Sir Joseph Rotblat, a physicist who received the 1995 Nobel Peace Prize for his work on nuclear disarmament, was born in Poland on this date in 1908. Prior to World War II, the mostly self-taught Rotblat conducted experiments in nuclear fission. When World War II broke out, he was working at Liverpool University under James Chadwick on a particle accelerator and was unable to get his wife out of Warsaw; she perished in the Holocaust. In 1944, Rotblat went with Chadwick’s group to the U.S. to work on the Manhattan Project, but once he saw that Germany had abandoned its own nuclear ambitions (and overheard General Leslie Groves saying that “the real purpose in making the bomb was to subdue the Soviets”), he became the only physicist to leave the Project on grounds of conscience. Soon after the bombing of Hiroshima and Nagasaki, he became an active campaigner against nuclear weapons, focusing his research on the deadly effects of nuclear fallout. Rotblat was a signatory to the Russell-Einstein Manifesto of 1955, which warned against the nuclear arms race, and served as secretary-general of the Pugwash Conferences on Science and World Affairs from its founding in 1957 until 1973. He was also a co-founder of the Stockholm International Peace Research Institute. Rotblat died in 2005.

“The time has come to formulate guidelines for the ethical conduct of scientists, perhaps in the form of a voluntary Hippocratic Oath.” — Joseph Rotblat