Stanisław Ulam (1909–1984) was a Polish-American mathematician. Born into a wealthy Polish Jewish family, Ulam earned his D.Sc. in mathematics at the Lwów Polytechnic Institute in 1933. He then worked on the ergodic theory at Harvard University, shuttling between Poland and America, and ultimately settled in the United States after the German invasion of Poland in 1939, becoming an assistant professor at the University of Wisconsin–Madison. In 1943, Ulam joined the Manhattan Project, where he made hydrodynamic calculations to predict the behavior of explosive lenses for an implosion-type nuclear weapon. After the war, he became an associate professor at the University of Southern California, but returned to Los Alamos in 1946 to help Edward Teller develop the Teller–Ulam design of thermonuclear weapons. Ulam contributed to such fields of mathematics as set theory, topology, transformation theory, group theory, projective algebra, number theory, combinatorics, and graph theory. With Enrico Fermi and John Pasta, he studied the Fermi–Pasta–Ulam problem, which became the inspiration for the vast field of nonlinear science. Ulam is perhaps best known for realising that electronic computers made it practical to apply statistical methods to functions without known solutions, and as computers have developed, the Monte Carlo method he invented has become a standard approach to many physical and mathematical problems. (Full article...)