Sir Joseph Rotblat was a Polish and British physicist. During World War II he worked on Tube Alloys and the Manhattan Project, but left the Los Alamos Laboratory on grounds of conscience after it became clear to him in 1944 that Germany had ceased development of an atomic bomb. The Nobel Peace Prize 1995, announced October 13, 1995. Joseph Rotblat and Pugwash Conferences on Science and World Affairs, “for their efforts to diminish the part played by nuclear arms in international politics and, in the longer run, to eliminate such arms”. Joseph Rotblat: born 1908, Warsaw, Russian Empire (now Poland). Wiki link Wiki link Data: the Nobel Foundation (CC0).