Albert Einstein

Einstein, Albert (14 Mar. 1879-18 Apr. 1955), theoretical physicist, was born in Ulm, Germany, to Hermann Einstein and Pauline Koch, who had married in 1876. In 1880 the family moved to Munich. There Hermann ran various industrial concerns, eventually managing an electrical business in which his younger brother Jakob provided the technical direction. The two Einstein families lived together in a large house in a Munich suburb. Albert Einstein and his younger sister Maria (Maja) grew up surrounded by Jakob's electrical innovations. Jakob also provided young Albert with science textbooks, notably a seminal exposition of Euclidean geometry. Einstein went to a local primary school and then attended the Luitpold Gymnasium, a progressive secondary school. He succeeded admirably in all his subjects. Following elementary school practice, he received lessons in Judaism, the registered religion of his free-thinking parents. His mother had him study violin privately, and the instrument provided him solace throughout his life.

The Einstein electrotechnical business foundered in the highly competitive environment of the middle 1890s. In 1894 Hermann and Jakob Einstein lost a bid to illuminate the streets of Munich. Hermann reestablished himself first in Milan and then in Pavia. Pauline and Maja accompanied him. Albert stayed behind to complete secondary school. After a number of months Albert abandoned school and joined his parents in Milan. He planned to study on his own in preparation for attending the Swiss Federal Polytechnic in Zurich, one of Europe's finest institutions of higher learning in science, which admitted students by examination.

Einstein spent a year in Italy. As his family's business was proceeding unevenly, financial support came from his mother's relatives. Einstein demonstrated his appreciation of this family solidarity by sending a scientific manuscript to a favorite uncle, Caesar Koch. It dealt with the electromagnetical ether and magnetical fields. Einstein traveled to Zurich in 1895, stayed with a family friend, Gustav Maier (a founder of the Swiss Ethical Culture Society), and failed the part of the polytechnic entrance examination that dealt with general culture. A sympathetic examiner urged him to attend the final year in the nearby Aarau cantonal school, whose diploma guaranteed admission to the polytechnic. Einstein's parents sent him to Aarau, where through Maier's intercession he boarded at the home of history professor Jost Winteler. The school's curriculum, physics laboratory, and natural history museum compared favorably with the environment at small universities of the period. The year at Aarau--and the model of his physics instructor August Tuchschmid--persuaded Einstein to give up plans to study engineering; he entered the general scientific section of the Zurich polytechnic, which prepared graduates for a career in secondary school teaching and provided the foundation for obtaining a doctorate at the adjoining University of Zurich.

Supported by a relative, Einstein attended the polytechnic from 1896 to 1900. During this time he was officially stateless, having renounced his Württemburg (and hence his German) citizenship early in 1896 so that he would not be arrested as a draft dodger if he visited Germany. Because he saved a portion of his allowance for purchasing Swiss citizenship (which he eventually did in 1901), he lived on the brink of destitution. At the polytechnic, he registered for many courses in pure and applied mathematics and in physics. Among his teachers were the German pure mathematician Hermann Minkowski, whose style he found unstimulating, and the Swiss experimental physicist Heinrich Friedrich Weber, in whose laboratory he happily toiled. Einstein was an independent student who did not endear himself to his professors. He succeeded in his final examinations by borrowing lecture notes from fellow students, notably Marcel Grossmann. Upon graduating, Einstein failed to be named assistant by any of his teachers--the usual post obtained by a young scientist working toward a doctorate.

In 1900 Einstein--a certified secondary school teacher working independently on a theoretical dissertation for the University of Zurich--faced an uncertain future. His financial support came to an end as his father's business collapsed and as family funds went to his sister who, like him, attended school at Aarau and found a happy reception among the Wintelers (Maja married Jost Winteler's son Paul and in 1910 completed a doctorate in Romance literature at the University of Bern). Einstein's need for a secure income was the more acute, as he had fallen in love with Mileva Mari, a Serbian student of physics at the polytechnic whose father was a Hungarian civil servant. Einstein held a succession of temporary teaching jobs while waiting for a permanent post to materialize in his area of expertise, electrotechnology, at the federal patent office in Bern. He received the entry-level post in 1902, through the intercession of Marcel Grossman's father, who was a friend of the patent office director. The position allowed him and Mari to establish a household in Bern. The death of Einstein's father--who along with his mother despised Mari – allowed the lovers to marry early in 1903 and to legitimize their daughter Lieserl, born early in 1902 at the home of Mari's parents in southern Hungary (later, Yugoslavia). There is neither trace nor mention of the daughter after 1903.

Einstein's patent office position, which occupied most of his working day, Monday through Saturday, obliged him to appraise submissions for new electrical machines. The position did not discourage an incumbent from undertaking scientific research, for which the patent office had a modest library dealing with topics in engineering. While a civil servant, Einstein admirably pursued his vocation. After at least one false start he finally obtained a doctorate from the University of Zurich in 1905. His short dissertation, rapidly published with minor changes, described a way of determining molecular dimensions from macroscopic measurements; he dedicated it to Marcel Grossmann. In 1908 the University of Bern named him privatdocent, or unsalaried instructor. This respectable progress, coupled with advancement at the patent office, was scant recognition of Einstein's spectacular production. The 400 pages that Einstein published between 1900 and 1909 fundamentally transformed large areas of physics.

His annus mirabilis was 1905. In that year he established a direct measure of molecular diffusion, thereby demonstrating the existence of an unseen world denied by some philosophically inclined scientists who held that thermodynamics was unrelated to molecular reality. Einstein applied the energy quantum (proposed in 1900 by Max Planck to solve the problem of black-body radiation) to explain the photoelectric effect, and in this way he laid the practical foundation for quantum physics and the electronic atom. He showed that if an absolute state of rest (and with it, the concept of an electromagnetic ether) were abandoned, Maxwellian electrodynamics (which formed the basis of the electrotechnical industry) could be retained intact. Around 1900 physicists had accepted that an electron's length and mass could vary with its speed; in Einstein's reorganization of basic physics--known as the theory of relativity--time (as measured by clocks) became a function of velocity. The germ of these achievements may be found in Einstein's student days and is alluded to in personal correspondence. It appears likely that his early work derived in part from cooperation with his wife, Mileva Mari.

Einstein's star rose dramatically between 1909 and 1913, the years when he held teaching positions at institutions of higher learning in Zurich and Prague, and when he declined a call to Utrecht. Beginning in 1906, Einstein's firmest patron had been Max Planck, professor of theoretical physics at the University of Berlin and coeditor of the Annalen der Physik, where Einstein placed his most important articles. In 1913 Planck arranged for him to come to Berlin as the highly paid head of a new physics institute in an imperial German foundation for advanced study, the Kaiser Wilhelm Gesellschaft. With the position came membership in the Berlin Academy of Sciences and a professorial title allowing (but not requiring) Einstein to lecture at the local university. Einstein went to Berlin early in 1914 and held his positions there until 1933. By his choice he worked at home, with only an assistant and a secretary. This mode of activity marks Einstein as an isolated, nineteenth-century savant, more in the image of theoreticians Ludwig Boltzmann and Hendrik Antoon Lorentz--men a generation older than he whom he admired--than in the mold of his aggressive contemporaries such as Philipp Lenard and Fritz Haber, who captained large institutes.

Einstein's unique achievement, general relativity, had been brewing since 1907, when he first indicated how gravitation might be integrated into the kinematical formulation of special relativity. The key notion, developed with what Einstein called a "thought experiment," was the principle of equivalence, according to which a kinematically accelerated mass behaved precisely as if the mass were subjected to a gravitational field. After initial hesitation, Einstein embraced Hermann Minkowski's four-dimensional space-time formalism for relativity, published in 1908. Einstein then used Tullio Levi-Civita and Gregorio Ricci-Curbastro's tensor calculus of differential geometry to express how a gravitational field deformed space-time. His first publication with the tensor calculus, in 1912, included a mathematical preface by Marcel Grossmann, in which Grossmann explained the technique, then unfamiliar to many physicists. Einstein wrestled with various aesthetic and physical principles until he arrived at the definitive covariant gravitational field equations late in 1915. They dominated his scientific work for the next forty years.

Einstein's early posts (where he was an immigrant or a foreigner) allowed him to abstract himself from his surroundings, and the Berlin call promised additional abstraction by offering freedom from routine teaching and administration. Berlin also resulted in Einstein's separation from his wife and their two sons (Hans Albert, born in 1903, and Eduard, born in 1910). At issue may have been Mari's unusual independence of mind and her cultural heritage. In the summer of 1914 Einstein's family returned to Zurich (where he had been professor of physics at the polytechnic) and then remained there. Swiss residency and about half of Einstein's salary spared them wartime deprivation, although up to her divorce from Einstein in 1919 and after it Mari claimed that Einstein did not support her adequately. For his part, Einstein lived in Berlin as a Swiss citizen (the local police considered him Swiss even though, according to a law of 1913, membership in the Berlin Academy of Sciences entailed German citizenship). He spoke openly against Germany's participation in the First World War and supported socialist causes without suffering imprisonment--the fate of his pacifist colleague at the University of Berlin, the biologist Georg Friedrich Nicolai.

Einstein craved female companionship, and he viewed women as objects of sexual desire and domestic satisfaction. Temporary liaisons gave way to a permanent relationship with his widowed first cousin Elsa Lowenthal (née Einstein), who nursed him as he recovered from a heart ailment and whom he married in 1919. Einstein's new wife reintegrated him into German Jewish society and revived his sentiments--which had been attenuated for more than twenty years--toward his "people." Einstein's Zionist sympathies coincided with his second marriage, while his socialist predilection--unshared by his second wife--led to no concerted political action.

Well before the First World War Einstein had indicated three astronomical tests that his gravitational theory would have to satisfy. The 1915 version of general relativity passed the first test, accounting for (as Newtonian physics could not account for) the precise orbit of the planet Mercury. The second test, the displacement in the direction of longer wavelengths of chemical spectra radiating from a large mass like the sun, was eventually verified by taking account of complicated secondary effects. The third test, according to which stars near the edge of the sun's disk would appear displaced from their usual position in the night sky (the sun's mass tending to focus stellar light passing near it), had been sought in photographs of solar eclipses since 1912. British astronomer Arthur Stanley Eddington observed this so-called light-bending during the solar eclipse of 1919.

Eddington's confirmation projected Einstein--already one of the world's most highly regarded physicists--into the public limelight. An "original" who expressed amusement and indifference at his notoriety, he traveled frequently over the next fifteen years: around the world in 1922-1923 (in part to escape from threats against his life in the anti-Semitic aftermath of Walther Rathenau's murder), to South America in 1925, to the United States in 1921 and then several times in the early 1930s. In his travels he spoke about physics--usually general relativity--and raised funds for the Zionist cause. His high-pitched voice, uncomplicated (not to say unrefined) manners and clumsy gait, and his large frame and mane of white hair made him an instant sensation. Institutions of higher learning vied for his attention, offering him honorary doctorates and visiting positions. His preferred arrangement was at the University of Leiden, where he could be near Hendrik Lorentz and Paul Ehrenfest, although he also found Oxford and Pasadena to his liking. Heads of state--President Warren G. Harding and King Albert of the Belgians--sought his audience. No scientist had ever enjoyed such encomium.

As a young man Einstein did not in principle oppose shouldering arms. He would have served willingly in the Swiss army had not flat feet invalidated him; his formal dress attire as a professor at Prague included a sword, and the costume made him feel somewhat "like a Brazilian admiral." The First World War transformed him into a hard-core pacifist. During the 1920s and 1930s he lectured tirelessly on the evils of armed struggle, and he urged young men to refuse military service. He lent his name to internationalist commissions, and he hoped that the League of Nations might prevent future wars. The absolutist incarnation of pacifism appealed to Einstein more than the practical compromises of Zionism, and spreading the pacifistic doctrine provided an aura of ethical utility to pleasurable foreign tours. But his pacifism broke on the monstrous evil of fascism.

Given his public commitments, the mature Einstein's scientific output is remarkable. He continued to explore the technical side of general relativity and sought a theory to unite gravitation and electromagnetism--work appearing in a regular stream of articles. He neglected new developments in atomic and nuclear physics. Einstein held the quantum theory--the elaboration of which had netted him the 1921 Nobel Prize in physics after years of studied neglect by the Nobel committee--to be a temporary construct. He steadfastly declined to embrace quantum mechanics, worked out during the 1920s by Wolfgang Pauli, Werner Heisenberg, Erwin Schrödinger, Louis de Broglie, and Max Born. The uncertainty principle and the wave-particle duality, cornerstones of Niels Bohr's philosophy of quantum mechanics, had no appeal. Einstein explicitly rejected Bohr's "Copenhagen interpretation" of quantum mechanics in a paper published jointly with Boris Podolsky and Nathan Rosen (Physical Review 47 [1935]: 777-80), and for the rest of his life he publicly contested Bohr about it.

The national socialist revolution of 1933 found Einstein in Pasadena. He renounced German citizenship (which he had added voluntarily to his Swiss nationality in the early years of the Weimar Republic) and never returned to Germany (the majority of his papers were saved by diplomatic intervention). He had--as he had known for many years he could have--a wide choice of positions: at the California Institute of Technology, the Collège de France, the Autonomous University of Madrid, the universities of Oxford and Leiden, or the Hebrew University in Jerusalem. He formally accepted both Madrid and Oxford but eventually decided on an experiment at Princeton--the new Institute for Advanced Study, a pure research center set up initially by educational reformer Abraham Flexner with $5 million in private donations. Einstein settled into a frame house on Mercer Street at Princeton's center. There he lived with his wife (who died in 1936), his divorced stepdaughter Margot, and his sister Maja.

Einstein's greatest emotional distance was not from the lay public--he got along easily with financiers in New York as well as farmers in nearby Freehold--but rather from professional physicists. Precision measurement and Baconian inventory had dominated exact sciences in the United States since the nineteenth century, and massive machines of research--enormous telescopes, diffraction-ruling engines, electrical power generators--naturally paved the way for particle accelerators in the 1930s. Physics, as well as other scientific disciplines, was organized into academic departments. The academic physics department was a federation of scientists sharing common principles and retailing a coherent syllabus. The system departed from the academic individuality of Central Europe, where universities could harbor two or three independent institutes in one discipline and where no authority prescribed the content of lectures. The Institute for Advanced Study had little in common with American Universities. Professors at the Institute were left to follow their karma, and this was just the environment that Einstein sought. Princeton was his ashram, and he worked there as he had worked in Europe.

Einstein became a U.S. citizen in 1940, by that act renouncing Switzerland. The naturalization reflected no dissatisfaction with his earliest chosen homeland. It signified pleasure with his new surroundings and revulsion at Germany's course under national socialism. Fascist attacks on Jews intensified Einstein's Zionist feelings, and he called on the civilized world to defeat Hitler's regime. In 1939 he wrote to President Franklin Roosevelt, urging that research be funded for an atomic bomb on the grounds that the United States had to possess the weapon before Germany did. He took no part in constructing the bomb (he was considered a security risk), although after the United States became a belligerent he consulted for the navy. Einstein willingly served this war machine, but he supported people who refused to do so for reasons of conscience. At the end of his life Einstein opposed Senator Joseph McCarthy's crusade against suspected communists, and he applauded young men who declined to fight in the Korean War. In 1955, the year of his death in Princeton, Einstein lent his name, with that of philosopher Bertrand Russell, to a nuclear disarmament movement. Part of Einstein's legacy is found in that final expression of reason and hope.