The Nobel Prize in Physics 1969
Born: 15 September 1929, New York, NY, USA
Affiliation at the time of the award: California Institute of Technology (Caltech), Pasadena, CA, USA
Prize motivation: "for his contributions and discoveries concerning the classification of elementary particles and their interactions."
Prize share: 1/1
During the 1950s and 1960s, new accelerators and apparatuses helped identify many new elementary particles. In theoretical works from the same period, Murray Gell-Mann classified particles and their interactions. He proposed that observed particles are in fact composite, that is, comprised of smaller building blocks called quarks. According to this theory, as-yet-undiscovered particles should exist. When these were later found in experiments, the theory was accepted.