Julian Seymour Schwinger (/ˈʃwɪŋər/; February 12, 1918 – July 16, 1994) was a Nobel Prize-winning American theoretical physicist.

Both his father and his mother's parents were prosperous clothing manufacturers, although the family business declined after the Wall Street Crash of 1929.

During high school, Julian had already started reading Physical Review papers by authors such as Paul Dirac in the library of the City College of New York, in whose campus Townsend Harris was then located.

CCNY automatically accepted all Townsend Harris graduates at the time, and both institutions offered free tuition.

Due to his intense interest in physics and mathematics, Julian performed very well in those subjects despite often skipping classes and learning directly from books.

On the other hand, his lack of interest for other topics such as English led to academic conflicts with teachers of those subjects.

Noticing Schwinger's academic problems, Lloyd decided to ask Isidor Isaac Rabi who he knew at Columbia for help.

But Rabi persisted and showed an unpublished paper on quantum electrodynamics written by Schwinger to Hans Bethe, who happened to be passing by New York.

Bethe's approval of the paper and his reputation in that domain were then enough to secure the scholarship for Julian, who then transferred to Columbia.

Schwinger later commented that this switch was in part a way to retain greater intellectual independence and avoid being "dominated" by Breit and Wigner by simply reducing the duration of contact with them by working different hours.

During the fall of 1939 Schwinger started working at the University of California, Berkeley under J. Robert Oppenheimer, where he stayed for two years as an NRC fellow.

His approach started with a quantum action and allowed bosons and fermions to be treated equally for the first time, using a differential form of Grassman integration.

In other notable early work, Rarita and Schwinger formulated the abstract Pauli and Fierz theory of the spin-3/2 field in a concrete form, as a vector of Dirac spinors, Rarita–Schwinger equation.

Schwinger had a mixed relationship with his colleagues, because he always pursued independent research, different from mainstream fashion.

It is a story widely told that Steven Weinberg, who inherited Schwinger's paneled office in Lyman Laboratory, there found a pair of old shoes, with the implied message, "think you can fill these?

In his last publications, Schwinger proposed a theory of sonoluminescence as a long-distance quantum radiative phenomenon associated not with atoms, but with fast-moving surfaces in the collapsing bubble, where there are discontinuities in the dielectric constant.

The mechanism of sonoluminescence now supported by experiments focuses on superheated gas inside the bubble as the source of the light.

[12] Schwinger was jointly awarded the Nobel Prize in Physics in 1965 for his work on quantum electrodynamics (QED), along with Richard Feynman and Shin'ichirō Tomonaga.

[14][15]Schwinger disliked Feynman diagrams because he felt that they made the student focus on the particles and forget about local fields, which in his view inhibited understanding.

The true difference is however deeper, and it was expressed by Schwinger in the following passage, Eventually, these ideas led to Lagrangian or action formulations of quantum mechanics, appearing in two distinct but related forms, which I distinguish as differential and integral.

The latter, spearheaded by Feynman has had all the press coverage, but I continue to believe that the differential viewpoint is more general, more elegant, more useful.

On Feynman's death, Schwinger described him as An honest man, the outstanding intuitionist of our age, and a prime example of what may lie in store for anyone who dares to follow the beat of a different drum.