Modern Physics: Particles, Black Holes, and Beyond

In 1964, the American physicist Murray Gell-Mann, and independently George Zweig, proposed that protons, neutrons, and the wider family of particles called hadrons were not fundamental at all but were built from smaller constituents, which Gell-Mann named "quarks," borrowing the word from a line in James Joyce's novel Finnegans Wake. Three quark flavors, later expanded to six as more were discovered experimentally, brought order to what had seemed a chaotic "particle zoo"; Gell-Mann received the 1969 Nobel Prize in Physics for this work.