Monday, March 7, 2005

Nobel Laureate in Physics Hans Bethe died in his home in Ithaca, New York on March 6, 2005, according to Cornell University, where he was professor emeritus of physics.

Hans Albrecht Bethe (pronounced Bay-ta) was born on July 2, 1906 in the city of Strasbourg, then part of Germany (now part of France). He studied physics at Frankfurt and obtained his doctorate from the University of Munich.

Bethe, whose mother was [[Judaism|Jewish}}, fled Germany in 1933 when the Nazi Party came to power. Bethe, along with hundreds of other Jewish academics, were fired from their posts as a result of one of Adolf Hitler’s first anti-Semitic acts. Bethe moved first to England and in 1935 to the USA where he taught at Cornell University.

Between 1935 and 1938, 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.

During World War II, he served as a prominent member 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 and served as the beginning of the Manhattan Project. 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. In 1968, he reflected upon the choice, noting that “It seemed quite logical. But sometimes I wish I were more consistent an idealist.” 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. He later characterized Stanislaw Ulam as the “father” of the hydrogen bomb, and Edward Teller as its “mother,” and himself as its “midwife.”

Among his many honors, Bethe received the Max Planck medal in 1955, and 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 was converted into helium.

During the 1980s and 1990s, Bethe campaigned for the peaceful use of nuclear energy, arguing against the nuclear arms ace and against nuclear testing. 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. In 2004, he signed a letter along with 47 other Nobel laureates endorsing John Kerry for president of the United States citing Bush’s apparent misuse of science.