The Nobel Prize , in the wake of the atomic bombings of Hiroshima and Nagasaki , focused public attention on a subject Muller had been publicizing for two decades - the dangers of radiation . In 1952 , nuclear fallout became a public issue ; since Operation Crossroads , more and more evidence had been leaking out about radiation sickness and death caused by nuclear testing . Muller and many other scientists pursued an array of political activities to defuse the threat of nuclear war . With the Castle Bravo fallout controversy in 1954 , the issue became even more urgent . In 1955 , Muller was one of 11 prominent intellectuals to sign the Russell-Einstein Manifesto , the upshot of which was the first 1957 Pugwash Conference on Science and World Affairs , which addressed the control of nuclear weapons . He was a signatory ( with many other scientists ) of the 1958 petition to the United Nations , calling for an end to nuclear weapons testing , which was initiated by the Nobel Prize-winning chemist Linus Pauling
Castle Bravo
Castle Bravo
Hermann Joseph Muller