- Person
- Hans Bethe
- Lived
- 1906–2005
- Field
- Theoretical physics
- From
- German-born American
The story
During the Second World War Hans Bethe led the Theoretical Division at Los Alamos, where the first atomic bombs were designed. Afterwards he became one of the most respected scientific voices on the dangers of nuclear weapons, campaigning with Albert Einstein and the Emergency Committee of Atomic Scientists against nuclear testing and the arms race.
By the late 1950s public anxiety was rising over hydrogen bomb tests and the radioactive fallout they spread around the world. From 1956 to 1964 Bethe served on the President's Science Advisory Committee. In the spring of 1958 he and Isidor Isaac Rabi joined the committee's chairman, James Killian, in a review of American test-ban policy. They concluded that a workable system for detecting underground tests could be built, and the review helped prompt President Eisenhower to propose technical talks with the Soviet Union. That year Bethe also headed a presidential study of nuclear disarmament.
Verification remained the central technical question. Data from American underground tests in 1958 convinced Bethe and other scientists that early estimates of how easily such tests could be detected were too optimistic. Among the experts advising the government, Bethe belonged to a group that remained wary of Soviet intentions but believed a test ban could work if it was properly verified. He acted as an informal adviser to Presidents Eisenhower, Kennedy and Johnson.
Negotiations for a total ban eventually stalled over the detection of underground tests and Soviet objections to inspections. The compromise was the Partial Test Ban Treaty, signed in Moscow on 5 August 1963 by the United States, the Soviet Union and Britain. It banned nuclear test explosions in the atmosphere, in outer space and under water, and came into force on 10 October 1963. The Atomic Heritage Foundation credits Bethe with helping to negotiate it, and he helped persuade the Kennedy administration to sign.
The treaty did not end the arms race, but its enactment coincided with a substantial decline in radioactive particles in the atmosphere. Since then 123 other states have become party to it.
Why it matters
The treaty sharply reduced radioactive fallout spreading around the globe and was the first major step in controlling the nuclear arms race.
About Hans Bethe
Refugee physicist who explained how the stars shine, led theory at Los Alamos, cracked the Lamb shift and spent half a century campaigning against the nuclear arms race; Nobel Prize 1967.
More about Hans Bethe
- Hans Bethe championed peaceful nuclear energyThroughout the 1980s and 1990s Hans Bethe campaigned for the peaceful use of nuclear energy, calling nuclear electricity 'a necessity, not merely an option'.
- Hans Bethe's 1931 method still solves quantum puzzlesWhile working with Enrico Fermi in Rome in 1931, Hans Bethe devised the Bethe ansatz, a method for exactly solving certain quantum many-body problems.
- 'Bethe's Bible' taught a generation nuclear physicsIn 1936–37 Hans Bethe, with Robert Bacher and Stanley Livingston, wrote three review articles so complete they became known as 'Bethe's Bible'.
- Hans Bethe explained how the stars shineIn 1938–39 Hans Bethe worked out the nuclear reactions that power the Sun and stars, work that won him the 1967 Nobel Prize in Physics.
- The Bethe formula tracks radiation through matterIn 1930 Hans Bethe derived a formula for how fast charged particles lose energy passing through matter, still used across physics today.
- Bethe showed missile defence could be fooled by decoysIn 1968 Hans Bethe and Richard Garwin argued that missile defences could be defeated by simple decoys, an argument that helped lead to the 1972 ABM Treaty.
- Hans Bethe cracked the Lamb shift on a trainIn 1947, on a train to Schenectady, Hans Bethe calculated the Lamb shift, showing quantum electrodynamics could work and opening modern particle physics.
- At 85, Hans Bethe helped solve the solar neutrino puzzleAt the age of 85, Hans Bethe wrote an important paper on the solar neutrino problem, helping establish that neutrinos change type on their way from the Sun.
Sources
- Hans Bethe Atomic Heritage Foundation
- Hans Bethe Wikipedia
- Partial Nuclear Test Ban Treaty Wikipedia
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