Julian Schwinger was one of the leading theoretical physicists of the 20th century. His contributions are as important, and as pervasive, as those of Richard Feynman, with whom he shared the 1965 Nobel Prize for Physics (along with Sin-itiro Tomonaga). Yet, while Feynman is universally recognised as a cultural icon, Schwinger is little known to many even within the physics community. In his youth, Schwinger was a nuclear physicist, turning to classical electrodynamics after World War II. In the years after the war, he was the first to renormalise quantum electrodynamics. Subsequently, he prese ... More

Julian Schwinger was one of the leading theoretical physicists of the 20th century. His contributions are as important, and as pervasive, as those of Richard Feynman, with whom he shared the 1965 Nobel Prize for Physics (along with Sin-itiro Tomonaga). Yet, while Feynman is universally recognised as a cultural icon, Schwinger is little known to many even within the physics community. In his youth, Schwinger was a nuclear physicist, turning to classical electrodynamics after World War II. In the years after the war, he was the first to renormalise quantum electrodynamics. Subsequently, he presented the most complete formulation of quantum field theory and laid the foundations for the electroweak synthesis of Sheldon Glashow, Steven Weinberg, and Abdus Salam, and he made fundamental contributions to the theory of nuclear magnetic resonance as well as many-body theory and quantum optics. Schwinger also developed a unique approach to quantum mechanics, measurement algebra, and a general quantum action principle. His discoveries include ‘Feynman's’ parameters and ‘Glauber's’ coherent states; in later years he also developed an alternative to operator quantum field theory which he called source theory, reflecting his profound phenomenological bent. His late work on the Thomas-Fermi model of atoms and on the Casimir effect continues to be an inspiration to a new generation of physicists. This first full-length biography describes the many strands of his research life, while tracing the personal life of this private and gentle genius.