Born in 1904, he was a theoretical physicist pivotal to the development of the atomic bomb during World War II as the head of the Los Alamos Laboratory. Educated at Harvard, Cambridge, and Göttingen, he made significant contributions to quantum mechanics and nuclear physics. Post-war, he became a chief advisor to the newly-created United States Atomic Energy Commission, advocating for international control of nuclear power. His career faced challenges during the Red Scare but he remained a prominent scientific figure until passing in 1967.