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This article is about Austrian-American physicist Wolfgang Pauli. You may be looking for German physicist Wolfgang Paul, co-developer of the ion trap.
Wolfgang Ernst Pauli (April 25, 1900 – December 15, 1958) was an Austrian-American physicist noted for his work on the theory of
spin.
Biography
Pauli was born in Vienna to Wolfgang Joseph Pauli and Berta Camilla Schütz. His
middle name was given in honor of his godfather, the physicist Ernst Mach.
Pauli attended the Döblinger Gymnasium in Vienna, graduating with distinction in 1918. Only two months after graduation, he
had published his first paper, on Einstein's theory of general
relativity. He attended the Ludwig-Maximilian University of Munich, working under Sommerfeld, where he received his doctorate in July 1921 for a thesis on the quantum theory of
ionised molecular hydrogen.
Sommerfeld asked Pauli to review relativity for the Encyklopaedie der
mathematischen Wissenschaften, a German encyclopedia. Two months after
receiving his doctorate, Pauli completed the article, which came to 237 pages. It was praised by Einstein; published as a monograph, it remains a standard reference on the subject to this day.
He spent a year at the University of Göttingen
as the assistant to Max Born, and the following year at what became the Niels Bohr Institute for Theoretical Physics in Copenhagen. He then spent 1923 to 1928 as a lecturer at the University of Hamburg. During this period, Pauli was instrumental in the
development of the modern theory of quantum mechanics. In
particular, he formulated the exclusion principle
and the theory of nonrelativistic spin. (See below for a list of
his scientific contributions.)
In May 1929, Pauli left the Roman Catholic Church; in December that year, he married
Käthe Margarethe Deppner. The marriage was an unhappy one, ending in divorce in 1930 after
less than a year.
In 1928, he was appointed Professor of Theoretical Physics at the Federal Institute of Technology in Zurich, Switzerland. He held visiting professorships at the University of Michigan in 1931, and the Institute for Advanced Study at Princeton in 1935.
In 1934, he married Franciska Bertram. This marriage would last for the rest of his
life. They had no children.
The German annexation of Austria in 1938 made him a German citizen, which became a
difficulty with the outbreak of the Second World War in 1939. Pauli moved to the United States in 1940, where he was
Professor of Theoretical Physics at Princeton. After the end of the war in 1945, he
returned to Zurich, where he mostly remained for the rest of his life.
Also in 1945, he received the Nobel
Prize in Physics for his "decisive contribution through his discovery in 1925 of a new law of Nature, the exclusion principle
or Pauli principle." He had been nominated for the prize by Einstein.
Pauli died in Zürich.
Scientific Career
Pauli made many important contributions in his career as a physicist, primarily in the subject of quantum mechanics. He seldom published papers, preferring lengthy
correspondences with colleagues (such as Bohr and Heisenberg, with whom he had close friendships.) Many of his ideas and
results were never published and appeared only in his letters, which were often copied and circulated by their recipients. Pauli
was apparently unconcerned that much of his work thus went uncredited. The following are the most important results for which he
has been credited:
In 1924, Pauli proposed a new quantum degree of freedom to resolve inconsistencies
between observed molecular spectra and the developing theory of quantum mechanics. He formulated the Pauli exclusion principle, perhaps his most important work, which stated that no two electrons
could exist in the same quantum state. Uhlenbeck and Goudsmit later identified this degree of freedom as electron spin.
In 1926, shortly after Heisenberg published the matrix theory of modern quantum mechanics, Pauli used it to derive the observed spectrum of the hydrogen atom. This result was important in securing credibility for Heisenberg's theory.
In 1927, he introduced the Pauli
matrices as a basis of spin operators, thus solving the nonrelativistic theory of spin. This work influenced Dirac in his discovery of the Dirac equation for the relativistic electron.
In 1931, he proposed the existence of a hitherto unobserved neutral and massless
particle, in order to explain the continuous spectrum of beta decay. In
1934, Fermi incorporated the
particle, which he called a neutrino, into his theory of radioactive decay. The
neutrino was first observed experimentally in 1959.
In 1940, he proved the spin-statistics theorem, a critical result of quantum mechanics which states that particles with
half-integer spin are fermions, while particles with integer spin are bosons.
Personality and Reputation
The Pauli Effect was named after his bizarre ability to break
experimental equipment simply by being in the vicinity. Pauli himself was aware of his reputation, and delighted whenever the
Pauli Effect manifested.
Regarding physics, Pauli was famously perfectionist. This extended not just to his own work, but also to the work of his
colleagues. As a result, he became known within the physics community as the "conscience of physics", the critic to whom his
colleagues were accountable. He could be scathing in his dismissal of any theory he found lacking, often labelling it ganz
falsch, utterly false. Famously, he once said of one such paper: "This isn't right. It isn't even wrong."
According to a story well known in the physics community, after his death in 1958 Pauli was granted an audience with God. Pauli asked God why the fine structure constant has the value 1/(137.036...). God nodded, went to a blackboard, and began
scribbling equations at a furious pace. Pauli watched Him with great satisfaction, but soon began shaking his head
violently...
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