Albert Einstein

Albert Einstein (1879–1955) was a German-born theoretical physicist widely regarded as one of the most influential scientists of the 20th century. He developed the special and general theories of relativity and made foundational contributions to quantum theory.

Biography

Einstein was born on March 14, 1879, in Ulm, in the Kingdom of Württemberg (part of the German Empire), to a secular middle-class Jewish family. His father, Hermann, was an engineer and salesman who later ran an electrochemical factory; his mother was Pauline Koch. The family moved to Munich, where Einstein showed early interest in mathematics, science, and music (he played the violin). He was a quiet child who spoke late and disliked rigid schooling.

In 1894–1895, the family moved to Italy after business troubles. Einstein left school, renounced German citizenship (becoming temporarily stateless), and later attended the Swiss Federal Polytechnic (ETH) in Zurich after preparatory studies. He graduated in 1900 as a teacher of mathematics and physics, became a Swiss citizen in 1901, and worked as a patent examiner

In 1903 he married Mileva Marić (a fellow physics student); they had three children (a daughter, Lieserl, and sons Hans Albert and Eduard). They divorced in 1919; that same year he married his cousin Elsa Löwenthal (who died in 1936).

1905 was his annus mirabilis (“miracle year”): while at the patent office he published four groundbreaking papers on the photoelectric effect, Brownian motion, special relativity, and the equivalence of mass and energy (

E=mc2E = mc^2E = mc^2

). He later held academic posts in Zurich, Prague, and Berlin (as director of the Kaiser Wilhelm Institute for Physics). He completed general relativity in 1915. The 1919 solar eclipse confirmation of light deflection made him world-famous. He received the 1921 Nobel Prize in Physics (awarded 1922) for the photoelectric effect.

A pacifist and later supporter of Zionism, Einstein emigrated to the United States in 1933 after the Nazis rose to power. He joined the Institute for Advanced Study in Princeton, New Jersey, became a U.S. citizen in 1940, and lived there until his death. He signed a letter to President Roosevelt warning about nuclear weapons (leading to the Manhattan Project, though he did not work on it directly) and later advocated nuclear disarmament. He spent his later years seeking a unified field theory. Einstein died on April 18, 1955, in Princeton from an abdominal aortic aneurysm rupture; he declined surgery.