Who was Albert Einstein?

Einstein graduated from the polytechnic in 1900 and struggled to find teaching work. In 1902 he secured a position as a patent examiner in Bern, Switzerland, evaluating inventions such as a gravel sorter and an electric typewriter. He married Mileva Marić in January 1903; the couple had already had a daughter, Lieserl, born in 1902 before their marriage, whose fate remains uncertain, possibly given up for adoption or dead of scarlet fever in infancy. Sons Hans Albert and Eduard were born in 1904 and 1910. In Bern, Einstein also formed an informal discussion group with friends, the Olympia Academy, where they read philosophers including Hume, Mach and Poincaré.

Einstein's personal life grew complicated over the following decade. In 1912 he began a relationship with his cousin Elsa Löwenthal, and when Marić discovered his infidelity after the family moved to Berlin in 1914, she returned to Zurich with their sons. Einstein and Marić divorced in 1919, with Einstein agreeing to give her any Nobel Prize money he might win, a promise fulfilled two years later. He married Elsa the same year. Their son Eduard was later diagnosed with schizophrenia and spent much of his life institutionalized.

While still working at the patent office, Einstein published four papers in 1905 later celebrated as his annus mirabilis. One explained the photoelectric effect by proposing that light itself is composed of discrete particles, later called photons, work that would eventually underpin his Nobel Prize. Another explained Brownian motion as evidence that molecules exist. A third introduced the special theory of relativity, reconciling the laws of electricity and magnetism with mechanics and showing that moving clocks run slow and moving objects contract in their direction of motion. A fourth derived the equivalence of mass and energy, expressed in the formula E equals mc squared.

These papers did not bring immediate fame. Einstein continued at the patent office until 1908, when he took a junior post at the University of Bern, before a series of professorships in Zurich and Prague led to his appointment in Berlin in 1914, where Max Planck and Walther Nernst secured him a research position at the Prussian Academy of Sciences free of teaching duties. He became director of the Kaiser Wilhelm Institute for Physics in 1917. Between 1907 and 1915 he developed his general theory of relativity, reconceiving gravity not as a force but as the curvature of spacetime caused by mass, a project aided mathematically by his friend Marcel Grossmann.

Confirmation came in 1919, when astronomer Arthur Eddington observed starlight bending around the sun during a total eclipse, matching Einstein's predictions. The result was reported worldwide, including a famous Times of London headline declaring Newtonian ideas overturned, and it transformed Einstein almost overnight into a global celebrity, arguably the first scientist to achieve that kind of fame. In 1922 he received the 1921 Nobel Prize in Physics, awarded specifically for his explanation of the photoelectric effect rather than for relativity, which some physicists still regarded with caution.

Through the 1920s Einstein became an international figure well beyond physics. He toured the United States in 1921, lectured across Asia in 1922 including Japan, Singapore and Ceylon, and spent twelve days in Mandatory Palestine, where he was welcomed with ceremony usually reserved for heads of state. He helped raise funds for the Hebrew University of Jerusalem, which opened in 1925, though he opposed the creation of an independent Jewish nation-state, favoring Jewish and Arab coexistence, a position he later revised as conditions changed. He served for a decade on the League of Nations' International Committee on Intellectual Cooperation.

Alongside relativity, Einstein made major contributions to quantum theory, including work with Indian physicist Satyendra Nath Bose that established Bose-Einstein statistics, and a 1917 paper introducing stimulated emission, the physical principle later used in lasers. Yet he grew increasingly uneasy with the quantum mechanics being developed by younger physicists in the 1920s, objecting to its reliance on fundamental randomness with the remark that God does not play dice. He spent much of his later career, largely without success, searching for a unified field theory that would merge gravitation and electromagnetism, a pursuit that left him somewhat isolated from mainstream physics.

Einstein was in the United States when Adolf Hitler became German chancellor in January 1933. With Nazi raids on his home in Berlin and his property in Germany confiscated, he renounced his German citizenship and did not return. Jewish scientists were being barred from university posts across Germany, and Einstein's own works were burned by the German Student Union that year; one magazine listed him as an enemy of the regime with a bounty on his head. He spent time in Belgium and England, where he met Winston Churchill and lobbied for Jewish scientists fleeing Germany to find refuge abroad, before accepting a position at the newly formed Institute for Advanced Study in Princeton, New Jersey, where he remained for the rest of his life.

In 1939, alerted by fellow physicists Leo Szilard and Eugene Wigner to the danger of Nazi Germany developing an atomic bomb, Einstein signed a letter to President Franklin Roosevelt urging the United States to pursue nuclear research, a letter credited with helping spur the Manhattan Project. He later called this one of the great regrets of his life, a pacifist's compromise made only because he feared what Germany might do first. Einstein became a United States citizen in 1940, joined the NAACP in Princeton, campaigned against racial discrimination, and was offered, and declined, the largely ceremonial presidency of Israel in 1952 following the death of Chaim Weizmann.

Einstein died in Princeton Hospital on 18 April 1955 after refusing surgery for a ruptured abdominal aortic aneurysm, saying he wished to go when he chose rather than prolong life artificially. He had continued working almost to the end, including on a speech for Israel's anniversary. His brain was removed during autopsy without family permission in hopes future science might learn what underlay his abilities, and his remains were cremated with his ashes scattered at an undisclosed site. He left his papers and intellectual legacy to the Hebrew University of Jerusalem, and in 1999 Time magazine named him Person of the Century.