Julian Seymour Schwinger was a Nobel Prize-winning American theoretical physicist. He is best known for his work on quantum electrodynamics (QED), in particular for developing a relativistically invariant perturbation theory, and for renormalizing QED to one loop order. Schwinger was a physics professor at several universities.
Schwinger in 1965
Julian Schwinger, winner of the 1965 Nobel Prize in Physics. Original caption: "His laboratory is his ballpoint pen."
The headstone of Julian Schwinger at Mt. Auburn Cemetery in Cambridge, MA.
In particle physics, quantum electrodynamics (QED) is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved. QED mathematically describes all phenomena involving electrically charged particles interacting by means of exchange of photons and represents the quantum counterpart of classical electromagnetism giving a complete account of matter and light interaction.
Paul Dirac
Hans Bethe
Feynman (center) and Oppenheimer (right) at Los Alamos.
Image: Qed rules