John Archibald Wheeler (July 9, 1911 – April 13, 2008) was an American theoretical physicist. He was largely responsible for reviving interest in general relativity in the United States after World War II. Wheeler also worked with Niels Bohr in explaining the basic principles behind nuclear fission. One of the later collaborators of Albert Einstein, he tried to achieve Einstein's vision of a unified field theory. Together with Gregory Breit, Wheeler developed the concept of Breit–Wheeler process. He is also known for popularizing the term "black hole", for coining the terms "neutron moderator", "quantum foam", "wormhole", and "it from bit", and for hypothesizing the "one-electron universe".
Wheeler earned his doctorate at Johns Hopkins University under the supervision of Karl Herzfeld, and studied under Breit and Bohr on a National Research Council fellowship. For most of his career, Wheeler was a professor at Princeton University, which he joined in 1938, remaining until his retirement in 1976. He was influential in mentoring a generation of physicists of the Golden Age of General Relativity, who made notable contributions to quantum mechanics and gravitation. At Princeton he supervised 46 PhDs, more than any other professor in the Princeton physics department.