born Feb. 11, 1898, Budapest, Hung., Austria-Hungary
died May 30, 1964, La Jolla, Calif., U.S.
Hungarian-born U.S. physicist.
He taught at the University of Berlin (192233), then fled to England (193437) and the U.S., where he worked at the University of Chicago from 1942. In 1929 he established the relation between entropy and transfer of information, and in 1934 he helped develop the first method of separating isotopes of artificial radioactive elements. He helped Enrico Fermi conduct the first sustained nuclear chain reaction and construct the first nuclear reactor. In 1939 he was instrumental in establishing the Manhattan Project , in which he helped develop the atomic bomb. After the first use of the bomb, he promoted the peaceful uses of atomic energy and the control of nuclear weapons, founding the Council for a Livable World. In 1959 he received the Atoms for Peace Award.