Leo Szilard

Leo Szilard conceived the idea of the nuclear chain reaction in 1933 after fleeing Nazi Germany. He later patented the concept of a neutron-induced nuclear chain reaction, which laid the critical theoretical groundwork for nuclear energy.

Leo Szilard was a central figure in the Manhattan Project, famously co-drafting the Einstein-Szilard letter in 1939 that prompted President Roosevelt to begin atomic research. He later worked directly with Enrico Fermi at the University of Chicago to build the first nuclear reactor.

Yes, Szilard became a vocal advocate for arms control and deeply regretted the military application of his research. He circulated the Szilard Petition in 1945, urging President Truman to demonstrate the bomb's power on an uninhabited island rather than dropping it on Japanese cities.

After leaving Germany, Szilard conducted much of his early nuclear physics research at the University of Oxford and the University of London. His collaborations in these European institutions directly preceded his move to the United States to continue his atomic research.