Hans Bethe

Origins and early life

Hans Albrecht Eduard Bethe was born in Strasbourg on 2 July 1906, then in the German Reichsland of Alsace-Lorraine, the only child of Albrecht Bethe, a physiologist at the university, and Anna Kuhn, daughter of Professor Abraham Kuhn. His mother had a Jewish background; Bethe was raised Protestant like his father, and in 1932 he took an assistant professorship at Tübingen.

Work and career

One of the first laws of the new Nazi government, the Law for the Restoration of the Professional Civil Service, cost him the post the following year because of that background — Arnold Sommerfeld restored his fellowship in Munich, and he left for Bristol and then Cornell, where he spent most of his life. In 1938 a conference challenged the physicists present to explain how the sun keeps burning. Bethe went home and worked through the nuclear reactions, arriving at the carbon-nitrogen-oxygen cycle, in which carbon acts as a catalyst that turns hydrogen into helium in the hotter stars.

He withdrew the paper from Physical Review to enter it for a $500 prize, needing $250 to release his mother's furniture; she had emigrated in June 1939, after Kristallnacht, on the French quota her Strasbourg birth allowed. The paper won, and won the 1967 Nobel Prize in Physics. Bethe led the Theoretical Division at Los Alamos during the war, calculated the Lamb shift in 1947, and then campaigned for decades against nuclear testing, helping bring about the 1963 test-ban and 1972 anti-ballistic-missile treaties. He published into his nineties and died at Ithaca, New York, on 6 March 2005.