  Julian Schwinger's influence on twentieth century science is profound and
pervasive. Of course, he is most famous for his renormalization theory of
quantum electrodynamics, for which he shared the Nobel Prize with Richard
Feynman and Sin-itiro Tomonaga. But although this triumph was undoubtedly his
most heroic work, his legacy lives on chiefly through subtle and elegant work
in classical electrodynamics, quantum variational principles, proper-time
methods, quantum anomalies, dynamical mass generation, partial symmetry, and
more. Starting as just a boy, he rapidly became the pre-eminent nuclear
physicist in the late 1930s, led the theoretical development of radar
technology at MIT during World War II, and then, soon after the war, conquered
quantum electrodynamics, and became the leading quantum field theorist for two
decades, before taking a more iconoclastic route during his last quarter
century.
