John von Neumann, (1903-1957) the Hungarian- American mathematician. He developed the branch of mathematics called 'Game Theory' which deals with optimal strategies in situations involving a conflict of interest. He made a thorough study of quantum mechanics and in 1944 he showed the mathematical equivalence of Schrodinger's wave mechanics and Heisenberg's matrix mechanics. It was this background that assured his place amongst the group of scientists who worked on the Manhattan Project, the American programme to develop and build the first atomic bomb during World War Two.