Oral Histories

Marshall Rosenbluth was an American physicist who worked in the theoretical division at Los Alamos from 1950 to 1956. In this interview, Rosenbluth addresses the theoretical issues involved in designing both the atomic and hydrogen bombs. He discusses how the pressure to create a nuclear bomb before the Soviet Union affected work in the laboratory, especially in performing and checking calculations. Rosenbluth also recounts his experiences during the nuclear weapons tests at Los Alamos and Bikini Atoll. He recalls the roles of top scientists, like Edward Teller, Hans Bethe, Enrico Fermi, and Carson Mark, in the building of the hydrogen bomb. He also explains how funding and other external factors affected the hydrogen bomb’s design.

Dr. J. Carson Mark joined the Manhattan Project in May 1945 with a delegation of British scientists. He worked in the Los Alamos Scientific Laboratory, and in 1947, went on to head its Theoretical Division. Mark stayed on after the end of the Second World War as part of the project aimed at developing the hydrogen bomb. In this interview, Mark addresses the challenges involved in making a hydrogen bomb, including the design process and the conflicts between other scientists in the laboratory. He also discusses the Soviet hydrogen bomb, and the problems their project faced, despite Soviet espionage in the United States.

George Cowan was a physical chemist who joined the Manhattan Project in 1942. In this interview, Cowan discusses the Soviet atomic program and their effort to build a nuclear bomb. In 1949, he helped convince U.S. government officials that the radiochemistry of air samples taken from the atmosphere proved that the Soviets had detonated their own atomic bomb, rather than what many assumed was just a peaceful nuclear reactor problem. Cowan also discusses Operation Crossroads, where he helped take air samples during atomic tests at Eniwetok Atoll in 1946.