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Hans Bethe

(Redirected from Hans Albrecht Bethe)

Hans Albrecht Bethe (born July 2, 1906), is a German-American physicist from Strassburg (then part of Germany, now Strasbourg, France).

Bethe (pronounced Bey-ta) studied physics at Frankfurt and obtained his doctorate from the University of Munich. He left Germany in 1933 when the Nazis came to power, moving first to England and in 1935 to the USA where he taught at Cornell University. During World War II, he served as part of a special summer session at the University of California, Berkeley at the invitation of Robert Oppenheimer, which outlined the first designs for the atomic bomb. When Oppenheimer started the secret weapons design laboratory, Los Alamos, he appointed Bethe as Director of the Theoretical Division. After the war, Bethe argued that a crash project for the hydrogen bomb should not be attempted, though after President Truman announced the beginning of such a crash project, and the outbreak of the Korean War, he signed up and played a key role in the weapon's development. Though he would see the project through to its end, in Bethe's account he was primarily hopeful that the weapon would be impossible to produce.

During 19351938, he studied nuclear reactions and reaction cross sections. This research was useful to Bethe in more quantitatively developing Niels Bohr's theory of the compound nucleus . He received the Max Planck medal in 1955. In 1961 he was awarded the Eddington Medal of the Royal Astronomical Society for his work in identifying the energy generating processes in stars. In 1967, Bethe was awarded the Nobel Prize in Physics for his studies of the production of solar and stellar energy, stellar nucleosynthesis. He postulated that the source of this energy are thermonuclear reactions in which hydrogen is converted into helium.

Bethe is noted for his theories on atomic properties.

During the '80s and '90s he campaigned for the peaceful use of nuclear energy. In 1995, at the age of 88, Bethe wrote an open letter calling on all scientists to "cease and desist" from working on any aspect of nuclear weapons development and manufacture.

He won the Bruce Medal in 2001.

The asteroid 30828 Bethe is named after him.

He is currently a Professor Emeritus in the Physics Department at Cornell University.


  • "Just a few months before, the Korean war had broken out, and for the first time I saw direct confrontation with the Communists. It was too disturbing. The cold war looked as if it were about to get hot. I knew then I had to reverse my earlier position. If I didn't work on the bomb, somebody else would -- and I had thought if I were around Los Alamos I might still be a force for disarmament. So I agreed to join in developing the H-bomb. It seemed quite logical. But sometimes I wish I were more consistent an idealist." - 1968 (in Schweber, p.166)
  • "After the H-bomb was made, reporters started to call Teller the father of the H-bomb. For the sake of history, I think it is more precise to say that Ulam is the father, because he provided the seed, and Teller is the mother, because he remained with the child. As for me, I guess I am the midwife." - 1968 (Schweber, p.166)


  • Bernstein, Jeremy, Hans Bethe, Prophet of Energy, 1980
  • Bethe, Hans A., The Road from Los Alamos, NY: Simon and Schuster, 1991, ISBN 0671740121, some collected essays on nuclear topics.
  • Schweber, S. S. In the shadow of the bomb: Bethe, Oppenheimer, and the moral responsibility of the scientist. Princeton, N.J.: Princeton University Press, 2000.

External links

  • Hans Bethe at Nobel lectures
  • Hans Bethe at World of Science
  • Hans Bethe at Britannica Nobel Prizes
  • Text of the Eddington Medal award speech
  • Bruce Medal page

Last updated: 02-09-2005 18:48:51
Last updated: 05-06-2005 01:27:49