Albert Einstein

Albert Einstein reformulated the physics of space, time and gravitation, and spent the second half of his life arguing with the quantum theory he had helped to start. Born in Ulm in 1879 and raised in Munich, he renounced his German citizenship at sixteen, studied at the Zurich Polytechnic, and failed to secure an academic post — taking work as a patent examiner in Bern in 1902, where he assessed electrical clock-synchronisation devices while thinking about simultaneity. In 1905, his annus mirabilis, he published four papers in a single year. One explained the photoelectric effect by treating light as quanta, which founded quantum theory and won him the 1921 Nobel Prize; one explained Brownian motion, settling the physical reality of atoms; one set out special relativity, abolishing absolute time; and one derived the equivalence of mass and energy. He completed general relativity in 1915, recasting gravity as the curvature of spacetime by mass. Its prediction that starlight bends around the sun was confirmed by Arthur Eddington's eclipse expedition in May 1919, and the result made him internationally famous within days. He was in the United States when Hitler took power in 1933 and never returned to Germany, taking a post at the Institute for Advanced Study in Princeton. A lifelong pacifist, in August 1939 he signed a letter to Franklin Roosevelt warning that Germany might build an atomic bomb — the impulse behind the Manhattan Project, which he took no part in and later called his one great mistake. He never accepted that quantum mechanics was a complete theory, objecting that God does not play dice, and spent thirty years on a unified field theory that did not come. He declined the presidency of Israel in 1952 and died in 1955.

• Lived: 1879 CE – 1955 CE
• Nationality: German
• Roles: physicist, mathematician