Hans Bethe: Prophet of Energy

Hans Bethe

Hans Albrecht Bethe was born in Strasbourg, Alsace-Lorraine, on July 2 1906. He attended the Gymnasium in Frankfurt from 1915 to 1924. He then studied at the University of Frankfurt for two years, and at Munich for two and one half years, taking his Ph. D. in theoretical physics with Professor Arnold Sommerfeld in July 1928.

He then was an Instructor in physics at Frankfurt and at Stuttgart for one semester each. From fall 1929 to fall 1933 his headquarters were the University of Munich where he became Privatdozent in May 1930. During this time he had a travel fellowship of the International Education Board to go to Cambridge, England, in the fall of 1930, and to Rome in the spring terms of 1931 and 1932. In the winter semester of 1932-1933,he held a position as Acting Assistant Professor at the University of Tubingen which he lost due to the advent of the Nazi regime in Germany.

Bethe emigrated to England in October 1933 where he held a temporary position as Lecturer at the University of Manchester for the year 1933-1934, and a fellowship at the University of Bristol in the fall of 1934. In February 1935 he was appointed Assistant Professor at Cornell University, Ithaca, N. Y. U.S.A., then promoted to Professor in the summer of 1937. He has stayed there ever since, except for sabbatical leaves and for an absence during World War II. His war work took him first to the Radiation Laboratory at the Massachusetts Institute of Technology, working on microwave radar, and then to the Los Alamos Scientific Laboratory which was engaged in assembling the first atomic bomb. He returned to Los Alamos for half a year in 1952. Two of his sabbatical leaves were spent at Columbia University, one at the University of Cambridge, and one at CERN and Copenhagen.

Bethe’s main work is concerned with the theory of atomic nuclei. Together with Peierls, he developed a theory of the deuteron in 1934 which he extended in 1949. He resolved some contradictions in the nuclear mass scale in 1935. He studied the theory of nuclear reactions in 1935-1938, predicting many reaction cross sections. In connection with this work, he developed Bohr’s theory of the compound nucleus in a more quantitative fashion. This work and also the existing knowledge on nuclear theory and experimental results, was summarized in three articles in the Reviews of Modern Physics which for many years served as a textbook for nuclear physicists.

His work on nuclear reactions led Bethe to the discovery of the reactions which supply the energy in the stars. The most important nuclear reaction in the brilliant stars is the carbon-nitrogen cycle, while the sun and fainter stars use mostly the proton-proton reaction. Bethe’s main achievement in this connection was the exclusion of other possible nuclear reactions. The Nobel Prize was given for this work, as well as his work on nuclear reactions in general.

In 1955 Bethe returned to the theory of nuclei, emphasizing a different phase. He has worked since then on the theory of nuclear matter whose aim it is to explain the properties of atomic nuclei in terms of the forces acting between nucleons.

Before his work on nuclear physics, Bethe’s main attention was given to atomic physics and collision theory. On the former subject, he wrote a review article inHandbuch der Physik in which he filled in the gaps of the existing knowledge, and which is still up-to-date. In collision theory, he developed a simple and powerful theory of inelastic collisions between fast particles and atoms which he has used to determine the stopping power of matter for fast charged particles, thus providing a tool to nuclear physicists. Turning to more energetic collisions, he calculated with Heitler the bremsstrahlung emitted by relativistic electrons, and the production of electron pairs by high energy gamma rays.

Bethe also did some work on solid-state theory. He discussed the splitting of atomic energy levels when an atom is inserted into a crystal, he did some work on the theory of metals, and especially he developed a theory of the order and disorder in alloys.

In 1947, Bethe was the first to explain the Lamb-shift in the hydrogen spectrum, and he thus laid the foundation for the modern development of quantum electrodynamics. Later on, he worked with a large number of collaborators on the scattering of pi mesons and on their production by electromagnetic radiation.

Bethe is married to the daughter of P.P. Ewald, the well-known X-ray physicist. They have two children, Henry and Monica.

From Nobel Lectures, Physics 1963-1970, Elsevier Publishing Company, Amsterdam, 1972

This autobiography/biography was written at the time of the award and first published in the book series Les Prix Nobel. It was later edited and republished inNobel Lectures. To cite this document, always state the source as shown above.


Hans Bethe died on March 6, 2005.


Copyright © The Nobel Foundation 1967


Hans Bethe

Hans Bethe’s arrival at Cornell University as a refugee from Nazi Germany, at age 28 in 1935, launched the Department of Physics into the top rank. It was at Cornell, before World War II, that Bethe published his famous reviews of nuclear physics, and conducted his groundbreaking work on the theory of energy production in stars for which he won the Nobel Prize in 1967.

During the war, Bethe was a key figure on the Manhattan Project as head of the theoretical physics division. After the war, he brought some of the most outstanding young physicists from Los Alamos to Cornell, in particular, Richard Feynman and Robert Wilson. Under their leadership, Cornell moved into what is now called high energy elementary particle physics, a field in which Cornell remains on the cutting edge. That Hans Bethe has devoted virtually his whole career to Cornell has been of inestimable value to the Department and to the University.

Hans Bethe was born in 1906 in Strasbourg, Germany. He attended the University of Munich, studying with Arnold Sommerfeld, and after receiving his degree in 1928, taught at Frankfurt, Stuttgart and Munich. In 1930 and 1931, he received fellowships first to Cambridge and then to Rome where he worked with Enrico Fermi.

Bethe’s career spans the evolution of nuclear physics as we know it today. He has made contributions to almost all phases of the exploration of nuclear interactions and nuclear forces, but his scientific accomplishments go far beyond this. He produced the first major paper on the theory of order-disorder transitions in alloys, and his 1947 calculation of the Lamb shift paved the way for the revolution in quantum electrodynamics.

In the decade following World War II, Bethe and Feynman and their students played a central role in developing quantum electrodynamics, work for which Feynman shared the Nobel Prize. From 1945, until his retirement from the Cornell faculty in 1975, Bethe trained and inspired a large number of graduate students. Many have gone on to become internationally known scientists, among them Freeman Dyson. Bethe and his co-workers published important work across the whole spectrum of physics. Even today, in his nineties, his unique mastery of such diverse subjects as thermonuclear processes, shock waves and neutrino reactions have kept Bethe at the forefront of research in astrophysics.

Bethe’s impact transcends the Cornell Physics Department. The distinction of astronomy at Cornell owes much to Bethe’s inspiration and initiatives. He has been an advisor to several United States presidents on national security policy and, since World War II, has played a leading role in the public debate about nuclear weapons, defense policy and nuclear power. He was one of the founders of the Federation of Atomic Scientists and was a member of the original Board of Directors of the Bulletin of the Atomic Scientists.

In his public role, Bethe’s position has been that of a responsible scientist and a man of conscience eager to contribute his special knowledge to the public discussion of the great issues of our time. Hans Bethe is a remarkable combination of a truly great scientist who has also made major contributions in the public service of his nation.

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Three Lectures by Hans BetheIN 1999, legendary theoretical physicist Hans Bethe delivered three lectures on quantum theory to his neighbors at the Kendal of Ithaca retirement community (near Cornell University). Given by Professor Bethe at age 93, the lectures are presented here as QuickTime videos synchronized with slides of his talking points and archival material.

Intended for an audience of Professor Bethe’s neighbors at Kendal, the lectures hold appeal for experts and non-experts alike. The presentation makes use of limited mathematics while focusing on the personal and historical perspectives of one of the principal architects of quantum theory whose career in physics spans 75 years.

A video introduction and appreciation are provided by Professor Silvan S. Schweber, the physicist and science historian who is Professor Bethe’s biographer, and Edwin E. Salpeter, the J. G. White Distinguished Professor of Physical Science Emeritus at Cornell, who was a post-doctoral student of Professor Bethe.

About Hans Bethe
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Hans Bethe’s publications span over 75 years and an incredible array of topics in physics, astrophysics, nuclear energy, arms control, and science policy. This page offers just a few starting points for those interested in learning about Professor Bethe and his profound influence as one of the great scientists of the twentieth century. Readers interested in learning more about quantum theory will readily find technical and popular references in libraries, bookstores, and online.

Web Pages

Nobel Prize biography, 1967
Includes the presentation speech and other resources

Hans Bethe Celebrates 60 Years at Cornell,” 1995
Several articles by Cornell University News Service

A Tribute to Hans Albrecht Bethe,” 1995
Originally published by Cornell Magazine

Writing the Biography of a Living Scientist: Hans Bethe,” 1995
Paper given by Silvan Schweber at the Pauling Symposium

Bruce Medalist page and bibliography, 2001
Awarded for lifetime contributions to astronomy


I Can Do That: Hans Bethe’s First 60 Years at Cornell,” 1995
Produced at Cornell University, available online. (After clicking the link, scroll down to the bottom of the page. Click “View/Open” to launch the RealMedia video.)

“An Evening with Hans Bethe: the German Atomic Bomb Project,” 1993
Produced at Cornell University, available at Cornell Library


Schweber, Silvan S., In the Shadow of the Bomb: Bethe, Oppenheimer, and the Moral Responsibility of the Scientist (Princeton University Press, Princeton, NJ, 2000).

Bernstein, Jeremy, Prophet of Energy: Hans Bethe (Basic Books, 1980; Elsevier-Dutton, NY, 1981).

Bethe, H.A., et. al., From a Life of Physics (World Scientific Publishing Co., Singapore, 1989).

Bethe, Hans A., The Road from Los Alamos, [Masters of Modern Physics series] (American Inst. of Physics, NY, 1991).

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