Work on theory of plasma between 1946 and 1953. Initial interest in plasma at Lawrence Radiation Laboratory during World War II continued interest at University of California, Berkeley and then at Princeton University (especially in collaboration with D. Grass and David Pines). Also prominently mentioned are: John Bardeen, Albert Einstein, E. P. Gross, J. Robert Oppenheimer, Julian R. Schwinger, and Tor Staver.