Murray Gell-Mann is an American physicist who has become famous for his postulation of the existence of the Quark particles. He was born September 15, 1929 in New York, earned a bachelor's degree in physics from Yale University in 1948, a PhD in physics from MIT in 1951, and received the 1969 Nobel Prize in physics for his discovery of a system for classifying subatomic particles.
In the 1950s and the early 1960s he worked on a classification of elementary particles, and in 1964 he (and, independently, George Zweig) postulated the existence of quarks, the particles from which the hadrons (protons and neutrons for example) are composed.
The name "Quark" was inspired by the line "Three quarks for Muster Mark!" in James Joyce's famous (but hard to understand) novel Finnegans Wake. In 1972 he introduced the "color" quantum number and was the leading character behind the full theory of quantum chromodynamics (QCD - "chromo" because of the "colors" of the quarks).
Later on, in the 1990s, he co-founded the Santa Fe Institute, studied complex and chaotic systems and published his popular book "The Quark and the Jaguar: Adventures in the Simple and the Complex". Today he works as a professor at Caltech and the University of New Mexico, and he's also a member of the editorial board of the Encyclopædia Britannica.