|
Recognized
in his own time as one of the most creative intellects in human history, Albert
Einstein, in the first 15 years of the 20th century, advanced a series of
theories that for the first time asserted the equivalence of mass and energy and
proposed entirely new ways of thinking about space, time, and gravitation. His
theories of relativity and gravitation were a profound advance over the old
Newtonian physics and revolutionized scientific and philosophic inquiry. (see
also mass-energy equivalence)
Herein
lay the unique drama of Einstein's life. He was a self-confessed lone traveller;
his mind and heart soared with the cosmos, yet he could not armour himself
against the intrusion of the often horrendous events of the human community.
Almost reluctantly he admitted that he had a "passionate sense of social
justice and social responsibility." His celebrity gave him an influential
voice that he used to champion such causes as pacifism, liberalism, and Zionism.
The irony for this idealistic man was that his famous postulation of an
energy-mass equation, which states that a particle of matter can be converted
into an enormous quantity of energy, had its spectacular proof in the creation
of the atomic and hydrogen bombs, the most destructive weapons ever known.
Albert
Einstein was born in Ulm, Germany, on March 14, 1879. The following year his
family moved to Munich, where Hermann Einstein, his father, and Jakob Einstein,
his uncle, set up a small electrical plant and engineering works. In Munich
Einstein attended rigidly disciplined schools. Under the harsh and pedantic
regimentation of 19th-century German education, which he found intimidating and
boring, he showed little scholastic ability. At the behest of his mother,
Einstein also studied music; though throughout life he played exclusively for
relaxation, he became an accomplished violinist. It was then only Uncle Jakob
who stimulated in Einstein a fascination for mathematics and Uncle Cäsar
Koch who stimulated a consuming curiosity about science.
By the
age of 12 Einstein had decided to devote himself to solving the riddle of the
"huge world." Three years later, with poor grades in history,
geography, and languages, he left school with no diploma and went to Milan to
rejoin his family, who had recently moved there from Germany because of his
father's business setbacks. Albert Einstein resumed his education in
Switzerland, culminating in four years of physics and mathematics at the
renowned Federal Polytechnic Academy in Zürich.
After
his graduation in the spring of 1900, he became a Swiss citizen, worked for two
months as a mathematics teacher, and then was employed as examiner at the Swiss
patent office in Bern. With his newfound security, Einstein married his
university sweetheart, Mileva Maric, in 1903.
Early
in 1905 Einstein published in the prestigious German physics monthly Annalen
der Physik a thesis, "A New Determination of Molecular
Dimensions," that won him a Ph.D. from the University of Zürich. Four
more important papers appeared in Annalen that
year and forever changed man's view of the universe.
The
first of these, "Über die von der molekularkinetischen Theorie der Wärme
geforderte Bewegung von in ruhenden Flüssigkeiten suspendierten
Teilchen" ("On the Motion--Required by the Molecular Kinetic Theory of
Heat--of Small Particles Suspended in a Stationary Liquid"), provided a
theoretical explanation of Brownian motion. In
"Über einen die Erzeugung und Verwandlung des Lichtes betreffenden
heuristischen Gesichtspunkt" ("On a Heuristic Viewpoint Concerning the
Production and Transformation of Light"), Einstein postulated that light
is composed of individual quanta (later called photons) that, in addition to
wavelike behaviour, demonstrate certain properties unique to particles. In a
single stroke he thus revolutionized the theory of light and provided an
explanation for, among other phenomena, the emission of electrons from some
solids when struck by light, called the photoelectric
effect.
Einstein's
special theory of relativity, first printed in "Zur Elektrodynamik bewegter
Körper" ("On the Electrodynamics of Moving Bodies"), had its
beginnings in an essay Einstein wrote at age 16. The precise influence of work
by other physicists on Einstein's special theory is still controversial. The
theory held that, if, for all frames of reference, the speed of light is
constant and if all natural laws are the same, then both time and motion are
found to be relative to the observer. (see also special
relativity)
In the
mathematical progression of the theory, Einstein published his fourth paper,
"Ist die Trägheit eines Körpers von seinem Energieinhalt abhängig?"
("Does the Inertia of a Body Depend Upon Its Energy Content?"). This
mathematical footnote to the special theory of relativity established the
equivalence of mass and energy, according to
which the energy E of a quantity of
matter, with mass m, is equal to the product of the mass and the square of the
velocity of light, c. This
relationship is commonly expressed in the form E = mc2.
Public
understanding of this new theory and acclaim for its creator were still many
years off, but Einstein had won a place among Europe's most eminent physicists,
who increasingly sought his counsel, as he did theirs. While Einstein continued
to develop his theory, attempting now to encompass with it the phenomenon of
gravitation, he left the patent office and returned to teaching--first in
Switzerland, briefly at the German University in Prague, where he was awarded a
full professorship, and then, in the winter of 1912, back at the Polytechnic in
Zürich. He was later remembered from this time as a very happy man, content
in his marriage and delighted with his two young sons, Hans Albert and Edward.
In
April 1914 the family moved to Berlin, where Einstein had accepted a position
with the Prussian Academy of Sciences, an arrangement that permitted him to
continue his researches with only the occasional diversion of lecturing at the
University of Berlin. His wife and two sons vacationed in Switzerland that
summer and, with the eruption of World War I, were unable to return to Berlin. A
few years later this enforced separation was to lead to divorce. Einstein
abhorred the war and was an outspoken critic of German militarism among the
generally acquiescent academic community in Berlin, but he was primarily
engrossed in perfecting his general theory of
relativity, which he published in Annalen
der Physik as "Die Grundlagen der allgemeinen Relativitätstheorie"
("The Foundation of the General Theory of Relativity") in 1916. The
heart of this postulate was that gravitation is
not a force, as Newton had said, but a curved field in the space-time continuum,
created by the presence of mass. This notion could be proved or disproved, he
suggested, by measuring the deflection of starlight as it travelled close by the
Sun, the starlight being visible only during a total eclipse.
Einstein predicted twice the light deflection that would be accountable under
Newton's laws.
His
new equations also explained for the first time the puzzling irregularity--that
is, the slight advance--in the planet Mercury's
perihelion, and they demonstrated why stars in a strong gravitational field
emitted light closer to the red end of the spectrum than those in a weaker
field. (see also red shift)
While
Einstein awaited the end of the war and the opportunity for his theory to be
tested under eclipse conditions, he became more and more committed to pacifism,
even to the extent of distributing pacifist literature to sympathizers in
Berlin. His attitudes were greatly influenced by the French pacifist and author Romain
Rolland, whom he met on a wartime visit to Switzerland. Rolland's diary
later provided the best glimpse of Einstein's physical appearance as he reached
his middle 30s:
Einstein
is still a young man, not very tall, with a wide and long face, and a great mane
of crispy, frizzled and very black hair, sprinkled with gray and rising high
from a lofty brow. His nose is fleshy and prominent, his mouth small, his lips
full, his cheeks plump, his chin rounded. He wears a small cropped mustache. (By
permission of Madame Marie Romain Rolland.)
Einstein's
view of humanity during the war period appears in a letter to his friend, the
Austrian-born Dutch physicist Paul Ehrenfest:
The
ancient Jehovah is still abroad. Alas, he slays the innocent along with the
guilty, whom he strikes so fearsomely blind that they can feel no sense of
guilt. . . . We are dealing with an epidemic delusion which, having caused
infinite suffering, will one day vanish and become a monstrous and
incomprehensible source of wonderment to later generations. (From Otto Nathan
and Heinz Norden [eds.], Einstein on Peace;
Simon and Schuster, 1960.)
It
would be said often of Einstein that he was naïve about human affairs; for
example, with the proclamation of the German Republic and the armistice in 1918,
he was convinced that militarism had been thoroughly abolished in Germany.
International
fame came to Einstein in November 1919, when the Royal
Society of London announced that its scientific expedition to Príncipe
Island, in the Gulf of Guinea, had photographed the solar eclipse on May 29 of
that year and completed calculations that verified the predictions made in
Einstein's general theory of relativity. Few could understand relativity, but
the basic postulates were so revolutionary and the scientific community was so
obviously bedazzled that the physicist was acclaimed the greatest genius on
Earth. Einstein himself was amazed at the reaction and apparently displeased,
for he resented the consequent interruptions of his work. After his divorce he
had, in the summer of 1919, married Elsa, the widowed daughter of his late
father's cousin. He lived quietly with Elsa and her two daughters in Berlin,
but, inevitably, his views as a foremost savant were sought on a variety of
issues.
Despite
the now deteriorating political situation in Germany, Einstein attacked
nationalism and promoted pacifist ideals. With the rising tide of anti-Semitism
in Berlin, Einstein was castigated for his "Bolshevism in physics,"
and the fury against him in right-wing circles grew when he began publicly to
support the Zionist movement. Judaism had played little part in his life, but he
insisted that, as a snail can shed his shell and still be a snail, so a Jew can
shed his faith and still be a Jew.
Although
Einstein was regarded warily in Berlin, such was the demand for him in other
European cities that he travelled widely to lecture on relativity, usually
arriving at each place by third-class rail carriage, with a violin tucked under
his arm. So successful were his lectures that one enthusiastic impresario
guaranteed him a three-week booking at the London Palladium. He ignored the
offer, but, at the request of the Zionist leader Chaim Weizmann, toured the
United States in the spring of 1921 to raise money for the Palestine
Foundation Fund. Frequently treated like a circus freak and feted from morning
to night, Einstein nevertheless was gratified by the standards of scientific
research and the "idealistic attitudes" that he found prevailing in
the United States.
During
the next three years Einstein was constantly on the move, journeying not only to
European capitals but also to the Orient, to the Middle East, and to South
America. According to his diary notes, he found nobility among the Hindus of
Ceylon, a pureness of soul among the Japanese, and a magnificent intellectual
and moral calibre among the Jewish settlers in Palestine. His wife later wrote
that, on steaming into one new harbour, Einstein had said to her, "Let us
take it all in before we wake up."
In
Shanghai a cable reached him announcing that he had been awarded the 1921 Nobel
Prize for Physics "for your photoelectric law and your work in the field of
theoretical physics." Relativity, still the centre of controversy, was not
mentioned.
Though
the 1920s were tumultuous times of wide acclaim, and some notoriety, Einstein
did not waver from his new search--to find the mathematical relationship between
electromagnetism and gravitation. This would be a first step, he felt, in
discovering the common laws governing the behaviour of everything in the
universe, from the electron to the planets. He sought to relate the universal
properties of matter and energy in a single equation or formula, in what came to
be called a unified field theory. This turned
out to be a fruitless quest that occupied the rest of his life. Einstein's peers
generally agreed quite early that his search was destined to fail because the
rapidly developing quantum theory uncovered an
uncertainty principle in all measurements of the motion of particles: the
movement of a single particle simply could not be predicted because of a
fundamental uncertainty in measuring simultaneously both its speed and its
position, which means, in effect, that the future of any physical system at the
subatomic level cannot be predicted. While fully recognizing the brilliance of
quantum mechanics, Einstein rejected the idea that these theories were absolute
and persevered with his theory of general relativity as the more satisfactory
foundation to future discovery. He was widely quoted on his belief in an exactly
engineered universe: "God is subtle but he is not malicious." On this
point, he parted company with most theoretical physicists. The distinguished
German quantum theorist Max Born, a close friend
of Einstein, said at the time: "Many of us regard this as a tragedy, both
for him, as he gropes his way in loneliness, and for us, who miss our leader and
standard-bearer." This appraisal, and others pronouncing his work in later
life as largely wasted effort, will have to await the judgment of later
generations.
The
year of Einstein's 50th birthday, 1929, marked the beginning of the ebb flow of
his life's work in a number of aspects. Early in the year the Prussian Academy
published the first version of his unified-field theory, but, despite the
sensation it caused, its very preliminary nature soon became apparent. The
reception of the theory left him undaunted, but Einstein was dismayed by the
preludes to certain disaster in the field of human affairs: Arabs launched
savage attacks on Jewish colonists in Palestine; the Nazis gained strength in
Germany; the League of Nations proved so impotent that Einstein resigned
abruptly from its Committee on Intellectual Cooperation as a protest to its
timidity; and the stock market crash in New York City heralded worldwide
economic crisis.
Crushing
Einstein's natural gaiety more than any of these events was the mental breakdown
of his younger son, Edward. Edward had worshipped his father from a distance but
now blamed him for deserting him and for ruining his life. Einstein's sorrow was
eased only slightly by the amicable relationship he enjoyed with his older son,
Hans Albert.
As
visiting professor at Oxford University in 1931, Einstein spent as much time
espousing pacifism as he did discussing science. He went so far as to authorize
the establishment of the Einstein War Resisters' International Fund in order to
bring massive public pressure to bear on the World Disarmament Conference,
scheduled to meet in Geneva in February 1932. When these talks foundered,
Einstein felt that his years of supporting world peace and human understanding
had accomplished nothing. Bitterly disappointed, he visited Geneva to focus
world attention on the "farce" of the disarmament conference. In a
rare moment of fury, Einstein stated to a journalist,
They
[the politicians and statesmen] have cheated us. They have fooled us. Hundreds
of millions of people in Europe and in America, billions of men and women yet to
be born, have been and are being cheated, traded and tricked out of their lives
and health and well-being.
Shortly
after this, in a famous exchange of letters with the Austrian psychiatrist Sigmund
Freud, Einstein suggested that people must have an innate lust for hatred
and destruction. Freud agreed, adding that war was biologically sound because of
the love-hate instincts of man and that pacifism was an idiosyncrasy directly
related to Einstein's high degree of cultural development. This exchange was
only one of Einstein's many philosophic dialogues with renowned men of his age.
With Rabindranath Tagore, Hindu poet and mystic,
he discussed the nature of truth. While Tagore held that truth was realized
through man, Einstein maintained that scientific truth must be conceived as a
valid truth that is independent of humanity. "I cannot prove that I am
right in this, but that is my religion," said Einstein. Firmly denying
atheism, Einstein expressed a belief in "Spinoza's God who reveals himself
in the harmony of what exists." The physicist's breadth of spirit and depth
of enthusiasm were always most evident among truly intellectual men. He loved
being with the physicists Paul Ehrenfest and Hendrick A. Lorentz at The
Netherlands' Leiden University, and several times he visited the California
Institute of Technology in Pasadena to attend seminars at the Mt. Wilson
Observatory, which had become world renowned as a centre for astrophysical
research. At Mt. Wilson he heard the Belgian scientist Abbé Georges
Lemaître detail his theory that the universe had been created by
the explosion of a "primeval atom" and was still expanding. Gleefully,
Einstein jumped to his feet, applauding. "This is the most beautiful and
satisfactory explanation of creation to which I have ever listened," he
said. (see also big-bang model)
In
1933, soon after Adolf Hitler became chancellor of Germany, Einstein renounced
his German citizenship and left the country. He later accepted a full-time
position as a foundation member of the school of mathematics at the new
Institute for Advanced Study in Princeton, New Jersey. In reprisal, Nazi storm
troopers ransacked his beloved summer house at Caputh, near Berlin, and
confiscated his sailboat. Einstein was so convinced that Nazi Germany was
preparing for war that, to the horror of Romain Rolland and his other pacifist
friends, he violated his pacifist ideals and urged free Europe to arm and
recruit for defense. (see also Princeton University)
Although
his warnings about war were largely ignored, there were fears for Einstein's
life. He was taken by private yacht from Belgium to England. By the time he
arrived in Princeton in October 1933, he had noticeably aged. A friend wrote,
It
was as if something had deadened in him. He sat in a chair at our place,
twisting his white hair in his fingers and talking dreamily about everything
under the sun. He was not laughing any more.
In
Princeton Einstein set a pattern that was to vary little for more than 20 years.
He lived with his wife in a simple, two-story frame house and most mornings
walked a mile or so to the Institute, where he worked on his unified field
theory and talked with colleagues. For relaxation he played his violin and
sailed on a local lake. Only rarely did he travel, even to New York. In a letter
to Queen Elisabeth of Belgium, he described his new refuge as a "wonderful
little spot, . . . a quaint and ceremonious village of puny demigods on
stilts." Eventually he acquired American citizenship, but he always
continued to think of himself as a European. Pursuing his own line of
theoretical research outside the mainstream of physics, he took on an air of
fixed serenity. "Among my European friends, I am now called Der
grosse Schweiger ("The Great Stone Face"), a title I well
deserve," he said. Even his wife's death late in 1936 did not disturb his
outward calm. "It seemed that the difference between life and death for
Einstein consisted only in the difference between being able and not being able
to do physics," wrote Leopold Infeld, the Polish physicist who arrived in
Princeton at this time.
Niels Bohr,
the great Danish atomic physicist, brought news to Einstein in 1939 that the
German refugee physicist Lise Meitner had split
the uranium atom, with a slight loss of total mass that had been converted into
energy. Meitner's experiments, performed in Copenhagen, had been inspired by
similar, though less precise, experiments done months earlier in Berlin by two
German chemists, Otto Hahn and Fritz
Strassmann. Bohr speculated that, if a controlled chain-reaction
splitting of uranium atoms could be accomplished, a mammoth explosion would
result. Einstein was skeptical, but laboratory experiments in the United States
showed the feasibility of the idea. With a European war regarded as imminent and
fears that Nazi scientists might build such a "bomb" first, Einstein
was persuaded by colleagues to write a letter to President Franklin D. Roosevelt
urging "watchfulness and, if necessary, quick action" on the part of
the United States in atomic-bomb research. This recommendation marked the
beginning of the Manhattan Project.
Although
he took no part in the work at Los Alamos, New Mexico, and did not learn that a
nuclear-fission bomb had been made until Hiroshima was razed in 1945, Einstein's
name was emphatically associated with the advent of the atomic age. He readily
joined those scientists seeking ways to prevent any future use of the bomb, his
particular and urgent plea being the establishment of a world government under a
constitution drafted by the United States, Britain, and Russia. With the spur of
the atomic fear that haunted the world, he said "we must not be merely
willing, but actively eager to submit ourselves to the binding authority
necessary for world security." Once more, Einstein's name surged through
the newspapers. Letters and statements tumbled out of his Princeton study, and
in the public eye Einstein the physicist dissolved into Einstein the world
citizen, a kind "grand old man" devoting his last years to bringing
harmony to the world.
The
rejection of his ideals by statesmen and politicians did not break him, because
his prime obsession still remained with physics. "I cannot tear myself away
from my work," he wrote at the time. "It has me inexorably in its
clutches." In proof of this came his new version of the unified field in
1950, a most meticulous mathematical essay that was immediately but politely
criticized by most physicists as untenable.
Compared
with his renown of a generation earlier, Einstein was virtually neglected and
said himself that he felt almost like a stranger in the world. His health
deteriorated to the extent that he could no longer play the violin or sail his
boat. Many years earlier, chronic abdominal pains had forced him to give up
smoking his pipe and to watch his diet carefully.
On
April 18, 1955, Einstein died in his sleep at Princeton Hospital. On his desk
lay his last incomplete statement, written to honour Israeli Independence Day.
It read in part: "What I seek to accomplish is simply to serve with my
feeble capacity truth and justice at the risk of pleasing no one." His
contribution to man's understanding of the universe was matchless, and he is
established for all time as a giant of science. Broadly speaking, his crusades
in human affairs seem to have had no lasting impact. Einstein perhaps
anticipated such an assessment of his life when he said, "Politics are for
the moment. An equation is for eternity." (P.Mi.)
|
아인슈타인 (Albert Einstein).
1879. 3. 14 독일 뷔르템베르크 울름~1955.
4. 18 미국 뉴저지 프린스턴.
독일의 물리학자.
 |
| 아인슈타인 |
20세기초의 창조성이 뛰어난 대표적 지식인이었던 알베르트
아인슈타인은 20세기초 15년 동안 질량과 에너지의
등가를 단언하고 공간·시간·중력에 관한 새로운
사고방식을 제안한 일련의 이론들을 내놓았다. 그의 상대성
원리와 중력에 관한 이론들은 뉴턴 물리학을 넘어서는
심오한 진전이었고 과학적 탐구와 철학적 탐구에 혁명을
일으켰으며, 1921년 노벨 물리학상을 받았다. 그는 자신이 '사회
정의와 사회적 책임이라는 열정적 감각'을 갖고 있음을
인정했다. 아인슈타인은 그의 명성 덕택으로 평화주의·자유주의·시오니즘과
같은 대의를 지지하는 데 영향력이 있었다. 그러나
아이러니컬하게도 이러한 이상주의적인 사람이 물질 입자가
엄청난 양의 에너지로 바뀔 수 있다는 에너지-질량 방정식
가설로 지금까지 알려진 가장 파괴적인 무기인 원자폭탄과
수소폭탄의 창조를 증명했다.
초기생애와 경력
그가 태어난 이듬해 그의 가족은 뮌헨으로 이사하여
아버지 헤르만 아인슈타인과 숙부 야코프 아인슈타인은
조그마한 전기공장을 세우고 전기일을 시작했다. 뮌헨에서
엄격한 학교에 다녔는데, 19세기 독일 교육의 엄하고
현학적인 단체훈련 속에서 아인슈타인은 학생으로서의
능력을 거의 보이지 못하고 무섭고 지루함을 느꼈다.
어머니의 명령으로 음악도 공부하게 되었는데, 생애를 통해
기분전환으로만 연주했음에도 불구하고 그는 능숙한
바이올린 연주자였다. 그무렵 단지 숙부 야코프 체자르
코흐만이 아인슈타인의 수학과 과학에 대한 관심을
자극시켜주었다. 12세가 된 아인슈타인은 '거시 세계'의
수수께끼를 푸는 데 헌신하려는 결심을 하게 된다. 3년 후
역사·지리·어학에서 낮은 점수를 받아 졸업장도 못 받고
학교를 나와 가족을 다시 만나기 위해 이탈리아 밀라노로
갔는데, 그의 가족은 아버지의 사업이 망해서 밀라노로
이사한 지 얼마 안 된 상태였다. 아인슈타인은 스위스에서
공부를 다시 시작했는데, 유명한 취리히의
연방공과대학에서 4년간 물리학·수학 공부에 몰두했다.
1900년 봄, 학교를 졸업한 후에 스위스 시민이 되었고 2개월간
수학교사로 일한 후에 베른에 있는 스위스 특허 사무소
심사관으로 채용되었다. 새로이 안정을 찾게 되면서 1903년
대학시절의 애인 밀레바 마리치와 결혼했다. 1905년초에
아인슈타인은 독일의 유명한 월간 학술지 〈물리학 연보
Annalen der Physik〉에 〈분자 차원의 새로운 결정
A New Determination of Molecular Dimensions〉이라는 논문을 냈는데, 이
논문으로 나중에 취리히대학교에서 박사학위를 받게 되었다.
그 해의 〈물리학 연보〉에 4개의 더 중요한 논문을
발표했고 이는 인간의 우주에 대한 견해를 영구히
바꾸어버렸다.
이중에서 첫번째 논문인 〈정지 액체 속에 떠 있는 작은
입자들의 (열의 분자운동론에 의한) 운동에 대하여 Über
die von der molekularkinetischen Theorie der Wärme geforderte Bewegung von
in ruhenden Flüssigkeiten suspendierten Teilchen〉는 브라운 운동에
대해 이론적으로 설명해주었다. 〈 빛의
발생과 변화에 관련된 발견에 도움이 되는 견해에 대하여
Über einen die Erzeugung und Verwandlung des Lichtes betreffenden
heuristischen Gesichtspunkt〉에서 빛은 파동적 작용에 더하여
입자에만 고유하게 나타나는 일정한 성질들을 보여주는
개별적 양자(量子：후에 광자로 불림)로 이루어져 있다고
가정했다. 그는 이 한 가지 가정으로 빛 이론에 혁명을
일으켰고 여러 현상들 가운데서 광전효과(光電效果)라고
하는, 빛을 비추었을 때 일어나는 몇몇 고체로부터의 전자(電子)
방출에 대해 설명할 수 있었다.
아인슈타인의 특수상대성이론은 〈운동하는 물체의
전기역학에 대하여 Zur Elektrodynamik bewegter Körper〉에
처음으로 실렸다. 특수상대성이론은 모든 좌표계에서 빛의
속도가 일정하고 모든 자연 법칙이 똑같다면, 시간과 물체의
운동은 관찰자에 따라 상대적이라는 것이다.
특수상대성이론의 수학적 표현에 대해 아인슈타인은 그의 4번째
논문 〈 물체의 관성은 에너지 함량에
의존하는가Ist die Trägheit eines Körpers von seinem Energieinhalt
abhängig〉를 썼다. 이 논문에서 질량과 에너지의 등가를
확립했는데, 이에 따르면 어떤 양의 물질이 갖는 에너지는
그 물질의 질량에 빛의 속도의 제곱을 곱한 값, 즉 E=mc2이다.
특수상대성이론이 알려짐에 따라 아인슈타인은 유럽의
저명한 물리학자 대열에 서게 되었다. 그는 중력 현상을
새로 포함시키려고 이론을 계속 발전시켰다. 특허사무소를
떠나서 처음에는 스위스에서, 그리고 잠시 프라하의
독일대학교에서 정교수로 있었으며, 1912년 겨울 취리히의
연방공과대학으로 돌아왔다. 그는 그때를 결혼생활에
만족했고 어린 두 아들 한스·에트바르트와 즐거웠던 행복한
시절로 회상했다.
1914년 4월 베를린으로 이주하여 프로이센 과학
아카데미에서 자리를 얻었는데, 아카데미 당국은
아인슈타인이 때때로 베를린대학교에서 강의를 하면서
연구를 계속하도록 허가해주었다. 아내와 아이들은
스위스에서 휴가를 보내고 있었는데, 제1차 세계대전이
일어나 베를린으로 돌아올 수가 없었다. 어쩔 수 없는
헤어짐으로 몇 해 뒤에 아인슈타인은 이혼하게 되었다. 그는
전쟁을 혐오했고 일반적으로 순종적인 학자사회에서 독일
군국주의에 대한 공공연한 비판자가 되었으나, 일반상대성이론을
완성하는 데 주로 열중했다. 일반상대성이론은 1916년
〈물리학 연보〉에 〈 일반상대성이론의 기초Die
Grundlagen der allgemeinen Relativitätstheorie〉로 출판되었다. 이
가설의 핵심은 중력이, 뉴턴이 이야기했던 것과 같은 힘이
아니라 시공연속체 속의 질량이 존재에 의해 생긴 굽어진 장(場)이라는
것이었다. 이러한 의미는 별빛이 태양 가까이를 지날 때
별빛의 휘어짐에 의해 증명되거나 반증될 수가 있는
것이었는데, 별빛은 개기일식 동안에만 볼 수가 있다.
아인슈타인은 뉴턴 법칙으로는 설명할 수 없는 2배의 빛의
휘어짐을 예측했다.
그의 새로운 방정식들은 또한 수성의 근일점(近日點)의
당혹스러운 불규칙성(약간의 이동)을 최초로 설명해주었고,
강한 중력장 속의 별들이 약한 장의 별들이 내는
스펙트럼보다 적색에 가까운 스펙트럼을 내는 이유를
증명했다. 아인슈타인은 전쟁이 끝나는 것과 일식이
일어나는 상황에서 그의 이론이 시험될 기회를 기다리면서,
점차 평화주의적 입장을 취하게 되었다.
국제적인 환호
1919년 아인슈타인은 국제적인 명성을 얻게 되었는데
그해에 런던 왕립학회는 기니 만에 있는 프린시페 섬에서
있었던 과학탐사에서 그해 5월 29일의 일식을 사진 찍었고
아인슈타인의 일반상대성이론에서의 예측을 검증시킨
계산값들을 내었다고 공표했던 것이다. 사람들은
상대성이론을 거의 이해하지 못했지만, 그 기본 가설들은
대단히 혁명적이었으며 과학계는 이 물리학자가 지구에서
가장 위대한 천재로 환호받은 데 강렬한 인상을 받았다.
아인슈타인은 그러한 반응에 깜짝 놀랐고 아주 기분이
상했는데, 왜냐하면 그결과 중단된 그의 연구 때문이었다.
이혼 후 1919년 그의 아버지의 작고한 사촌의 딸로 과부였던
엘자와 재혼했다.
당시 독일의 악화되어가는 정치적 상황에도 불구하고,
아인슈타인은 국가주의를 공격했고 평화주의 사상을
장려했다. 베를린에서 반유대주의 물결이 거세어지자,
아인슈타인은 '물리학에서의 볼셰비키주의자' 범주로
구분되었고, 그가 시오니즘 운동을 대중적으로 지지하기
시작하자 우익집단들의 그에 대한 격노가 거세졌다.
아인슈타인은 베를린에서 적대를 받았으나 유럽의 다른
도시에서 그에게 요청한 것 때문에 상대성이론을 강의하러
유럽의 여러 도시들을 널리 다녔는데, 보통 3등열차를
타고다녔고 늘 바이올린을 지니고 있었다. 이후 3년
동안에도 유럽의 수도들뿐만 아니라 동양·중동·남아메리카
등지도 다녔다. 여기에는 실론 섬, 일본, 팔레스타인 등도
포함된다. 1921년 상하이[上海]에서 "당신의 광전법칙과
이론물리학 분야에서의 업적으로 노벨 물리학상을 받게
되었다"는 국제전보를 받게 되었는데, 상대성이론에
대한 언급은 없었다.
1920년대의 시끄러운 상황에도 불구하고 새로운 연구, 즉
전자기와 중력 사이의 수학적 관계를 찾아내려는 노력을
중단하지 않았다. 그가 느끼기에 이것은 전자로부터
행성까지의 우주 안에 있는 모든 것의 작용을 지배하는 일반
법칙을 발견하는 첫 단계가 되는 것이었다. 그는 단일한
방정식이나 공식으로 물질과 에너지의 보편적 속성들을
연관시키려고 했는데 이는 나중에 통일장이론으로 불리게
되었다. 이것은 그의 나머지 삶을 차지한 성과 없는
질문으로 판명되었다. 아인슈타인의 동료들은 일반적으로
그의 탐구가 실패할 운명을 갖고 있다는 데에 일찍부터
동의했는데, 왜냐하면 급속히 발전하고 있던 양자이론은
입자의 운동에 대한 모든 측정에서의 불확정성원리를
밝혀냈기 때문이다. 단일한 입자의 운동은 그 입자의 속도와
위치를 동시에 측정할 때의 근본적 불확정성 때문에
단순하게 예측될 수가 없었는데, 이는 사실상 원자구성입자
수준의 어떤 물리계의 미래를 예측할 수가 없음을 의미한다.
아인슈타인은 양자역학의 탁월성을 충분히 인정했음에도
불구하고, 이 이론이 절대적이고 미래의 발견에 대한 더욱
만족스러운 기초로서 일반상대론에 맞설 수 있다는 관념을
거부했다. 그는 정확하게 만들어진 우주에 대한 믿음, 즉
"신은 교묘하지만 심술궂지는 않다"라는 말을
인용했다. 이러한 점에서 그는 대부분의 이론물리학자들과
의견이 상이했다. 외롭게 그의 길을 고집했고 결과적으로
낭비되어버린 노력이었다고 이야기되는 그에 대한 평가는
후대의 판단에 맡겨야 할 것이다.
1931년 교환교수로 옥스퍼드대학교를 방문했을 때, 과학을
논의하는 것만큼의 많은 시간을 평화주의를 옹호하는 데
보냈다. 그는 1932년 제네바에서 일정이 잡혀 있었던
세계비무장회의에 대중적 압력을 가하려고 아인슈타인
반전기금을 설립했다. 이 회담이 실패하자 그는 세계 평화와
인간의 이해를 지지해왔던 여러 해의 노력이 아무런 소득이
없었음을 깨닫게 되었다. 아인슈타인은 과학적 진리가
인간성과 독립해 있는 타당한 진리로 개념화되어야 한다고
주장했다. "나는 이것에 대해 옳음을 증명할 수는 없지만
이것은 나의 종교이다"라고 말했다. 그는 무신론을
강하게 반대했는데, "존재하는 것의 조화 안에서
스스로를 드러내 보이는 스피노자의 하느님"에 대한
믿음을 표현했다. 그는 네덜란드 레이덴대학교의 물리학자
파울 에렌페스트와 헨드리크 A.로렌츠와 함께 있는 것을
좋아했으며, 세미나에 참석하려고 패서디나에 있는
캘리포니아공과대학을 몇 차례에 걸쳐 방문했다. 1933년
아돌프 히틀러가 독일 집권자가 된 후 독일 시민권을
포기하고 독일을 떠났다. 뒤에 그는 프린스턴대학교
고등연구소 수학과정 기초임원이라는 정식자리를
받아들였다. 그결과 나치주의자들은 그가 애용하는 베를린
근처에 있는 여름 별장을 수색하고 그의 배를 압수했다.
그는 독일이 전쟁을 준비하고 있음을 확신하고 유럽
자유세계가 방위력을 보충하고 무장하도록 촉구했다.
미국에서의 말년
프린스턴에서 아인슈타인은 20년 이상을 거의 변화가 없는
생활을 유지했다. 그는 소박한 2층 목조가옥에서 아내와
살았고, 아침마다 산책을 하거나 연구소까지 걸어다녔다.
연구소에서 통일장이론을 연구했고 동료들과 토론했다.
마침내 그는 미국 시민권을 획득했지만, 자신을 항상
유럽인으로 생각했다. 전쟁이 임박함에 따라 나치
과학자들이 '원자탄'을 최초로 만들 것이라는 공포감으로
아인슈타인은 루스벨트 대통령에게 "경계를 해야 하며
만일 필요하다면 빠른 조치를 취하라"는 편지를 썼다.
아인슈타인이 루스벨트 대통령에게 했던 그러한 권고는
맨해튼 계획의 시작을 의미했다.
그는 뉴멕시코 로스알라모스에서의 작업에 참여하지
않았으며, 1945년 히로시마[廣島]가 괴멸될 때까지
핵분열탄이 만들어지고 있었다는 것을 몰랐으나
아인슈타인의 이름은 원자시대의 등장과 강하게 연결되었다.
그는 미래의 원자탄 사용을 막을 방법을 찾고 있었던
과학자들과 즉시 합류했고, 그의 긴급한 탄원은 미국·영국·러시아가
기초한 규정 밑에 있는 세계정부를 수립하는 것이었다.
세계를 괴롭힌 핵공포에 자극받아 아인슈타인은 "우리는
단지 의도만 해서는 안 되고, 세계 안전에 필요한 속박된
권위에 우리 자신을 복속시키려는 적극적인 열성을 가져야
한다"고 이야기했다. 정치인과 정치꾼에 의하여
좌절했지만 가장 주요하게 매달렸던 것은 여전히
물리학이었기 때문에 극복할 수 있었다. 1955년 아인슈타인은
프린스턴 병원에서 잠을 자다가 숨을 거두었다. 그의
책상에는 이스라엘 독립일에 대해 씌어진 미완성의
언명들이 적혀 있었는데 부분적으로 다음과 같은 내용이
있었다. "내가 성취하고자 추구했던 것은 단지 나의
부족한 능력으로 진리와 아무도 즐겁게 하지 못하는 위험에
대한 정의에 봉사하고자 한 것이다." 우주에 대한 인간의
이해에 대한 그의 기여는 비길 데 없으며, 그는 언제나
과학의 거인이었다. 넓게 말해서 인간사에 대한 그의
개혁운동은 지속적인 영향을 갖지 못한 것으로 보인다.
아인슈타인이 "정치는 순간을 위한 것이다. 방정식은
영원을 위한 것이다"라고 말했을 때 그는 아마도 자신의
삶에 대한 평가를 예견했던 것 같다.
P. Michelmore 글 | 李相元 참조집필
|
|
MAJOR
WORKS
SCIENTIFIC
PAPERS: "Über einen die Erzeugung und Verwandlung des Lichtes
betreffenden heuristischen Gesichtspunkt," in Annalen
der Physik (1905); "Über die von der molekularkinetischen Theorie
der Wärme geforderte Bewegung von in ruhenden Flüssigkeiten
suspendierten Teilchen," in Annalen
der Physik (1905); "Zur Elektrodynamik bewegter Körper," in Annalen der Physik (1905), the initial paper on special relativity;
"Ist die Trägheit eines Körpers von seinem Energieinhalt abhängig?"
in Annalen der Physik (1905);
"Zur Theorie der Brownschen Bewegung," in Annalen der Physik (1906), translated separately as Investigations
on the Theory of the Brownian Movement (1926); "Zur Theorie der
Lichterzeugung und Lichtabsorption," in Annalen
der Physik (1906); "Plancksche Theorie der Strahlung und die Theorie
der spezifischen Wärme," in Annalen
der Physik (1907); "Entwurf einer Verallegemeinerten Relativitätstheorie
und einer Theorie der Gravitation," in Zeitschrift
für Mathematik und Physik (1913); "Grundlagen der allgemeinen
Relativitätstheorie," in Annalen
der Physik (1916), on the general theory of relativity;
"Strahlungs-emission und - absorption nach der Quantentheorie," in Verhandlungen
der Deutschen physikalischen Gesellschaft (1916); "Quantentheorie der
Strahlung," in Physikalische
Zeitschrift (1917); "Quantentheorie des einatomigen idealen
Gases," in Sitzungsberichte der
Preussischen Akademie der Wissenschaften (1924 and 1925). Some of Einstein's
important papers were collected in the joint work (with H.A. Lorentz and H.
Minkowski), H.A. Lorentz: Das Relativitätsprinzip,
eine Sammlung von Abhandlungen (1913; trans. as H.A. Lorentz: The Principle of Relativity: A Collection of Original
Memoirs on the Special and General Theory of Relativity, 1923). See also The
Meaning of Relativity, which includes the generalized theory of gravitation
(1953), the first edition of Einstein's unified-field theory.
OTHER
WORKS: About Zionism: Speeches and
Letters, Eng. trans. by Sir Leon Simon (1931); Builders of the Universe (1932); with Sigmund Freud, Warum
Krieg? (Why War?, Eng. trans. by Stuart Gilbert, 1933); with Leopold Infeld,
The Evolution of Physics (1938); The
World As I See It (Eng. trans. by Alan Harris, 1949); Out
of My Later Years (1950).
BIBLIOGRAPHY.
JOHN STACHEL et al. (eds.), The
Collected Papers of Albert Einstein (1987- ), contains all his papers,
notes, and letters, with companion translation volumes. HELEN DUKAS and BANESH
HOFFMAN (eds.), Albert Einstein, the Human
Side: New Glimpses from His Archives (1979), samples the letters of Albert
Einstein to provide a good introduction to his personality and thought.
Studies
of his life and work include PHILIPP FRANK, Einstein:
His Life and Times, trans. from German (1947, reprinted 1989), a scientific
biography focusing on Einstein's early life and achievement; ANTONINA VALLENTIN,
The Drama of Albert Einstein (also
published as Einstein, a Biography,
1954; originally published in French, 1954), a personal story of Einstein's
European years; PETER MICHELMORE, Einstein:
Profile of the Man (1962), a popular, richly anecdotal treatment of Einstein
as man and scientist; RONALD W. CLARK, Einstein: The Life and Times (1971, reissued 1984), a distinguished,
definitive, and well-illustrated work; BANESH HOFFMAN and HELEN DUKAS, Albert
Einstein: Creator and Rebel (1972, reissued 1986), a significant biography,
laced with a thorough but exciting interpretation of Einstein's scientific work;
JEREMY BERNSTEIN, Einstein, 2nd ed.
(1991), a biography emphasizing the scientific theories; CORNELIUS LANCZOS, The Einstein Decade: 1905-1915 (1974), a biography that includes
detailed synopses of each Einstein paper written during the years covered; A.P.
FRENCH (ed.), Einstein: A Centenary Volume
(1979), a collection of essays, reminiscences, illustrations, and
quotations--for the general audience; ABRAHAM PAIS, "Subtle is the Lord . .
.": The Science and the Life of Albert Einstein (1982), a scientific
biography; PETER A. BUCKY and ALLEN G. WEAKLAND, The Private Albert Einstein (1992), a chronicle of conversations and
personal anecdotes as remembered by one of Einstein's friends; MICHAEL WHITE and
JOHN GRIBBIN, Einstein: A Life in Science
(1994); and DENIS BRIAN, Einstein: A Life
(1996).
Studies
of Einstein's impact on science and philosophy include PAUL ARTHUR SCHILPP
(ed.), Albert Einstein:
Philosopher-Scientist, 3rd ed., 2 vol. (1970), a discussion by eminent
scholars; LINCOLN BARNETT, The Universe
and Dr. Einstein, 2nd rev. ed. (1957, reissued 1974), a lucid exposition of
Einstein's contribution to science; THOMAS F. GLICK (ed.), The Comparative Reception of Relativity (1987); and DAVID CASSIDY, Einstein
and Our World (1995). (P.Mi. /Ed.)
|
