born Aug. 9, 1911, Pittsburgh, Pa., U.S.
died March 14, 1995, Pasadena, Calif.
U.S. nuclear astrophysicist.
He received his Ph.D. from Caltech and became a professor there in 1939. His theory of element generation ( nucleosynthesis ) suggests that, as stars evolve, chemical elements are synthesized progressively (light to heavy) by means of nuclear fusion that also produces light and heat and that the heaviest elements are synthesized in supernova s. For his theory he shared a 1983 Nobel Prize with Subrahmanyan Chandrasekhar . He is also known for his work in radio astronomy with Fred Hoyle .