FROM QUARKS TO EFFECTIVE COMPLEXITY: GELL-MANN'S TWO REVOLUTIONS

Murray Gell-Mann took a mess and made it small. In the 1950s physicists were drowning in new particles, discovering them faster than they could invent names, and one Nobel laureate proposed fining anyone who found another. Gell-Mann invented a quantum number nobody could see, arranged the whole crowded catalog into neat geometrical families, predicted a particle that had to exist and then watched it show up on a photographic plate at Brookhaven, and finally announced that everything in the zoo was built from three things he named after a line in Finnegans Wake. A hundred particles became three letters. He was thirty-four. Then he did something stranger. He left the smallest objects in the universe and went to New Mexico to ask what it means for a description to be short at all. Out of that came effective complexity, an attempt to measure how much regularity a thing actually contains, and a research institute that has been trying to build a general science of complicated systems ever since. >Keywords: Murray Gell-Mann, quarks, particle physics, complexity, information theory, Santa Fe Institute, history of science