gave a dinner in his honor and
gave him permission to enter the United States as a permanent
resident.

293

Einstein: His Life and Times

Only then was Einstein able to announce Ms intention of
becoming a citizen of the United States and to receive his first
citizenship papers. He still had to wait five years before he could
become a citizen. During this time he had to prepare himself
for an examination on the American Constitution and the rights
and duties of an American citizen. This he did with zeal. In
1941 Einstein together with his stepdaughter Margot and his
secretary, Miss Dukas, received American citizenship. He was
asked to broadcast to the public the ideas and emotions which
he felt at that moment.

Thus this mighty tree with its roots was transplanted into new
earth. What is his life here ?

Various things from his Berlin apartment have been brought
to his cottage, situated in the midst of a large garden on a sub-
urban street. Here various rare objects such as adorned the
living-room of a well-to-do Berlin family can be seen again, for
example, Byzantine icons from Russia with their gold back-
ground mysteriously darkened by incense. At Princeton Ein-
stein actually lives like a strange guest just as he did in the upper
middle-class household in Berlin. His profoundly bohemian
nature has not changed even with his sixtieth birthday, which
he celebrated at Princeton in 1939.

He has no social life in the traditional meaning of the word.
He takes no part in the series of dinners and receptions that are
given by the faculty members in university communities. The
conclusion should not be drawn, however, that he does not like
to see people. On the contrary, he likes to receive people whom
he can advise or help, with whom he can discuss some interesting
subject or have a pleasant chat, or, what he prefers most of all,
with whom he can play music together. He likes people who are
ready and enthusiastic to accompany his violin playing on the
bass viol, or cello, or the piano. Most of his visitors are not mem-
bers of Princeton University or of the Institute for Advanced
Study. His thoughts are always more occupied with things that
are distant than with those that are near. Nevertheless, hardly
an afternoon passes without a visitor from out of town coming
to talk with him.

Among these visitors are, first of all, physicists, philosophers,
or even theologians who come to Princeton and want to use
the occasion to obtain some impression of the man who has given
their particular field so many new ideas. There is also the great
number of refugees from Europe who seek advice and help from
him. Sometimes there are people from Europe who stay with

294

Einstein in his study at the Institute of Advanced Study, Princeton, 1940

Einstein in the study of his home in Mercer Street, Princeton, 19 38

Einstein in the United States

him for a few days because they are destitute. There are Zionists
who want to hear his position on certain political questions. Even
'members of the faculty of the University of Jerusalem come to
him because they want him to intervene in their favor. There are
writers, journalists, artists, who want to interest him in their
work, hoping thereby to find a larger audience. The number of
people who wish to see him is great, and Miss Dukas has to use
a good deal of tact, energy and kindness to keep the atmosphere
around him as quiet as he needs it.

His attitude in this matter is the same as in all problems of
social life; he feels himself very much apart from other people
and he can never identify himself very strongly with others.
He always has a certain feeling of being a stranger, and even a
desire to be isolated. On the other hand, however, he has a great
curiosity about everything human and a great sense of humor,
with which he is able to derive a certain, perhaps artistic pleas-
ure from everything that is strange and even unpleasant. Fi-
nally, he is very good-natured and feels strongly the equality
of all human beings. Perhaps he often says to himself: It is just
the most unpleasant people with whom one should be least in-
clined to be short, since they suffer most because no one wants
to talk with them.

As a result it is often the rejected inventors and other mis-
understood geniuses who come to him. Ever since the time when
he was employed in the patent office at Bern he has retained a
certain pleasure in listening to the most senseless projects. All
of them contain some element of human inventive faculty, even
though in a distorted state; and for Einstein's active and pene-
trating mind it has always been a pleasure to follow through a
confused train of thought, to unravel it, and to find the errors
in it.

Occasionally he is also visited by physicists who are carrying
on research on the basis of ideas that do not agree with those
recognized as correct by present-day physicists. Such aberrant
scientists can equally well be forerunners of important innova-
tions or simply muddle-headed fellows. Einstein is more willing
than others to listen to such physicists and to give careful con-
sideration to their ideas, since it is always a pleasure for him to
see the possible seeds of future ideas. At any rate, it is pleasant
mental exercise for him to follow through logically a series of
deductions, without being sure at the start whether they lead to
any reasonable or useful conclusion.

It sometimes happens, however, that some of these inventors

Einstein: His Life and Times

and scientists would feel insulted if he did not accept their con-
clusions as correct. Just because he is possibly the only famous
physicist who is willing to listen to them and to consider their
ideas, all the hatred of an unrecognized physicist for those who
have achieved fame occasionally concentrated itself against Ein-
stein. This led to the paradoxical result that he was sometimes
attacked and condemned most severely by the very persons to
whom he had devoted the most attention.

Since immigrating to America, Einstein has rarely spoken at
public meetings. Organizations of all kinds have tried to induce
him to do so, but he has spoken only when the subject con-
cerned was one in which he was greatly interested. Neither has
he attended scientific meetings very often. Only very few times
has he discussed his actual researches in professional circles. Nor
has he done it very readily, because he often felt that his work
was not in line with the trend of research preferred by most
physicists. His work has been devoted through many years to
the construction of a "unified field theory" that would eventu-
ally account for the subatomic phenomena too. He often thought
that the researches with which he was occupied would not be
received with much interest by those who believed that they
should not divert their attention from the central task of today's
physics, the interpretation of atomic phenomena by means of
Bohr's quantum theory or his principle of complementarity. On
some occasions, however, Einstein lectured at scientific con-
gresses on his views on the present and future of physical sci-
ence in general One such rare instance was his address in
Philadelphia "On Physical Reality," in which the sentence oc-
curs that forms the motto of this book.

The world around Einstein has changed very much since he
published his first discoveries. He began his work during ^the
time of the German Kaiser in the environment characteristic
of the German and Swiss petty bourgeoisie; he lived during the
second World War in the last bulwark of democracy, the United
States of America, He was able to make a substantial contribu-
tion toward an earlier conclusion of the war than had been ex-
pected, and is now anxious to help in making the peace a last-
ing one. But his attitude to the world around him has not
changed. He has remained a bohemian, with a humorous, even
seemingly skeptical approach to facts of human life, and at the
same time a prophet with the intense pathos of the Biblical tra-
dition. He has remained an individualist who prefers to be
unencumbered by social relations, and at the same time a fighter

296

Einstein in the United States

for^ social equality and human fraternity. He has remained a
believer in the possibility of expressing the laws of the universe
in simple, even though ingenious mathematical formulae, but
at the same time doubting all ready-made formulae that claim
to be the correct solution for human behavior in private and
political life.

When a visitor whom he has known in the old country comes
to his home in Princeton, Einstein often says: "You are sur-
prised, aren't you, at the contrast between my fame through-
out the world, the fuss over me in the newspapers, and the isola-
tion and quiet in which I live here ? I wished for this isolation
all my life, and now I have finally achieved it here in Princeton."

Many famous scholars live in the distinguished university
town, but no inhabitant will simply number Einstein as one
among many other famous people. For the people of Princeton
in particular and for the world at large he is not just a great
scholar, but rather one of the legendary figures of the twentieth
century. Einstein's acts and words are not simply noted and
judged as facts; instead each has its symbolic significance
symbolic of his time, his people, and his profession*

People in Princeton tell many anecdotes about Einstein. It
Is related that one of his neighbors, the mother of a ten-year-
old girl, noticed that the child often left the house and went to
Einstein's home. The mother wondered at this, whereupon the
child said: "I had trouble with my homework in arithmetic.
People said that at number 112 there lives a very big mathema-
tician, who is also a very good man. I went to him and asked
him to help me with my homework. He was very willing, and
explained everything very well. It was easier to understand than
when our teacher explained it in school. He said I should come
whenever I find a problem too difficult" The girl's mother was
alarmed at the child's boldness and went to Einstein to apolo-
gize for her daughter's behavior. But Einstein said: "You don't
have to excuse yourself. I have certainly learned more from the
conversations with the child than she did from me."

I do not know, nor have I made any effort to check, whether
this story is true. People tell it in different versions together
with the much simpler story that in summer Einstein is often
to be seen walking through the streets of Princeton in sandals
without stockings, in a sweater without coat, eating an ice-cream
cone, to the delight of the students and the amazement of the
professors.

Since not only Einstein's personality but also his times and

297

Einstein: His Life and Times

environment should be described in this book, all such stories
are certainly true. Even if they do not tell us anything that is
factual about Einstein, they are a true description of the world
in which he has lived.

In 1945 Einstein retired from his position as professor at the
Institute for Advanced Study. This change in his official status,
however, did not mean any change in his actual work. He con-
tinues to live in Princeton and to carry on research at the
Institute.

298

INDEX

Aarau, 18-19, 293

Aberration of starlight, 33

Absolute motion, 34-5, 52; as expend-
iture of divine energy, 36

Absolute simultaneity, 217

Absolute space, 34-5, 39-40, 52, 94

Absolute time, 35, 39, 59

Academic Assistance Council, Lon-
don, 246

Academic: science, 118; vanity, Ein-
stein's lack of, 89

Acceleration, 31; centrifugal, 93, 95;
due to gravity, 95; from inertial and
gravitational forces, 95; of labora-
tory, 92-4; relative to fixed stars,
92

Adler, Friedrich, 70, 75, 174

Adler, Victor, 20

Affidavit of support, 278

Africa, West, 140

Alembert, d\ 113, 234

Aliotta, 46

Alphonso XIII, King of Spain, 201

American: citizenship of Einstein,
294; clergymen, 288; democracy,
285; Jews, 178; pragmatism, 44;
professor, 267

American Youth Congress, 245

Ammonia, manufacture of, 121

Ampere, Andre*, 163

Analogies: between light and sound
waves in nature, 33; of traditional
philosophy, 26-7

Anglican Church, 189

Anglo-Saxons, 233

Animism, of Newton's conception of
force, 36

Anti-intellectualism, 47

Anti-mechanistic aspects, 250

Anti-race, 230

Anti-Semitism, in postwar Germany,

149

Apennines, 17

Apparatus, construction of, in
Applied physics, 124
Aprioristic knowledge, 282
Aquinas, St. Thomas, 28

Arabs: and Jews, 200-1; nationalism,
151

Arago, D. F. J., 32

Aristotle, 28

Armistice (1918), 160

Artillery, heavy, 73

Aryan: physics, 252, 279; race, 228; sci-
entists, 252, 255; spirit, 232

Assassin, 241, 242

Assyrian cuneiform inscription, 219

Astronomer Royal of England, 140

Astrophysicai Observatory at Pots-
dam, 34, 118, 191

Athenseum: Club, 189; Faculty Club,
268

Atomic age, 289

Atomic bomb, 66, 291

Atomic nucleus, 287

Atomic physics, 205

Atoms, 208-9; artificial transmutation
of, 66; as natural clocks, 60; be-
havior of, 209; existence of, 105;
hypothesis of, 105; mechanics of,
209; spectral lines of, 60; structure
of, 208

Atrocity: propaganda, 194; stories,

234

Auerbach, Berthold, 4
Austria, 20, 99; character, 99; foreign

policy of, 119, 150; professor in, 100;

universities in, 100

Austro-Hungarian monarchy, 100, 171
Automatons, people as, 153
Averroes, 28
Axioms of geometry, 41

Bach, J. S., 198, 279

Bad Nauheim, 163

Balkan countries, 275

Bamberger, Louis, 266

Bankruptcy of science, 45

Bargmann, Valentin, 274

Barracks, 10

Battle of words, 121-2

Bavarian Academy of Science, 237

Bayreuth, 256

Beethoven, 5; piano sonatas of, 7

Index

Belgium, 120, 239; royal family of,
240

Bell Telephone Laboratories, 60

Bergmann, Hugo, 84

Bergmann, Peter, 274

Bergson, Henri, 196

Bermuda, 293

Berlin, 7, 161-2, 204, 217, 222, 225,
236, 269, 271; as center of science,
169; Einstein's position in academic
life of, 109; gutter literature, 5;
Mayor of, 223; Philharmonic, 193;
tormented atmosphere of, 167; Uni-
versity of, 108, in, 124

Berliner Borsenzeitung, 203

Berliner TageUatt, 203

Bern, 23, 50, 67, 92, 98, 293; Ein-
stein's life in, 49; patent office at, 22

Bernstein, Aaron, 13

Besso, 50

Bismarck, 5, 7-8, 225

Bible, 4, 7; Einstein's respect for ethi-
cal value of, 15; Old Testament, 14;
Proverbs of Solomon, 14; religion
of, 255, 280

Bohemian Insane Asylum, 98

Bohr, Niels, 209, 212, 215, 258, 273-4

Bohr's complementary principle, 212-

13
Bohr's theory, 210; in accord with

radical positivism, 216
Boiling-point, 171
Bolshevism, 192, 204, 231; Einstein's

theory as, in physics, 146, 159, 203;

in Europe, 248; materialistic, 143
Boltzmann, Ludwig, 20, 67; statistical

law of, 69-70

Bonaparte, Prince Roland, 196
Born, Max, 211
Bosch, Dr., 191
Boston, 185
Bouasse, 233
Bourgeois: 258; intelligentsia, 146,

259; life, 90
"Brass hats," 292
Brazil, 140; Sobral, 138
Breuer, Josef, 176
Bridgman, P. W., 42, 128
Brod, Max, 84-5
Broglie, Prince Louis de, 210-11
"Broglie waves, de," 210
Brown, Robert, 68

Brownian motion, 67-8
Briining, Heinrich, 225
Brussels, 101
Buber, Martin, 84
Biichner, Ludwig, 13
Bucky, Dr., 24
Bunsen burner, 171
Burtt, E. A., 36

California Institute of Technology,
224, 268

Canada, 292

Canterbury, Archbishop of, 189, 262

Cantonal School, 18

Capitalistic countries, 258

Caputh, 223, 226, 269

Carnap, R., 215

Carnegie, Andrew, 106

Carr, Wildon, 263

Catholicism, 9

"Chain reactions," 289

Chamber music, 14

China, 198

Christ Church College, 269

Christian: liberal churches, 286; reli-
gion, 229; theology, 286

Church, task of, 287

Cleveland, O., 183

Clock, 58, 60, 62

Closed world, 34

Coercion, Einstein's hatred of, 8

Collaboration, 197

College de France, 194-5

College of the City of New York;
276

Columbia University, 183, 290

Comic journals, 176

Commission pour la Coop&ration In-
tellectuelle of the League of Na-
tions, 154

Common sense, 43, 62, 164, 260; ver-
sus science, 142

Communism, 46, 149, 231, 249, 250

Communist Academy, 257

Communist Party, 230, 236

Compte, Auguste, 39

Compulsory service, 227

Congress: of German physicists at
Prague, 215; of German Scientists
at Vienna, 103; Solvay, 101-2

Congressional Record, 184-5

Conscientious objectors, 148

Index

Constancy: of the velocity of light, 58;
principle of, 56

Contraction and expansion of time, 61

Control of atomic energy, 292

Conventionalism, 41

Cook, Dr. Frederick A., 184

Co-operation, Einstein's attitude to,
no

Copenhagen, 212, 273

Copernican: system, 37, 46, 248; the-
ory, 25, 28

Copernicus, 26, 160, 258

Copley Plaza Hotel, 185

Corpuscular theory, 32, 34

Cosmic religion, 284

Cosmological problems, 134

Criteria, empirical and logical, 43

Curie, Mme, 101, 196

Curved space, 129-30, 132, 134, 141,
177

Cynicism, 120, 281-2

Czech: Einstein disapproves dispar-
agement of, 81; German attitude to-
ward, 80; professors, 80; Republic,
ioo, 171, 239; separate culture from
Germans, 83; students in Einstein's
classes, 81; university, 80, 171

Davisson, Clinton J., 211

Democracy, 249, 285; as Einstein's po-
litical ideal, 156

Democrats, 225, 230, 288

Density of matter in the universe, 136

Despair, attitude of, 46

"Destructive'* Einstein philosophy,
251

Deutsche Allgemeine Zeltung, 203

Deutschland, Deutschland, uber alles,
198

Devaluation of intellect, 48

Dewey, John, 44, 47

Dialectical materialism, 46, 257, 260

Diffraction of light, 208

Dilettantism, in; in science, 117

Dingier, Hugo, 252

Direct experiment, 175

"Discovered fact," 202

Discoveries of Einstein, 75

Doppler effect, 61

Dream world and Einstein's theory,

145
Dreyfus affair, 197

Du Bois-Reymond, 45
Dukas, Helen, 293, 295
Duration: actual and apparent, 62; of
time, 62

Economic crisis, 276

Eddington, Sir Arthur, 138-9, 262,
284

Edison, Thomas, 185

Ehrenfest, Paul, 168

Ehrenhaft, Felix, 175; wife of, 175

Eighteenth century, 30, 36, 45, 113,
217

Einstein, Albert: absence of academic
vanity, 89; adept at art of conver-
sation, 207; admitted to Polytechnic
School in Zurich, 19; adviser of
young men, 274; advocate of Jew-
ish colonization, 199; alleged trip
to Russia, 201; aloofness, 50, no;
appointment to Prague, 77; arrival
in New York, 178; artistic taste of,
7; attends Roman Catholic elemen-
tary school, 9;

attitude toward: co-operation, no;
politics, 148; military service, 245;
religion, 9, 14, 280!;
aversion to: drill, 153; formality, 79;
orthodox religious practices, 15;
personal relations, 89; pure research
as a profession, no;
avoidance of war and military serv-
ice, 158; barrier against, 114; be-
comes German citizen, 169; birth,
6; birth of two sons, 23; bohemian
nature, 124, 294; called Copernicus
of twentieth century, 160; cam-
paigns against, 158; "case," 99, 161;
charm of his lectures, 90; childhood,
6; colleagues at Prague, 80; con-
firmation of his theory, 140; conver-
sation of, 77; criticism of, 77;
"cynicism" of, 287; Czech students
in his classes, 81; decides physics,
not mathematics, his main interest,
19; definitions called lifeless, 256;
departure from Munich, 15; depar-
ture from Prague, 98, ioo; devoutly
religious, 284; disapproves of dis-
paraging Czechs, 81;
dislike of: modern music, 279; play-
ing soldier, 8;

111

Index

Einstein, Albert (continued}
drops ether theory of light, 55; ef-
fect, 61; eliminates absolute space,
94; enfant terrible, 159, 163; equa-
tion: E = mc 2 , 66, 165, 173; expec-
tation for American youth, 186; ex-
peditions to test his theory, 137;
experimental tests of his theory,
133; family background, 3; "film,"
190; follows spirit, not letter, of
Mach, 78; for world government,
292; French-speaking fluent, 196;
influence on the development of the
quantum theory, 69; given freedom
of New York City, 184; good na-
u 1 ^ 995 gymnasium in Munich,
10 ; hatred of coercion, 8; hikes
through Appennines to Genoa, 17;
hypothesis on discontinuous nature
of light, 73; idea of a personal God,
285; impression of cynicism, 77; in
China, 198; in comic journals, 176;
m Czechoslovakia, 169; in England,
187; in France, 194; in Holland,
167; in Japan, 198; in Palestine, 198;
in Pasadena, 224; in Spain, 198;
instruction in the Jewish religion
at the gymnasium, 15; intellectual
interests, 12;

interest in: construction of scien-
tific apparatus, 24; mathematics, 13-
14; philosophy, 50; scientific inven-
tions, 24; social matters, HI;
invitation to: Berlin, 106; United
States, 176;

Jewish religion officially adheres to,
79; language of his deductions, 62;
League of Nations and, 154; lec-
ture at King's College, 187; letter
to Roosevelt, 291; life in Bern, 49;
life in Princeton, 293 f.; liking for
jokes, 113, 170; love of Ms children,
23; manner of speech, 281; mar-
riage to Mileva Maritsch, 23; mathe-
matical method of, 103; messenger
of international understanding,
204; middle-class life, 124; moves to
Princeton, 270; naive questions,
112; new discoveries, 75; new the-
ory of gravitation, 127; no political
party, 148; not a child prodigy, 8;
not a killjoy, 179; not cut for team-

Einstein, Albert (continued)
work, 49; office of, 170; official in
patent office, 21, 23; old-fashioned-
ness, 7; opponents of, 162; origin
in a provincial, semi-rural milieu,
7; as a pacifist, 153; paradoxical re-
lation to society, 76; passionate
smoker, 187; personality portrayed
in a novel as Kepler, 85; philosophy
of science of, 215; plays Mozart,
172; pleasure in thinking in soci-
ety, 21 ; political attitude, 147; pop-
ularizations vex, 190; position in
academic life in Berlin, 109; profes-
sional philosophers struggle against
theories of, 30; prediction of, veri-
fied, 140;

predilection for: isolation, 49;
Schiller, 8;

presence in class destroys fellow
students* respect for school, 17;
pride in always having time, 119;
principle of relativity, see Relativity;
as a professor, 89; professor at Zu-
rich, 79; professor extraordinary,
76; as a public figure, 147; quantum
theory, new, of, 73; receives Amer-
ican citizenship, 294; relation to
environment, in; relation to stu-
dents, 89, 116; relativity principle
founded, 54; religious feeling, 10;
as representative of German science,
184; respect for ethical value of Bib-
lical tradition, 15; responsibility of
fame, 147; revolt against customs of
bourgeois life, 80; school like bar-
racks, 10 ; science and philosophy,
115; on science and religion, 285;
on scientists in international under-
standing, 155; second marriage, 124;
sense of humor, 76, no, 178; skep-
tical attitude toward school, 16;
"skepticism" of, 281; social life of,
294; solitary position in academic
circles, 114; son of, 293; speculation
on properties of light, 56; as spir-
itual leader of Jews, 183; stays out
of intrigues, 1x2; stepdaughters of,
293; student at Zurich, 18; supporter
of Zionism, 152; Swiss nationality
of, 120; sword of, 100; symbolic sig-
nificance of acts and words, 297;

IV

Index

Einstein, Albert (continued)

sympathy for all sufferers, 278;
teacher in Berlin, 205; temporary
teaching job at Winter thur, 22;
theories: as arguments for religion,
262!; as political weapons and tar-
gets, 248; drawn into party and na-
tional struggle, 122; idealistic or
materialistic, 262; removed from
materialism in mechanistic sense,
254; truth not fiction, 161;
on third term for Roosevelt, 159;
trip to Vienna, 103 ; two hypotheses,
57, 60, 64; undemocratic sound of
some statements of, 157; uneasy in
Berlin, 162; uniform as Austrian
professor, 100; on unresolved con-
tradictions in nature, 148; unsym-
pathetic to Machian philosophy, 52;
use of caustic words, 281; views on
democracy, 157; views on military
service, 243; violin lessons, 14; vital-
ity of single lectures, 91; and War
Registers International Fund, 159;
wins Nobel Prize, 201; wish to re-
nounce German citizenship, 17;
women's clubs oppose entry into the
United States, 126; Zionist move-
ment helped by, 149

Einstein, Elsa (second wife), 4, 123-

5>293
Einstein, Hermann (father), 6-7, 17,

21

Einstein, Maja (sister), 293

Einstein, Mileva (first wife), 20-1, 23,
109, 124, 129, 293

Einstein, Paulina Koch (mother), 7

"Einstein house, the," 222

Einstein Tower, 191

Electricity, 37, 64, 104

Electromagnetic: fields, 39; light vi-
brations in nature, 32; phenomena,
64; waves, 37, 104

Electromagnetism, 29

Electrons, 65

Elimination of force, 255

Emancipating effect of science, 46

Empiricists, 43, 143, 196

Encyclopedia, Soviet, 256

Energy, 41, 65-7, 73> ^

Enlightenment, 36, 254

Eagels, R, 249, 260-1

England, 159, 204

English: blockade, 121; clergymen,
288; cool-headed, 144; Enlighten-
ment, 51-2, 251; science, 122, 188

Enthusiasm for Einstein's theory, 179-
81

Equation E = mc 2 , of Einstein, 66,
l6 5> 173

Equivalence: of energy and mass, 65;
principle of, 96

Eternal lif e as four dimensions, 264

Ether, 32-4, 53-6, 168, 254, 257

Ethical relativism, 249

Etiquette, 200

Euclidean: geometry, 129, 141; space,
129, 206

Europe, 20-1, 43, 52

Existence, 283

Expanding Universe, The, 240

Expansion and contraction of time, 61

Experimental physicists, 30

Faraday, M., 165

Farben, I. G., 191

Farewell letter of Einstein to Acad-
emy, 235

Fascism, 46, 155, 248-51, 289

Faust, 241

Fermi, Enrico, 289-91

Fichte, 46, 85

Fight against Einstein's theory, 192

Fine Hall, 268

Finley-Freundlich, Erwin, 191

Finns, 229

Five-dimensional, 274

Fixed stars, 34, 40, 92, 133

Flexner, Abraham, 226, 266

Florence, 293

Flow of time, 61, 63

Force (see also Law of force), 36, 41-
2, 44, 95, 248, 255 ^

Force and Matter (Biichner), 13

Foucault, 32; pendulum of, 40

Four-dimensional: geometry, 206, 219;
space, 130; as eternal life, 264

France, 194, 204

Franck, James, in

Franco-Prussian War, 5

Frankel, Dr. O., 169

Franklin, Benjamin, 104, 224

Franz Josef, Emperor of Austria, 77,
79, 100

Index

Frederick the Great, 113

Freedom of science, 227

Free imagination, 282

French: Academy, 196; patriots, 197;

Revolution, 143; science, 122
Freud, Sigmund, 175
Friction, 33
Friedmann, 240
Fuld, Felix, 266
Full-fledged particles, 212
Fundamental system, 56, 60

Galileo, 25-6, 28, 34, 95, 165, 258

Gandhi, 158

Gaustudentenbund, 252

Gehrcke, E., 161

General labor service, 176

Geodesic lines, 129-30, 132

Geometry, 10, 14, 16, 41, 78, 123, 128,
177

Genoa, 17

German: citizenship, 13, 169, 237;
classics, 7; culture, 107, 120, 279;
dialect, 228; elementary schools, 9;
Empire, 119; enthusiasm for World
War I, 119; government, 168, 228;
intellectuals, 113, 145, 158; Jews,
150, 152, 177; militarism, 120; mi-
nority in Prague, 169; mission, 228;
music, 7, 279; nation, 113; national-
ists, 52, 161; Nazism of Sudeten,
87; philosophy, 227, 250; public,
159; physics, 25, 122; Reich, 106,
113; Republic, 192, 194, 225, 269;
ruling class, 3, 158, 279; science,
103, 121-2, 163, 193; scholars, 5;
spirit, 238; attitude toward Czechs,
80; theory of relativity, 122; univer-
sity, 43, 223, 227 , 280

Germany, 8, 17, 120, 123, 145, 149,
168, 187, 203-4, 206, 225, 259, 279

Germer, L. H., 211

God, 35-6, 208, 282, 285-6

Goebbels, Joseph, 250

Goethe, 5, 12; autobiography of, 241

Goring, Hermann, 232

Gothic style, 268

Goteborg, 203

Gottingen, University of, 206

Gravity, 28-9, 96-7, 128, 134

Great Britain, 292; see also England

Gregory, David, 35

Greek: drama, 140; in Einstein's gym-
nasium, ii ; orthodox religion, 20,
23, 155, 280

Greenwich Observatory, 140

Grossmann, Marcel, 22, 103

Guggenheim, 106

Haber, Fritz, 121, 237, 242

Haeckel, Ernst, 287

Hahn, Otto, 202, 289

Haldane, Lord, 187-200

Haller (director of Bern patent office),

22

Hanisch, 168

Hapsburg Monarchy, 169

Harding, Warren G., 182

Harnack, Adolph, 106

Harvard University, 185

Harvard Physics Laboratory, 185!

Hasenohrl, Franz, 101, 166; principle
of, 165

Heat, 29, 37, 208

Hebrew, 83, 237

Hebrew University, Jerusalem, 152-3,
162, 178, 182, 186, 242, 295

Hegel, 249

Heidelberg, 163, 192

Heine, 4, 7

Heisenberg, W., 211-13, 258

Helium, 65

Helmholtz, 20

Hermann und Dorothea (Goethe), 12

Hertz, Gustav, in

Hertz, Heinrich, 20, 32, 37-9, 252, 255

Heuristic point, 209-10

Hibben, John Grier, 267

Hilbert, David, 206

Hindenburg, 225-6

Hindus, 198

Hiroshima, 67, 174

Historic conception of physical real-
ity, 274

Hitler, Adolf, 150, 176, 191, 225-7,
232, 236, 279

Holland, 167-8

Holy Land, 180

Hostility to Einstein, 251

Human heart, 61

Human mind, 40-1

Humanity, 250

Hume, David, 50-2, 251

Hungary, 20, 150, 171, 229

VI

Index

Huygens, 32
Hydrogen, 65
Hylan, Mayor, 182
Hypotheses, 57, 60, 64, 73, 160

Idealism, 43, 143, 145, 248, 250, 257-

8, 262-3, 282

Idealistic Reaction against Science, 46
Ignorabimus, 45, 47
Ignoramus, 45

Immigration regulations, 278
Indecision of democratic states, 254
Inertia (see also Law of inertia), 29-

32, 34-5, 42, 93-4, 96, 133
Inferior races, 80
Infeld, Leopold, 273
Influence of fixed stars on observable

events, 92
Institute for Advanced Studies in

Princeton, in, 226, 265
Instrumentalism, 47
Intellectual: arrogance, 233; class, 5;

front, 120-1; German, 158, 225;

interests of Einstein, 12; sterility,

supposed, of Jews, 231; tradition of

Jews, 6; weapons, 120
Intuition, 173
Inventors, 23-4
Italy, 16
Ives, H., 60

James, William, 44

Japan, 198

Japanese, 198, 229, 256

Jaumann, Gustav, 78

Jeans, Sir James, 13, 384

Jehovah's Witnesses, 158

Jerusalem, 265

Jewish International, 231

Jews, 4, 6-7, 14, 22, 78, 83-4, 145-6,

*S<>-3> *5$, i77~8, 181-2, 199-201,

228-30, 232, 238, 251-2, 255, 275,

280, 286

Joffe, A. F., 163, 258
Jokes, ti3, 164, 176, 179
Jordan, Pascual, 21 1> 251
Judeo-Christian religious tradition,

288
Junkers, 226

Kafka, Franz, 84

Kaiser Wilhelm Gesellschaf t, 106, xo8,
289

Kant, Immanuel, 51-2, 114, 250, 286;
philosophy of, as religion in Ger-
many, 43, 107

Kasner, Professor, 183

Kepler, J, 85, 165

Kieler Zeitung, 203

Kindred, J. J., 184

Kirchoff, Gustav, 20, 37, 39, 254-5

Kleiner, 74-5

Kobe, Japan, 198

Kottler, Friedrich, 104

Kraus, Oskar, 172-3

Krieck, E., 228

Ladenburg, R., no
La Guardia, Fiorello, 184
Lampa, Anton, 77-8, 101
Langevin, Paul, 101, 194-5, 210
Lanczos, Cornelius, 207, 216; equation

of, 272
Latin: in Einstein's gymnasium, n;

lucidity, 233

Laue, Max von, in, 193, 206
Law of: conservation of energy, 41;

inertia, 29-30, 35, 39-41, 127; force,

29> 3* 57, 95; gravitation, 29
Laws of: geometry, 29; mechanics, 29,

34, 41, 45; motion, 64, 71; physics,

38, 40, 216

League of Nations, 154, 196
Le Cocque, 234, 239
Leiden, University of, 162, 168
Leipzig, 193
Lemaitre, Abbe*, 239
Lenard, Philipp, 72-3, 162-4, 192-3,

202, 232, 238, 252, 254, 259-60
Lenin, 257, 260-1
Lessing, 4
Levi-Civita, 103
Liberal: Christianity, 286; Judaism,

286

Liberalism, 45-6, 52, 107, 248
Light, 32-3, 69, 76, 97-8, 134, 208-9
Lloyd George, 189
Lodge, Sir Oliver, 141
Logic(al), 43, 55; criterion of, 134;

economy of, 105; empirical, 249;

simplicity, 133

Logical positivism, 215, 217, 282
London, 138; Times f 140, 143-4
Lorentz, H. A., 101
Ludendorjff, Erich, General, 191

Index

LudendorfT, F. W. (astronomer), 191
Lyman, T., Harvard physicist, 185

Mach, Ernst, 38-40, 42-3, 47, 50, 52,
78, 82, 92, 104-5, 133, 135, 176* si 1>
213, 215, 217, 254-5, 2 57> 260

MacLeish, Archibald, 246

Madmen, 98

Madrid, 265

Magyar domination, 21

Maimonides, 28

Manhattan Project, 291

Manifesto of Ninety-two German In-
tellectuals, 120

Mann, Erika, 279

Mann, Klaus, 279

Margin, 212-13

Maritsch, Mileva, see Einstein, M.

Married philosophers, 126

Marseille, 201

Marx, Karl, 46, 160, 260-1

Marxism, 227, 232, 254-5

Masaryk, President, 169, 171

Mass, 65-7

Mass Suggestion of the Relativity The-
ory, The, 167

Master race, 80

Materialism, 13, 44, 46, 143, 225, 248,
250, 254, 262

Materialism and Empiriocritidsm,
258

Mathematics, 13, 19-20, 26, 30, 37, 61-
2, 82, 103, 206

Matter, 136, 210

Maupertuis, 234

Maxirnov, A., 145, 258-9

Maxwell, James Clerk, 20, 32, 39, 67

Mayer, Walter, 207, 273

Meaning of general statements, 43

Meaningless: conglomeration of
words, 215; problems, 47

Measuring: rod, 63; physical opera-
tions, 215

Mechanics, 25-6, 28-30* 3 2 ~4 3&~7>
45~6> 54 5$ 64, 164, 249-50, 254,
259-60

Medieval: philosophy, 30; remnants
of, in mechanical physics, 34, 37, 39

Meitner, Lise, in, 289

Mercury, 133

Merry-go-round, 31, 93

Metabolic processes, 61

Metaphor of the flow of time, 65

Metageometrical concepts, 47

Metaphysical: stage, 39; foundation
of science, 42-3; reality, 48, 63, 216;
view, 215-16, 259; touch, 245

Michelson, A. A., 34, 225; experiment
of, 34, 53-4

Microscope, 68

Middle Ages, 25, 30, 34, 46

Milan, 15, 17

Militarism, 121; feeling of, 148

Military service, 245

Milky Way, 135-6

Mill, J. S., 249

Millerand, Alexandra, 176

Millikan, R. A., 224-5, 268, 288

Minkowski, Hermann, 20, 131-2, 206

Misunderstood geniuses, 295

Mitin, M., 261

Molecules: direct proof of existence
of, 67-8; number of, in unit volume
of matter, 68

Moltke, 7

Momentum, 95

Monarchist groups, 230

Moscow, 20

Motion: violent, 27; inertial, 28-9; of
celestial bodies, 28; annual appar-
ent, 34; absolute, 34; God as ulti-
mate originator of, 36; as expendi-
ture of divine energy, 36; definition
of, 42

Mount Wilson Observatory, 224

Movement: of celestial bodies, 28; in
a straight line, 30; absolute, 31; of
molecules, 67; irregular, 68

Moving: bodies, 69; trains, 64, 92

Mozart; 5, 8, 14, 172, 198, 279, 282

Munich, 6, 8-9, 15-16, 123, 252

Music, 253, 279

Mysterious Universe, The, 13

Mystical: sense of reality, 46; interpre-
tation, rejected by Bohr, 273; feel-
ing, 284

Mystics, 258

Nationalism, 149, 170

National Socialists (see also Nazi),
1 66, 177, 249, 160; student associa-
tion, 253

Natural: measure of time, 34; position,
27; science, 25-6

VUI

Index

Naturalism, 13

Nature, 263, 283; animate and inani-
mate, 26; of force, 42

Nazi: 229; storm troops, 242; physi-
cist, Lenard, 260; revolution, 270

Neckar River, 192

Nernst, Walter, 85, 101-2, 106-7, in >
121, 234

Neurath, O., 215

Neutron, 65-6, 289

New theories: compared to beautiful
dresses, 137; absurdity of, 161

Newton, Sir Isaac, 25, 28-9, 31-2, 34-
7, 45, 54, 56-7, 59, 64, 92, 94, 165,
189, 248, 259

Newtonian mechanics, validity of,
doubted, 56

New York, 7, 180-2, 280; harbor, 262

Nietzsche, F., 46, 50, 126, 249

Nineteenth century, 36-7, 40-1, 45,
47-8, 69, 94, 128, 217, 254

Nobel, Alfred, 202

Nobel prize, 162, 201

Nohel, E., 82

Non- Aryans, 228 .; wives of, 230

Non-Euclidean space, 206

Non-non-Aryans, 229

Nordic-Aryan: race, 150, 160; philoso-
phy, 1 60

Nordmann, Charles, 195

Nucleus, 65-6, 209; forces of, 65-6; en-
ergy of, 66; atomic, 289; uranium,
289

Observation, general laws of physics
as summaries of, 38

O'Connell, Cardinal, 262

Old Testament, 15

Operational definitions, 42, 128, 216

Oppenheimer, R., 292

Optical phenomena: applied to, by
mechanical laws, 29, 35; explanation
of, 32, 54> 56; experiments, 96, 254

Optics, 37

O'Rahilly, A., 263

Organismic conception, 20, 25; tran-
sition from, to mechanistic, 26

Organismic: physics of the Middle
Ages, 27-8, 46; philosophy, 30

Oriental Music, 198

Orthodox Judaism, 85

Ostend, 234

Oxford, 217, 269, 282; patriotic youth
of, 195

Packing effect, 66

Pacifism, 159, 162, 231

Painleve, Paul, 194-5

Palestine, 151, 178, 198-9, 280

Papen, Franz von, 225

"Paper Swiss," 22

Paris, 195, 197, 265

Particles, statistical behavior of, 67

Pasadena, 224, 226, 268, 270

Patent Office at Bern, 22-3

Pendulum, 58, 60, 62

Perrin, Jean, 69

Perry, R. B., 47

Personal God, 285-6

Philadelphia, 296

Philosophers, professional, struggle
against Einstein, 30

Philosophical Institute of the Commu-
nist Academy, 258

Philosophy, 25-6, 30, 37, 43-4, 105,
145, 160, 200, 206, 248, 257-8

Photochemical equivalence law, 98

Photoelectric: effect, 208; law, 209

Photographic: film, 24; plates, 139

Photon, 72, 206, 209; violet, 73

Phototelegraphy, 219

Physical content of a theory, 249

Physical reality, 213, 218, 296

Physicists, 30, 35, 160, 162, 188

Physics, 19-20, 25-30, 45, 62, in, 143,
164, 252

Pick, Georg, 82, 103

Peirce, C. S., 43, 47

Place of mind in nature, 263

Planck, Max, 70-3, 101, 106-7, 111-14,
163-4, 209, 213, 215, 236, 241

Platform, revolving, 33

Pocket: compass, 12; watch, 58

Podolsky, B., 273

Poincar4 Henri, 40-3, 47, 50, lot, 128

Poland, 99, 123, 150

Political: ideologies, 248!; physicists,
238; purge, 230

Polytechnic School, Zurich, 19-22, 98

Popper-Lynkeus, 176

Popular Boofys on Natural Science^ 13

Popular taste in New York, 181

Popularizations, 190

Popularizers, 172

Index

Positivism, 39, 42-4, 47-8, 52, 215 ,

274, 283, 287

Potsdam, 118-19, 191, 223, 269, 272
Pragmatism, 42-4, 47, 215, 228
Prague, 43, 77, 83-4, 92, 99, 109, 119,

161, 169, 215

Prediction of Einstein verified, 140
Presence of God in everything, 35
Pressburg, 239
Princeton University, no, 183, 225,

270, 272, 290, 293 f.
Principle of the excluded middle, 229
Privatdozent, 75
Prize Contest of $5,000, 190-1
Pro-Fascist interpretation of relativity,

250!

Progress, 45, 246
Projectiles, 33, 73
Proletarian ideology, 259
Propagation of light through ether,

33

Protestant churches, liberal, 288
Proton, 65-6
Prussia, 3, 5, 7, u, 16, 113, 168, 205,

222

Prussian Academy of Science (Royal),

107-8, 123-4, 161, 198, 219, 225,

234 ., 241

Psychoanalysis of Freud, 176
Psychological: economy, 105; situation

in Europe, 144; situation of new

refugees, 278
Psychology, 55; of Jews, 151; political,

1 60

Public, the, 142
Pupin, Michael, 183
Purge of German universities, 227!,

230
Pythagorean theorem, 58

Quaker, 138, 158

Quantum theory, 69; Einstein's new,

73

Quantum: of radiation, 72; mechan-
ics, 212

Race theory applied to mathematics,
etc., 230

Racial: purging in German universi-
ties, 227!, 230; dependence of
physics, 252

Radical, 246

Radioactive: substances, 208; atoms,

209

Rate of a time-keeper, 60
Rathenau, Walter, 190-1, 203-4
Rationality of nature, 283
Reactionary, 292
Real: 41; different senses of, 132;

world, 215
Red Army, 100
Redemption of Tycho Brake* The,

85

Reflection and refraction of light, 32,

5 6

Refugee, 277, 294; psychological situ-
ation of, 278, 286; scholars, 276

Refutation of materialism, 258

Reichswehr, 225

Reign of Relativity, The (Haldane),
188

Reinhardt, M., 205

Relation: between cause and effect, 51;
of science and religion, 280

Relativism, 249

Relativity, 32, 56-9, 62-3, 67, 69, 92,
94, 118, 122, 131, 141, 217, 232, 238,
251, 259; principle in Newtonian
mechanics, 30; fundamental hy-
potheses of, 53; Einstein founds
principle of, 54; of time, 57, 61, 63;
idealism surrounding, 145; as Bol-
shevism in physics, 146; regarded
as Jewish, 146; philosophical system
inconsistent with, 160; only twelve
people in world understand, 179; in
Congressional Record , 184; not in-
fluencing religion, 190

Religion, 229, 248, 280; Einstein at-
tracted to tradition, 9; Einstein's
feeling of, 10; Einstein's change in
attitude for, 14; Einstein's aversion
for orthodox practices of, 15; Kant-
ism as, in Germany, 43, 107; ortho-
dox, 149; not influenced by rela-
tivity, 190; Einstein's theories as
argument for, 262 .; Einstein's
view on, 282; ritual of, 287

Rembrandt, 265

Renan, Ernst, 196

Research: institutions in Germany,
106; as a profession, no

Revolution: first great, in physical
thought, 25; second, 26, 28; of heav*

Index

Revolution (continued)
enly bodies, 34; of quantum the-
ory, 69; from the right, 192; Nazi,
177, 270

Key, Abel, 46

Ricci, 103

Rockefeller, 106

Roman Church, 258

Roman Inquisition, 26

Romanticism, 180

Roosevelt, President F. D., 290-2; Ein-
stein's letter to, 291

Rosen, N., 273

Royal Society, 137 f.

Ruess, II-I2

Rumania, 150

Russell, Bcrtrand, 215, 246, 277

Russia, 97, 100, 145, 149-5? 3C 9 2 > 20 3"
4, 232, 256 f., 275

Russian Academy of Science, 261

Rust, Bernard, 233

Rutherford, Sir Ernest, 101, 209, 233,
246

Samuel, Viscount Herbert, 200, 248

Santayana, George, 227

Skepticism, 281

Schaffhausen, 22

Schiller, Priedrich, 4-8, 12

Schleicher, 226

Schlick, Moritz, 193, 215

School: Einstein's compared to bar-
racks, 10 ; at Winter thur, 22

Schopenhauer, 50

Schrodinger, Brwlr^ 112-13, 210-11,
250

Schweitzer, Albert, 158

Science, 280; at end of nineteenth cen-
tury, 45; bankruptcy of, 45; de-
feated, 6 1 ; religion and philosophy,
115; against common sense, 142;
invaded by unrest, 143

Scientific: apparatus, 24; viewpoint
versus philosophical, 25

Scientists: many unable to grasp
meaning of relativity, 141; part in
international understanding, 155

"Secret 1 * of the atomic bomb, 291

Seismic waves, 33

Semantics, 63-4, 131

Semitic: Arabs, 229; race, 330

Serbia, 30, 23

Shakspere, 12

Shanghai, 198

Shapley, Harlow, 136, 292

Shaw, G. B., 189-90

Simultaneity, 64

Slavic peasant, 104

Slovakia, 239

Social Democrats, 20, 75, 168, 230

Social: matters, Einstein's interest in,

ii ; life of Einstein, 294
Socialism, 156
Socialists, 162

Society of French Physicists, 196
Solar eclipse: total, 97, 137; expedi-
tion, 138-40, 159; 190
Soldiers: Einstein's dislike of playing

at, 8; for peace, Jews as, 156
Solvay Congress, 101-2
Sophisticated forms of anti-intellec-
tual, 47

Sorbonne, 197, 265
Sorel, 249
Sovereignty of nations, 292

Sound, 33

South America, 204

Soviet: political philosophy, 145;
spokesmen, 146; doctrines, 256; phi-
losophers, 257, 260

Space, 57, 63, 129-30, 135-6, 141, 177,
179, 256

Spain, 198, 201

Spectral lines of moving atoms, 60

Spencer Lecture, Herbert, 217

Stark, Johannes, 238

Stars, 139; sec also Fixed stars

State Opera House, Berlin, 237

"Steering" waves, 210

Straight lines, 41

Structure of the atom, 208

Students, 20; Einstein's relation to,
89, 206

Stumpf, Professor, 115

Subatomic particles, 210-12

Sudeten Germans, 84, 169-70

Sum of angles: of a triangle, 41;
more than two right angles, 129

Superiority of the German nation, em-
phasis on, 114

Superstitions, 45

Swabians, 4, 6, 124

Sweden, King of, 203

Swedish Academy of Science, 201-2

XI

Index

Switzerland, 21-2, 99, 120, 126, 184,

293 ...
Symbolic significance of Einstein's

acts and words, 297
System of reference, 63-4
Szilard, Leo, 290-1

Talmud, 255-6

Technical Institute of Brno, 78

Tel-Aviv, 200

Tensor analysis, 206

Teutonic speculation, 233

Theological: reflections of Newton,
35; Seminar at Princeton, 287

Theology, 264, 285

Theorems, geometrical validity of
(Poincare), 41

"Thing-in-itself," 250

Thompson, Sir J. J., 141, 189

Thought, pure, 143

Time, 57 , 256; as measuring device,
60; contraction and expansion of,
61; flow of, 61; duration of, 62; in-
terval, 63; Einstein's pride in hav-
ing, 1 1 8, and space disappear,

179

Timiryasev, A. K., 259
Tolstoy, 275
Transformation of mass into energy,

65

Treaty: of Versailles, 121; of Rapallo,

192
Twentieth century, 46, 48, 69, 180, 216,

251

Uhland, 5

Ulm, Einstein's birthplace, 6

Ultimate reality behind phenomena,

4 8

Understanding, 37, 44
Underworld, 225
Unified field theory, 218, 296
United States, 276, 292; see also Amer-

ica

United States Naval Academy, 34
Unity of field and matter, 273
Universe as an island in empty space,

Urania Society, 169, 172
Uranium: fission, 202; nucleus, 289;
bombs, 289

Velocity: of earth through ether, 34,
53; of light, 53, 55, 57, 66; con-
stancy of, 58; of the laboratory, 59,
92

Versailles Treaty, 243

Vibrations of molecules, 33

Vienna, 20, 104, 174, 215; University
of, 43; Ministry of Education of,
99; Einstein's trip to, 103

Vienna Circle (Wiener Krels), 215

Violin, Einstein's lessons on, 14

Volfyische Beobachter, 232

Voltaire, 113, 234

Volume of space, 136

Wagner, Richard, 256

Walsh, David, 184

War criminals, 121

Wave: theory, 32, 98; length, 134;

mechanics, 211
Weber, W., 163

Weizmann, Chaim, 153, 177-8, 182
Weltanschauung, 227, 258
Western culture, decline of, 145
Weyland, Paul, 159, 161
Whitehead, A. N., 140, 189
Wien, Wilhelm, 233
Wiener Kreis, see Vienna Circle
Wigner, Eugene, 290
Wilhelm I, Emperor, 7
Wilhelm II, Emperor, 106, 113, 280,

296

Wilson, Woodrow, 159-60
Winteler, 293; see also Einstein, Maja
Winternitz, Maurice, 83
Winterthur, 22

Wirth, Catholic Chancellor, 192
World's Fair, 280
World War I, 84, 97, 119, 147, 151,

158, 162, 165, 230
World War II, 169, 289

X-rays, 21 1

Yardstick, 58-9; length of, 63
Yiddish, 83, 228

Zionists, 84-5, 151, 201, 280, 295;
movement, 149, 159, 177; leaders
of, 182

Zurich, 20, 6r, 74-6, 92, 99-100, 107,
124; Einstein student at, 18; Uni-
versity of, 74-5; canton of,

Xll

A NOTE ON THE TYPE

This boo\ is set on the Linotype in GRANJON, a type named in com-
pliment to Robert Granjon, type-cutter and printer 1523-1590,
Antwerp, Lyons, Rome, Paris. Granjon, the boldest and most original
designer of his time f was one of the first to practice the trade of type-
founder apart from that of printer.

Linotype GRAN JON was designed by George W. Jones, who based
his drawings upon a face used by Claude Garamond (1510-1561) in
his beautiful French boofys* GRAN JON more closely resembles Gara-
mond's own type than do any of the various modern faces that bear
his name.

The booJ{ was composed^ printed, and bound by The Plimpton
Press, Norwood, Massachusetts. The typography and binding design
arc by W, A. Dwiggms.

124389