7 From Millikan to Einstein

Our next five remarkable physicists were born in the twelve years from 1868 to

1879. Two came from Germany and one from each of Austria, New Zealand and

America.

Robert Millikan (1868–1953)

In America, individual physicists, such as Joseph Henry and Willard Gibbs,

seem to have chosen to work in isolation, rather than develop a research

school. Towards the end of the nineteenth century the situation began to

change. The leading universities established something in the nature of a

department of physics, with appropriate staff, and there was usually no division

between experimental and theoretical physics. Our next subject was

one of the key figures in this process. He wrote an autobiography consisting

mainly of extracts from addresses he had given at various times, which was

published two years before he died. What follows is largely based on that

account. After his death a life-long friend and colleague made the following

assessment: ‘I do not think Millikan is a great physicist in the sense that we

look upon Newton, Kelvin, Helmholtz or J.J. Thomson, that is as a man who

has produced or will produce revolutionary ideas. His place is rather that

of a great consolidator and experimenter, a man who is capable of gleaning

by critical analysis from the suggestions of others those hypotheses which

are most nearly correct, subjecting them to properly devised and carried out

experimental verification and transforming them from the realm of hypothesis

to the realm of exact proved fact.’

Robert Andrew Millikan’s paternal grandfather was a typical American

pioneer of Scottish descent who moved west from New England first to

Ohio in 1825 and then on to Illinois in 1839, where he settled on the banks

of the Rock river, not far from the present town of Sterling. He was one of

those who helped runaway slaves to escape into Canada by the ‘underground

railroad’. Later he took his family yet further west, to the Upper Mississippi

valley, near Prairie du Chien, Iowa. The future physicist was born on

March 22, 1868, before this last move, but grew up in fertile prairie country

by the great river. His parents were Silas Franklin Millikan, a Congregational

222 From Millikan to Einstein

preacher, who married Mary Jane Andrews, formerly dean of women at a

small college in Michigan.

The school education the boy received in rural Iowa was adequate

except that there was next to no science teaching. Outside school he learned

how to live in the practical self-sufficient way of the American pioneers.

After leaving school he entered the first stage of the famous liberal arts

college of Oberlin, which had been founded in part by a distant relative and

was the alma mater of both his parents. The college reinforced the Christian

values and goals he had acquired at home, which guided his whole life. Before

he had been there long, he was asked to help teach elementary physics to

other students. He was so good at this that he was appointed tutor in physics

as soon as he graduated. At the same time he was employed as an instructor

in the college gymnasium, having always been keen on sport.

Next Millikan moved to New York City as the sole graduate student

in physics at Columbia University. At this time the study of physics in

America was just beginning to develop, but, when Rutherford visited

Columbia a few years later, he described the status of physical science

there as ‘miserable’. Millikan was taken in hand by an able young teacher

from Serbia named Michael Pupin. After emigrating to America, Pupin had

Robert Millikan (1868–1953) 223

gone back to Europe to take a doctorate under Helmholtz in Berlin and he

had also worked under Kirchhoff in Heidelberg. Pupin was now working

on an invention to improve long-distance telephony, which later brought

him fame and fortune. He encouraged Millikan, who by then had obtained

a Ph.D. for a thesis on optics, to go to Germany for post-doctoral work and

lent him the money he needed to do so. Millikan began at Jena, where he

became proficient in the German language. Then he made a bicycle tour,

covering 3500 miles in all. This took him to Paris, where he heard Poincar´e

lecture, and to several places in Germany. He decided to base himself in

Berlin, where he could work with Planck, Warburg, Neesen and Schwartz.

He also spent a semester at G¨ ottingen, where he took a course in thermodynamics

from Voigt and another in geometry from Klein. He also saw something

of Arnold Sommerfeld, then acting as Klein’s assistant, but what he

found most stimulating was the seminar led by the physical chemistWalter

Nernst.

As he was about to leave the Georgia Augusta, Millikan received a

cable from the physicist Albert Michelson of the new University of Chicago

offering him an assistantship in his department. Millikan took the next train

to London, then travelled on to New York and Chicago, arriving in time

for the fall semester of 1896. He turned down the offer of a better-paid position

from Oberlin because, as he told President William Rainey Harper, he

wanted the opportunity to do research. The university was a new institution,

strategically located both in time and in space to exercise a profound

influence on the evolution of the American university. President Harper

was a dynamic personality who had a definite programme for transforming

the American collegiate system into a university system influenced in

many respects by the German model. However, the British model was too

strongly entrenched to be easily displaced.

To start with, at the University of Chicago about half of Millikan’s

time was occupied in writing badly needed textbooks and organizing

courses. In 1900 he was sent to Paris by Harper to manage the university’s

exhibit at the World’s Fair, which won a Grand prize. Harper was delighted

by this success, which attracted much useful publicity. Two years later

Millikan married Greta Irvin Blanchard, the daughter of a successful

Chicago manufacturer; they spent most of their seven months’ honeymoon

in London and Paris, ending with a rapid tour of western Europe. While

in England he was given a warm welcome by British physicists, notably

J.J. Thomson. In Chicago he was promoted to assistant professor. The salary

was not especially generous, but he was also receiving useful royalties from

224 From Millikan to Einstein

his highly successful textbooks, which was fortunate since he already had

two sons to bring up and a third was on the way.

Throughout the twenty-five years they were together Michelson, a

Polish ´emigr´e, always treated Millikan with the utmost courtesy and consideration.

While Michelson pursued the experimental research which would

make him the first American national to receive a Nobel prize, Millikan

was left to look after the department’s graduate students. With his family

Millikan made another European tour, visiting Rutherford at Manchester

on the eve of some of his greatest discoveries, and then went on to Berlin to

revisit Planck and his research group.

In 1914 Millikan was elected to the National Academy of Sciences

of Washington, at the age of forty-six, having been awarded the Academy’s

Comstock medal the year before. Four years earlier he had been promoted

to full professor at the University of Chicago. Millikan was involved in

the successful effort to develop a telephone repeater, which soon made it

possible to communicate by telephone across the USA. This involved him

in a major lawsuit over patent rights, but he said afterwards that he learned

a great deal from the painstaking way the patent lawyers dealt with the case.

In the summer of 1916 Millikan made his first visit to the Pacific

Coast, to lecture at the Berkeley campus of the University of California, and

then went on to repeat his lectures at what was then the Throop College of

Technology in Pasadena, later to become world-famous as the California

Institute of Technology. Also in 1916 he was elected president of the

American Physical Society. By this time theUSAhad entered the FirstWorld

War and Millikan decided that he must go to Washington and devote himself

full-time to the war effort. Submarine detection was the first priority; it

was essential that the resources of American industry should be harnessed

to the project, and for once competing firms could be persuaded to cooperate

in the common cause. The new applications of physics were shared with

the Allies and played an important part in the conduct of the war, especially

in combatting the menace of the German submarines.

In its relation to the American state, the situation of American science

has tended to be the result of war-time requirements. Thus President

Lincoln first gave official recognition to science as an institution through

the creation of the National Academy of Sciences to provide technological

advice during the Civil War. The Academy was a semigovernmental body,

the official adviser of the American government in scientific matters, but it

was still a small body, had no permanent home and did not include engineering

in its scope. The Royal Society of London was its model, rather than the

Robert Millikan (1868–1953) 225

scientific academies of continental Europe, although the complementary

role played by the Royal Institution was altogether missing.

In the First World War President Wilson, finding that an honorary

academy of this type was ill-suited for providing the technical advice that

modern war required, added a new operational arm, the National Research

Council, which could draw on the up-to-date knowledge of the active core

of the American scientific community. However, the need to plan for the

future, when the war was over, was not lost sight of. The outcome of much

discussion was a programme of National Research Fellowships in physics

and chemistry, but initially not in mathematics and biology, open to Americans

and Canadians under thirty-five years of age. Each such fellow was

to be attached to some American university where he or she would undertake

an approved research project, the necessary funding to come from the

Rockefeller Foundation. A few years later the programme was extended

to include the mathematical and biological sciences, but there was no

intention of extending it to include non-American universities. Meanwhile

efforts were being made to establish the National Research Council itself

on a permanent basis, and it was decided to combine with the National

Academy over aWashington headquarters. The Carnegie Corporation agreed

to pay five million dollars towards this, provided that matching funds could

be raised from other sources. Millikan was heavily involved in all the negotiations

and fund-raising, which took him away from his department at the

University of Chicago.

Millikan had already been to Pasadena once, as we know, and now he

began making regular visits. The California Institute ofTechnology – known

informally as Caltech – was still at an early stage of development, with only

three permanent buildings of its own. However, it had the advantage that

the Huntington Library was nearby, as was the Mount Wilson observatory;

moreover, the Pasadena area was the most rapidly growing in the whole

country. The institute had the status of a university, its graduate school

one of the best in the USA, but it also had an undergraduate programme.

In a great university like Chicago it is practically impossible to persuade

the administration to break step and push one department out in front of

the others, no matter how much the general interests might demand such

discrimination. However, the powers-that-be at the institute were able and

willing to do just that in the case of physics, so Millikan was persuaded to

move there permanently and build it up. He said afterwards that his leaving

the university which had given him his chance was the greatest service he

could render it, since there was a need for new blood in Chicago.

226 From Millikan to Einstein

Millikan had agreed with the trustees of the California Institute of

Technology that he was to be chief executive officer and would concentrate

on building the best department of physics he could. Before long the privilege

of doing research at Caltech was so highly prized that no less than fifteen of

the new National Research Fellows were working there, as well as other

gifted young scientists, notably Robert Oppenheimer. Famous visitors came

to lecture from all over the world, including Max Born, Albert Einstein,

Werner Heisenberg and Erwin Schr ¨ odinger. In 1923 he was awarded the

Nobel prize in physics ‘for his work on the elementary charge of electricity

and on the photo-electric effect’. After determining the first accurate value

of the charge and hence of Planck’s constant, Millikan turned his attention

to the mysterious cosmic rays. He measured their intensities at great heights

and great depths and observed their seasonal variations.

By this time Millikan was probably the best-known American scientist

of his day. He wrote magazine articles popularizing the latest achievements

in science and technology. In the face of growing attacks on modern

science by religious fundamentalists, he organized a group of prominent

businessmen, academics and religious leaders to sign a joint statement on

the complementary role they believed science and religion played in the

progress of humanity. The honours he received included membership of the

Paris Academy and of the Royal Society of London. In politics he was a

staunch Republican, strongly opposed to the New Deal and something of a

racist. After being manoeuvred into retirement in 1946, he continued to give

lectures, mainly on science and religion. He died in Pasadena on December

19, 1953 at the age of eighty-five.

There is no denying that Millikan had stormy days in his varied activities.

His many vigorous debates on the nature and origin of cosmic rays were

major events in the world of science in the 1930s. His determination to elevate

the prestige of Caltech as rapidly as possible led to him being dubbed

one of the great publicity agents in the field of education. He often differed

vigorously from his colleagues on matters of politics, philosophy and

religion. His administrative methods were hardly conventional and often

confusing, yet his strong personal leadership always pulled things back into

shape. A long-time associate of his said that ‘the secret of his success lay

to a large extent in the simple virtues instilled in his upbringing. He had a

single-minded devotion to all that he was doing, and he put his work above

his personal desires and aspirations. His combination of native good sense

and intellectual honesty led him far both in science and in public life. In

spite of his success and high public position, he always remained a simple

man of true humility.’

Ernest Rutherford (Lord Rutherford) (1871–1937) 227

Ernest Rutherford (Lord Rutherford) (1871–1937)

Einstein described Rutherford as one of the greatest experimental physicists

of all time. In New Zealand he is rightly regarded as a national hero, held

up as an example to all the aspiring young. Both his parents emigrated there

as youngsters in the middle of the nineteenth century. His father, James

Rutherford, had been a wheelwright working in the Scottish city of Perth.

When he reached the South Island he tried his hand at farming and processing

flax, cutting railway sleepers and constructing bridges. Although

he was moderately successful in each of these enterprises, his family of a

dozen children learned the value of hard work and thrift. The future physicist’s

mother, Martha Thompson, accompanied her own widowed mother

to New Zealand from England and a few years later took over her mother’s

teaching post when she remarried. Martha was the dominant parent, who

endeavoured to instil in her children an interest in literature and learning.

She died in 1935 at the age of ninety-two. In their different ways both parents

contributed to their son’s characteristic traits of simplicity, directness,

economy, energy, enthusiasm and respect for education.

Ernest Rutherford was born on August 30, 1871 at Brightwater, a settlement

near the town of Nelson; when he was seven the family moved to

Havelock, also near Nelson. Success in the local primary school won him a

scholarship to Nelson College, which was rather like an English grammar

228 From Millikan to Einstein

school. In his spare time the boy enjoyed tinkering with clocks and making

models of the waterwheels his father used in his mills. By the age of ten

he had read a scientific textbook, but otherwise there was not yet any sign

of a special interest in science; he was expecting to become a farmer when

he grew up. At Nelson College he excelled in nearly every subject, particularly

mathematics, as well as becoming school captain or head boy. Another

scholarship took him on to Canterbury College, in the city of Christchurch,

which later became the University of Canterbury. At the conclusion of the

standard three-year course he was awarded a mathematical scholarship that

enabled him to remain for an extra year. He gained an M.A. in 1893, with

double first-class honours in mathematics and mathematical physics and in

physical science, and was encouraged to stay on at the college for yet another

year to gain a B.Sc. He taught briefly at the local high school, during which

time he became engaged to a fellow student at Canterbury College named

Mary Newton, eldest daughter of the landlady of the house in which he was

lodging. In a tiny basement workshop Rutherford began investigating the

radio waves discovered by Hertz not long before. He devised a magnetometer

that could detect radio signals over short distances and might be useful

in lighthouse-to-shore communication. However, unknown to Rutherford,

the American scientist Joseph Henry had already thought of this.

In 1895 Rutherford, as we know, was awarded a scholarship by the

Commissioners of the Great Exhibition of 1851 and chose the Cavendish

Laboratory because J.J. Thomson was the leading authority on electromagnetic

phenomena. He brought his magnetometer with him to England and

soon was able to show that he could receive radio signals from sources up

to half a mile away. This demonstration impressed a number of Cambridge

dons, Thomson included. Early in 1896, following the discovery of X-rays,

Thomson asked Rutherford to join him in studying the effect of this radiation

on electrical conduction in gases. Although Rutherford was anxious

to earn enough to marry his fianc´ee in New Zealand, he could hardly turn

down this opportunity.

While this work was in progress Rutherford was seriously considering

his future prospects. Although the Thomsons went out of their way

to be helpful, and Rutherford had been an academic and social success, he

was conscious of the prevailing Cambridge snobbery towards those who

had been undergraduates elsewhere, especially in the colonies. Seeing little

chance of a Cambridge post, he started to look further afield. Without

much hope of success, Rutherford applied for the professorship of physics

at McGill University in Canada, where the authorities were looking for

Ernest Rutherford (Lord Rutherford) (1871–1937) 229

someone to direct work in their well-equipped laboratory. Older men with

far greater experience had also applied, but Thomson’s emphatic testimonial

‘I have never had a student with more enthusiasm or ability than Ernest

Rutherford’ persuaded them to appoint him.

Arriving in Montr´eal to a warm welcome in September 1898,

Rutherford found perhaps the best laboratory in the western hemisphere

(it was financed by a tobacco millionaire who considered smoking a disgusting

habit) and a self-denying department chairmanwho soon voluntarily

assumed some of Rutherford’s administrative and teaching duties when he

recognized his genius. In research Rutherford embarked on the field which

was to occupy him for the next forty years, namely the study of radioactivity.

After two years he felt sufficiently well established in Montr´eal to

return to New Zealand in order to marry his fianc´ee Mary Newton after

their five-year-long engagement and take her back with him to Canada.

Their daughter and only child Eileen was born the following year; she was

to die suddenly following childbirth at the age of twenty-nine.

Rutherford’s nine years at McGill, dominated by the research which

made him famous, were no less busy in other ways. He was in great demand

as a speaker and travelled frequently to distant places to give a lecture or a

course. Much of his time was consumed in writing Radioactivity, the first

textbook on the subject and recognized as a classic as soon as it appeared in

1904. ‘Rutherford’s book has no rival as an authoritative exposition of what

is known of the properties of radio-active bodies’, wrote Lord Raleigh in a

review, ‘A very large share of that knowledge is due to the author himself.

His amazing activity in that field has excited universal admiration. Scarcely

a month had passed for several years without some important contribution

from the pupils he has inspired, on this branch of science; and what is more

wonderful still, there has been in all this vast mass of work scarcely a single

conclusion which has since been shown to be ill-founded . . .’ So rapidly

was physics advancing, however, that, when Rutherford prepared a second

edition the following year, it proved to be half as long again. No sooner was

this finished than he embarked on the task of writing another book arising

from the Silliman lectures he had delivered at Yale University. Friends urged

him to limit his outside engagements, but he was often in London to deliver

some prestige lecture and to keep in touch with what was happening.

Rutherford thoroughly enjoyed this recognition for, while not vain,

he was fully aware of his own worth. The Royal Society elected him to

the fellowship in 1903, at the early age of thirty-two, and awarded him

the Rumford medal the following year. Various universities kept trying to

230 From Millikan to Einstein

tempt him away from McGill, and the time arrived when Rutherford began

looking for an opportunity to return to England, where he would be closer

to the world’s leading scientific centres. In 1907 Arthur Schuster offered to

relinquish the Langworthy chair of physics at the University of Manchester

on condition that Rutherford was invited to succeed him. This was agreed

and Rutherford accepted. The following year he was awarded the Nobel

prize, for his work on the decay of radioactive elements. Curiously it was a

prize for chemistry rather than physics.

If the Cavendish, under Thomson, was the premier physics laboratory

in England, then Manchester, under Rutherford, was easily the second.

Schuster had built a fine structure less than a decade earlier and bequeathed

to his successor a strong research department, including his invaluable

young research assistant Hans Geiger. Rutherford’s great and growing fame

attracted to Manchester (and later to Cambridge) an extraordinarily talented

research team who made profound contributions to physics and chemistry.

One of them was the exceptionally able H.G.J. Moseley, whose death in

action at Gallipoli in 1915 at the age of twenty-seven was such a great loss

to science. It was Moseley, ‘a born experimenter’ according to Rutherford,

who demonstrated the fundamental importance of the atomic number.

Another Manchester colleague was Chaim Weizmann, better known for

his promotion of the Zionist cause, who described Rutherford as being

‘youthful, energetic, boisterous. He suggested anything but a scientist. He

talked readily and vigorously on any subject under the sun, often without

knowing anything about it . . . He was quite devoid of any political knowledge

or feelings, being entirely taken up with his epoch-making scientific

work. He was a kindly person but did not suffer fools gladly.’

In Rutherford’s gift, as Langworthy Professor, there was a personally

endowed readership in mathematical physics. He used this to bring Niels

Bohr to Manchester for a period including the early years of the First World

War. Although their personalities were very different, Bohr and Rutherford

became close friends. In 1926 Bohr looked back on his Manchester days and

described how he felt at the time:

This effect [the large-angle scattering of alpha particles] though to all

intents insignificant was disturbing to Rutherford, and he felt it

difficult to reconcile with the general idea of atomic structure then

favoured by the physicists. Indeed it was not the first, nor has it been

the last, time that Rutherford’s critical judgement and intuitive power

have called forth a revolution in science by inducing him to throw

Ernest Rutherford (Lord Rutherford) (1871–1937) 231

himself with his unique energy into the study of a phenomenon, the

importance of which would probably escape other investigators on

account of the smallness and apparently spurious nature of the effect.

This confidence in his judgement and our admiration for his powerful

personality was the basis for the inspiration felt by all in his

laboratory, and made us all try our best to deserve the kind and

untiring interest he took in the work of everyone. However modest

the result might be, an approving word from him was the greatest

encouragement for which any of us could wish.

Rutherford remained at Manchester for fourteen fruitful years. When

J.J. Thomson relinquished the Cavendish Professorship on his appointment

to the Mastership of Trinity in 1921, no-one was surprised when

Rutherford was elected as his successor. Increasingly beset by outside calls

on his time, Rutherford had less and less opportunity for his own research

and for keeping abreast of his students’ work. Yet, with the tradition of

enthusiasm for research that he had established earlier, his still frequent

rounds to ‘ginger up’ his ‘boys’, the Cavendish Laboratory’s output remained

far more than just respectable. Usually half his students came from outside

the United Kingdom, and after working in Cambridge they helped to spread

his teaching throughout the world.

Rutherford was outspoken, outgoing and direct; swearing, he used to

say, will make an experiment work better. He liked to keep his physics

and his experiments simple and described his work in straightforward and

precise language. He had a loud booming voice and it is said that, in the days

when counting circuits tended to be sensitive to noise, his collaborators’

equipment went wrong whenever he came near. He made decisions early

and firmly, and once a matter was decided did not give it any further thought.

He could be rude and even unreasonable on occasion, but, when he had

cooled off, would put matters right with a handsome apology. One of his

remarks, made at the British Association in September 1933, ‘anyone who

looked for a source of power in the transformation of atoms was talking

mere moonshine’, is often quoted; in private, however, he said he thought

there might be something in it.

During most of his career, especially the Cambridge part, his wife

Mary acted as his private secretary. As well as their Cambridge house, they

had a rural retreat, first a cottage in Snowdonia and later an isolated country

cottage near Chute in Hampshire. He was an enthusiastic motorist, one of

the pioneers, and was also a keen golfer. The eminent physicist Sir James

232 From Millikan to Einstein

Chadwick, who knew him well, has given some personal impressions of

Rutherford at this stage in his life:

The Rutherfords lived at Newnham Cottage, a low house in Queen’s

Road with a fine old garden, which belonged to Caius College. It was

encircled by a wall of dirty Cambridge brick. One entered through a

heavy door, and walked along a covered tiled way to the house itself.

There was a very fine garden, in which Lady Rutherford took great

pride. Rutherford’s study was on the left, immediately after entering

the house. Like the desk the room was littered with books and papers.

For some years a niece of Lady Rutherford’s lived with them and acted

as his secretary and her companion.

The Rutherfords occupied separate bedrooms, and there were no

overt acts of affection between them. Yet they were devoted to one

another. Lady Rutherford understood little or nothing of her husband’s

work, but she was very proud of the honours which showered upon

him and reacted violently to any criticism. She treated him in

ordinary matters as a child, still attempting to correct his faults when

eating, for instance. ‘Ern, you’ve dropped marmalade on your jacket.’

When, rarely, Rutherford caught a cold or influenza she nursed him

with loving care.’

From 1921, when he succeeded Thomson, until his death, Rutherford

also held the chair of natural philosophy at the Royal Institution. In 1922 he

received the Copley medal from the Royal Society. There were also numerous

other public lectures to which great honour was attached, such as the

presidential lecture to the British Association in 1923. Between 1925 and

1930 he was president of the Royal Society and subsequently he became

chairman of the important advisory council which had been set up to allocate

public money for the support of scientific and industrial research in the

United Kingdom. That involved many public appearances, such as opening

conferences and new laboratories, in addition to administrative and policymaking

chores.

From 1933 Rutherford was president of the Academic Assistance

Council and Chairman of its Executive Committee. This body, which

sought to obtain positions and financial assistance for the displaced scholars,

particularly Jews from Nazi Germany, raised a fund to provide maintenance

for displaced university scholars, from whatever country. The Council also

acted as a centre of information, putting individuals in touch with institutions

that could best help them. The British government was sympathetic,

Ernest Rutherford (Lord Rutherford) (1871–1937) 233

regarding it as in the public interest to ‘try and secure for [the United

Kingdom] prominent Jews who were being expelled from Germany and

who had achieved distinction whether in pure science, applied science . . .

music or art’. Many of the refugees brought intellectual riches to Britain.

Of the 2600 rescued by the Academic Assistance Council and its successor

body in the period before the war, twenty became Nobel laureates, fiftyfour

were elected Fellows of the Royal Society, thirty-four became Fellows

of the British Academy and ten received knighthoods. Of the scientists,

some were already famous but most were young and unknown when they

arrived. Unlike Lindemann in Oxford, Rutherford made no special effort to

encourage the physicists to come to Cambridge.

To continue with Chadwick’s reminiscences:

In appearance Rutherford was more like a successful business man or

Dominion farmer than a scholar . . . when I knew him he was of

massive build, had thinning hair, a moustache and a ruddy complexion.

He wore loose, rather baggy clothes, except on formal occasions. A

little under six feet in height, he was noticeable but by no means

impressive . . . it seemed impossible for Rutherford to speak softly. His

whisper could be heard all over the room, and in any company he

dominated through the sheer volume and nature of his voice, which

remained tinged with an antipodean flavour despite his many years in

Canada and England. His laughter was equally formidable.

He appeared to possess no fountain pen. He wrote slowly and

laboriously with an old steel-nibbed pen, or more often with a short

pencil. However with such a pencil he did arithmetic with surprising

accuracy. Mumbling to himself he would use what appeared to be

gross approximations to reduce multiplication or division to simple

addition or subtraction, remembering to correct the final result by the

necessary percentage. The answer he obtained was invariably within

the overall accuracy of the experiment.

Rutherford smoked interminably, usually a pipe and only

occasionally a cigar or cigarette. His pipe tobacco was reduced to

tinder dryness by being spread on a piece of newspaper in front of the

fire or on a sheet of paper placed on top of a hot water radiator in his

office or laboratory. When he lit his pipe it produced sparks and even

flames, like a volcano. A result of this was that his waistcoat was

peppered with small holes, and he often had to brush red hot grains of

tobacco from the papers before him on his desk.

234 From Millikan to Einstein

On October 15, 1937 Rutherford was suddenly taken ill at his Cambridge

home and was operated on the next day for a strangulated hernia.

Although at first the treatment he received seemed to be successful, the

internal organs did not recover their functions and he died peacefully four

days later, at the age of sixty-six. After his body had been cremated the

ashes were buried in Westminster Abbey, just west of the tomb of Newton.

In work that may be characterized as radioactivity at McGill, atomic physics

at Manchester and nuclear physics at Cambridge, Rutherford, more than any

other, formed the views later held concerning the nature of matter. As was

to be expected, numerous scientific and other honours came to him. Dozens

of universities awarded him honorary degrees and dozens of scientific societies

conferred on him honorary memberships and other distinctions. In

1914 he was knighted; later he was awarded the Order of Merit and raised to

the peerage, as Baron Rutherford of Nelson, the place in New Zealand from

which he came. Lady Rutherford returned to live there after her husband’s

death, uncomfortable socially and demanding to the end, but the one love

of his life and his most devoted admirer.

Lise Meitner (1878–1968)

Lise Meitner’s name has become widely known for her part in the discovery

of nuclear fission, which made nuclear power possible, as well as the atomic

bomb. Among physicists she is particularly noteworthy as one of the early

Lise Meitner (1878–1968) 235

pioneers in the study of radioactivity. Einstein described her as ‘the German

Madame Curie’; but, although most of her scientific work was done in

Berlin, she came from Austria and retained her nationality, even after she

became a Swedish citizen about eight years before her death. Lise Meitner

was born on November 7, 1878 in Vienna, where she spent the first third of

her life; she remained very much attached to the imperial city, never more

splendid than in those last autumn days of its glory. Another third of her

life was spent in Germany. When Austria was taken over by the Nazis she

found refuge in Sweden, where she lived for twenty-two years. It was only

at the age of eighty-one that she gave up scientific research and retired to

England to live out the rest of her days in Cambridge.

Lise Meitner’s father Philipp was a respected lawyer and keen chess

player. His ancestors came from Moravia, now part of the Czech Republic;

the family of her mother Hedwig (n ´ee Skovran) came from Russia. Being the

third of eight children, she was used both to being ruled by her two older

sisters and ruling over the four younger children. Although her parents were

Jewish, her father was a freethinker and the Jewish religion played no part

in her education. Indeed, all the children were baptized, and Lise Meitner

grew up as a Protestant; in later years her views were very tolerant, although

she would not accept atheism.

Lise Meitner said that she became a physicist because of a burning

desire to understand the working of nature, a desire that appears to go back

to her childhood. At the end of her school career she first had to pass the

state examination in French, so that, if necessary, she would be able to

support herself as a teacher; only then did she obtain permission to sit for the

Matura, the school-leaving examination, equivalent to the German Abitur,

that qualified her to enter the University of Vienna in 1901. For two years

she worked intensively to prepare herself to pass this hurdle, coached by

Arthur Szarvasy, later professor of physics in Brno. Her sisters used to tease

her; she had only to walk across the room for them to predict that she would

fail because she had interrupted her studies to do so. She was one of the four

women who passed that year, out of fourteen candidates.

In her university days she encountered occasional rudeness on the

part of the students (a female student was regarded as a freak) but also much

encouragement from her teachers. In later years she often spoke particularly

highly of the lectures of Boltzmann; it was probably he who inspired her

with his vision of physics as a search for the ultimate truth, a vision she

never lost. When she obtained her doctorate in physics in 1905 she was

only the second woman in Vienna to have done so. She remained at the

236 From Millikan to Einstein

university for another year or so, clearing up a question raised by Rayleigh.

Thus encouraged to aim for a career in theoretical physics, she obtained her

father’s permission and promise of financial support for post-doctoral study

in Berlin.

She had already made her first contact with the new subject of radioactivity,

which was to become the chief topic of her life’s work. In 1905 it was

not known for sure whether certain rays were deflected in passing through

matter; she designed and performed one of the first experiments in which

some degree of deflection could be observed. She had met Planck briefly

when he had visited Vienna in response to the invitation to be Boltzmann’s

successor and wanted to study under him. On arriving in Berlin in 1907, she

arranged to attend his lectures. After he had invited her to his home, she

recalled that ‘even with my first visit I was very impressed by the refined

modesty of the house and entire family. In Planck’s lectures, however, I

fought a certain feeling of disappointment at first . . . Boltzmann had been

full of enthusiasm . . . he did not refrain from expressing his enthusiasm in

a very personal way . . . Planck’s lectures, with their extraordinary clarity,

seemed at first somewhat impersonal, almost dry.’ Although Planck, like

so many of his colleagues, did not believe that women generally should be

permitted to study at universities, he was prepared to make exceptions and

Lise Meitner received his whole-hearted support. In her early days in Berlin

she found cheerful, informal company and good music in the Gru¨ newald

house. She was often to seek Planck’s advice in the years to come.

At first she had some difficulty in finding anywhere to carry out experimental

work. Then she met the young chemist Otto Hahn, whose profile

comes next. He was a frank and informal man of her own age from whom

she felt that she could learn a great deal. He was looking for a physicist to

help him with his own research into radioactivity. There was the difficulty

that Hahn was to work at the chemical institute under the Nobel laureate

Emil Fischer, who banned women from his laboratory (they might set fire to

their hair); in any case, women were not allowed access to laboratories used

by male students. However, an old carpenter’s workshop was equipped for

doing radiation measurements, and this was where Lise Meitner was permitted

to work. Soon she and Hahn were collaborating in research on radioactive

substances, Lise Meitner taking responsibility for the more physical aspects

and Hahn being more concerned with the chemistry. In the years leading up

to the First World War, they published a large number of papers on radioactivity,

most of which are no longer of interest. To Hahn, the chemist, the

discovery of new elements and the study of their chemical properties was

Lise Meitner (1878–1968) 237

the most exciting part of the work; Lise Meitner was more interested in

understanding their radiations.

In 1908 Rutherford, as we know, was awarded the Nobel prize and, on

the way back from Stockholm, the Rutherfords spent a few days in Berlin.

While Rutherford had a valuable discussion with Hahn, Meitner was sent off

to help Rutherford’s wife Mary with her shopping. Although she and Hahn

became close friends as well as colleagues, they never had a meal together

except on formal occasions. She was very reserved, even shy, and had been

brought up strictly.

In 1914 the outbreak of war caused their programme of research to be

interrupted; Hahn was called up and Lise Meitner volunteered to serve as an

X-ray nurse with the Austrian army. It was a harrowing time for her, working

up to twenty hours a day with inadequate equipment and coping with large

numbers of Polish soldiers with every kind of injury, without knowing their

language. In the study of radioactive substances, measurements at fairly long

intervals may be needed in order to let activities build up or allow unwanted

ones to decay. Periodically she went back to Berlin on leave to make such

measurements, and Hahn sometimes succeeded in synchronizing his leave

with hers.

By then they were no longer working in the carpentry shed. The ban

which kept her out of the chemical laboratories had been lifted in 1909,

when women were at last admitted to academic studies in Germany. Hahn

was offered a small independent department in the KaiserWilhelm Institute

for chemistry, which was opened in 1912 on a (then) rural site in Berlin-

Dahlem. Lise Meitner worked there with him for twenty-five years, first as

a ‘guest’ and from 1918 as head of a department of physics. In her laboratory

she maintained strict discipline, so that in a quarter of a century it never

became contaminated with radioactivity, despite the large amounts of radioelements

that were handled in the same building. Although her students

feared her strictness, they came to her with their personal problems even

so, and later her warm, practical humanity was remembered with fondness.

Lise Meitner regularly attended the weekly colloquium at the University

of Berlin, where new papers were discussed before an impressive

bench of Berlin scientists. She was assistant to Max Planck from 1912 to

1915 and in 1922 received the venia legendi; the subject, cosmic physics, of

her inaugural lecture was reported as cosmetic physics in the press. In 1926

she was made titular professor, but never gave any courses of lectures.

The discoveries of the neutron in 1932, the positron in 1933 and artificial

radioactivity in 1934 caused a turmoil in the world of nuclear physics,

238 From Millikan to Einstein

reflected in a number of short papers in which Lise Meitner and her collaborators

tried to keep pace with the rapid new developments. After Hitler

came to power, when ‘non-Aryan’ scientists lost their university posts, the

scientists in the institutes of the KaiserWilhelm Gesellschaft were less vulnerable,

being partly controlled by industrialists. Even so, the Nazis tried to

enforce party loyalty by various forms of infiltration, and Hahn and Meitner

had to be increasingly cautious in order to avoid open conflict and to avoid

losing those of their staff who were partly Jewish or who refused to join the

Nazi party. Although her venia legendi was rescinded in 1933 and she lost

her external professorship at the university, this did not affect her position

at the institute. People in her position were no longer allowed to give reports

at scientific meetings; she stopped attending them. Her name was dropped

from citations of papers of which she was a co-author.

The Anschluss (annexation) of Austria by Germany in March 1938

created serious problems for Lise Meitner: she was no longer a foreigner

protected by her Austrian nationality and consequently became subject to

the racial laws of Nazi Germany. As a person who was ‘over 50 per cent non-

Aryan’ she could expect to be dismissed from her post and to suffer other

penalties. Her honesty did not permit her to conceal her Jewish descent (as

some people did), and her dismissal could only be a question of time. Her

position looked even worse when her friend and colleague Max von Laue

said that he had heard of an order, issued by Heinrich Himmler, head of the

Gestapo, that no university teachers – whether Jewish or not – should in

future be allowed to leave Germany without special permission. An attempt

by the president of the KaiserWilhelm Gesellschaft to obtain a permit for her

was unsuccessful. There appeared to be a very real risk that she might not

only lose her position in Germany but also be prevented from seeking a new

one abroad. She decided that she must leave without delay and arrangements

were made by sympathizers in the Netherlands for her to escape to their

country. On the day of her departure she had just an hour and a half in

which to pack her most necessary belongings. In the laboratory no-one but

Hahn knew that she was leaving Germany for good; he gave her a diamond

ring to sell in case of need.

The Netherlands has a distinguished tradition in physics but at that

time lacked good facilities for nuclear research, so Lise Meitner quickly

moved on to Denmark, where for some weeks she enjoyed the hospitality of

the Bohrs. The facilities for nuclear research in Copenhagen were excellent,

and there were some young and active physicists at work. It was probably her

wish not to compete with those younger people that led to her decision not

Lise Meitner (1878–1968) 239

to remain there but instead to accept an invitation to join Manne Siegbahn,

head of the new Nobel Institute for Physics in Stockholm. In 1924 Siegbahn

had been awarded the Nobel prize in physics for his research work in the

field of X-ray spectroscopy; he and his pupils had created a Swedish tradition

of precision physics.

It was shortly after her arrival in Sweden in 1938 that she made her

most spectacular contribution to science. After she left Germany, Hahn and

his assistant Strassmann had continued the research, as before, until they

started discovering barium in the products of uranium bombardment. Hahn

wrote to consult Lise Meitner for an explanation of what was happening in

physical terms. His letter reached her before the discovery had been published,

and thus she became the first scientist outside Germany to learn of

this extraordinary phenomenon. It arrived during the Christmas vacation

when she was visiting friends in a small Swedish village. In the party there

was another refugee physicist, her nephew Otto Robert Frisch. Lise talked

to him about Hahn’s letter, but at first the young man did not believe that

uranium atoms could split into two almost equal parts. He thought that

Hahn and Strassmann must have made a mistake.

In order to talk the matter over at leisure, aunt and nephew took a

long walk in the snow. Physical exercise, they thought, might clear their

minds. Lise Meitner did most of the talking, urgently, convincingly. At

last she persuaded Frisch that Hahn and Strassmann had made no mistake,

that uranium atoms underwent fission, and that the energy released in the

process was probably very great. Once they felt quite sure they hastened

to Copenhagen to break the news to Niels Bohr. He listened eagerly to

what they told him, exclaiming ‘Oh, what idiots we have been. We could

have foreseen it all. This is just as it must be.’ He suggested an experiment

whereby they might measure the energy released when uranium atoms split.

Bohr was so engrossed in this extraordinary new phenomenon that he almost

missed the ship which was about to take him to New York for a meeting of

the American Physical Society. When he told the American physicists the

news of the sensational discovery of nuclear fission, they said that his gaze,

troubled and insecure, moved from person to person but stopped on no-one.

In a state of great excitement, the experimental work was repeated by several

research groups and confirmed. In Berlin Hahn was deeply worried: ‘God

cannot have intended this’, he is reputed to have said.

The 1945 Nobel prize for physics went to the theoretician Wolfgang

Pauli, although there were many who thought that Lise Meitner deserved it

more. Bohr nominated Meitner and Frisch for the Nobel prize for physics in

240 From Millikan to Einstein

1946 and for chemistry later, but to no avail. However, her work did not go

unrecognized, since later she shared with Hahn the Max Planck medal of the

Society of Physics, and the institute of nuclear research in Berlin was named

the Hahn–Meitner Institute. Her relationship with Otto Hahn remained

close, but he became increasingly inclined to undervalue her contribution

to their great discovery. Yet she had been the physicist member of the team

for thirty years and Hahn had always deferred to her judgement when it

was a question of physics. Later Strassmann commented that ‘she was the

intellectual leader of our team, and therefore she belonged to us – even if she

was not present for the discovery of fission’. This close working relationship

between the head of a scientific institute in Nazi Germany and an ´emigr´ee

Jewish scientist was a tribute to Hahn’s stability of character and personal

loyalty. However, it was widely felt that, by encouraging her to leave Berlin

when she did, he might have saved her life, but he had effectively blighted

her scientific career.

Lise Meitner remained in Sweden for twenty-two years, during which

a cyclotron was constructed in Siegbahn’s institute, the first to be built on

the mainland of Europe. The experience of Lise Meitner was invaluable for

making the best use of this new atom-splitting machine and for training

students in the required ancillary techniques. She acquired a good command

of the Swedish language, built up a small research group of her own

and published a number of short papers, mostly describing the properties

of some new radioactive species formed with the help of the cyclotron.

Inevitably she felt cut off at the Nobel Institute since Sweden, as a neutral

country, was isolated during the war; she had few students and lacked

the stimulus that Hahn had given her during her years in Berlin. She also

felt that Siegbahn was more interested in his precision physics than in

the comparatively crude measurements that were possible in the study of

radioactive isotopes. Initially there seemed to be a chance that she could

go to Britain, which she would have preferred, but at Oxford Lindemann

had the reputation of being unsympathetic to women, while from Cambridge

there was such a lukewarm response that she did not think it worth

following up. In July 1939, just before the war began, she nevertheless

accepted Lawrence Bragg’s invitation to visit Cambridge and was pressed

to remain on a three-year research contract, but she hesitated and, to her

lasting regret, returned to Sweden. During the war she contributed to the

Allied war effort by helping to provide information about nuclear research in

Germany, but she was adamant that she would have nothing to do with the

atomic bomb.

Lise Meitner (1878–1968) 241

In 1946 she spent half the year in the USA as visiting professor at the

Catholic University in Washington and was nominated as ‘woman of the

year’ by the American press. In 1947 she retired from the Nobel Institute and

accepted an offer from the Swedish atomic-energy committee to set up a

small laboratory for her at the Royal Institute for Technology. Later she

moved to a laboratory of the Royal Academy of Engineering Sciences, where

an experimental nuclear reactor was being built deep down in a hall blasted

out of the solid granite on which Stockholm stands. There she remained for

the rest of her time in Sweden, first directing the work of a research assistant,

later mainly engaged in reading, attending colloquia and discussing

problems with other physicists. Her mind was still active when in 1960

she retired to Cambridge in order to be nearer her relatives, including her

nephew Otto Robert Frisch, who by then held the Jacksonian chair of natural

philosophy at the Cavendish.

In Cambridge, Lise Meitner led a quiet life, but she still travelled a

good deal, to meet friends and give lectures, often about the rightful place of

women and, in particular, of women scientists. In 1963 she went to Vienna

to address a conference about ‘fifty years of physics’, a talk that was later

published in English. She had always taken great pleasure in music, as did all

her brothers and sisters (one sister became a concert pianist). In old age she

still fondly recalled the weekly musical evenings at the home of Planck. She

went to concerts as long as she could walk, and tried to follow contemporary

trends in music, although loss of hearing made this difficult.

After an exhausting visit to the USA at the end of 1964, Lise Meitner

suffered a heart attack, which caused her to spend some months in a nursing

home, from which she returned to her flat much enfeebled. Yet her strength

only failed slowly, and in 1967 she made a good recovery after a fall in

which she broke her hip. After that accident she did not travel any more

and gradually gave up all other activity. For the last two months she was in a

nursing home in Cambridge, where her life slowly ebbed away. She died on

October 27, 1968, a few days before her ninetieth birthday, having outlived

all her brothers and sisters, and was buried in a country churchyard, where

her youngest brother had been buried some years previously.

In spite of her close friendship with Planck and other great physicists,

Lise Meitner never quite lost the shyness of her youth, but among her friends

she could be lively and cheerful, and was an excellent story-teller. She was

interested in almost everything; always ready to learn and ready to admit

her ignorance of things outside her own field of study. Within that field,

however, she moved with great assurance and was convinced of the power

242 From Millikan to Einstein

of the human mind to arrive at correct conclusions from the great laws of

nature. The advance of knowledge was always her first concern and she felt

the delight of every good scientist in an excellent piece of work whoever it

was done by.

Otto Hahn (1879–1968)

The borderline between physics and chemistry is one that should not be

drawn too definitely. The chemists Dalton and Lavoisier have been mentioned

incidentally and would certainly have been given profiles if this had

been a book on remarkable chemists. However, Marie Curie is one exception,

and Otto Hahn, who figured prominently in the preceding profile, is

another. They seem to me to be chemists whose lives were so bound up

with those of physicists that it is only natural to profile them here.

Otto Hahn was born on March 8, 1879 in Frankfurt. His father,

Heinrich Hahn, was a glazier by trade and came from the village of Gungersheim

near Worms. The family derived from Rhenish peasant stock but,

while some of its members were farmers, others had pursued professional

careers, becoming either teachers or doctors. Heinrich settled in Frankfurt

in 1866, where he met a young widow named Charlotte Stutzmann (n ´ee

Giese), who belonged to a North German family of some distinction. They

Otto Hahn (1879–1968) 243

were married in 1875 and had three children, their sons Heiner, Julius and

Otto, besides Charlotte’s son Karl from her former marriage. One of Otto

Hahn’s cousins, Friedrich Thimme, was a historian who became director of

the Landesbibliotek in Hanover, and another, Heinz von Trubzschler, was

a member of the German foreign service and later became ambassador in

Dublin.

The construction boom in Frankfurt after the Prussian victory in

the Franco-Prussian war provided an opportunity for small tradesmen to

expand their businesses and Heinrich Hahn was among those able to do so,

becoming a contractor with several employees. Even so, the family lived

plainly with few luxuries. Karl attended the Goethe Gymnasium and specialized

in classics, while the other sons, including Otto, went to the Klinger

Realschule instead. In childhood his health was not good, but after the age of

fifteen this ceased to be a problem. His brother Heiner went into the family

business, as did Julius at first, before opening what became a successful art

gallery. Otto was sent to a technical school since his father had wanted to

become an architect himself and hoped that his son would enter the profession.

However, the youth soon came to the conclusion that architecture

did not suit him and instead he turned to science, especially chemistry.

On the advice of a friend, he went to the University of Marburg, a

town not far from Frankfurt. The science courses did not strike him as very

inspiring: the chemistry lectures were scholarly but not well presented, the

physics dull and the mathematics too difficult, although in later years he

regretted that he had not pursued these subjects further. Following German

custom, he did not remain at Marburg but migrated to the University of

Munich. Until then he had managed to avoid taking part in the regular

activities of the student fraternities, such as drinking beer and picking quarrels,

but was obliged, in the Easter of 1899, to fight another student who

had insulted him in the street by calling him a sissy. Although it was not

unknown for one of the contestants in a duel to be permanently disabled,

Hahn received only a few scratches. He began work on his doctorate, while

living an active social life as chief officer of a student fraternity, which

involved much carousing and other traditional activities. Nevertheless, the

thesis he wrote was accepted.

In most of Europe a period of military service was required of ablebodied

young men, two years in Germany and three years in Austria-

Hungary. However, those with sufficient education and social standing

could offer themselves for just one year’s training as officer cadets. Hahn

did so, but, although he passed out successfully at the end of the year, he

244 From Millikan to Einstein

did not apply for a commission. Instead he returned to Marburg to work

as an assistant demonstrator, planning to go into industry afterwards. For

this a knowledge of foreign languages would be an advantage, so in 1904

he went to work at University College, London, under SirWilliam Ramsay,

discoverer of the inert gases. Ramsay was impressed by the young German

and advised him to continue research in radiochemistry, rather than go into

industry. Hahn took his advice and gained a place at the University of Berlin,

but, before taking this up, he arranged a six-month visit to Rutherford’s

laboratory at McGill. Hahn was delighted with the easy, informal and yet

stimulating atmosphere he found there.

Hahn returned home to write up his research and found time to holiday

in the Tyrol with his brother Julius before settling down to work in

Berlin in October 1906. The first step was to report to Geheimrat Fischer

at the institute of chemistry. After six months he was given the status of

Privatdozent, on the strength of his published research. The next year Lise

Meitner, as we know, came from Vienna to study theoretical physics under

Planck. She too wished to do experimental work in the chemical institute

and Fischer agreed that she could work with Hahn.

Hahn was a handsome man who took pleasure in the company of

women, both as friends and as colleagues. When he was on an excursion

to Stettin by steamship, he met Edith Junghans, the daughter of the chairman

of the Stettin city council; soon they had become engaged. Hahn’s

professional position became more secure with the formation of a separate

department for radioactive work, enabling them to get married in March

1913. When the First World War broke out the following year, Hahn, being

a reservist, was called up at once; he was involved in action on the western

front at an early stage and participated in the fraternization between the

British and German troops which took place at Christmas 1914.

Shortly afterwards he was ordered to attend a meeting at army headquarters

in Brussels, where he was told that poison gas was to be used to

achieve a breakthrough. When Hahn protested that this would contravene

the Hague Convention, he was told that the French had already started using

gas; moreover, if the war could be ended quickly through the use of chemical

weapons, many lives might in the end be saved. So Hahn took part in their

development and was horrified later when he saw the results and realized

that his own work was partly responsible. A decision had been taken to

attempt to break through the Italian line with the support of a gas attack.

Hahn was sent there in September 1917 to make the necessary preparations

and the attack the next month was completely successful. Soon he

Otto Hahn (1879–1968) 245

was back on the western front, taking part in chemical operations throughout

the spring and early summer of 1918. Finally he went to Danzig for

experiments with a new type of chemical weapon.

After the end of the war there were disturbances and strikes in Berlin

for some time, and at one stage Hahn found himself acting as a stoker in

a power station. His wife Edith was expecting a baby, after nine years of

marriage; their first and only child, Hanno, was born in April 1922. Conditions

were still difficult in post-war Germany and financial problems, which

became increasingly severe during the remainder of the year, reached a

climax in the early part of 1923 when the currency lost all value. Although

domestic life was by no means easy under hyperinflation, scientific work

at the institute continued much as before.

By 1932 Hahn had been invited to lecture on radioactivity at Cornell

University. He gave a review of what he and Lise Meitner had been doing,

later published as a book: Applied Radiochemistry. The alarming news from

Germany made him cut short his stay and return to Berlin, when he went

at once to Planck with a proposal for an organized protest by German scientists

against the persecution of Jewish scientists. Planck advised him that

this would have no chance of success; it was already too late for protest:

‘if today thirty professors get up and protest against the government’s

actions, by tomorrow there will be 150 individuals declaring their solidarity

with Hitler, simply because they are after the jobs’. Although Hahn

steadfastly refused to join the Nazi party and continued to occupy his post

without molestation, as the weeks went by he became increasingly aware of

the political constraints. When the student fraternity to which he belonged

decided to exclude non-Aryans, Hahn promptly resigned, while keeping in

touch with some of the individual members. More significantly, he resigned

his lectureship at the University of Berlin, although as a member of the

Berlin Academy he could still lecture there whenever he wished.

In 1933 Hahn was made interim director of the Kaiser Wilhelm Institute

of physical chemistry until a loyal Nazi could be found to take over. He

was persistently and openly contemptuous of the Nazis, but at the end of his

few months of office he reported that ‘he had done his best with the unpleasant

and thankless task of cleansing the institute of non-party members’;

one of them, as we know, was Lise Meitner. At this point the able Fritz

Strassmann was brought into the research project. He had originally joined

the institute in 1929 and by 1935 was already an experienced radiochemist.

Since he wished to enter academic life, Hahn had urged him to apply to the

university for admission to the academic staff, but when he was informed

246 From Millikan to Einstein

that he must first join one of the Nazi organizations, he refused to proceed

with the application. His attitude towards the new political masters of

Germany was therefore much the same as Hahn’s; they were to remain close

associates and collaborators for the next ten years.

Five years later, as we also know, the experimental work reached a

climax with the discovery of what proved to be nuclear fission. Once it

had been established that huge amounts of energy were released by the

fission process, the excitement grew intense. After celebrating his sixtieth

birthday, Hahn went to the Scandinavian centres and to England to lecture

on the discoveries. However, the impending conflict was sharpening official

interest and obstacles began to be placed in the way of free publication. An

office for nuclear research was established by the German war department

as early as the summer of 1939, and leading nuclear scientists, including

Hahn, were drawn into the national discussions.

Hahn’s position during the war was in many ways typical. He had

always been a loyal German. Although he felt that he owed no loyalty to

the Nazis, who could be held responsible for starting the war, he nevertheless

recognized that the whole German nation was involved. His presence

at high-level meetings and the cooperation of his institute were bound to

be regarded as essential. The most useful thing they could do was to characterize

the fission products and to study relative yields, a programme that

was in fact a continuation of Hahn and Strassmann’s personal research and

therefore quite acceptable to them.

Five years later the war in Europe was coming to an end. The bombing

offensive against Berlin intensified. Hahn’s institute was destroyed and the

staff were moved to the small town ofTailfingen in southwest Germany. The

Hahns’ son Hanno joined his parents to convalesce after losing an arm on

the eastern front. The details of what happened after the area was occupied

by the Allied forces will be told in the profile of Heisenberg, who was more

closely involved with the German nuclear project. Suffice it to say here

that Hahn was taken to England in 1945, with nine other leading German

nuclear scientists, and interned.

Soon afterwards the first atomic bomb was exploded over Hiroshima,

and then a second dropped on Nagasaki, killing altogether more than a hundred

thousand people. Hahn felt partly responsible for the Japanese casualties

and contemplated suicide. Then a letter arrived from Planck saying

that he wished to retire as president of the KaiserWilhelm Gesellschaft and

that Hahn was being proposed to succeed him. Hahn was duly appointed;

soon afterwards he was awarded the 1944 Nobel prize in chemistry for the

Albert Einstein (1879–1955) 247

discovery of nuclear fission. Lise Meitner was not included, but Hahn gave

ten per cent of the prize money to Strassmann.

The internees returned to Germany in January 1946 and were resettled

in Go¨ ttingen, where the Kaiser Wilhelm Gesellschaft was restarted, under

Hahn’s presidency, and renamed the Max Planck Gesellschaft. At first it

mainly operated in the British zone of occupation, one of four. G¨ ottingen

was close to the border with the Russian zone; Hahn went to bed each

night wondering whether he might be kidnapped and wake up in Russia.

Rumours kept circulating that the Germans had also constructed atomic

bombs; Heisenberg and Hahn vehemently denied this, saying ‘at no time

did Germany have any atomic bombs or installations for the manufacture

of atomic bombs’.

Hahn was now almost sixty-seven, a respected figure in the new

Germany. This rather unassuming scientist, who had spent most of his life

in the laboratory, spent the next few years helping to rebuild German science

after the war. He wrote two autobiographical books, giving a somewhat

biased account of the Nazi period and of the post-war years when many of

those who, thanks to political opportunism or conviction, had flourished

during the Nazi regime still held important positions and were using their

influence to the detriment of their anti-Nazi colleagues.With other German

scientists, he presented to the West German government a statement that

they would not cooperate in the development of nuclear weapons.

Hahn was awarded various honorary degrees, lectured in Germany

and England, travelled in many other parts of Europe, but his declining

years were clouded by misfortune. One evening as he opened the door of

his house in G¨ ottingen he was shot by a disgruntled inventor, who wished

to draw attention to the neglect of his ideas by established scientists. He

had hardly recovered from this incident when his wife Edith had a nervous

breakdown. Then, in 1952, he was injured in a car accident; the following

year he had a heart attack. His son and daughter-in-law were killed in a

motor accident. Edith never recovered from the shock and remained an

invalid for the rest of her life. Hahn himself had a fall getting out of a car,

became progressively weaker and died in Go¨ ttingen on July 28, 1968, at the

age of eighty-nine. His wife survived him by no more than a fortnight.

Albert Einstein (1879–1955)

Einstein realized that each of the separate fields of physics could devour a

short working life without having satisfied the hunger for deeper knowledge,

but he had an unmatched ability to scent out the paths that led to the depths

248 From Millikan to Einstein

and to disregard everything else, all the many things that clutter the mind

and divert it from the essential. This ability to grasp precisely the particular

simple physical situation that could throw light on questions of general

principle characterized much of his thinking.

Albert Einstein was born in the peaceful German town of Ulm, in

the state of Wu¨ rttemberg, on March 14, 1879. He was the only son of

Hermann and Pauline (n ´ee Koch); both sides of the family were from Swabia.

His father Hermann was a kind, inoffensive but somewhat ineffectual

person; his mother the more dominant parent. His father’s brother, who

lived with the family, was a trained electrical engineer; father and uncle

together ran a business designing and manufacturing electrical apparatus,

such as dynamos. Not long after Albert was born the family moved to

Munich, and a year after that a sister Maria (known as Maja) was born.

There were no other children.

The future physicist grew up in suburban Munich. Although the

family was Jewish, he attended a Catholic primary school before proceeding

to the Leopold Gymnasium, a conventional school of good repute. His

scientific interests were awakened early by a small magnetic compass his

father gave him when he was about four; by the algebra he learned from

his uncle; and by the books he read, mostly popular science works of the day.

Albert Einstein (1879–1955) 249

A textbook on Euclidean geometry that he studied at the age of twelve made

a deep impression. We have an account of his childhood from his son Hans

Albert:

He was a very well-behaved child. He was shy, lonely and withdrawn

from the world even then. He was even considered backward by his

teachers. He told me that his teachers reported to his father that he

was mentally slow, unsociable and adrift forever in his foolish dreams.

Very early Einstein set himself the task of establishing himself as an

entirely separate entity, influenced as little as possible by other

people. In school he did not revolt, he simply ignored authority. His

parents, although Jewish, were largely indifferent to religion. Einstein,

while still a schoolboy, deliberately emphasized his Jewish origin and

went through a period of religious fervour which he later described as

his ‘first attempt to liberate myself from purely personal links’. At the

age of twelve he finally freed himself from conventional religious

belief, although he retained a firm belief in some rather undefined

‘cosmic religion’, which was entirely suprapersonal. When asked

about this, later on in his life, he used to say that although he did not

think there was a God who was interested in people he thought, like

Spinoza, that there might be one who created the universe.

As a child Einstein was echolalic, repeating to himself what he heard

in order to make sure that he had heard it correctly. He did not learn to speak

before he was three and did not speak fluently until he was seven. Later

in life he was a confusing lecturer, giving specific examples followed by

seemingly unrelated general principles. Sometimes he would lose his train

of thought while writing on the blackboard. A few minutes later he would

emerge as from a trance and go on to something different. He explained that

‘thoughts do not come in any verbal formulation. I rarely think in words

at all. A thought comes and I try to explain it in words afterwards’. He did

poorly at school, where so much teaching is verbal rather than visual; he

is believed to have been dyslexic. He was also a loner: ‘I’m not much with

people’, he would say. The mature Einstein impressed everyone who met

him by his gentleness and wisdom, but, as one of his biographers remarks,

‘he has never really needed human contacts; he deliberately freed himself

more and more from all emotional dependence in order to become entirely

self-sufficient’.

When the family business failed in 1894 after an over-ambitious

attempt to compete with much stronger firms, the rest of the family moved

250 From Millikan to Einstein

from Munich to Pavia in Lombardy, leaving the fifteen-year-old Einstein in

the care of distant relatives. The intention was to allow him to continue

his education, but he felt abandoned. He found the authoritarian Leopold

Gymnasium, with its emphasis on classics, increasingly unbearable. He

became ill and before long left, officially on medical grounds, but perhaps

partly to avoid liability for military service, and joined the family in Pavia.

One of his first actions was to renounce his German citizenship, thereby

becoming stateless. After spending most of a year enjoying life in Italy,

he resumed his education, but the family business was again failing and he

could expect no financial support from his parents. An aunt in Genoa gave

him a monthly allowance to see him through school and university, but

after that he would need to support himself.

Einstein’s aim was to enter the Polytechnikum (ETH) in Zu¨ rich, but

to do so he had to pass the entrance examination. After one unsuccessful

attempt, due to a poor performance in non-scientific subjects, he was advised

to complete his school education first. Accordingly, he spent a year at the

liberal gymnasium in the Swiss town of Aarau, where the regime was influenced

by Pestalozzi. His teachers thought him lazy and were unimpressed,

but he gained the certificate needed for university entrance. By the time

he was admitted to the Polytechnikum his main interests centred on theoretical

physics rather than mathematics. His mathematical abilities were

not exceptional; he was slow and made mistakes. The professors of mathematics,

Hurwitz and Minkowski, were outstanding, but Einstein had not

yet fully realized the creative value of mathematics in physical research.

Later he attributed his failure to learn from them as due to his lack of mathematical

instinct. He avoided normal classes and spent most of his time

studying the classics of physics, especially the works of Clerk Maxwell.

Einstein was impressed both by the successes and by the failures of the old

physics and was attracted to what he later called the ‘revolutionary’ ideas

of Maxwell’s field theory of electromagnetism. His study of the writings of

the nineteenth-century masters received a new impetus from Ernst Mach’s

Science of Mechanics.

After graduation Einstein became a Swiss citizen; this again made

him liable for military service, but he was rejected on medical grounds.

For two years he applied for schoolteaching posts but was unable to obtain

regular employment. While supporting himself by occasional tutoring and

substitute teaching, he published several scientific papers. Then, in 1902,

he was appointed an examiner at the Swiss patent office in Berne. The

Albert Einstein (1879–1955) 251

seven years Einstein spent there, examining applications for patents in

electrotechnology, were the years in which he laid the foundations of large

parts of twentieth-century physics. He liked the fact that his official work,

which occupied only part of the day, was entirely separate from his scientific

work, so that he could pursue this freely and independently, and he

often recommended this arrangement to others later on.

In 1905 Einstein received his doctorate from the University of

Zu¨ rich with a dissertation entitled Eine neue Bestimmung der Moleku¨ ldimensionen,

which contained the germ of his later theory of Brownian

motion. At this stage in his life he was about five and a half feet tall, with

regular features, warm brown eyes, a mass of jet-black hair and a slightly

raffish moustache. In 1903, against strong opposition from his mother (his

father had died the previous year), Einstein married Mileva Mari´ c, a Serbian

woman, a fellow physics student from the Polytechnikum, more or less

his contemporary academically although five years senior in age. Their two

sons were born in Switzerland, Hans Albert in 1904 and Eduard in 1910. A

previous child, Lieserl, was born at the home of Mileva’s parents and given

for adoption; there is no trace of her afterwards. Hans Albert emigrated to

the USA before the Second World War and became professor of hydraulic

engineering at the University of California; for various reasons he felt bitter

towards his father. Eduard was a gifted child; as a young man his resemblance

to his father was said to be ‘almost frightening’. He suffered from

paranoid schizophrenia, and after he had been institutionalized his father

had nothing more to do with him.

Einstein never publicly acknowledged any contributions by his wife

to his work; neither did she make any such claim. Yet some of his letters at

the beginning of the twentieth century refer to her role in the development

of ‘our papers’; for example, in one of them he wrote ‘How happy and proud

I will be when both of us together will have brought our work on relative

motion to a successful end’. Whatever this may mean, the consensus among

his biographers seems to be that she gave up scientific work to devote herself

to raising a family, while he did the opposite.

All biographers agree that he had a passion for music, as a way of

experiencing and expressing emotion that is impersonal. Einstein was an

enthusiastic violinist; Mozart, Bach and Schubert were his favourite composers.

When he was world-famous as a physicist he is reported to have

said that music was as important to him as physics: ‘it is a way for me

to be independent of people’; on another occasion he described it as the

252 From Millikan to Einstein

most important thing in his life. Photographs of him playing with Born,

Ehrenfest, Hadamard, Hurwitz or Planck show a different Einstein from the

more familiar images.

Einstein started his scientific work at the beginning of the twentieth

century. The closing decades of the nineteenth century were the period

when the long-established goal of physical theory – the explanation of all

natural phenomena in terms of mechanics – came under serious scrutiny

and was directly challenged. Mechanistic explanation had achieved many

successes, particularly in the theory of heat and in various aspects of optics

and electromagnetism; but even the successful mechanistic theory of heat

had its serious failures and unresolved paradoxes, and physicists had not

been able to provide a really satisfactory mechanical foundation for electromagnetic

theory. It was a time of startling experimental discoveries, but

the problems which drew Einstein’s attention and forced him to produce the

boldly original ideas of a new physics had developed gradually and involved

the very foundations of the subject.

In 1905, one marvellous year, Einstein produced three masterly papers

on three different subjects, which revolutionized the way scientists regarded

space, time and matter. These papers dealt with the nature of Brownian

motion, the quantum nature of electromagnetic radiation and the special

theory of relativity. Einstein considered the second paper, on the quantum

of light, or photon, as the most important, and it was for this that he was

to be awarded the Nobel prize, but it was relativity that caught the popular

imagination. It was not a new idea. Poincar´e had already considered

relativity from a mathematical point of view, in which the speed of light

was regarded as an absolute constant. Of course, the idea of treating time

as a fourth dimension has a long history; it had already been suggested by

d’Alembert in the eighteenth century. The structure for the space-time continuum

known as Minkowski space was developed by Minkowski only after

he had moved to G¨ ottingen; at the Polytechnikum he lectured on analytical

mechanics. While Einstein was by no means alone in thinking about relativity,

notably Langevin had been thinking on similar lines, it was only he who

understood its revolutionary implications and worked out its consequences.

Significantly, his original paper on the subject contained no references and

very little mathematics.

Although Planck strongly influenced Einstein, it was more Henrik

Antoon Lorentz who was his scientific father-figure. From his student days

Lorentz had been a disciple of Clerk Maxwell, one of the few people in

the Netherlands who understood the theory of electromagnetism. He was

Albert Einstein (1879–1955) 253

also an admirer of the work of Fresnel and of Hertz. He loved mathematics

and was invited by the University of Utrecht to become professor in

the subject, but preferred physics. Before long a new chair was created at

Leiden, his alma mater, and at the beginning of 1878 he returned there as

professor of theoretical physics, although he was not yet twenty-five. Three

years later, when he was twenty-seven years old, Lorentz was elected to the

Royal Academy of Sciences at Amsterdam. Amongst many other honours

he received the Nobel prize for physics in 1902. When Lorentz died in 1928,

at the age of seventy-four, Einstein represented the Berlin Academy at his

funeral and said ‘I stand at the grave of the greatest and noblest man of our

times. His genius was the torch which lighted the way from the teachings

of Clerk Maxwell to the achievements of contemporary physics . . . his life

was ordered like a work of art down to the smallest detail. His never failing

kindness and magnanimity and his sense of justice, coupled with an intuitive

understanding of people and things, made him a leader in any sphere

he entered. Everyone followed him gladly, for they felt that he never set out

to dominate but always simply to be of use. His work and his example will

live on as an inspiration and guide to future generations.’

It took a few years for Einstein’s research to receive recognition. When

he submitted the relativity paper to support his application to become

Privatdozent at the University of Berne, it was rejected, although he was

invited to give some lectures. His academic career did not really get started

until three years later, when he was appointed associate professor at Zu¨ rich

University; two years after that he became full professor at the German

University in Prague and then returned to Zu¨ rich as full professor at the

ETH, as the former Polytechnikum had become, the following year. Finally,

in the spring of 1914, Einstein was persuaded to move to Berlin as a professor

of the Berlin Academy, free to lecture at the university or not as he

chose, and as first director of the Kaiser Wilhelm Institute of physics. He

had mixed feelings about the move, partly because he disliked the Prussian

life-style and partly because in physics he felt that he would be expected

to produce one brilliant idea after another. As it turned out, however, he

found the atmosphere in the German capital quite stimulating, although

he missed the freedom of Switzerland, and he greatly appreciated having

Planck, Nernst and, later, Schro¨ dinger and von Laue as his colleagues. In

the First World War Einstein refused to join in the widespread support of

the German cause by German intellectuals and did what he could to preserve

a rational international outlook and to urge an immediate end to the

war.

254 From Millikan to Einstein

However, while Einstein’s scientific work was flourishing, his private

life was not. His marriage had been under strain for some years. He was physically

attractive to women and had a number of affairs. His wife Mileva and

their two sons followed him to Berlin, but before long they returned to

Zu¨ rich, which remained Mileva’s home for the rest of her life. Legal separation

and finally divorce followed soon after the end of the war. Earlier, when

Einstein became ill and was bedridden for some months, he was nursed back

to health by his cousin and childhood friend Elsa Lo¨ wenthal, a widow with

two daughters; when the divorce came through, in which violence towards

Mileva and adultery with Elsa were cited, they married. She was three years

older than he was, more maternal and protective towards him than Mileva

had been, and totally ignorant of science. The film actor Chaplin, who knew

her later, described her as ‘a square-framed woman with abundant vitality;

she frankly enjoyed being the wife of the great man and made no effort to

hide the fact; her enthusiasm was endearing’. Einstein gradually lost interest

in her.

Meanwhile Einstein had been developing the general theory of relativity,

the kind of theory which the mathematician Riemann may have

been seeking in vain, wherein gravitational forces arise from the geometry

of space-time. For the necessary mathematics Einstein turned for assistance

to Tullio Levi-Civit` a, an Italian geometer of the old school; later the theory

was recast in a more modern fashion by Hermann Weyl. A new scientific

theory needs to be tested by experiment, and an opportunity for this came

in 1919 when the deviation of light passing near the sun, as predicted by the

general theory of relativity, was observed during the solar eclipse. Already

famous among scientists, Einstein now became a celebrity to the general

public. The publicity, even notoriety, which ensued changed the pattern

of his life. He crossed the Atlantic for the first time and was lionized to

an embarrassing extent. He spent three months in Leiden and then went

on a grand tour of China, Japan, Israel and Spain. In 1921 he was awarded

the Nobel prize in physics, for his 1905 paper on light quanta; the prize

money he received went to his former wife Mileva, as part of the divorce

settlement.

As usual the Nobel prize, to which he attached little importance,

was followed by a whole cornucopia of other honours. He was now able to

put the prestige of his name behind the causes he believed in and he did

this, frequently naively, always bravely, but trying not to misuse the status

his scientific reputation had given him. The two movements he backed

most vigorously in the 1920s were pacifism and Zionism, particularly the

Albert Einstein (1879–1955) 255

creation of the Hebrew University in Jerusalem. He also took an active part

for a few years in the work of the Committee on Intellectual Cooperation

of the League of Nations.

Einstein’s chief outdoor recreation was sailing a dinghy on the numerous

lakes formed by the river Havel around Berlin. He was very skilful at

manipulating the little boat, enjoying the gliding motion and the quiet mindsoothing

scenery. He could be seen almost every day out sailing, but he had

no mooring for his boat. As the date of his fiftieth birthday approached,

the municipality conceived the plan of giving its most distinguished citizen

a birthday present: a house beside the lakes, which would give him perfect

quiet and direct access to the water. Unfortunately the project became

so entangled in politics that Einstein rejected the idea and simply built a

lakeside house for himself. It was there that he began meditating on the

final goal of his scientific life, the discovery of one unifying theory that

would bring together the hitherto separate phenomena of gravitation and

the electromagnetic field. With characteristic concentration and obstinacy,

he advanced numerous ideas on this subject during the rest of his life, but

none of them commanded widespread acceptance.

After the end of the war it had been the policy of the organizing committee

of the Solvay conferences to exclude Germans, but this restriction

was lifted for the fifth conference in 1927, the last time that Lorentz was in

the chair.Muchof Einstein’s scientific work after the end of the war had been

concerned with quantum mechanics, so he took the opportunity to present

an extended critique of Bohr’s ideas, with which he did not agree. There

was a vigorous discussion after which most of the participants departed

believing that the positivist Copenhagen view had prevailed, but Einstein

and his followers were not convinced. The controversy continued for years;

even today there are problems with quantum theory, although it works so

remarkably well in practice.

In Germany Einstein became increasingly the target of the anti-

Semitic extreme right. He was viciously attacked in speeches and articles,

even his life was threatened. Despite this treatment, he remained based in

Berlin, declining many offers of positions elsewhere. He still went regularly

to the Netherlands to see Lorentz. In 1931 he spent some time in Oxford as

Rhodes Memorial Lecturer, staying at Christ Church, where he accepted a

five-year research fellowship, with no duties attached, the only condition

being one of residence. Although in the end he did not take this up, he

returned to Oxford in 1933 as Herbert Spencer Lecturer. He also visited the

California Institute of Technology for three successive winters.

256 From Millikan to Einstein

By this time the Nazis had seized power in Germany and the attacks

on him were intensifying. His papers on relativity were publicly burned

before the Berlin State Opera House and all his property was confiscated.

When resigning from the Bavarian Academy he wrote ‘To the best of my

knowledge the learned societies of Germany have stood by passively and

silently while substantial numbers of scholars, students and academically

trained professionals have been deprived of employment and livelihood. I

do not want to belong to a society which behaves in such a manner, even if

it does so under compulsion.’ He had been considering an arrangement that

would have enabled him to divide his time between the Berlin Academy

and the Institute for Advanced Study in Princeton. Such a compromise was

clearly no longer viable and so he simply resigned from the Berlin Academy

and moved to Princeton. With Einstein on the faculty, the institute was

in a strong position to attract other leading scientists. Fortunately most of

Einstein’s scientific correspondence had been saved and brought to America

by diplomatic bag. Having automatically become a German citizen again

when he was appointed to the Berlin Academy, he relinquished this just

before the Nazis could deprive him of it. Many other Jewish scientists were

also leaving Germany; some stayed behind and, ironically, a few of them

tended to blame Einstein for what befell them.

So Princeton became Einstein’s home for the remaining twenty-two

years of his life. He described it as ‘a wonderful piece of earth and at the same

time an exceedingly amusing ceremonial backwater of tiny spindle-shanked

demigods’. His Heldenzeit lasted a good twenty years, but well before he left

Europe his great days were over. He was noticeably aged; scientifically the

Princeton years were much less fruitful than what came before. Although

he thought the chances of success were small, he continued to seek a unified

field theory and became increasingly isolated from the mainstream of

physical research. Princetonians respected his desire for solitude. On one

occasion he said that really his only friend in Princeton was Kurt G¨ odel, the

mathematical logician, who used to call for him every morning at 11 o’clock

so that, whatever the weather, they could walk together to Fuld Hall. He

continued ‘I do not socialize because social encounters would distract me

from my work and I really only live for that, and it would shorten even

further my very limited lifespan. I do not have any close friends here as I

had in my youth or later in Berlin with whom I could talk and unburden

myself. That may be due to my age. I often have the feeling that God has

forgotten me here. Also my standard of decent behaviour has risen as I grew

older: I cannot be sociable with people whose fame has gone to their heads.’

Albert Einstein (1879–1955) 257

During the 1930s Einstein renounced his former pacifist stand, since

he became convinced that the menace to civilization embodied in Hitler’s

regime could only be put down by force. He never returned to Europe, in fact

the only time he left America was in 1935 as part of the process of becoming

an American citizen. He did not participate in the American efforts

that eventually produced the nuclear reactor and the atomic bomb. After

the bomb had been used and the war ended, he devoted his energies to the

attempt to achieve a world government and to abolish war once and for

all. He also spoke out against repression, arguing that intellectuals must be

prepared to risk everything to preserve freedom of expression. Nonetheless,

despite his concern for world problems and his willingness to use whatever

influence he had towards alleviating them, his ultimate loyalty was

to science. As he said once with a sigh to an assistant during a discussion

of political activities: ‘yes, time has to be divided this way between politics

and our equations. But our equations are much more important to me

because politics is for the present but an equation like that is something for

eternity.’

After 1936, when his second wife Elsa died, Einstein was looked after

by his sister Maja, his stepdaughter Margot and his secretary-housekeeper

Helen Dukas. Maja had come to live with her brother in 1939; she suffered a

stroke in 1946, after which she was bedridden, and died in 1951. Einstein had

retired from the Institute for Advanced Study in 1945 and was living almost

like a recluse, trying to avoid the endless stream of people who wanted to

see him about something, or just to see him. He suffered much harassment

by press photographers; no other scientist has become so well known to

the public in appearance. He was generally quite a merry person, with a

strong sense of humour and a loud laugh; on one occasion he put out his

tongue to express his annoyance and that photograph has been reproduced

endlessly. Around Princeton he could often be seen at the local cinema –

he was particularly fond of Western films. Although he kept a wardrobe

of seven identical suits to wear on formal occasions, his ordinary dress was

casual, he favoured sweatshirts, leather jackets and sandals. He never learnt

to drive a car, but used to sail a dinghy on Lake Carnegie. Otherwise he

stayed peacefully at home in number 112 Mercer Street, a colonial-style

house no different from others in the neighbourhood.

For many years Einstein experienced recurrent health problems,

including anaemia and digestive attacks, and he also suffered from an

enlarged heart. He was drafting a speech on the tensions between Israel

and Egypt when he became ill and died a few days later, on April 18, 1955,

258 From Millikan to Einstein

in his seventy-sixth year; the immediate cause was a haemorrhage after a

large aneurysm of the abdominal aorta burst. One of his last acts was to

sign a plea, initiated by Bertrand Russell, for the renunciation of nuclear

weapons and the abolition of war. He left his brain for use in research, his

body for cremation, which was carried out privately, and all his scientific

and other papers to the Weizmann Institute in Jerusalem; this did not prevent

historians having difficulty in obtaining access to study this material

and permission to publish in scholarly works.

Einstein never identified with any particular country, living and working

in many different places, and, although he had quite a few individual

collaborators, he never set out to create a research school in any sense. In

his own words:‘I have never belonged wholeheartedly 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 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 by being

rendered independent of the customs, opinions and prejudices of others, and

am not tempted to rest my peace of mind upon such shifting foundations.’