Freeman John Dyson. Portrait of Freeman John Dyson (born 1923), British-American theoretical physicist. Educated at the University of Cambridge, Dyson became Professor of Physics at Cornell University, USA, in 1953. Dyson worked on a number of topics but his most significant contribution was to the study of interactions between matter and electromagnetic waves. Mathematical solutions to this phenomenon of quantum electrodynamics had been independently proposed during 1946-8 by J. Schwinger, S.I. Tomonaga and R. Feynman. Dyson showed that the three methods were consistent and unified them into a single theory. Photographed in the 1940s.