Murray Gell-Mann

Physicist

• Born: September 15, 1929
• Birthplace: New York, New York
• Died: May 24, 2019
• Place of death: Santa Fe, New Mexico

American physicist

Twentieth-century American physicist Murray Gell-Mann earned fame for his discovery of the subatomic particles known as quarks and for developing the theory of elementary particles. In 1969, he was awarded the Nobel Prize in Physics.

Primary field: Physics

Specialties: Atomic and molecular physics; theoretical physics

Early Life

Murray Gell-Mann was born on September 15, 1929, in New York City. His mother and father had emigrated from the Austro-Hungarian Empire before the start of the World War I. Gell-Mann demonstrated superior intellectual abilities at a very young age. A child prodigy, he learned multiple languages on his own, including German, Latin, and Greek, and was fascinated with natural history and ornithology. He graduated from the Columbia Grammar and Preparatory School and enrolled at Yale University's Jonathan Edwards College at age fifteen.

At Yale, Gell-Mann became passionately interested in physics, and his professors marked him as a student of great potential. Upon graduation, Gell-Mann applied to several Ivy League schools for graduate work, but was accepted only at the Massachusetts Institute of Technology. After finishing his dissertation on quantum physics there in 1951, he went on to work at the Institute for Advanced Study at Princeton University, alongside physicists Robert Oppenheimer and Albert Einstein.

In 1952, Gell-Mann accepted an offer from the University of Chicago to study under renowned physicist Enrico Fermi. At Chicago, Gell-Mann made his first great discovery. For several years, particle detectors had been collecting strange cosmic rays that seemed to defy the laws of physics. In particle accelerator and "atom-smashing" experiments, these particles lingered for roughly a hundredth of a millionth of a second in the detectors. Physicists were baffled, and many suspected there was an underlying order to these renegade particles.

Gell-Mann studied the particles and soon worked out their physical properties, which were so rare that Gell-Mann termed them "strangeness." He also predicted that other "strange particles" would be detected, and accurately described their composition. After uncovering the identity of these additional particles, Gell-Mann established his position as a leading scientist of the day. In 1955, he accepted a position at the California Institute of Technology in Pasadena, California. He moved there with his wife and soon embarked upon an intense collaboration with physicist Richard Feynman.

Life's Work

Gell-Mann and Feynman were two of the most enterprising young physicists of their generation. Highly intelligent and incredibly ambitious, the men spent long hours working together. In 1957, Gell-Mann and Feynman were competing to publish the same theory on the weak nuclear force. Eventually, they agreed to publish a joint paper. The theory, known as the V-minus-A model, was well received, but the competing personalities and ambitions of the two men led to disagreements. In 1959, Gell-Mann took a sabbatical in Europe.

During his time in Europe, Gell-Mann continued to study the "strange particles" he had discovered at the University of Chicago, and whose seeming randomness continued to baffle scientists. Gell-Mann turned to mathematics to explain the random groupings. Through long hours of calculations in the mathematical field of group theory, he detected an order to the strange particles. He called his theory the "Eightfold Way," a reference to Buddhism's eight-step plan for righteous living. This theory grouped the strange particles into eight families that could be predicted accurately through experimentation. Gell-Mann shared credit for his idea with Israeli physicist Yuval Ne'eman.

Gell-Mann realized the eight member families of strange particles were actually composed of one basic particle that varied according to its quantum number. He figured out that this basic particle was the building block of atoms. Gell-Mann called these particles "quarks," taking the term from the experimental language of James Joyce's 1939 novel Finnegan's Wake.

Quarks were discovered simultaneously by George Zweig at the European Center for Nuclear Research in Zurich, Switzerland. In 1964, the two men published a joint paper on the existence of quarks. The scientific world was divided about the theory. Some, including Feynman, were dismissive, but other physicists began to incorporate the idea into their own work.

Gell-Mann had stressed that it would be impossible to observe quarks separate from the atom, but experiments with particle accelerators soon detected that electrons shot into an atom were bouncing off something small and elemental in the proton. Physicists theorized these were the quarks from Gell-Mann's calculations, and experiments proved that atoms were composed of subatomic particles. After more than two thousand years of speculation by scientists, Gell-Mann had helped discover the fundamental building blocks of atoms.

In recognition of his work with elementary particles, Gell-Mann was awarded the Nobel Prize in Physics in 1969.

Impact

The discovery of the quark led to the development of the new scientific field of quantum chromodynamics. Gell-Mann became one of the leading innovators in the field, and helped classify numerous types of quarks. By classifying and understanding the structure and groupings of quarks, Gell-Mann and other scientists were able to explore the fundamentals of matter. As a result, many modern physicists worked on a unified field theory, which attempts to explain all of the interactions and behaviors of elementary particles and other forms of matter.

In the years after winning the Nobel Prize, Gell-Mann became increasingly interested in "complexity theory," a branch of science that explores how elaborate forms such as the human brain or biological cells can evolve from the function of a few simple physical laws. In essence, complexity theory attempts to understand why life exists rather than not.

Gell-Mann helped found the Santa Fe Institute, a think tank dedicated to bringing together scientists and intellectuals for further research into complexity theory. In 1994, in an effort to present complexity theory to the public, Gell-Mann published The Quark and the Jaguar. The book develops his ideas on complexity, and illustrates the way life begins from simple building blocks such as quarks but can eventually grow to become a complex life form.

Gell-Mann became one of the most respected physicists in the scientific world. He was involved in many of the most significant physics discoveries in the second half of the twentieth century. He also brought the breadth of his knowledge to many other fields, including linguistics, biology, and environmental studies, and he served on the boards of such organizations as the Santa Fe Institute and the MacArthur Foundation. Gell-Mann did face criticism due to his abrasive and combative personality, and he publicly feuded with Richard Feynman and other physicists over their reputations and importance. Nevertheless, he was widely recognized as one of the world's leading theoretical physicists. In 2005, he was named Humanist of the Year by the American Humanist Association. In 2014 he was awarded the Helmholtz Medal, a prestigious honor awarded by the Berlin-Brandenburg Academy of Sciences and Humanities.

Gell-Mann married J. Margaret Dow in 1955, and the couple had two children. After his first wife's death of cancer, he married poet Marcia Southwick in 1992; they later divorced. Gell-Mann died on May 24, 2019, at the age of eighty-nine.

Bibliography

Feynman, Richard P. QED: The Strange Theory of Light and Matter. Princeton: Princeton UP, 2006. Print. Introduction to the concept of quantum electrodynamics (QED). Includes nonmathematical diagrams and visualizations of QED theories.

Fritzsch, Harald. Murray Gell-Mann: Selected Papers. Hackensack: World Scientific, 2010. Print. Presents a collection of Gell-Mann's work, including conference presentations and lectures. Includes papers from Gell-Mann's work on strangeness and his work with Feynman.

Johnson, George. "Murray Gell-Mann, Who Peered at Particles and Saw the Universe, Dies at 89." The New York Times, 24 May 2019,www.nytimes.com/2019/05/24/obituaries/murray-gell-mann-died-.html. Accessed 1 Jul. 2019.

Johnson, George. Strange Beauty: Murray Gell-Mann and the Revolution in Twentieth-Century Physics. New York: Vintage, 2000. Print. Biography of Gell-Mann, with details about his upbringing, rivalries with colleagues, and personal life.

"Murray Gell-Mann." The Nobel Prize, Nobel Media, 2019, www.nobelprize.org/prizes/physics/1969/gell-mann/biographical/. Accessed 1 Jul. 2019.