Freeman Dyson was a physicist and educator best known for his speculative work on extraterrestrial civilizations and for his work in quantum electrodynamics, solid-state physics, astronomy and nuclear engineering. He theorized several concepts that bear his name, such as Dyson's transform, Dyson tree, Dyson series, and Dyson sphere.
The son of a musician and composer, Dyson was educated at the University of Cambridge. As a teenager he developed a passion for mathematics, but his studies at Cambridge were interrupted in 1943, when he served in the Royal Air Force Bomber Command. He received a B.A. from Cambridge in 1945 and became a research fellow of Trinity College. In 1947 he went to the United States to study physics and spent the next two years at Cornell University, Ithaca, N.Y., and Princeton, where he studied under J. Robert Oppenheimer, then director of the Institute for Advanced Study. Dyson returned to England in 1949 to become a research fellow at the University of Birmingham, but he was appointed professor of physics at Cornell in 1951 and two years later at the Institute for Advanced Study, where he became professor emeritus in 2000. He became a U.S. citizen in 1957.