Hans (Albrecht) Bethe - Biography, Manhattan Project, Hydrogen bomb, Political stances, Awards and legacy, Honors

Physicist, born in Strasbourg, NE France (formerly Germany). He studied at the universities of Frankfurt and Munich (1926), and taught in Germany until 1933. He lost his job, when Hitler became Chancellor of Germany, and moved to England, teaching first at Manchester and then gaining a fellowship at Bristol University. In early 1935 he went to the USA, where he held the chair of physics at Cornell University until his retirement (1937–75). During World War 2 he was director of theoretical physics for the atomic bomb project based at Los Alamos. In 1939 he proposed the first detailed theory for the generation of energy by stars through a series of nuclear reactions, and for this work received the 1967 Nobel Prize for Physics. In 1995 he called on all scientists to cease work on nuclear weapons, and in 2001 was awarded the Bruce Medal for outstanding lifetime contributions to astronomy.

Hans Bethe

Hans Albrecht Bethe
Born	July 2, 1906 Strassburg, Germany
Died	March 6, 2005 Ithaca, NY, USA
Residence	USA
Nationality	German- American
Field	Physicist
Institution	University of Tübingen Cornell University
Alma Mater	University of Frankfurt University of Munich
Doctoral Advisor	Arnold Sommerfeld
Doctoral Students	Jeffrey Goldstone Roman Jackiw Freeman Dyson Robert Eugene Marshak
Known for	Atomic physics
Notable Prizes	Nobel Prize for Physics (1967)
His name is pronounced as the US pronunciation of beta.

Hans Albrecht Bethe (pronounced 'bay-tuh';

During the early 1950s, Bethe also played an important role in the development of the larger hydrogen bomb, though he had originally joined the project with the hope of proving it could not be made. Bethe later campaigned together with Albert Einstein in the Emergency Committee of Atomic Scientists against nuclear testing and the nuclear arms race.

Biography

Bethe was born in Strassburg (then part of Germany, now Strasbourg, France) to a Christian father and a Jewish mother. Bethe left Germany in 1933 when the Nazis came to power and he lost his job at the University of Tübingen, moving first to England where he held a provisory position of Lecturer for the year 1933-1934 and in the fall of 1934, a fellowship at the University of Bristol. In England, Bethe worked with the theoretician Rudolf Peierls on a comprehensive theory of the deuteron.

In 1935 Bethe moved to the United States, and joined the faculty at Cornell University, a position which he occupied throughout his career.During 1948-1949,he was a Visiting Professor at Columbia University. At Cornell, Bethe became known as one of the leading theoretical physicists of his generation, and along with other upcoming physicists like Stanley Livingston (a cyclotron pioneer) and later, after the war, experimentalist Robert R. He published a series of articles on nuclear physics, summarizing most of what was known until that time, an account that became informally known as 'Bethe's Bible', and remained the standard work on the subject for many years. This research was later useful to Bethe in more quantitatively developing Niels Bohr's theory of the compound nucleus.

Manhattan Project

When the war began, Bethe wanted to contribute to the war effort. Following the advice of the Caltech aerodynamicist Theodore Von Karman, Bethe collaborated with his friend Edward Teller, then at George Washington University, on a theory of shock-waves which are generated by the passage of a projectile through a gas. Bethe also worked on a theory of armor penetration. Initially, Bethe had been skeptical about the possibility of making a nuclear weapon from uranium (in fact, in the late 1930s, he had written a theoretical paper that argued against fission), but at the urging of Teller he agreed to join the Manhattan Project. When Oppenheimer was put in charge of forming a secret weapons design laboratory, Los Alamos, he appointed Bethe as Director of the Theoretical Division, a move that irked Teller, who had coveted the job for himself.

Bethe's work at Los Alamos included calculating the critical mass of uranium-235 and the multiplication of nuclear fission in an exploding atomic bomb. After November 1943, when the laboratory had been re-oriented to solve the implosion problem of the plutonium bomb, Bethe spent much of his time studying the hydrodynamic aspects of implosion, a job which he continued into 1944. (see Nuclear weapon design)

During the project, Klaus Fuchs who was leaking nuclear secrets to the Russians, was also in Bethe's division (often doing work which had originally been assigned to Teller).

When the first atomic bomb (an implosion weapon) was detonated in the New Mexico desert on July 16, 1945, at the Trinity test, Bethe's only immediate concern at the time was for its efficient working, and not for its moral implications — "I am not a philosopher", he was reported as saying at the time.

Hydrogen bomb

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, Bethe signed up and played a key role in the weapon's development. But sometimes I wish I were more consistent an idealist. (quoted in Schweber, p.166)

As for his own role in the project, and its relation to the famous Teller-Ulam priority dispute, Bethe later said that:

After the H-bomb was made, reporters started to call Teller the father of the H-bomb. As for me, I guess I am the midwife. (quoted in Schweber, p.166)

In 1954, Bethe testified on behalf of Oppenheimer during the latter's high-profile security clearance hearing. Specifically, Bethe argued that Oppenheimer's stances against developing the hydrogen bomb in the late 1940s had not hindered its actual development, a topic which was seen as a key motivating factor behind the hearing. While Bethe and Teller had been on very good terms during the pre-war years, the conflict between them during the Manhattan Project, and especially during the Oppenheimer episode, permanently marred their relation.

Political stances

In 1968, Bethe, along with IBM physicist Richard Garwin, wrote an article criticising in detail the new anti-ICBM defense system that the government was planning to install.

During the 1980s and 1990s, Bethe campaigned for the peaceful use of nuclear energy. After the Chernobyl accident, Bethe put together a committee of experts that analysed the incident, and concluded that a similar episode would not happen in any good US reactor, as the Russian reactor suffered from a fundamentally faulty design and human error also had significantly contributed to the accident. 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.

Awards and legacy

In 1967, Bethe was awarded the Nobel Prize in Physics "for his contributions to the theory of nuclear reactions, especially his discoveries concerning the energy production in stars".

Bethe was also noted for his theories on atomic properties.

Bethe's hobbies included a passion for history and also stamp-collecting. Bethe was also known for his great sense of humor, and once published a spoof paper in 1931, "On the Quantum Theory of the Temperature of Absolute Zero" (Beck, Bethe, Riezler) where he calculated the fine structure constant from the absolute zero temperature in Celsius units, causing a scandal in the scientific world.

Hans Bethe died in his home in Ithaca, New York. Since his death, Cornell has announced that the third of five new residential colleges, each of which will be named after a distinguished former member of the Cornell faculty, will be named the Hans Bethe House.

Honors

Awards

Henry Draper Medal (1947) Max Planck medal (1955) Eddington Medal of the Royal Astronomical Society (1961) Enrico Fermi Award (1961) Rumford Prize (1963) Nobel Prize in Physics (1967) Lomonosov Gold Medal (1989) Oersted Medal (1993) Bruce Medal (2001)

Named after him

Asteroid 30828 Bethe Hans Bethe Prize of the American Physical Society Hans Bethe House at Cornell University