Schwinger, Julian Seymour (1918-1994), of the United States shared the 1965 Nobel Prize in physics with Richard P. Feynman and Sin-Itiro Tomonaga. Working independently, the three men developed an improved theory of quantum electrodynamics in the late 1940's. Quantum electrodynamics is the study of the interaction between electrically charged subatomic particles and electromagnetic radiation. The theory enables scientists to predict accurately the effects of charged particles on each other in a radiation field. Schwinger was born in New York City on Feb. 12, 1918. He earned A.B. and Ph.D. degrees from Columbia University. He taught at Harvard University from 1945 to 1972. He died on July 16, 1994.