Murray Gell-Mann

Happy Birthday Murray Gell-Mann! The Nobel physics laureate was born in New York City in 1929. Gell-Mann entered Yale University at age 15 and earned his PhD from MIT at 21. After a brief stint at the Institute for Advanced Study, where Einstein was working at the time, Gell-Mann became a professor at the California Institute of Technology. He had a famous love-hate relationship with Richard Feynman, whose office was next door. Gell-Mann’s research focused on making sense of the dozens of particles that were being discovered in particle accelerator experiments. Physicists love simplicity, and Gell-Mann smartly noticed similarities in the properties of certain particles. In 1961 he and Israeli theoretical physicist Yuval Ne’eman independently proposed a means of classifying the newly discovered particles into groups. Gell-Mann called the classification scheme the Eightfold Way (after the Eightfold Path in Buddhism), since many groups consisted of eight particles. Based on those groupings, he then proposed that protons, neutrons, and many other particles are not fundamental but instead are made up of even more basic building blocks with fractional amounts of electric charge. Always eager to devise names, he called the fundamental particles quarks (pronounced “kworks”), after a poem in James Joyce’s Finnegans Wake. (George Zweig independently came up with a similar proposal at the same time, and he called the particles aces.) Gell-Mann’s quark model gained traction when he correctly predicted the existence of the omega-minus particle. Subsequently physicists discovered six quarks: top, bottom, up, down, charm, and strange. A proton, for example, is composed of one down and two up quarks. Since 1984 Gell-Mann has been working at the Santa Fe Institute in New Mexico, which he cofounded to encourage scientists to pursue interdisciplinary research. (Photo credit: World Economic Forum, CC BY-SA 2.0)

Date in History: 15 September 1929