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J. Robert Oppenheimer

the "father of the atomic bomb"

J. Robert Oppenheimer

Early Life and Work

Julius Robert Oppenheimer was born to Julius S. and Ella Friedman Oppenheimer in New York, New York, on April 22, 1904. He graduated as valedictorian of his class from the Ethical Culture Society School, whose physics laboratory has since been named for him, in 1921, but fell ill with a near-fatal case of dysentery and was forced to postpone enrolling at Harvard. After being bedridden for months, his parents arranged for him to spend the summer of 1922 at a dude ranch 25 miles northeast of Santa Fe, New Mexico, where he regained his health.

Oppenheimer entered Harvard in 1922, intending to become a chemist but soon switching to physics. He graduated summa cum laude in 1925 and then went to England to conduct research at Cambridge University's Cavendish Laboratory, under the direction of Lord Ernest Rutherford. In 1926 he moved to Göttigen University in Germany, where he studied under Max Born. By the time he received his doctorate in 1927 Oppenheimer had published more than a dozen articles, including a paper on the so-called Born-Oppenheimer approximation.

In 1927, Oppenheimer returned to Harvard to study mathematical physics. He moved to the California Institute of Technology in early 1928, and accepted an assistant professorship in physics at the University of California, Berkeley, soon after. He maintained a joint appointment with the California Institute of Technology, and in the ensuing 13 years he "commuted" between the two universities. Most of his research during this time focused on energy processes of subatomic particles, but he also made important contributions to astrophysics, spectroscopy, and quantum field theory. At Berkeley, he became good friends with Ernest Lawrence, one of the world’s top experimental physicists and the inventor of the cyclotron.

Manhattan Project

Oppenheimer was put in charge of the atomic bomb project, as research leader, in 1941. His first task was to calculate the amount of uranium-235 needed to sustain a chain reaction. He then gathered together at Berkeley a small group of some of the best theoretical physicists in the country to talk about the actual bomb design. By the end of the summer of 1942 they had concluded that the bomb project would require a major scientific effort, as well as a dedicated research facility. Oppenheimer chose a mesa in the New Mexico desert he had visited as a young man, and it was there that the U.S. Army established Los Alamos. By July 1945, Los Alamos was ready to test its bomb. The test, code-named "Trinity," took place on July 16. It exploded with a force equivalent of 18,000 tons of TNT. That successful test led to development of "Little Boy," which was dropped on Hiroshima, Japan, on August 6, 1945, and to "Fat Man," which was dropped on Nagasaki, Japan, three days later.

Later Life and Work

Almost immediately after resigning as director of Los Alamos in 1945, Oppenheimer began pushing hard for international control of atomic energy. He was appointed Chairman of the General Advisory Committee to the Atomic Energy Commission in 1947, and served in that capacity until 1952. He also became Director of Princeton's Institute for Advanced Study, and served in that capacity from 1947 to 1966. In the latter position, he stimulated discussion and research on quantum and relativistic physics in the School of Natural Sciences.

In October 1949, Oppenheimer used his position with the Atomic Energy Commission to voice strong opposition to the development of the hydrogen bomb. That opposition, combined with revelations that he had been a financial supporter of various Communist Party organizations in the 1930's, led to the Atomic Energy Commission stripping Oppenheimer of his security clearance in 1953. Despite impassioned pleas from many well-respected members of the scientific community, and the awarding of the Enrico Fermi Award to him in 1963, Oppenheimer never regained his security clearance, and he spent the rest of his career in academia.

J. Robert Oppenheimer died of throat cancer in Princeton, New Jersey, on February 18, 1967. He was survived by his wife, the former Katherine Peuning Harrison, son Peter, and daughter, Katherine.

Atomic Archive
Atomic Heritage Foundation
American Experience: Race for the Superbomb PBS

Lord Ernest Rutherford
Little Boy
Fat Man

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This page was last updated on 05/17/2017.