Eugene Paul Wigner
1902–1995, Budapest, Austria-Hungary, Princeton, New Jersey, USA
Hungarian-American theoretical physicist who established the role of symmetry and group theory in quantum mechanics and nuclear physics.
Trained as a chemical engineer in Berlin alongside Leo Szilard, Wigner brought the mathematics of group theory into quantum mechanics in the late 1920s, a move initially derided as the 'Gruppenpest' but which became foundational. In the United States he developed the theory of nuclear reactions — the Wigner-Eisenbud R-matrix — and contributed decisively to the design of the first nuclear reactors at Chicago.
Nobel-winning work
Wigner received half of the 1963 Nobel Prize for 'his contributions to the theory of the atomic nucleus and the elementary particles, particularly through the discovery and application of fundamental symmetry principles'. Beginning with his 1927 work on conservation laws, he showed that invariance under reflections, rotations and time reversal dictates the allowed states and transitions of quantum systems.
His classification of nuclear states by the representations of symmetry groups — notably the Wigner supermultiplet SU(4) theory of nuclear forces — turned group theory into the basic language of nuclear and particle physics, a path later followed by the quark model.
Workplaces: Princeton University
United States, Hungary