Genius_ The Life and Science of Richard Feynman - James Gleick [233]
There was always more. Dick wore shirtsleeves, Murray wore tweed. Murray ate at the Atheneum, the faculty club, while Dick ate at “the Greasy,” the cafeteria. (This was only half true. Either man could be found at either place on occasion, although Feynman, when the Atheneum still required ties and jackets, would show up in shirtsleeves and demand the most garish and ill-fitting of the spare items kept on hand for emergencies.) Feynman talked with his hands—with his whole body, in fact—whereas Gell-Mann, as the physicist and science writer Michael Riordan observed, “sits calmly behind his desk in a plush blue swivel chair, hands folded, never once lifting them to make a gesture… . Information is exchanged by words and numbers, not by hands or pictures.” Riordan added:
Their personal styles spill over into their theoretical work, too. Gell-Mann insists on mathematical rigor in all his work, often at the expense of comprehensibility… . Where Gell-Mann disdains vague, heuristic models that might only point the way toward a true solution, Feynman revels in them. He believes that a certain amount of imprecision and ambiguity is essential to communication.
Yet they were not so different in their approach to physics. Those who knew them best as physicists felt that Gell-Mann was no more likely than Feynman to hide behind formalism or to use mathematics as a stand-in for physical understanding. Those who considered him pretentious about language and cultural trivia felt nonetheless that when it came to physics he was as honest and direct as Feynman. Over a long career Gell-Mann made his vision not only comprehensible but irresistible. Both men were relentless on the trail of a new idea, able to concentrate absolutely, willing to try anything.
Both men, it seemed to a few perceptive colleagues, presented a mask to the world. “Murray’s mask was a man of great culture,” Sidney Coleman said. “Dick’s mask was Mr. Natural—just a little boy from the country that could see through things the city slickers can’t.” Both men filled their masks until reality and artifice became impossible to pry apart.
Gell-Mann, as naturalist, collector, and categorizer, was well primed to interpret the exploding particle universe of the 1960s. New technology in the accelerators—liquid hydrogen bubble chambers and computers for automating the analysis of collision tracks—seemed to have spilled open a bulky canvas bag from which nearly a hundred distinct particles had now tumbled forth. Gell-Mann and, independently, an Israeli theorist, Yuval Ne’eman, found a way in 1961 to organize the various symmetries of spins and strangeness into a single scheme. It was a group, in the mathematicians’ sense of the word, known as SU(3), though Gell-Mann quickly and puckishly dubbed it the Eightfold Way. It was like an intricate translucent object which, when held to the light, would reveal families of eight or ten or possibly twenty-seven particles—and they would be different, though overlapping, families, depending on which way one chose to view it. The Eightfold Way was a new periodic table—the previous century’s triumph in classifying and thus exposing the hidden regularities in a similar number of disparate “elements.” But it was also a more dynamic object. The operations of group theory were like special shuffles of a deck of cards or the twists of a Rubik’s cube.
Much of SU(3)’s power came from the way it embodied a concept increasingly central to the high-energy theorist’s way of working: the concept of inexact symmetry, almost symmetry, near symmetry, or—the term that won out—broken symmetry. The particle world was full of near misses in its symmetries, a dangerous problem, since it seemed to permit an ad hoc escape route whenever an expected relationship failed to match. Broken symmetry implied a process, a change in status. A symmetry