Stanislaw Ulam

Born on 13 April 1909 in Lemberg, Poland (now Lviv, Ukraine), Stanislaw Ulam was a mathematician and physicist who played a central role in US development of the hydrogen bomb. He earned a PhD from the Polytechnic Institute in Lvov in 1933. In 1936 he came to the US to join John von Neumann at the Institute for Advanced Study in Princeton, New Jersey. Ulam later worked with von Neumann to develop the Monte Carlo method for understanding complex systems. In 1943 Ulam became a US citizen and joined the team at Los Alamos that was developing nuclear weapons. His greatest contribution to the effort concerned the mechanism for driving a thermonuclear bomb. Ulam showed that the shock waves from a fission bomb could compress hydrogen fuel sufficiently to trigger a fusion bomb. Edward Teller ran with Ulam’s idea and proposed a configuration in which x rays emitted by the fission primary drive the process that compresses the fusion secondary. The resulting Teller–Ulam design became the model for extremely high yield hydrogen bombs. Beyond atomic weapons, Ulam was influential in set theory, logic, topology, and other fields of math. He considered the possibility of nuclear propulsion of spacecraft and performed early investigations into what would come to be known as chaos theory. He died in Santa Fe, New Mexico in 1984 at age 75.

Date in History: 13 April 1909