J. Robert Oppenheimer

J Robert Oppenheimer (Julius Robert Oppenheimer) was an American theoretical physicist known for being the director of the Los Alamos Laboratory at the time of the Manhattan Project, the American-led effort to produce a functional atomic weapon during World War II. Referred to as the "father of the atomic bomb," Oppenheimer oversaw the development and testing of the world's first nuclear weapons, which led to the dropping of two atomic bombs by US forces on Japan in August 1945.

Oppenheimer was born in 1904 to Jewish parents in New York City. Oppenheimer's academic abilities were recognized at an early age, and he would go on to attend Harvard University, graduating with a degree in chemistry before transitioning to physics for his graduate studies. Oppenheimer worked with British Physicist JJ Thomson at Cavendish Laboratory in Cambridge, England, and German-British physicist Max Born at the Institute of Theoretical Physics at the University of Göttingen, Germany. After receiving his doctorate in 1927 while working with Born in Germany, Oppenheimer accepted professorships at the University of California, Berkeley, and the California Institute of Technology.

During his career, Oppenheimer did significant research in astrophysics, nuclear physics, spectroscopy, and quantum field theory, including a famous paper describing the Born-Oppenheimer approximation, which separates nuclear motion from electronic motion in the mathematical treatment of molecules. He made important contributions to the theory of cosmic ray showers and did work that led toward descriptions of quantum tunneling. He was also the first to write papers suggesting the existence of what we today call black holes.

When Oppenheimer joined the Manhattan Project in the fall of 1942, he was a widely respected physicist who had already been involved in exploring the theoretical possibilities of an atomic bomb. The previous year, he was researching fast neutrons, how much material could be needed for a bomb, and how efficient a potential atomic weapon could be.

J Robert Oppenheimer had a younger brother called Frank (born in 1912), who also grew up to be a physicist, earning degrees in physics from Johns Hopkins University and the California Institute of Technology, where he researched artificially induced radiation. In 1940, Oppenheimer married biologist Katharine (Kitty) Puening Harrison. The couple had two children, Peter and Katherine.

After the war, Oppenheimer became an advisor to the Atomic Energy Commission, lobbying for international arms control, and became the director of the Institute for Advanced Study in Princeton, New Jersey. Oppenheimer's past communist sympathies meant his security clearance was revoked in 1954, thirty-two hours before it was set to expire. Oppenheimer established the World Academy of Art and Science in 1960 with Albert Einstein, Bertrand Russell, and Joseph Rotblat. He continued lecturing around the world and was awarded the Enrico Fermi Award in 1963. Oppenheimer died on February 18, 1967, at the age of sixty-two, after a prolonged battle with throat cancer.