Murray Gell-Mann

Murray Gell-Mann was an American theoretical physicist who brought order to the growing zoo of subatomic particles discovered in the 1950s and 1960s. His Eightfold Way classification scheme, developed in the early 1960s, grouped particles by shared properties the way Mendeleev's periodic table grouped elements, and it predicted the existence of a then-undiscovered particle, the omega-minus baryon, found experimentally in 1964. That same year Gell-Mann, and independently George Zweig, proposed that protons, neutrons and related particles were themselves composed of smaller, fractionally charged constituents; Gell-Mann named them quarks, adapting the word from a line in James Joyce's Finnegans Wake. The quark model was confirmed experimentally at the Stanford Linear Accelerator Center in 1968 and became a foundation of the Standard Model of particle physics. Gell-Mann won the 1969 Nobel Prize in Physics for his contributions to the classification of elementary particles. Born in New York City on September 15, 1929, he spent most of his career at the California Institute of Technology and later helped found the Santa Fe Institute, working on complexity theory in his later years. He died in 2019 at the age of 89.