Nobel Laureate Hans A. Bethe died peacefully at home in Ithaca, New York, at the age of 98 on March 6, 2005.
"A monumental figure in the history of physics has passed on,” said Dr. Raymond L. Orbach, Director of the Department of Energy’s Office of Science. “We have lost a giant among giants. We shall all miss his remarkable scientific insight and contributions, not only to physics, but also to our nation and world. He will long be remembered for his fundamental contributions to our understanding of the properties of matter, from the atomic nucleus, to materials, to the cosmos."
Professor Bethe’s earliest work still remains the cornerstone of many-body physics, Dr. Orbach noted. The "Bethe ansatz" serves as the basis of our understanding of complex interacting systems, from the antiferromagnetic ground state to the Kondo problem.
When he first came to Cornell University from Germany via Cambridge, England in 1935, he wrote a brilliant series of papers on nuclear physics which became known as “Bethe's Bible” and which, according to Edward Teller, contained everything there was to know about nuclear physics. In 1938, Bethe developed the carbon cycle, a nuclear process for generating energy in the Sun, and stars like it, by fusing hydrogen into helium. For this work, Bethe was awarded the Nobel Prize in Physics in 1967. (Neutrinos are one byproduct of the carbon cycle, and it was the determination to detect them that started Raymond Davis on his quest, which led eventually to a share of the Nobel Prize in 2002.)
In 1943, Bethe joined the then secret Los Alamos laboratory as head of the theoretical division, and he played a key role in the complex calculations leading to the design of the atomic bomb. A brilliant man himself, with the steadiness and determination of a battleship, he kept a collection of brilliant minds and idiosyncratic personalities, such as Richard Feynman, John von Neumann and Edward Teller firmly focused on the goals of the Manhattan Project.
After the Second World War, Bethe returned to Cornell to his first love, teaching and research into the structure of atoms, molecules and condensed matter, and the theory of quantum electrodynamics. He did, however, maintain his interest in matters of national security and while he never regretted his role in developing nuclear weapons, he had definite views on the proper role for them in world affairs. He served on the President's Science Advisory Committee from 1956 to 1964.
In 1961, Bethe received the Fermi Award from the Atomic Energy Commission, the predecessor of the Department of Energy,"for contributions to nuclear and theoretical physics, to peaceful uses of atomic energy, and to the security of the United States." (Fellow Fermi Award recipients in following years included Edward Teller (1962), Robert Oppenheimer (1963), and Lise Meitner (1966).)
In recent years, Bethe’s interests turned to nuclear astrophysics and the phenomenon of supernova explosions. In his 90's, he was still giving lectures to non-physicists about quantum mechanics.
“Hans Bethe’s passing marks the end of a prodigious group of pioneers in the quantum nature of our world,” said Dr. Orbach. “He symbolizes the finest amongst us--a scientist with a deep understanding of, and commitment to, scientific discovery; and a world citizen who recognized the importance of science and society, and contributed so much to making this a better world.”
Note: Hans Bethe’s obituaryand three lectures he delivered in 1999 are available on the Cornell University web site.