Biography of Hans Bethe

A Giant in the Scientific Community

Hans Bethe at a press conference
 Getty Images

German-American physicist Hans Albrecht Bethe (pronounced BAY-tah) was born on July 2, 1906. He made key contributions to the field of nuclear physics and helped to develop the hydrogen bomb and the atomic bomb used in World War II. He died on March 6, 2005.

Early Years

Hans Bethe was born on July 2, 1906 in Strasbourg, Alsace-Lorraine. He was the only child of Anna and Albrecht Bethe, the latter of whom worked as a physiologist at the University of Strasbourg. As a child, Hans Bethe showed an early aptitude for mathematics and often read his father's calculus and trigonometry books.

The family moved to Frankfurt when Albrecht Bethe took a new position at the Institute of Physiology at the University of Frankfurt am Main. Hans Bethe attended secondary school at Goethe-Gymnasium in Frankfurt until he contracted tuberculosis in 1916. He took some time off school to recover before graduating in 1924.

Bethe went on to study at the University of Frankfurt for two years before transferring to the University of Munich so that he could study theoretical physics under German physicist Arnold Sommerfeld. Bethe earned his PhD in 1928. He worked as an assistant professor at the University of Tubingen and later worked as a lecturer at the University of Manchester after immigrating to England in 1933. Bethe moved to the United States in 1935 and took a job as a professor at Cornell University.

Marriage and Family

Hans Bethe married Rose Ewald, the daughter of German physicist Paul Ewald, in 1939. They had two children, Henry and Monica, and eventually, three grandchildren.

Scientific Contributions

From 1942 to 1945, Hans Bethe served as the director of the theoretical division at Los Alamos where he worked on the Manhattan Project, a team effort to assemble the world's first atomic bomb. His work was instrumental in calculating the bomb's explosive yield.

In 1947 Bethe contributed to the development of quantum electrodynamics by being the first scientist to explain the Lamb-shift in the hydrogen spectrum. At the beginning of the Korean War, Bethe worked on another war-related project and helped to develop a hydrogen bomb.

In 1967, Bethe was awarded a Nobel Prize in Physics for his revolutionary work in stellar nucleosynthesis. This work offered insight into the ways in which stars produce energy. Bethe also developed a theory related to inelastic collisions, which helped nuclear physicists understand the stopping power of matter for fast charged particles. Some of his other contributions include work on solid-state theory and a theory of the order and disorder in alloys. Late in life, when Bethe was in his mid-90s, he continued to contribute to research in astrophysics by publishing papers on supernovae, neutron stars, black holes.


Hans Bethe "retired" in 1976 but studied astrophysics and served as the John Wendell Anderson Emeritus Professor of Physics Emeritus at Cornell University until his death. He died of congestive heart failure on March 6, 2005 at his home in Ithaca, New York. He was 98 years old.

Impact and Legacy

Hans Bethe was the head theoretician on the Manhattan Project and was a key contributor to the atomic bombs that killed more than 100,000 people and wounded even more when they were dropped on Hiroshima and Nagasaki during World War II. Bethe also helped to develop the hydrogen bomb, despite the fact that he was opposed to the development of this type of weapon.

For more than 50 years, Bethe strongly advised caution in using the power of the atom. He supported nuclear nonproliferation treaties and frequently spoke out against missile defense systems. Bethe also advocated for the use of national laboratories to develop technologies that would lower the risk of nuclear war rather than weapons that could win a nuclear war.

Hans Bethe's legacy lives on today. Many of the discoveries that he made in nuclear physics and astrophysics during his 70+ year career have stood the test of time, and scientists are still using and building upon his work to make progress in theoretical physics and quantum mechanics.

Famous Quotes

Hans Bethe was a key contributor to the atomic bomb used in World War II as well as the hydrogen bomb. He also spent a significant portion of his life advocating for nuclear disarmament. So, it is really no surprise that he was often asked about his contributions and the potential for nuclear war in the future. Here are some of his most famous quotes on the topic:

  • "When I started participating in thermonuclear work in the summer of 1950, I was hoping to prove that thermonuclear weapons could not be made. If this could have been proved convincingly, this would of course have applied to both the Russians and ourselves and would have given greater security to both sides than we can now ever achieve. It was possible to entertain such a hope until the spring of 1951, when it suddenly became clear that it was no longer tenable."
  • "If we fight a war and win it with H-bombs, what history will remember is not the ideals we were fighting for but the methods we used to accomplish them. These methods will be compared to the warfare of Genghis Khan who ruthlessly killed every last inhabitant of Persia."
  • ''Today the arms race is a long-range problem. The Second World War was a short-range problem, and in the short range I think it was essential to make the atomic bomb. However, not much thought was given to the time 'after the bomb.' At first, the work was too absorbing, and we wanted to get the job done. But I think that once it was made it had its own impulse - its own motion that could not be stopped.''
  • "Today we are rightly in an era of disarmament and dismantlement of nuclear weapons. But in some countries nuclear weapons development still continues. Whether and when the various Nations of the World can agree to stop this is uncertain. But individual scientists can still influence this process by withholding their skills. Accordingly, I call on all scientists in all countries to cease and desist from work creating, developing, improving and manufacturing further nuclear weapons - and, for that matter, other weapons of potential mass destruction such as chemical and biological weapons." 

Hans Bethe Fast Facts

  • Full Name: Hans Albrecht Bethe 
  • Occupation: Physicist
  • Born: July 2, 1906 in Strasbourg, Germany (now Strasbourg, France)
  • Died: March 6, 2005 in Ithaca, New York, USA
  • Education: Goethe University Frankfurt, Ludwig Maximilian University of Munich
  • Key Accomplishment: Received the Nobel Prize in Physics in 1967 for his work in stellar nucleosynthesis. Served as head theoretician on the Manhattan Project. 
  • Spouse's Name: Rose Ewald
  • Children's Names: Henry Bethe, Monica Bethe


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Schweitzer, Karen. "Biography of Hans Bethe." ThoughtCo, Aug. 27, 2020, Schweitzer, Karen. (2020, August 27). Biography of Hans Bethe. Retrieved from Schweitzer, Karen. "Biography of Hans Bethe." ThoughtCo. (accessed June 6, 2023).