Freeman Dyson
Freeman John Dyson FRS (born December 15, 1923) is a British-born American theoretical physicist and mathematician, famous for his work in quantum electrodynamics, solid-state physics, astronomy and nuclear engineering. Although Dyson has won numerous scientific awards, he has never won a Nobel Prize.
Dyson is best known for demonstrating in 1949 the equivalence of the formulations of quantum electrodynamics that existed by that time – Richard Feynman\'s diagrams, on the one hand, and, on the other, the operator method developed by Julian Schwinger and Sin-Itiro Tomonaga. Dyson was the first person (besides Feynman) to appreciate the power of Feynman diagrams. He developed rules for the diagrams that completely solved the renormalization problem. Dyson\'s paper and also his lectures presented Feynman\'s theories of QED (quantum electrodynamics) in a form that other physicists could understand and undoubtedly facilitated the physics community\'s acceptance of Feynman\'s work.
A seminal work by Dyson came in 1966 when, together with Andrew Lenard and independently of Elliott H. Lieb and Walter Thirring, he proved rigorously that the exclusion principle plays the main role in the stability of bulk matter. Hence, it is not the electromagnetic repulsion between electrons and nuclei that is responsible for two wood blocks that are left on top of each other not coalescing into a single piece, but rather it is the exclusion principle applied to electrons and protons that generates the classical macroscopic normal force. In condensed matter physics, Dyson also did studies in the phase transition of the Ising model in 1 dimension and spin waves.
