Genius_ The Life and Science of Richard Feynman - James Gleick [167]
In Chicago, Fermi, too, heard from Feynman—a long “Dear Fermi” letter just before Christmas from the Miramar Palace Hotel in Copacabana. Feynman, following the thread he had picked up in the episode of Case v. Slotnick, was working on meson theory. It was messy—divergences everywhere—but he had reached a hodgepodge of conclusions. “I should like to make some comments at the risk of saying what is obvious to everybody in the U.S.,” he wrote Fermi. Mesons are pseudoscalar … Yukawa’s theory is wrong. He had heard some experimental news via the ham-radio link—“I am not entirely in the dark in Brazil.” He had some predictions that he wanted checked. His approach to these particles, so essential to the binding of the atomic nucleus, centered increasingly on an even more abstract variant of spin: yet another quantum number called isotopic spin. So did Fermi’s approach, as it turned out. Feynman was duplicating some of the Chicago work. In their ways they were trying to take the measure of a theory that resembled quantum electrodynamics yet resisted the lion tamers’ favorite whips, renormalization, perturbation theory. “Don’t believe any calculation in meson theory which uses a Feynman diagram!” Feynman wrote Fermi. Meanwhile, as they pushed more energetically inside the atom, they were watching the breakup of the prewar particle picture. With each new particle, the dream of a manageable number of building blocks faded. In this continually subdividing world, what was truly elementary?
What was made of what? “Principles,” Feynman had written in the tiny address book he carried with him. “You can’t say A is made of B or vice versa. All mass is interaction.” That did not solve the problem, though. Cloud chamber photographs showed new kinds of forks and kinks in the trajectories—new mesons, it seemed, before anyone had understood the old. Fermi set the tone for the coming proliferation of particles with a declaration in the Physical Review.
In recent years several new particles have been discovered which are currently assumed to be “elementary,” that is, essentially structureless. The probability that all such particles should be really elementary becomes less and less as their number increases.
It is by no means certain that nucleons, mesons, electrons, neutrinos are all elementary particles… .
Feynman had made his escape shortly after arriving in Pasadena. He accepted Caltech’s offer of an immediate sabbatical year and fled to the most exotic place he could find. The State Department subsidized his salary. For the first time since Far Rockaway he could spend days at the beach, where he looked over the crowds in sandals and bathing suits and gazed at the endless waves and sky. He had never before seen a beach where mountains loomed just behind. At night the Serra da Carioca were black humps in the moonlight. Royal palms like dressed-up telephone poles—taller by far than the palms of Pasadena—lined the coast and the broad avenues of Rio. Feynman went down to the sea for inspiration. Fermi teased him: “I wish I could also refresh my ideas by swimming off Copacabana.” Feynman liked the idea of helping build a new seat of physics at the Centro Brasiliero de Pesquisas Físicas. Fifteen years before, physics had hardly existed in Brazil or elsewhere in South America. A few lesser German and Italian physicists had grafted branches in the middle 1930s, and within a decade their students’ students were creating new facilities with the support of industry and government agencies.
Feynman taught basic electromagnetism to students at the University of Brazil in Rio, who disappointed him by meekly refusing to ask questions. Their style seemed rote and hidebound after freewheeling Americans. European influence