Julian Schwinger

Origins and early life

Julian Seymour Schwinger was born in New York City on 12 February 1918 to Ashkenazi Jewish parents, Belle Rosenfeld and Benjamin Schwinger, a garment manufacturer whose family had come from Poland; the household followed the Orthodox tradition, and the family business declined after the crash of 1929.

Work and career

He was a prodigy who read the physics literature as a schoolboy and wrote a paper on quantum electrodynamics before he had a degree; his grades at City College were poor enough to block a scholarship until Isidor Rabi, shown that unpublished paper, pushed it in front of Hans Bethe, got his approval, and brought Schwinger to Columbia. He spent the war at the MIT Radiation Laboratory rather than Los Alamos, working on radar, and the mathematics of waveguides gave him the methods he used afterwards.

The problem waiting was that quantum electrodynamics, asked to compute anything precisely, returned infinity. Schwinger rebuilt the theory in a form that respects relativity at every step, which let the infinities be identified and absorbed into the measured mass and charge of the electron rather than appearing in the answer — renormalisation — and then computed the small correction to the electron's magnetic moment, a number that agreed with experiment to several decimal places.

Later years

He taught at Harvard from 1945 to 1974 and later at UCLA, shared the 1965 Nobel Prize in Physics with Richard Feynman and Shin'ichiro Tomonaga, and died on 16 July 1994; that correction is engraved on his headstone.