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J. Robert Oppenheimer (1904-1967) was an American theoretical physicist.  During the Manhattan Project, Oppenheimer was director of the Los Alamos Laboratory and responsible for the research and design of an atomic bomb. He is often known as the “father of the atomic bomb.”

By the time the Manhattan Project was launched in the fall of 1942, Oppenheimer was already considered an exceptional theoretical physicist and had become deeply involved in exploring the possibility of an atomic bomb. Throughout the previous year he had been doing research on fast neutrons, calculating how much material might be needed for a bomb and how efficient it might be. 

Although Oppenheimer had little managerial experience and some troublesome past associations with Communist causes, General Leslie Groves recognized his exceptional scientific brilliance. Less than three years after Groves selected Oppenheimer to direct weapons development, the United States dropped two atomic bombs on Japan. As director of the Los Alamos Laboratory, Oppenheimer proved to be an extraordinary choice.

Oppenheimer was married to a botanist, Kitty. They had two children, Peter and Toni.


Early Life

Oppenheimer was born on April 22, 1904. Oppenheimer’s family was part of the Ethical Culture Society, an outgrowth of American Reform Judaism founded and led at the time by Dr. Felix Adler. The progressive society placed an emphasis on social justice, civic responsibility, and secular humanism. Dr. Adler also founded the Ethical Culture School, where Oppenheimer enrolled in September 1911. His academic prowess was apparent very early on, and by the age of 10, Oppenheimer was studying minerals, physics, and chemistry. His correspondence with the New York Mineralogical Club was so advanced that the Society invited him to deliver a lecture—not realizing that Robert was a twelve-year-old boy.

He graduated as valedictorian of his high school class 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 in New Mexico, a haven for health-seekers.

Robert stayed at a dude ranch 25 miles northeast of Santa Fe with high school teacher Herbert Smith as a companion and mentor. From there, he took five- or six-day horseback trips in the wilderness. This experience restored Oppenheimer’s health and instilled a deep love for the desert high country.

Oppenheimer enrolled at Harvard in September 1922. He graduated in three years, excelling in a wide variety of subjects. Although he majored in chemistry, Oppenheimer eventually realized his true passion was the study of physics.

In 1925, Oppenheimer began his graduate work in physics at Cavendish Laboratory in Cambridge, England. J. J. Thomson, who had been awarded the 1906 Nobel Prize in Physics for detecting the electron, agreed to take on Oppenheimer as a student. At Cavendish, Oppenheimer realized that his talent was for theoretical, not experimental, physics, and he accepted an invitation from Max Born, director of the Institute of Theoretical Physics at the University of Göttingen, to study with him in Germany.

Oppenheimer had the good fortune to be in Europe during a pivotal time in the world of physics, as European physicists were then developing the groundbreaking theory of quantum mechanics. Oppenheimer received his doctorate in 1927 and accepted professorships at the University of California, Berkeley, and the California Institute of Technology. At Berkeley, he became good friends with Ernest Lawrence, one of the world’s top experimental physicists and the inventor of the cyclotron. Lawrence named his second son after Robert.


Later Years

After the war Oppenheimer became an advisor of the Atomic Energy Commission, lobbying for international arms control. Beginning in 1947, Oppenheimer directed the Institute for Advanced Study in Princeton, New Jersey, where he convened great scientists. “What we don’t understand, we explain to each other.” 

His security clearance was revoked in 1954 in a hearing during the Second Red Scare. Oppenheimer’s old Communist sympathies were dredged up and his clearance was revoked a mere 32 hours before it was set to expire. Oppenheimer had made political enemies by arguing against the development of the hydrogen bomb, and revoking his clearance stripped him of political power. The scientific community was outraged at the treatment of Oppenheimer, and reviled Edward Teller, who testified against him at the hearing. For more information, please see Oppenheimer Security Hearing.

Along with Albert Einstein, Bertrand Russell, and Joseph Rotblat he established the World Academy of Art and Science in 1960. He continued lecturing around the world, and was awarded the Enrico Fermi Award in 1963. He died of throat cancer in 1967.

J. Robert Oppenheimer's Timeline
1904 Apr 22nd Born in New York, New York.
1911 Sep Enrolled in the Ethical Cultural School in New York City.
1921 Graduated as valedictorian of his high school class.
1922 After being bedridden with dysentery, spent the summer in New Mexico to recuperate.
1922 Enrolled at Harvard University.
1925 Began graduate work in physics at Cavendish Laboratory in Cambridge, England under J. J. Thomson.
1926 Moved from Cavendish Laboratory to the University of Göttingen to finish his graduate studies under Max Born.
1927 Received Ph.D. in Physics from the University of Göttingen.
1927 Joined the faculty at the University of California, Berkeley, and Caltech.
1942 Jan Organized a program on fast neutron theoretical physics at the University of California at Berkeley.
1942 Jun Joined the Chicago Met Lab to lead an effort on fast neutron physics, and prepared an outline for the entire neutron physics program.
1942 Jul1942 Sep Assembled theoretical study group in Berkeley to examine the principles of bomb design. Emerged as the natural leader.
1942 Sep 29th Proposed that a "fast-neutron lab" to study fast neutron physics and develop designs for an atomic bomb be created.
1942 Oct 15th General Leslie R. Groves asked J. Robert Oppenheimer to head Project Y, planned to be the new central laboratory for weapon physics research and design.
1942 Oct 19th Vannevar Bush approves Oppenheimer's appointment in meeting with Oppenheimer and General Groves.
1942 Nov 16th General Groves and Oppenheimer visit the Los Alamos, NM mesa in New Mexico and select it for "Site Y.
19431945 Director of the Los Alamos Laboratory.
1945 Jul 16th To his immense relief, witnessed the successful Trinity test.
1945 Oct 16th Resigns as director of Los Alamos Laboratory, accepting a post at CalTech.
1947 Became director of the Institute for Advanced Study in Princeton, New Jersey.
1954 Jun 29th Oppenheimer's security clearance was revoked by the US Atomic Energy Commission, just 32 hours before it was set to expire.
1963 Dec 2nd Received the Enrico Fermi Award.
1967 Feb 18th Died in Princeton, New Jersey.

J. Robert Oppenheimer and Ernest Lawrence

Oppenheimer with the "Gadget" before the Trinity test

J. Robert Oppenheimer as a young man

J. Robert Oppenheimer and Ernest Lawrence

General Leslie R. Groves and J. Robert Oppenheimer after the successful Trinity test

J. Robert Oppenheimer

J. Robert Oppenheimer and Gregory Breit.

Ernest Lawrence, Glenn Seaborg, and J. Robert Oppenheimer

John von Neumann, J. Robert Oppenheimer, and the MANIAC computer

Badge photo from Los Alamos

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