Albert Einstein
Albert Einstein
American physicist
born March 14, 1879, Ulm, Württemberg, Ger.
died April 18, 1955, Princeton, N.J., U.S.
Main
German-born physicist who developed the special and general theories of
relativity and won the Nobel Prize for Physics in 1921 for his
explanation of the photoelectric effect. Einstein is generally
considered the most influential physicist of the 20th century.
Education
Einstein’s parents were secular, middle-class Jews. His father, Hermann
Einstein, was originally a featherbed salesman and later ran an
electrochemical factory with moderate success. His mother, the former
Pauline Koch, ran the family household. He had one sister, Maja, born
two years after Albert.
Einstein would write that two “wonders” deeply affected his early
years. The first was his encounter with a compass at age five. He was
mystified that invisible forces could deflect the needle. This would
lead to a lifelong fascination with invisible forces. The second wonder
came at age 12 when he discovered a book of geometry, which he devoured,
calling it his “sacred little geometry book.”
Einstein became deeply religious at age 12, even composing several
songs in praise of God and chanting religious songs on the way to
school. This began to change, however, after he read science books that
contradicted his religious beliefs. This challenge to established
authority left a deep and lasting impression. At the Luitpold Gymnasium,
Einstein often felt out of place and victimized by a Prussian-style
educational system that seemed to stifle originality and creativity. One
teacher even told him that he would never amount to anything.
Yet another important influence on Einstein was a young medical
student, Max Talmud (later Max Talmey), who often had dinner at the
Einstein home. Talmud became an informal tutor, introducing Einstein to
higher mathematics and philosophy. A pivotal turning point occurred when
Einstein was 16. Talmud had earlier introduced him to a children’s
science series by Aaron Bernstein, Naturwissenschaftliche Volksbucher
(1867–68; Popular Books on Physical Science), in which the author
imagined riding alongside electricity that was traveling inside a
telegraph wire. Einstein then asked himself the question that would
dominate his thinking for the next 10 years: What would a light beam
look like if you could run alongside it? If light were a wave, then the
light beam should appear stationary, like a frozen wave. Even as a
child, though, he knew that stationary light waves had never been seen,
so there was a paradox. Einstein also wrote his first “scientific paper”
at that time (“The Investigation of the State of Aether in Magnetic
Fields”).
Einstein’s education was disrupted by his father’s repeated failures
at business. In 1894, after his company failed to get an important
contract to electrify the city of Munich, Hermann Einstein moved to
Milan, Italy, to work with a relative. Einstein was left at a boarding
house in Munich and expected to finish his education. Alone, miserable,
and repelled by the looming prospect of military duty when he turned 16,
Einstein ran away six months later and landed on the doorstep of his
surprised parents. His parents realized the enormous problems that he
faced as a school dropout and draft dodger with no employable skills.
His prospects did not look promising.
Fortunately, Einstein could apply directly to the Eidgenössische
Polytechnische Schule (“Swiss Federal Polytechnic School”; in 1911,
following expansion in 1909 to full university status, it was renamed
the Eidgenössische Technische Hochschule, or “Swiss Federal Institute of
Technology”) in Zürich without the equivalent of a high school diploma
if he passed its stiff entrance examinations. His marks showed that he
excelled in mathematics and physics, but he failed at French, chemistry,
and biology. Because of his exceptional math scores, he was allowed into
the polytechnic on the condition that he first finish his formal
schooling. He went to a special high school run by Jost Winteler in
Aarau, Switz., and graduated in 1896. He also renounced his German
citizenship at that time. (He was stateless until 1901, when he was
granted Swiss citizenship.) He became lifelong friends with the Winteler
family, with whom he had been boarding. (Winteler’s daughter, Marie, was
Einstein’s first love; Einstein’s sister Maja would eventually marry
Winteler’s son Paul; and his close friend Michele Besso would marry
their eldest daughter, Anna.)
Einstein would recall that his years in Zürich were some of the
happiest years of his life. He met many students who would become loyal
friends, such as Marcel Grossmann, a mathematician, and Besso, with whom
he enjoyed lengthy conversations about space and time. He also met his
future wife, Mileva Maric, a fellow physics student from Serbia.
Albert Einstein
Independent scholar and special relativity
After graduation in 1900, Einstein faced one of the greatest crises in
his life. Because he studied advanced subjects on his own, he often cut
classes; this earned him the animosity of some professors, especially
Heinrich Weber. Unfortunately, Einstein asked Weber for a letter of
recommendation. Einstein was subsequently turned down for every academic
position that he applied to. He later wrote,
I would have found [a job] long ago if Weber had not played a
dishonest game with me.
Meanwhile, Einstein’s relationship with Maric deepened, but his
parents vehemently opposed the relationship. His mother especially
objected to her Serbian background (Maric’s family was Eastern Orthodox
Christian). Einstein defied his parents, however, and he and Maric even
had a child, Lieserl, in January1902, whose fate is unknown. (It is
commonly thought that she died of scarlet fever or was given up for
adoption.)
In 1902 Einstein reached perhaps the lowest point in his life. He
could not marry Maric and support a family without a job, and his
father’s business went bankrupt. Desperate and unemployed, Einstein took
lowly jobs tutoring children, but he was fired from even these jobs.
The turning point came later that year, when the father of his
lifelong friend, Marcel Grossman, was able to recommend him for a
position as a clerk in the Swiss patent office in Bern. About then
Einstein’s father became seriously ill and, just before he died, gave
his blessing for his son to marry Maric. For years, Einstein would
experience enormous sadness remembering that his father had died
thinking him a failure.
With a small but steady income for the first time, Einstein felt
confident enough to marry Maric, which he did on Jan. 6, 1903. Their
children, Hans Albert and Eduard, were born in Bern in 1904 and 1910,
respectively. In hindsight, Einstein’s job at the patent office was a
blessing. He would quickly finish analyzing patent applications, leaving
him time to daydream about the vision that had obsessed him since he was
16: What will happen if you race alongside a light beam? While at the
polytechnic school he had studied Maxwell’s equations, which describe
the nature of light, and discovered a fact unknown to James Clerk
Maxwell himself—namely, that the speed of light remained the same no
matter how fast one moved. This violated Newton’s laws of motion,
however, because there is no absolute velocity in Isaac Newton’s theory.
This insight led Einstein to formulate the principle of relativity: “the
speed of light is a constant in any inertial frame (constantly moving
frame).”
During 1905, often called Einstein’s “miracle year,” he published
four papers in the Annalen der Physik, each of which would alter the
course of modern physics:
1. Über einen die Erzeugung und Verwandlung des Lichtes betreffenden
heuristischen Gesichtspunkt (“On a Heuristic Viewpoint Concerning the
Production and Transformation of Light”), in which Einstein applied the
quantum theory to light in order to explain the photoelectric effect. If
light occurs in tiny packets (later called photons), then it should
knock out electrons in a metal in a precise way.2. Über die von der
molekularkinetischen Theorie der Wärme geforderte Bewegung von in
ruhenden Flüssigkeiten suspendierten Teilchen (“On the Movement of Small
Particles Suspended in Stationary Liquids Required by the
Molecular-Kinetic Theory of Heat”), in which Einstein offered the first
experimental proof of the existence of atoms. By analyzing the motion of
tiny particles suspended in still water, called Brownian motion, he
could calculate the size of the jostling atoms and Avogadro’s number
(see Avogadro’s law).3. Zur Elektrodynamik bewegter Körper (“On the
Electrodynamics of Moving Bodies”), in which Einstein laid out the
mathematical theory of special relativity.4. Ist die Trägheit eines
Körpers von seinem Energieinhalt abhängig? (“Does the Inertia of a Body
Depend Upon Its Energy Content?”), submitted almost as an afterthought,
which showed that relativity theory led to the equation E = mc2. This
provided the first mechanism to explain the energy source of the Sun and
other stars.
Einstein also submitted a paper in 1905 for his doctorate.
Other scientists, especially Henri Poincaré and Hendrik Lorentz, had
pieces of the theory of special relativity, but Einstein was the first
to assemble the whole theory together and to realize that it was a
universal law of nature, not a curious figment of motion in the ether,
as Poincaré and Lorentz had thought. (In one private letter to Mileva,
Einstein referred to “our theory,” which has led some to speculate that
she was a cofounder of relativity theory. However, Mileva had abandoned
physics after twice failing her graduate exams, and there is no record
of her involvement in developing relativity. In fact, in his 1905 paper,
Einstein only credits his conversations with Besso in developing
relativity.)
In the 19th century there were two pillars of physics: Newton’s laws
of motion and Maxwell’s theory of light. Einstein was alone in realizing
that they were in contradiction and that one of them must fall.
Albert Einstein
General relativity
At first Einstein’s 1905 papers were ignored by the physics community.
This began to change after he received the attention of just one
physicist, perhaps the most influential physicist of his generation, Max
Planck, the founder of the quantum theory.
Soon, owing to Planck’s laudatory comments and to experiments that
gradually confirmed his theories, Einstein was invited to lecture at
international meetings, such as the Solvay Conferences, and he rose
rapidly in the academic world. He was offered a series of positions at
increasingly prestigious institutions, including the University of
Zürich, the University of Prague, the Swiss Federal Institute of
Technology, and finally the University of Berlin, where he served as
director of the Kaiser Wilhelm Institute for Physics from 1913 to 1933
(although the opening of the institute was delayed until 1917).
Even as his fame spread, Einstein’s marriage was falling apart. He
was constantly on the road, speaking at international conferences, and
lost in contemplation of relativity. The couple argued frequently about
their children and their meager finances. Convinced that his marriage
was doomed, Einstein began an affair with a cousin, Elsa Löwenthal, whom
he later married. (Elsa was a first cousin on his mother’s side and a
second cousin on his father’s side.) When he finally divorced Mileva in
1919, he agreed to give her the money he might receive if he ever won a
Nobel Prize.
One of the deep thoughts that consumed Einstein from 1905 to 1915 was
a crucial flaw in his own theory: it made no mention of gravitation or
acceleration. His friend Paul Ehrenfest had noticed a curious fact. If a
disk is spinning, its rim travels faster than its centre, and hence (by
special relativity) metre sticks placed on its circumference should
shrink. This meant that Euclidean plane geometry must fail for the disk.
For the next 10 years, Einstein would be absorbed with formulating a
theory of gravity in terms of the curvature of space-time. To Einstein,
Newton’s gravitational force was actually a by-product of a deeper
reality: the bending of the fabric of space and time.
In November 1915 Einstein finally completed the general theory of
relativity, which he considered to be his masterpiece. In the summer of
1915, Einstein had given six two-hour lectures at the University of
Göttingen that thoroughly explained general relativity, albeit with a
few unfinished mathematical details. Much to Einstein’s consternation,
the mathematician David Hilbert, who had organized the lectures at his
university, then completed these details and submitted a paper in
November on general relativity just five days before Einstein, as if the
theory were his own. Later they patched up their differences and
remained friends. Einstein would write to Hilbert,
I struggled against a resulting sense of bitterness, and I did so
with complete success. I once more think of you in unclouded friendship,
and would ask you to try to do likewise toward me.
Today physicists refer to the equations as the Einstein-Hilbert
action, but the theory itself is attributed solely to Einstein.
Einstein was convinced that general relativity was correct because of
its mathematical beauty and because it accurately predicted the
perihelion of Mercury’s orbit around the Sun (see Mercury: Mercury in
tests of relativity). His theory also predicted a measurable deflection
of light around the Sun. As a consequence, he even offered to help fund
an expedition to measure the deflection of starlight during an eclipse
of the Sun.
Albert Einstein
Delayed confirmation
Einstein’s work was interrupted by World War I. A lifelong pacifist, he
was only one of four intellectuals in Germany to sign a manifesto
opposing Germany’s entry into war. Disgusted, he called nationalism “the
measles of mankind.” He would write, “At such a time as this, one
realizes what a sorry species of animal one belongs to.”
In the chaos unleashed after the war, in November 1918, radical
students seized control of the University of Berlin and held the rector
of the college and several professors hostage. Many feared that calling
in the police to release the officials would result in a tragic
confrontation. Einstein, because he was respected by both students and
faculty, was the logical candidate to mediate this crisis. Together with
Max Born, Einstein brokered a compromise that resolved it.
After the war, two expeditions were sent to test Einstein’s
prediction of deflected starlight near the Sun. One set sail for the
island of Principe, off the coast of West Africa, and the other to
Sobral in northern Brazil in order to observe the solar eclipse of May
29, 1919. On Nov. 6, 1919, the results were announced in London at a
joint meeting of the Royal Society and the Royal Astronomical Society.
Nobel laureate J.J. Thomson, president of the Royal Society, stated:
This result is not an isolated one, it is a whole continent of
scientific ideas.…This is the most important result obtained in
connection with the theory of gravitation since Newton’s day, and it is
fitting that it should be announced at a meeting of the Society so
closely connected with him.
The headline of The Times of London read, “Revolution in Science—New
Theory of the Universe—Newton’s Ideas Overthrown—Momentous
Pronouncement—Space ‘Warped.’” Almost immediately, Einstein became a
world-renowned physicist, the successor to Isaac Newton.
Invitations came pouring in for him to speak around the world. In
1921 Einstein began the first of several world tours, visiting the
United States, England, Japan, and France. Everywhere he went, the
crowds numbered in the thousands. En route from Japan, he received word
that he had received the Nobel Prize for Physics, but for the
photoelectric effect rather than for his relativity theories. During his
acceptance speech, Einstein startled the audience by speaking about
relativity instead of the photoelectric effect.
Einstein also launched the new science of cosmology. His equations
predicted that the universe is dynamic—expanding or contracting. This
contradicted the prevailing view that the universe was static, so he
reluctantly introduced a “cosmological term” to stabilize his model of
the universe. In 1929 astronomer Edwin Hubble found that the universe
was indeed expanding, thereby confirming Einstein’s earlier work. In
1930, in a visit to the Mount Wilson Observatory near Los Angeles,
Einstein met with Hubble and declared the cosmological constant to be
his “greatest blunder.” Recent satellite data, however, have shown that
the cosmological constant is probably not zero but actually dominates
the matter-energy content of the entire universe. Einstein’s “blunder”
apparently determines the ultimate fate of the universe.
During that same visit to California, Einstein was asked to appear
alongside the comic actor Charlie Chaplin during the Hollywood debut of
the film City Lights. When they were mobbed by thousands, Chaplin
remarked, “The people applaud me because everybody understands me, and
they applaud you because no one understands you.” Einstein asked
Chaplin, “What does it all mean?” Chaplin replied, “Nothing.”
Einstein also began correspondences with other influential thinkers
during this period. He corresponded with Sigmund Freud (both of them had
sons with mental problems) on whether war was intrinsic to humanity. He
discussed with the Indian mystic Rabindranath Tagore the question of
whether consciousness can affect existence. One journalist remarked,
It was interesting to see them together—Tagore, the poet with the
head of a thinker, and Einstein, the thinker with the head of a poet. It
seemed to an observer as though two planets were engaged in a chat.
Einstein also clarified his religious views, stating that he believed
there was an “old one” who was the ultimate lawgiver. He wrote that he
did not believe in a personal God that intervened in human affairs but
instead believed in the God of the 17th-century Dutch Jewish philosopher
Benedict de Spinoza—the God of harmony and beauty. His task, he
believed, was to formulate a master theory that would allow him to “read
the mind of God.” He would write,
I’m not an atheist and I don’t think I can call myself a pantheist.
We are in the position of a little child entering a huge library filled
with books in many different languages.…The child dimly suspects a
mysterious order in the arrangement of the books but doesn’t know what
it is. That, it seems to me, is the attitude of even the most
intelligent human being toward God.
Albert Einstein
Coming to America
Inevitably, Einstein’s fame and the great success of his theories
created a backlash. The rising Nazi movement found a convenient target
in relativity, branding it “Jewish physics” and sponsoring conferences
and book burnings to denounce Einstein and his theories. The Nazis
enlisted other physicists, including Nobel laureates Philipp Lenard and
Johannes Stark, to denounce Einstein. One Hundred Authors Against
Einstein was published in 1931. When asked to comment on this
denunciation of relativity by so many scientists, Einstein replied that
to defeat relativity one did not need the word of 100 scientists, just
one fact.
In December 1932 Einstein decided to leave Germany forever (he would
never go back). It became obvious to Einstein that his life was in
danger. A Nazi organization published a magazine with Einstein’s picture
and the caption “Not Yet Hanged” on the cover. There was even a price on
his head. So great was the threat that Einstein split with his pacifist
friends and said that it was justified to defend yourself with arms
against Nazi aggression. To Einstein, pacifism was not an absolute
concept but one that had to be re-examined depending on the magnitude of
the threat.
Einstein settled at the newly formed Institute for Advanced Study at
Princeton, N.J., which soon became a mecca for physicists from around
the world. Newspaper articles declared that the “pope of physics” had
left Germany and that Princeton had become the new Vatican.
Albert Einstein
Personal sorrow
The 1930s were hard years for Einstein. His son Eduard was diagnosed
with schizophrenia and suffered a mental breakdown in 1930. (Eduard
would be institutionalized for the rest of his life.) Einstein’s close
friend, physicist Paul Ehrenfest, who helped in the development of
general relativity, committed suicide in 1933. And Einstein’s beloved
wife, Elsa, died in 1936.
To his horror, during the late 1930s, physicists began seriously to
consider whether his equation E = mc2 might make an atomic bomb
possible. In 1920 Einstein himself had considered but eventually
dismissed the possibility. However, he left it open if a method could be
found to magnify the power of the atom. Then in 1938–39 Otto Hahn, Fritz
Strassmann, Lise Meitner, and Otto Frisch showed that vast amounts of
energy could be unleashed by the splitting of the uranium atom. The news
electrified the physics community.
In July 1939 physicist Leo Szilard asked Einstein if he would write a
letter to U.S. President Franklin D. Roosevelt urging him to develop an
atomic bomb. Following several translated drafts, Einstein signed a
letter on August 2 that was delivered to Roosevelt by one of his
economic advisers, Alexander Sachs, on October 11. Roosevelt wrote back
on October 19, informing Einstein that he had organized the Uranium
Committee to study the issue. (See primary source document: Einstein’s
letter to President Roosevelt, 1939.)
Einstein was granted permanent residency in the United States in 1935
and became an American citizen in 1940, although he chose to retain his
Swiss citizenship. During the war, Einstein’s colleagues were asked to
journey to the desert town of Los Alamos, N.M., to develop the first
atomic bomb for the Manhattan Project. Einstein, the man whose equation
had set the whole effort into motion, was never asked to participate.
Voluminous declassified Federal Bureau of Investigation (FBI) files,
numbering several thousand, reveal the reason: the U.S. government
feared Einstein’s lifelong association with peace and socialist
organizations. (FBI director J. Edgar Hoover went so far as to recommend
that Einstein be kept out of America by the Alien Exclusion Act, but he
was overruled by the U.S. State Department.) Instead, during the war
Einstein was asked to help the U.S. Navy evaluate designs for future
weapons systems. Einstein also helped the war effort by auctioning off
priceless personal manuscripts. In particular, a handwritten copy of his
1905 paper on special relativity was sold for $6.5 million. It is now
located in the Library of Congress.
Einstein was on vacation when he heard the news that an atomic bomb
had been dropped on Japan. Almost immediately he was part of an
international effort to try to bring the atomic bomb under control,
forming the Emergency Committee of Atomic Scientists.
The physics community split on the question of whether to build a
hydrogen bomb. J. Robert Oppenheimer, the director of the atomic bomb
project, was stripped of his security clearance for having suspected
leftist associations. Einstein backed Oppenheimer and opposed the
development of the hydrogen bomb, instead calling for international
controls on the spread of nuclear technology. Einstein also was
increasingly drawn to antiwar activities and to advancing the civil
rights of African Americans.
In 1952 David Ben-Gurion, Israeli’s premier, offered Einstein the
post of president of Israel. Einstein, a prominent figure in the Zionist
movement, respectfully declined.
Albert Einstein
Increasing professional isolation
Although Einstein continued to pioneer many key developments in the
theory of general relativity—such as wormholes, higher dimensions, the
possibility of time travel, the existence of black holes, and the
creation of the universe—he was increasingly isolated from the rest of
the physics community. Because of the huge strides made by quantum
theory in unraveling the secrets of atoms and molecules, the majority of
physicists were working on the quantum theory, not relativity. In fact,
Einstein would engage in a series of historic private debates with Niels
Bohr, originator of the Bohr atomic model. Through a series of
sophisticated “thought experiments,” Einstein tried to find logical
inconsistencies in the quantum theory, particularly its lack of a
deterministic mechanism. Einstein would often say that “God does not
play dice with the universe.”
In 1935 Einstein’s most celebrated attack on the quantum theory led
to the EPR (Einstein-Podolsky-Rosen) thought experiment. According to
quantum theory, under certain circumstances two electrons separated by
huge distances would have their properties linked, as if by an umbilical
cord. Under these circumstances, if the properties of the first electron
were measured, the state of the second electron would be known
instantly—faster than the speed of light. This conclusion, Einstein
claimed, clearly violated relativity. (Experiments conducted since then
have confirmed that the quantum theory, rather than Einstein, was
correct about the EPR experiment. In essence, what Einstein had actually
shown was that quantum mechanics is nonlocal; i.e., random information
can travel faster than light. This does not violate relativity, because
the information is random and therefore useless.)
The other reason for Einstein’s increasing detachment from his
colleagues was his obsession, beginning in 1925, with discovering a
unified field theory—an all-embracing theory that would unify the forces
of the universe, and thereby the laws of physics, into one framework. In
his later years he stopped opposing the quantum theory and tried to
incorporate it, along with light and gravity, into a larger unified
field theory. Gradually Einstein became set in his ways. He rarely
traveled far and confined himself to long walks around Princeton with
close associates, whom he engaged in deep conversations about politics,
religion, physics, and his unified field theory. In 1950 he published an
article on his theory in Scientific American, but because it neglected
the still-mysterious strong force, it was necessarily incomplete. When
he died five years later of an aortic aneurysm, it was still unfinished.
Assessment
In some sense, Einstein, instead of being a relic, may have been too far
ahead of his time. The strong force, a major piece of any unified field
theory, was still a total mystery in Einstein’s lifetime. Only in the
1970s and ’80s did physicists begin to unravel the secret of the strong
force with the quark model. Nevertheless, Einstein’s work continues to
win Nobel Prizes for succeeding physicists. In 1993 a Noble Prize was
awarded to the discoverers of gravitation waves, predicted by Einstein.
In 1995 a Nobel Prize was awarded to the discoverers of Bose-Einstein
condensates (a new form of matter that can occur at extremely low
temperatures). Known black holes now number in the thousands. New
generations of space satellites have continued to verify the cosmology
of Einstein. And many leading physicists are trying to finish Einstein’s
ultimate dream of a “theory of everything.”
Michio Kaku
Encyclopaedia Britannica
