Джеймс Глик - Genius - The Life and Science of Richard Feynman

“Pasadena is ten miles from Los Angeles as the Rol s-Royces fly,” one commentator said in 1932. “It is one of the prettiest towns in America, and probably the richest.” Albert Einstein wintered there for three years, posing for pictures on a bicycle to the delight of the institute administrators, attending, as Wil Rogers said, “every luncheon, every dinner, every movie opening, every marriage and two-thirds of the divorces,” before he final y decided Princeton suited him better. Even as the Depression began to reverse Pasadena’s fortunes, Caltech’s rose on every new tide in science. A new Caltech laboratory polished the giant lens for the great telescope under way at Palomar Mountain.

Caltech made itself the American center of systematic earthquake science; one of its young graduates, Charles Richter, devised the ubiquitous measurement scale that carries his name. The school moved quickly into aeronautic science, and a group of enthusiastic amateurs firing off rockets in the hil s about the Rose Bowl became, by 1944, the

Jet

Propulsion

Laboratory.

Foundations

and

industrialists were eager to look beyond their usual East Coast funding targets. A cornflakes manufacturer paid for a

building that became the Kel ogg Radiation Laboratory, and its reigning expert, Charles Lauritsen, made it a national center for fundamental nuclear physics. Lauritsen spent much of the thirties investigating the nuclear properties of the light elements—hydrogen and deuterium, helium, lithium, up through carbon and beyond—fil ing in details of energy levels and spin with a patched-together arsenal of equipment.

He was stil working in Kel ogg in the winter of 1951, when oracular messages started coming in by ham radio.

A blind operator in Brazil would establish a link every week or so with a student at Caltech. Lauritsen would receive terse predictions: Could it be that nitrogen has two levels very close together at the lowest state, not just a single level? He would check these, and often they would prove correct. His Brazilian informant apparently had a theory …

In Chicago, Fermi, too, heard from Feynman—a long

“Dear Fermi” letter just before Christmas from the Miramar Palace Hotel in Copacabana. Feynman, fol owing 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 cal ed 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 energetical y 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 continual y 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. Al 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, essential y structureless. The probability that al such particles should be real y elementary becomes less and less as their number increases.

It is by no means certain that nucleons, mesons, electrons, neutrinos are al 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—tal er 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 had dominated the construction of a curriculum.

The nascent graduate programs did not have the luxury of a liberal mix of confident instructors. Memorization replaced understanding, or so it seemed to Feynman, and he began to proselytize the Brazilian educational establishment.

Students learned names and abstract formulations, he said. Brazilian students could recite Brewster’s Law: “Light impinging on a material of index n is 100 percent polarized with the electric field perpendicular to the plane of incidence if the tangent …” But when he asked what would happen if they looked out at the sunlight reflecting off the bay and held up a piece of polarized film and turned the film this way and that, he got blank stares. They could define

“triboluminescence”—light emitted by crystals under mechanical pressure—and it made Feynman wish the professors would just send them into a dark room with a pair of pliers and a sugar cube or a Life Saver to see the faint blue flash, as he had when he was a child. “Have you got science? No! You have only told what a word means in terms of other words. You haven’t told them anything about

nature— what crystals produce light when you crush them, why they produce light… .” An examination question would read, “What are the four types of telescope?” (Newtonian, Cassegrainian, …) Students could answer, and yet, Feynman said, the real telescope was lost: the instrument that helped begin the scientific revolution, that showed humanity the humbling vastness of the stars.

Words about words: Feynman despised this kind of knowledge more intently than ever, and when he returned to the United States he found out again how much it was a part of American education, a mind-set showing itself not just in the habits of students but in quiz shows, popular what-should-you-know books, and textbook design. He wanted everyone to share his strenuous approach to knowledge. He would sit idly at a café table and cock his ear to listen to the sound sugar made as it struck the surface of his iced tea, something between a hiss and a rustle, and his temper would flare if anyone asked what the phenomenon was cal ed—even if someone merely asked for an explanation. He respected only the not-knowing, first-principles approach: try sugar in water, try sugar in warm tea, try tea already saturated with sugar, try salt … see when the whoosh becomes a fizz. Trial and error, discovery, free inquiry.