Wolfgang Ernst Pauli
Pauli in 1945
Born	Wolfgang Ernst Pauli (1900-04-25)25 April 1900 Vienna, Austria-Hungary
Died	15 December 1958(1958-12-15) (aged 58) Zürich, Switzerland
Citizenship	Austria United States Switzerland
Alma mater	University of Munich
Known for	Pauli exclusion principle Pauli matrices Pauli effect Pauli equation Pauli group Pauli repulsion Pauli paramagnetism Pauli's conjecture Pauli–Jordan function Pauli–Jung conjecture Pauli–Lubanski pseudovector Pauli–Villars regularization Fierz–Pauli–Kofink identities Lüders–Pauli theorem Aufbau principle Massive gravity Neutrino Quantum field theory
Relatives	Wolfgang Joseph Pauli (father) Hertha Pauli (sister)
Awards	Lorentz Medal (1931) Nobel Prize in Physics (1945) Franklin Medal (1952) ForMemRS (1953)[1] Matteucci Medal (1956) Max Planck Medal (1958)
Scientific career
Fields	Theoretical physics
Institutions	University of Göttingen University of Copenhagen University of Hamburg ETH Zurich Institute for Advanced Study
Thesis	About the Hydrogen Molecular Ion Model[2] (1921)
Doctoral advisor	Arnold Sommerfeld[2][1]
Other academic advisors	Max Born[3]
Doctoral students	Nicholas Kemmer[2] José Leite Lopes Felix Villars Charles Enz
Other notable students	Markus Fierz Sigurd Zienau Hans Frauenfelder[2]
Signature
Notes
His godfather was Ernst Mach. He is not to be confused with Wolfgang Paul, who called Pauli his "imaginary part",[4] a pun with the imaginary unit i.

Wolfgang Ernst Pauli (/ˈpɔːli/;^[5] German: [ˈvɔlfɡaŋ ˈpaʊli]; 25 April 1900 – 15 December 1958) was an Austrian theoretical physicist and one of the pioneers of quantum physics. In 1945, after having been nominated by Albert Einstein,^[6] Pauli received the Nobel Prize in Physics for his "decisive contribution through his discovery of a new law of Nature, the exclusion principle or Pauli principle". The discovery involved spin theory, which is the basis of a theory of the structure of matter.

Early life

Pauli was born in Vienna to a chemist, Wolfgang Joseph Pauli (né Wolf Pascheles, 1869–1955), and his wife, Bertha Camilla Schütz; his sister was Hertha Pauli, a writer and actress. Pauli's middle name was given in honor of his godfather, physicist Ernst Mach. Pauli's paternal grandparents were from prominent Jewish families of Prague; his great-grandfather was the Jewish publisher Wolf Pascheles.^[7] Pauli's mother, Bertha Schütz, was raised in her mother's Roman Catholic religion; her father was Jewish writer Friedrich Schütz. Pauli was raised as a Roman Catholic.^[8]

Pauli attended the Döblinger-Gymnasium in Vienna, graduating with distinction in 1918. Two months later, he published his first paper, on Albert Einstein's theory of general relativity. He attended the University of Munich, working under Arnold Sommerfeld,^[1] where he received his PhD in July 1921 for his thesis on the quantum theory of ionized diatomic hydrogen (H⁺
₂).^[2][9]

Career

Sommerfeld asked Pauli to review the theory of relativity for the Encyklopädie der mathematischen Wissenschaften (Encyclopedia of Mathematical Sciences). Two months after receiving his doctorate, Pauli completed the article, which came to 237 pages. Einstein praised it; published as a monograph, it remains a standard reference on the subject.^[10]

Wolfgang Pauli lecturing (1929)

Pauli spent a year at the University of Göttingen as the assistant to Max Born, and the next year at the Institute for Theoretical Physics in Copenhagen (later the Niels Bohr Institute).^[1] From 1923 to 1928, he was a professor at the University of Hamburg.^[11] 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.

In 1928, Pauli was appointed Professor of Theoretical Physics at ETH Zurich in Switzerland.^[1] He was awarded the Lorentz Medal in 1930.^[12] He held visiting professorships at the University of Michigan in 1931 and the Institute for Advanced Study in Princeton in 1935.

Scientific research

Part of a series of articles about
Quantum mechanics
${\displaystyle i\hbar {\frac {\partial }{\partial t}}|\psi (t)\rangle ={\hat {H}}|\psi (t)\rangle }$ Schrödinger equation
Introduction Glossary History
Background Classical mechanics Old quantum theory Bra–ket notation Hamiltonian Interference
Fundamentals Complementarity Decoherence Entanglement Energy level Measurement Nonlocality Quantum number State Superposition Symmetry Tunnelling Uncertainty Wave function Collapse
Experiments Bell's inequality Davisson–Germer Double-slit Elitzur–Vaidman Franck–Hertz Leggett–Garg inequality Mach–Zehnder Popper Quantum eraser Delayed-choice Schrödinger's cat Stern–Gerlach Wheeler's delayed-choice
Formulations Overview Heisenberg Interaction Matrix Phase-space Schrödinger Sum-over-histories (path integral)
Equations Dirac Klein–Gordon Pauli Rydberg Schrödinger
Interpretations Bayesian Consistent histories Copenhagen de Broglie–Bohm Ensemble Hidden-variable Local Superdeterminism Many-worlds Objective collapse Quantum logic Relational Transactional Von Neumann–Wigner
Advanced topics Relativistic quantum mechanics Quantum field theory Quantum information science Quantum computing Quantum chaos EPR paradox Density matrix Scattering theory Quantum statistical mechanics Quantum machine learning
Scientists Aharonov Bell Bethe Blackett Bloch Bohm Bohr Born Bose de Broglie Compton Dirac Davisson Debye Ehrenfest Einstein Everett Fock Fermi Feynman Glauber Gutzwiller Heisenberg Hilbert Jordan Kramers Pauli Lamb Landau Laue Moseley Millikan Onnes Planck Rabi Raman Rydberg Schrödinger Simmons Sommerfeld von Neumann Weyl Wien Wigner Zeeman Zeilinger

Paul Dirac, Wolfgang Pauli and Rudolf Peierls, c 1953

Pauli made many important contributions as a physicist, primarily in the field of quantum mechanics. He seldom published papers, preferring lengthy correspondences with colleagues such as Niels Bohr from the University of Copenhagen in Denmark and Werner 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. In 1921 Pauli worked with Bohr to create the Aufbau Principle, which described building up electrons in shells based on the German word for building up, as Bohr was also fluent in German.

Pauli proposed in 1924 a new quantum degree of freedom (or quantum number) with two possible values, 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, identified by four quantum numbers including his new two-valued degree of freedom. The idea of spin originated with Ralph Kronig. A year later, George Uhlenbeck and Samuel Goudsmit identified Pauli's new degree of freedom as electron spin, in which Pauli for a very long time wrongly refused to believe.^[18]

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.

Pauli introduced the 2×2 Pauli matrices as a basis of spin operators, thus solving the nonrelativistic theory of spin. This work, including the Pauli equation, is sometimes said to have influenced Paul Dirac in his creation of the Dirac equation for the relativistic electron, though Dirac said that he invented these same matrices himself independently at the time. Dirac invented similar but larger (4x4) spin matrices for use in his relativistic treatment of fermionic spin.

In 1930, Pauli considered the problem of beta decay. In a letter of 4 December to Lise Meitner et al., beginning, "Dear radioactive ladies and gentlemen", he proposed the existence of a hitherto unobserved neutral particle with a small mass, no greater than 1% the mass of a proton, to explain the continuous spectrum of beta decay. In 1934, Enrico Fermi incorporated the particle, which he called a neutrino, "little neutral one" in Fermi's native Italian, into his theory of beta decay. The neutrino was first confirmed experimentally in 1956 by Frederick Reines and Clyde Cowan, two and a half years before Pauli's death. On receiving the news, he replied by telegram: "Thanks for message. Everything comes to him who knows how to wait. Pauli."^[19]

In 1940, Pauli re-derived the spin-statistics theorem, a critical result of quantum field theory that states that particles with half-integer spin are fermions, while particles with integer spin are bosons.

In 1949, he published a paper on Pauli–Villars regularization: regularization is the term for techniques that modify infinite mathematical integrals to make them finite during calculations, so that one can identify whether the intrinsically infinite quantities in the theory (mass, charge, wavefunction) form a finite and hence calculable set that can be redefined in terms of their experimental values, which criterion is termed renormalization, and which removes infinities from quantum field theories, but also importantly allows the calculation of higher-order corrections in perturbation theory.

Pauli made repeated criticisms of the modern synthesis of evolutionary biology,^[20][21] and his contemporary admirers point to modes of epigenetic inheritance as supporting his arguments.^[22]

Paul Drude in 1900 proposed the first theoretical model for a classical electron moving through a metallic solid. Drude's classical model was also augmented by Pauli and other physicists. Pauli realized that the free electrons in metal must obey the Fermi–Dirac statistics. Using this idea, he developed the theory of paramagnetism in 1926. Pauli said, “Festkörperphysik ist eine Schmutzphysik”—solid-state physics is the physics of dirt.^[23]

Pauli was elected a Foreign Member of the Royal Society (ForMemRS) in 1953 and president of the Swiss Physical Society in 1955 for two years.^[1] In 1958 he became a foreign member of the Royal Netherlands Academy of Arts and Sciences.^[24]

Personality and friendships

Wolfgang Pauli, ca. 1924

The Pauli effect was named after his anecdotal bizarre ability to break experimental equipment simply by being in its vicinity. Pauli was aware of his reputation and was delighted whenever the Pauli effect manifested. These strange occurrences were in line with his controversial investigations into the legitimacy of parapsychology, particularly his collaboration with C. G. Jung on synchronicity.^[25] Max Born considered Pauli "only comparable to Einstein himself... perhaps even greater". Einstein declared Pauli his "spiritual heir".^[26]

Pauli was famously a perfectionist. This extended not just to his own work, but also to that of his colleagues. As a result, he became known in 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 wrong".

But this was not his most severe criticism, which he reserved for theories or theses so unclearly presented as to be untestable or unevaluatable and thus not properly belonging within the realm of science, even though posing as such. They were worse than wrong because they could not be proved wrong. Famously, he once said of such an unclear paper: "It is not even wrong!"^[1]

His supposed remark when meeting another leading physicist, Paul Ehrenfest, illustrates this notion of an arrogant Pauli. The two met at a conference for the first time. Ehrenfest was familiar with Pauli's papers and quite impressed with them. After a few minutes of conversation, Ehrenfest remarked, "I think I like your Encyclopedia article [on relativity theory] better than I like you," to which Pauli retorted, "That's strange. With me, regarding you, it is just the opposite."^[27] The two became very good friends from then on.

A somewhat warmer picture emerges from this story, which appears in the article on Dirac:

Werner Heisenberg [in Physics and Beyond, 1971] recollects a friendly conversation among young participants at the 1927 Solvay Conference, about Einstein and Planck's views on religion. Wolfgang Pauli, Heisenberg, and Dirac took part in it. Dirac's contribution was a poignant and clear criticism of the political manipulation of religion, that was much appreciated for its lucidity by Bohr, when Heisenberg reported it to him later. Among other things, Dirac said: "I cannot understand why we idle discussing religion. If we are honest – and as scientists honesty is our precise duty – we cannot help but admit that any religion is a pack of false statements, deprived of any real foundation. The very idea of God is a product of human imagination. [ ... ] I do not recognize any religious myth, at least because they contradict one another. [ ... ]" Heisenberg's view was tolerant. Pauli had kept silent, after some initial remarks. But when finally he was asked for his opinion, jokingly he said: "Well, I'd say that also our friend Dirac has got a religion and the first commandment of this religion is 'God does not exist and Paul Dirac is his prophet'". Everybody burst into laughter, including Dirac.^[28]

Many of Pauli's ideas and results were never published and appeared only in his letters, which were often copied and circulated by their recipients. Pauli may have been unconcerned that much of his work thus went uncredited, but when it came to Heisenberg's world-renowned 1958 lecture at Göttingen on their joint work on a unified field theory, and the press release calling Pauli a mere "assistant to Professor Heisenberg", Pauli became offended, denouncing Heisenberg's physics prowess. The deterioration of their relationship resulted in Heisenberg ignoring Pauli's funeral, and writing in his autobiography that Pauli's criticisms were overwrought, though ultimately the field theory was proved untenable, validating Pauli's criticisms.^[29]

Philosophy

In his discussions with Carl Jung, Pauli developed an ontological theory that has been dubbed the "Pauli–Jung Conjecture" and has been seen as a kind of dual-aspect theory. The theory holds that there is "a psychophysically neutral reality" and that mental and physical aspects are derivative of this reality.^[30] Pauli thought that elements of quantum physics pointed to a deeper reality that might explain the mind/matter gap and wrote, "we must postulate a cosmic order of nature beyond our control to which both the outward material objects and the inward images are subject."^[31]

Pauli and Jung held that this reality was governed by common principles ("archetypes") that appear as psychological phenomena or as physical events.^[32] They also held that synchronicities might reveal some of this underlying reality's workings.^[32][31]

Beliefs

He is considered to have been a deist and a mystic. In No Time to Be Brief: A Scientific Biography of Wolfgang Pauli he is quoted as writing to science historian Shmuel Sambursky, "In opposition to the monotheist religions – but in unison with the mysticism of all peoples, including the Jewish mysticism – I believe that the ultimate reality is not personal."^[33][34]

Personal life

Bust of Wolfgang Pauli (1962)

In 1929, Pauli married Käthe Margarethe Deppner, a cabaret dancer.^[35] The marriage was unhappy, ending in divorce after less than a year. He married again in 1934 to Franziska Bertram (1901–1987). They had no children.

Death

Pauli died of pancreatic cancer on December 15, 1958, at age 58.^[16][17]

Bibliography

• Pauli, Wolfgang; Jung, C. G. (1955). The Interpretation of Nature and the Psyche. Ishi Press. ISBN 978-4-87187-713-8.
• Pauli, Wolfgang (1981). Theory of Relativity. New York: Dover Publications. ISBN 978-0-486-64152-2.
• Pauli, Wolfgang; Jung, C. G. (2001). C. A. Meier (ed.). Atom and Archetype, The Pauli/Jung Letters, 1932–1958. Princeton, NJ: Princeton University Press. ISBN 978-0-691012-07-0.

See also

• List of Jewish Nobel laureates

References

Further reading

• Enz, Charles P. (2002). No Time to be Brief: A Scientific Biography of Wolfgang Pauli. Oxford Univ. Press.
• Enz, Charles P. (1995). "Rationales und Irrationales im Leben Wolfgang Paulis". In H. Atmanspacher; et al. (eds.). Der Pauli-Jung-Dialog. Berlin: Springer-Verlag.
• Fischer, Ernst Peter (2004). Brücken zum Kosmos. Wolfgang Pauli – Denkstoffe und Nachtträume zwischen Kernphysik und Weltharmonie. Libelle. ISBN 978-3-909081-44-8.
• Gieser, Suzanne (2005). The Innermost Kernel. Depth Psychology and Quantum Physics. Wolfgang Pauli's Dialogue with C.G. Jung. Springer Verlag.
• Jung, C.G. (1980). Psychology and Alchemy. Princeton, New Jersey: Princeton Univ. Press.
• Keve, Tom (2000). Triad: the physicists, the analysts, the kabbalists. London: Rosenberger & Krausz.
• Lindorff, David (1994). Pauli and Jung: The Meeting of Two Great Minds. Quest Books.
• Pais, Abraham (2000). The Genius of Science. Oxford: Oxford University Press. ISBN 978-0-19-850614-0.
• Enz, P.; von Meyenn, Karl, eds. (1994). Wolfgang Pauli – Writings on Physics and Philosophy. Translated by Schlapp, Robert. Berlin: Springer Verlag. ISBN 978-3-540-56859-9.
• Laurikainen, K. V. (1988). Beyond the Atom – The Philosophical Thought of Wolfgang Pauli. Berlin: Springer Verlag. ISBN 978-0-387-19456-1.
• Casimir, H. B. G. (1983). Haphazard Reality: Half a Century of Science. New York: Harper & Row. ISBN 978-0-06-015028-0.
• Casimir, H. B. G. (1992). Het toeval van de werkelijkheid: Een halve eeuw natuurkunde. Amsterdam: Meulenhof. ISBN 978-90-290-9709-3.
• Miller, Arthur I. (2009). Deciphering the Cosmic Number: The Strange Friendship of Wolfgang Pauli and Carl Jung. New York: W.W. Norton & Co. ISBN 978-0-393-06532-9.
• Remo, F. Roth: Return of the World Soul, Wolfgang Pauli, C.G. Jung and the Challenge of Psychophysical Reality [unus mundus], Part 1: The Battle of the Giants. Pari Publishing, 2011, ISBN 978-88-95604-12-1.
• Remo, F. Roth: Return of the World Soul, Wolfgang Pauli, C.G. Jung and the Challenge of Psychophysical Reality [unus mundus], Part 2: A Psychophysical Theory. Pari Publishing, 2012, ISBN 978-88-95604-16-9.

External links

Wikiquote has quotations related to Wolfgang Pauli.

Wikimedia Commons has media related to Wolfgang Pauli.

• Publications by and about Wolfgang Pauli in the catalogue Helveticat of the Swiss National Library
• Wolfgang Pauli on Nobelprize.org
• Pauli bio at the University of St Andrews, Scotland
• Wolfgang Pauli bio at "Nobel Prize Winners"
• Wolfgang Pauli, Carl Jung and Marie-Louise von Franz
• Virtual walk-through exhibition of the life and times of Pauli
• Annotated bibliography for Wolfgang Pauli from the Alsos Digital Library for Nuclear Issues Archived 28 August 2006 at the Wayback Machine
• Pauli Archives at CERN Document Server
• Virtual exhibition Archived 10 June 2016 at the Wayback Machine at ETH-Bibliothek, Zürich
• Key Participants: Wolfgang Pauli – Linus Pauling and the Nature of the Chemical Bond: A Documentary History
• Pauli's letter (December 1930) Archived 15 March 2016 at the Wayback Machine, the hypothesis of the neutrino (online and analyzed, for English version click 'Télécharger')
• Pauli exclusion principle with Melvyn Bragg, Frank Close, Michela Massimi, Graham Farmelo "In Our Time 6 April 2017"