Otto Frisch
Early Life and Education
Otto Robert Frisch was born on October 1, 1904, in Vienna, Austria, into a family with a rich scientific heritage. His father, Justinian Frisch, was a painter, and his mother, Auguste Meitner-Frisch, was a concert pianist. Otto was the nephew of physicist Lise Meitner, who played a significant role in his scientific development. Frisch showed an early interest in science and mathematics, which led him to pursue a degree in physics at the University of Vienna, where he studied under the tutelage of notable physicists such as Hans Thirring and Erwin Schrödinger.
Career Beginnings
After earning his Ph.D. in physics in 1926, Frisch began his career at the University of Vienna, where he conducted research on the properties of electrons in metals. His early work focused on the photoelectric effect, which laid the groundwork for his future contributions to nuclear physics. In 1930, Frisch moved to Berlin to work with Otto Stern on molecular beam experiments, which further honed his experimental skills.
Contributions to Nuclear Physics
Discovery of Nuclear Fission
In December 1938, while working at the Kaiser Wilhelm Institute in Berlin, Frisch visited his aunt Lise Meitner in Sweden. During this visit, they discussed the recent experiments of Otto Hahn and Fritz Strassmann, who had discovered that bombarding uranium with neutrons produced barium. Frisch and Meitner realized that this was evidence of nuclear fission, a process in which the nucleus of an atom splits into smaller parts, releasing a tremendous amount of energy. Frisch returned to Copenhagen, where he was working at the Niels Bohr Institute, and conducted experiments to confirm the fission hypothesis. He coined the term "fission" to describe the process, drawing an analogy to the biological process of cell division.
The Frisch-Peierls Memorandum
In early 1940, Frisch, along with fellow physicist Rudolf Peierls, wrote the Frisch-Peierls Memorandum. This document outlined the theoretical feasibility of constructing an atomic bomb using uranium-235. The memorandum was instrumental in convincing the British government to initiate the Tube Alloys project, which later merged with the American Manhattan Project. The Frisch-Peierls Memorandum provided detailed calculations on the critical mass needed for a chain reaction and the potential explosive power of an atomic bomb.
Later Career and Research
Work at Los Alamos
During World War II, Frisch was recruited to work on the Manhattan Project at Los Alamos National Laboratory in New Mexico. There, he contributed to the development of the Fat Man and Little Boy atomic bombs. Frisch was involved in the critical assembly experiments, also known as "tickling the dragon's tail," which were crucial for determining the critical mass of fissile material. His work at Los Alamos was vital in ensuring the success of the atomic bomb tests and the subsequent bombings of Hiroshima and Nagasaki.
Post-War Contributions
After the war, Frisch returned to England and took up a position at the University of Cambridge's Cavendish Laboratory. He continued his research in nuclear physics and made significant contributions to the understanding of nuclear reactions and particle physics. Frisch also played a key role in the development of the scintillation counter, an instrument used to detect and measure ionizing radiation. His work on the scintillation counter had far-reaching implications for both medical imaging and nuclear research.
Personal Life and Legacy
Otto Frisch was known for his modesty and dedication to science. He married Ursula Burghardt, a fellow physicist, and they had two children. Frisch was also an accomplished pianist, a talent he inherited from his mother. He passed away on September 22, 1979, in Cambridge, England.
Frisch's contributions to nuclear physics, particularly his role in the discovery of nuclear fission and the development of the atomic bomb, have left an indelible mark on the field. His work continues to influence contemporary research in nuclear energy and particle physics.