ULAM, STANISLAW MARCIN

ULAM, STANISLAW MARCIN (1909–1984), mathematician. Ulam was born in Lvov, Poland (then Austro-Hungary), and educated at the Lvov Polytechnic Institute, receiving his doctorate in mathematics in 1933. In 1935 he was invited to work at the Institute for Advanced Study in Princeton. After a brief period in Poland, he returned to the U.S. in 1938, first to Harvard and then in 1940 to the University of Wisconsin as assistant professor. He became a U.S. citizen in 1943, the same year that he joined the Manhattan Project group at Los Alamos working on the development of nuclear weapons. With Von Neumann, he developed the "Monte Carlo" approach to computational problems, paving the way for the "simulation" methods of physics research. His major contribution to the development of thermonuclear weapons was to suggest that compression was essential to inducing a sustained fusion reaction. With edward teller , he devised the system by which this was achieved with radiation implosion from a fission explosion rather than mechanical shock. In 1965 he left Los Alamos for the chair in mathematics at the University of Colorado in Boulder, a post he retained until his death in Santa Fe. With   K.C. Everett, he proposed a scheme for nuclear propulsion of space vehicles. He was essentially a theorist and his intellectual creativity survived the effects of encephalitis contracted in 1946. He was elected a member of the U.S. National Academy of Sciences, the President's Science Advisory Committee, and the Board of Governors of the Weizmann Institute (1975). His publications mainly feature books on mathematical theory. (Joseph Gillis / Michael Denman (2nd ed.)