(Paul) (1902-1995) Hungarian-born US physicist who introduced the notion of parity, or symmetry theory, into nuclear physics, showing that all nuclear processes should be indistinguishable from their mirror images. For this and other work on nuclear structure, he shared the 1963 Nobel Prize for Physics.
The Wigner effect is a rapid rise in temperature in a nuclear reactor pile when, under particle bombardment, such materials as graphite deform, swell, then suddenly release large amounts of energy. This was the cause of the fire at the British Windscale plant 1957.
Educated at the Lutheran Gymnasium in Budapest, Wigner took up postgraduate studies in Berlin where he was present at Albert Einstein's seminars in the 1920s. He emigrated to the US in 1930, and became a US citizen 1937. He was one of the scientists who persuaded President Roosevelt to commit the US to developing the atomic bomb. In 1960, he was awarded the Atoms for Peace Award, in recognition of his vigorous support for the peaceful use of atomic energy. He taught as a professor of mathematics at Princeton University for 40 years until his retirement 1971.