Pugwash Conferences on Science and World Affairs
Sir Józef Rotblat (1908–2005), a Polish physicist, who left the US Manhattan Project on grounds of conscience. His work on nuclear fallout was a major contribution toward the ratification of the 1963 Partial Nuclear Test Ban Treaty. A signatory of the Russell–Einstein Manifesto, he was secretary-general of the Pugwash Conferences on Science and World Affairs from their founding until 1973. He shared, with the Pugwash Conferences, the 1995 Nobel Peace Prize for efforts toward nuclear disarmament.