German-American physicist, famous for his research into the energy and formation of stars. He was a key figure in the development of the atomic bomb as chief of the theoretical physics division of Los Alamos. The Bethe carbon cycle is named after him, the first explanation of solar and stellar energy which met all the known facts. He won the 1967 Nobel Prize for physics for his contribution to the theory of nuclear reactions.
The son of a Jewish mother, he fled Germany in 1933 to England, then moved to the United States in 1935 where he became a naturalized citizen. Hans Albrecht Bethe was an only child in a family where university professors had proliferated for generations. His father was an eminent German physiologist who had written much on the nervous system and who held both an M. D. and Ph.D.
Young Bethe attended the Goethe Gymnasium in Frankfurt-am-Main and the University of Frankfurt. He received his doctorate in 1928 from the University of Munich. As a Ph.D. candidate, he was the first person to apply the “new” system of quantum mechanics to solving problems. His first papers, “Scattering of Electrons by Crystals” and “Theory of the Diffraction of Electrals” both appeared in 1927.
After receiving his doctorate, Bethe returned to Frankfurt as a physics teacher, and in 1929 moved to Stuttgart to fill a similar position. Between 1930 and 1932, he was lecturer at the University of Munich and worked simultaneously under scholars in Cambridge and Rome on a fellowship from the Rockefeller International Education Board. The fellowship brought Bethe in contact with Niels Bohr, a Nobel Prize winner who was considered the founder of modern atomic theory.
When Hitler came to power, Bethe was an assistant professor at the University of Tubingen, lecturing also at Munich. He was among many scientists who fled Germany during those years. From 1933-1934, he was at the University of Manchester as a lecturer, and from 1934-1935 at Bristol as a fellow. In 1935, he went to the United States to become an assistant professor at Cornell, where he became a full professor in 1937.
One of his most important works was “Energy Production in Stars,” the first two sections of which, appearing in 1938, won him the New York Academy of Sciences A. Cressy Morrison Prize. His star theories focused on the sun.
When America entered World War II, Bethe devoted himself to the secret operations of the Manhattan Project that created the atomic bomb, becoming a key figure. From 1943-1946, he served as chief of the Theoretical Physics Division of the atomic bomb laboratory at Los Alamos. After the war, Bethe found himself a public figure. He was part of a nine-man Emergency Committee of Atomic Scientists, headed by Albert Einstein, which started a campaign in November 1946 to educate the public to the facts of atomic energy. In 1947, he became a member of the American Physical Society’s board of editors and in June 1948 he was appointed visiting professor at Columbia University as he had been in 1940-1941.
When the possibility of a hydrogen bomb came to light in early 1950, Bethe served as spokesman for a group of 12 top researchers who urged that the U.S. never use it first, but who still felt the country needed it in the face of international problems. Though asked to work on the hydrogen bomb, Bethe refused to do so and remained vigorously opposed to the H-bomb.
Bethe became a member of the President’s Science Advisory Committee in 1956, a position he held until 1959. It was in this role that he was involved in the failed negotiations with the Soviet Union for a ban on nuclear testing. He received the Nobel Prize in physics in 1967 for his theory of the production of energy in stars.
As recently as February 1997, Bethe, by then 90 years old, wrote a letter to US President Clinton, urging him to stop all tests of nuclear weapons and the sponsorship of “computational experiments…to produce new categories of nuclear weapons.”
He married Rose Ewald in 1939, the daughter of the Nazi-exiled German theoretical physicist and they had two children.
The physicist who helped to usher in the nuclear age died quietly at his Ithaca, NY home late in the day on March 6, 2005. He was nearly 99 years old.
Link to Wikipedia biography