How quarks made their entrance into our worldview via cosmic rays and proton accelerators

Sixty years ago Gell-Mann introduced, with a striking sense of caution, a new fundamental layer in the structure of matter. He christened the associated particles 'quarks', a name borrowed from the psychedelic flood of words of James Joyce's novel Finnegans Wake. Independently and simultaneously, Zweig arrived at similar ideas. We outline the circumstances that led to the introduction of quarks.