Wolfgang Ernst Pauli
April 25th, 1900 - December 15th, 1958
Nobel Prize winning Physicist
First suggested what is now known as the Pauli Exclusion Principle.
First suggested the existence of the neutrino.
A contemporary of Einstein, Bohr and Heisenberg he was an integral contributor to the fields of theoretical physics and quantum mechanics, specifically quantum field theory.
Wolfgang Pauli was born in Vienna, Austria to Wolfgang Joseph and Berta Camilla Schütz. Wolfgang Joseph, originally a physician trained in Prague, gave up his successful medical practice to train in, and eventually teach, chemistry and physics. Inspired by Ernst Mach to become a physicist, he would give his son the middle name Ernst in his honor. Christened on May 31st, 1900, Ernst Mach was also young Pauli's godfather.
A precocious student, Pauli was reading about Einstein's work in relativity while still attending school at the Döblingen Gymnasium. His self directed studies and lack of attention in class would not prevent him from graduating with distinction at age 18. From the Gymnasium he went on to his undergraduate studies at Ludwig-Maximilian University of Munich where he come under the influential tutelage of Arnold Sommerfeld. While in Munich, Pauli published three papers on the theory of relativity. Quick to recognize his genius, Sommerfeld asked Pauli to write a review of relativity for the Encyclopädie der mathematischen Wissenschaften, a distinct honor for one so young.
Published in 1921, a few months after he received his doctorate, Einstein said of his 237 page monograph on relativity:
"Whoever studies this mature and grandly conceived work might not believe that its author is a twenty-one year old man. One wonders what to admire most, the psychological understanding for the development of ideas, the sureness of mathematical deduction, the profound physical insight, the capacity for lucid, systematical presentation, the knowledge of the literature, the complete treatment of the subject matter, or the sureness of critical appraisal."
Following his graduation in Munich, Pauli was appointed to Göttingen in October, 1921, to be Max Born's assistant. It was during this appointment that he first met Niels Bohr, who was giving a series of lectures on his theoretical investigations on the periodic system of elements. Bohr invited Pauli to join him in Copenhagen, to work at Bohr's Institute. He spent a year there working to explain the anomalous Zeeman effect before moving back to the University in Hamburg to assume a position as a privatdozent (an unsalaried teacher, usually held by young mathematicians or, in his case, physicists). He would remain a lecturer in Hamburg until 1928.
The next few years would see Pauli doing some of his most seminal work. In 1924, stemming from his studies on the Zeeman effect, Pauli proposed a quantum spin number for electrons. In 1925 came his most famous proposition, the Pauli exclusion principle. That same year, Heisenberg published a paper on quantum mechanics which would change everyone's approach to the field. Working with this new knowledge, Pauli would publish the hydrogen spectrum near the end of the year.
Near the end of his appointment in Hamburg a series of distressing events would befall Pauli. The first was the suicide of his mother in 1927. This struck Pauli particularly harshly as he had maintained a very close relationship to his mother. The second blow came when his father remarried, the "evil step-mother", a year later. It was this year he accepted his new post as Professor of Theoretical Physics at the Federal Institute of Technology in Zurich. Shortly after moving to Zurich he married for the first time, one Käthe Margarethe Deppner. It was a brief, unhappy marriage, lasting less than a year.
In 1931, during his first appointment as visiting Professor at the University of Michigan, he predicted, mathematically, the necessity for a new particle, one which he called the 'neutron.' It was not until 1933, however, that he became comfortable enough with his understanding of the particle to publish a paper on it. His paper stated that the particle had zero mass. Those who recall high school physics will recall that the neutron does not have zero mass. The neutron we know today, the particle of no charge residing in the nucleus of atoms, was discovered by James Chadwick in 1932. Pauli's particle would be renamed the neutrino by Enrico Fermi in 1934. It was also during these years, however, that Pauli developed a small problem with drinking and began to consult with Carl Jung. Pauli, a believer in psychology, would later write:
"It is my personal opinion that in the science of the future reality will neither be "psychic" nor "physical" but somehow both and somehow neither."
In 1934 things began to turn around for him when married, on April 4th, Franciska Bertram. His second marriage would prove to be as positive as his first was negative.
In the following years Pauli would go on to work at the Institute for Advanced Study in Princeton, New Jersey as a visiting Professor from 1935 to 1936. He was later elected to the Chair of Theoretical Physics at Princeton in 1940. He also served as a visiting Professor for a second time at the University of Michigan, in 1941 and at Purdue University in 1942.
Finally, in 1945, nominated by none other Albert Einstein, Pauli received the Nobel Prize in Physics for his exclusion principle. Unable to travel to Stockholm until the following year, there was a special ceremony for him at Princeton. He would spend the years following World War II studying the history and philosophy of science, psychology and the relationship between religion and natural science. Aside from the Nobel Prize, Pauli received many other honors, including: being made a Fellow of the Royal Society of London, election as a member of the Swiss Physical Society, the American Physical Society, and the American Association for the Advancement of Science. He also won the Lorentz Medal in 1931.
From his obituary in The Times:
"Pauli was one of the great theoretical physicists of his generation. As an originator of simple yet penetrating ideas he was perhaps the greatest. He was also a man of great charm, known personally to most of his colleagues, and held in great affection as well as admiration by very many - young as well as old. He attained in his later years to a position approaching that of an oracle - one quick of opinion, yet happy as well as willing to change his mind when new facts had been discovered."
For further, related, reading on E2:
Angular Momentum in Quantum Mechanics
Pauli spin matrices
electron spin resonance
Nobel Lectures. Physics 1942-1962, Elsevier Publishing Company, Amsterdam, 1964
and a fantastic article by J. J. O'Connor and E. F. Robertson