Freeman J. Dyson developed a general theory of quantum electrodynamics that integrates a number of specific concepts previously developed by Richard P. Feynman, Julian Schwinger, and Sin-Itiro Tomonaga, among others. As a result of his work with Edward Teller on nuclear power plants and the fusion bomb, he became active in the debate over the nuclear test ban treaty, arguing first one side of the issue and then, at a later date, the opposite side. Since the late 1950s, Dyson has also been interested in space travel and in research on the possible existence of intelligent life elsewhere in the universe.

Freeman John Dyson was born on December 15, 1923, in Crowthorne, a village in the south of England. His father, George Dyson, was a music teacher at Winchester College, and later became director of the Royal College of Music in London. His mother, Mildred Atkey Dyson, was a lawyer...