A Hungarian physicist, he was best known for encouraging Albert Einstein to warn President Roosevelt about the atomic bomb. Szilard received his doctorate in physics in 1922. He later worked with Enrico Fermi at the University of Chicago’s Metallurgical Laboratory to construct the first nuclear reactor. By 1945, it was clear that the U.S. was planning to use the bomb against Japan. Szilard began a campaign against its use. He circulated petitions among the scientists demanding greater scientific input on the future use of atomic weapons. After the bombs
