A tanner’s son in Budapest
Jenő Pál Wigner, later Eugene Paul Wigner, was born in Budapest on 17 November 1902, the middle of three children of Antal Wigner, the director of a leather-tanning factory, and Erzsébet (Elisabeth) Einhorn. His parents were middle-class Jews who did not practise their religion; his bar mitzvah was a secular one. His younger sister Margit, ‘Manci’, would one day marry the British physicist Paul Dirac.
Jenő was taught at home until he was nine. At eleven, doctors wrongly diagnosed tuberculosis and sent him to a sanatorium in the Austrian mountains for six weeks. Lying on a deck chair for days on end, he later recalled, he worked terribly hard on a geometry problem, constructing a triangle from its three altitudes. The mistaken diagnosis gave the world a mathematician.
The Lutheran Gymnasium and the ‘Martians’
From 1915 he attended the Fasori Lutheran Gymnasium in Budapest, the school his father had attended. Religious instruction was compulsory, and as a Jewish pupil he took classes in Judaism from a rabbi. One year below him was János, later John, von Neumann. Both were taught by the legendary mathematics teacher László Rátz. Wigner admired von Neumann’s mathematical gifts but felt he himself knew more physics. With Leó Szilárd, Edward Teller and others, they would later be counted among the ‘Martians’, the extraordinary generation of Hungarian Jewish scientists who transformed twentieth-century physics.
In 1919, when Béla Kun’s short-lived communist regime took power in Hungary, the family fled briefly to Austria. After their return, partly in reaction to the prominent role of Jews in the Kun regime, the family converted to Lutheranism. Wigner later explained that the decision ‘was not at heart a religious decision but an anti-communist one’, and described himself as only mildly religious.
Berlin: chemistry, colloquia and friendship
His father wanted him in the tannery, and so Wigner studied chemical engineering, first in Budapest and from 1921 at the Technische Hochschule in Berlin. He went to few lectures but worked hard in the laboratory, and on Wednesday afternoons attended the physics colloquia where Max Planck, Max von Laue, Walther Nernst, Wolfgang Pauli, Werner Heisenberg and Albert Einstein discussed the latest ideas. In Berlin he met Leó Szilárd, who became his closest friend, and Michael Polanyi, who supervised his doctoral thesis on the formation and decay of molecules, completed in 1925.
Wigner returned dutifully to Budapest to work in his father’s tannery, but he did not feel it was his life. In 1926 an invitation to become assistant to the crystallographer Karl Weissenberg at the Kaiser Wilhelm Institute brought him back to Berlin, and to the problem that would define his career.
Symmetry: the hidden order of quantum mechanics
Weissenberg wanted to know why atoms in crystals sit at positions matching the crystal’s axes of symmetry. Wigner realised that the answer lay in group theory, the branch of mathematics that describes symmetry. With von Neumann’s advice, he applied it to the new quantum mechanics, showing how the symmetries of an atom determine the structure of its spectrum. In 1927 he introduced the quantum concept of parity, the behaviour of a system under mirror reflection, and the mathematical objects now called Wigner D-matrices.
In 1931 he published Group Theory and Its Application to the Quantum Mechanics of Atomic Spectra, which made these tools usable by a generation of physicists, and proved what is now known as Wigner’s theorem: any physical symmetry, such as a rotation or translation, must be represented in quantum mechanics by a particular kind of mathematical transformation. Together with Hermann Weyl, he made symmetry one of the organising principles of modern physics, from atomic spectra to particle physics. After a year as assistant to the aged David Hilbert in Göttingen, he returned to teach in Berlin.
Princeton and the atomic nucleus
In 1930 Princeton University recruited Wigner and von Neumann at once, offering Wigner a salary seven times what he earned in Europe; the two anglicised their names to Eugene and John. For a few years Wigner divided his time between Princeton and Berlin, until Hitler came to power in 1933 and Jewish-born scholars were driven from German universities. Wigner settled in the United States and became an American citizen on 8 January 1937. He brought his parents to America.
He turned to the atomic nucleus, developing theories of nuclear forces and nuclear reactions. At the University of Wisconsin he married the physicist Amelia Frank, who died the following year, in 1937, leaving him distraught. In 1938 he returned to Princeton as Thomas D. Jones Professor of Mathematical Physics, a chair he held until 1971. In 1941 he married Mary Annette Wheeler, a physicist at Vassar College; they had two children, David and Martha.
Warning Roosevelt, building reactors
Wigner knew what nuclear fission might mean, and he feared that Nazi Germany would build an atomic bomb first. On 2 August 1939 he took part, with Szilárd, in the meeting with Albert Einstein that produced the Einstein–Szilárd letter to President Franklin D. Roosevelt, which led to the first American government committee on uranium. He was so afraid of a German victory that he refused to have his fingerprints taken, lest they be used to track him down. ‘Thoughts of being murdered’ he later recalled, ‘focus your mind wonderfully.’
During the Manhattan Project, at the University of Chicago’s Metallurgical Laboratory, he led the team that designed the huge production reactors to turn uranium into plutonium for bombs, at a time when no reactor had yet operated. He was present on 2 December 1942 when Chicago Pile-1 achieved the first controlled nuclear chain reaction. He discovered the ‘Wigner effect’, the swelling of graphite moderators under neutron bombardment, which became a serious problem for the Hanford reactors after the war. With Leonard Eisenbud he developed the R-matrix theory of nuclear reactions, and with Alvin Weinberg he later wrote a standard text on reactor theory. Wigner said he did not regret helping to build the bomb; his regret was that it had not been done sooner.
Nobel Prize and the unreasonable effectiveness of mathematics
In 1946–47 Wigner was director of research and development at Clinton Laboratories, now Oak Ridge National Laboratory, but he disliked administration and the Atomic Energy Commission’s bureaucracy and returned to Princeton. He served on the AEC’s influential General Advisory Committee from 1952 to 1957 and again from 1959 to 1964.
In 1963 he received half of the Nobel Prize in Physics ‘for his contributions to the theory of the atomic nucleus and the elementary particles, particularly through the discovery and application of fundamental symmetry principles’, sharing the prize with Maria Goeppert Mayer and J. Hans D. Jensen. He remarked that he had never expected to get his name in the newspapers without doing something wicked.
His 1960 essay ‘The Unreasonable Effectiveness of Mathematics in the Natural Sciences’ asked why abstract mathematics describes the physical world so astonishingly well, and it still provokes responses from physicists, computer scientists, biologists and economists. He also proposed the ‘Wigner’s friend’ thought experiment, arguing that consciousness plays a role in quantum measurement, a view that remains controversial.
A Cold Warrior
Wigner’s experience of communism in Hungary and of Nazism made him a committed anti-communist. He became a leading advocate of civil defence, arguing in 1963 that a tenth of the US defence budget should go to blast shelters and survival supplies, and he believed America could recover from a nuclear attack faster than Germany had recovered from the Second World War. In later years his political associations drew criticism: he became a prominent defender of the Unification Church’s International Conference on the Unity of the Sciences and was listed on the advisory board of the right-wing Western Goals Foundation.
Jewish origins and legacy
Wigner was born Jewish, converted with his family to Lutheranism as a teenager for reasons he described as political rather than religious, and practised little religion of any kind. Yet his life followed the path of so many Jewish-born scientists of Central Europe: excluded from German academia by Nazi race laws, welcomed by the United States, and driven by fear of Hitler to help build the weapon that ended the war. In 1982 he received the Herzl Prize.
After Mary’s death in 1977 he married Eileen (Pat) Hamilton in 1979. He published his memoirs in 1992, at the age of ninety, and died of pneumonia in Princeton on 1 January 1995. Wigner’s ideas about symmetry run through all of modern physics, from the classification of elementary particles to quantum computing; Wigner functions, Wigner’s theorem and Wigner’s friend keep his name in daily use, and his reactor designs helped launch the nuclear age.
Sources & further reading
Eugene Wigner, Wikipedia · Eugene Wigner, Biographical (Nobel Prize) · Eugene Paul Wigner, MacTutor History of Mathematics, University of St Andrews · Eugene Wigner, Jewish Virtual Library · Researched from the sources above and checked against them. Spotted an error? Tell us.
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