Albert Einstein

Albert Einstein was born on 14 March 1879 in Ulm, a town in the German kingdom of Wurttemberg, to Hermann Einstein, a salesman and engineer, and Pauline Koch ^[1]. The family moved to Munich the following year, where Hermann and his brother ran an electrical equipment firm. The boy spoke late, a fact that worried his parents, but two childhood gifts left deep marks: a magnetic compass at age five, whose invisible force struck him as a wonder, and a geometry book at twelve that he later called holy ^[1][2].

School suited him poorly. He resented the drill and rote of the Munich Gymnasium, and when the family business failed and his parents moved to Italy in 1894, the fifteen-year-old soon abandoned the school and followed them. He renounced his German citizenship in 1896, partly to avoid military service, and finished secondary school in Aarau, Switzerland, before entering the Swiss Federal Polytechnic in Zurich to train as a physics and mathematics teacher ^[1][3]. There he met Mileva Maric, a Serbian physics student who became his first wife in 1903.

Graduation in 1900 brought no academic post. Professors he had skipped and needled declined to recommend him, and after two lean years he took a job in 1902 as a technical examiner, third class, at the Swiss patent office in Bern ^[1][2]. The work was steady and left his evenings free. With a few friends he formed a reading circle they jokingly called the Olympia Academy, working through Hume, Mach, and Poincare over sausage and coffee ^[2].

Then came 1905, the year physicists still call the annus mirabilis. In the space of months the unknown examiner, aged twenty-six, sent the journal Annalen der Physik four papers of the first rank ^[4]. One proposed that light comes in discrete quanta, an idea that helped found quantum theory and later earned him the Nobel Prize. A second explained Brownian motion and gave persuasive evidence that atoms are real. A third, on the electrodynamics of moving bodies, introduced special relativity, showing that measurements of time and length depend on the observer's motion while the speed of light stays fixed ^[4][5]. A brief follow-up derived the equivalence of mass and energy, condensed later into E = mc squared. Academic recognition arrived slowly, then all at once: Bern, Zurich, Prague, Zurich again, and in 1914 a professorship in Berlin created almost expressly for him ^[1][3].

Special relativity dealt only with uniform motion and left gravity untouched. Einstein spent eight further years chasing what he called the happiest thought of his life: the realization, in 1907, that a person falling freely does not feel their own weight ^[1][5]. From that seed grew general relativity, a theory in which matter and energy curve the geometry of space and time, and bodies simply follow the straightest available paths through that curved geometry. He presented the field equations to the Prussian Academy of Sciences in November 1915, after a final month of feverish revisions and a near race with the mathematician David Hilbert ^[1][2].

The theory made testable claims. It accounted exactly for a long-standing anomaly in the orbit of Mercury, and it predicted that starlight passing the Sun would bend by a measurable amount. In May 1919 British expeditions led by Arthur Eddington photographed a solar eclipse from Brazil and the island of Principe, and that November the Royal Society announced that the deflection matched Einstein's prediction ^[3][5]. Newspapers on both sides of the Atlantic declared Newton overthrown. Almost overnight, Einstein became a global celebrity, his face and untamed hair a shorthand for genius itself ^[2].

The 1920s turned Einstein into a traveling institution. He lectured in the United States, Japan, and South America, raised funds for the Hebrew University of Jerusalem, and received the 1921 Nobel Prize in Physics, awarded formally not for relativity, which the committee still considered unproven, but for his explanation of the photoelectric effect ^[3][6]. Under the terms of his 1919 divorce, the prize money went to Mileva and their two sons. That same year he married his cousin Elsa Lowenthal, who managed the practical side of his crowded life until her death in 1936 ^[1].

Inside physics, he became the great dissenter from the theory he had helped to start. The quantum mechanics built by Bohr, Heisenberg, and Schrodinger in the mid-1920s worked brilliantly but described nature in probabilities, and Einstein could not accept that as the last word. His running debate with Niels Bohr, sharpened in the phrase usually rendered as "God does not play dice," produced in 1935 the famous EPR paper on entanglement, a thought experiment that quietly seeded whole fields of later research ^[1][5].

Einstein was a Jew, a pacifist, and an internationalist, and in Weimar Germany that made him a target. Nationalist agitators disrupted his lectures and denounced relativity as "Jewish physics" ^[1][2]. When Hitler took power in January 1933, Einstein was abroad; he never returned. He resigned from the Prussian Academy, saw his property seized and his books burned, and in October 1933 settled at the new Institute for Advanced Study in Princeton, New Jersey ^[1][3]. He became a United States citizen in 1940.

In August 1939, at the urging of the physicists Leo Szilard and Eugene Wigner, he signed a letter to President Franklin Roosevelt warning that Germany might build a bomb based on nuclear fission and urging American attention to uranium research ^[1][6]. The letter helped set in motion what became the Manhattan Project, though Einstein himself was denied a security clearance and did no work on the weapon. After Hiroshima he called the letter the one great mistake of his life and gave his remaining energy to arms control, co-signing with Bertrand Russell, days before his death, a manifesto against nuclear war ^[2][6].

At Princeton, Einstein worked to the end on a unified field theory that would join gravity and electromagnetism in a single framework. The effort never succeeded, and much of the physics community moved on without him, but he kept at the blackboard into his seventies with a stubbornness he freely admitted ^[1][5]. He also used his fame deliberately. He spoke against racial segregation, calling it a disease of white people, joined the NAACP, and in 1946 accepted an honorary degree from Lincoln University, a historically Black institution, when many public figures would not visit ^[2].

In 1952, after the death of Chaim Weizmann, Israel offered Einstein the presidency of the state. He declined, saying he lacked both the aptitude and the experience to deal properly with people ^[1][3]. On 17 April 1955 an abdominal aortic aneurysm that had been repaired years earlier began to fail. He refused further surgery, saying it was tasteless to prolong life artificially, and died in Princeton Hospital early on 18 April, aged seventy-six ^[1]. Following his wishes, his body was cremated the same day and the ashes scattered at an undisclosed place.

The reach of Einstein's achievements grew after his death. Gravitational lensing, black holes, the expanding universe, and gravitational waves, detected directly by LIGO in 2015, are all consequences of the 1915 field equations ^[5]. Relativistic corrections are built into every GPS satellite, and the photon concept from 1905 sits under lasers, solar cells, and digital imaging ^[3][5]. His scientific papers, more than 30,000 documents in all, are being published by the Einstein Papers Project at Caltech in cooperation with the Hebrew University, to which he willed his literary estate ^[6].

Anyone asking who Albert Einstein was ends up with two answers that fit together. He was the physicist who twice rebuilt the foundations of his science before turning forty, and he was a moral witness of his century: a refugee who warned against fascism, a signer of appeals against the bomb his own equation had made conceivable, and a man who defined his politics simply, as the wish that human dignity be respected everywhere ^[1][2]. Time magazine named him Person of the Century in 1999, and few quarreled with the choice ^[3].