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

You can’t say A is made of B

or vice versa.

Al mass is interaction.

Even when quantum physics worked, in the sense of predicting nature’s behavior, it left scientists with an uncomfortable blank space where their picture of reality was supposed to be. Some of them, though never Feynman, put their faith in Werner Heisenberg’s wistful dictum, “The equation knows best.” They had little choice.

These scientists did not even know how to visualize the atom they had just split so successful y. They had created and then discarded one sort of picture, a picture of tiny particles orbiting a central nucleus as planets orbit the sun.

Now they had nothing to replace it. They could write numbers and symbols on their pads, but their mental picture of the substance beneath the symbols had been reduced to a fuzzy unknown.

As the Pocono meeting began, Oppenheimer had reached the peak of his public glory, having risen as hero of the atomic bomb project and not yet having fal en as the antihero of the 1950s security trials. He was the meeting’s nominal chairman, but more accomplished physicists were scattered about the room: Niels Bohr, the father of the quantum theory, on hand from his institute in Denmark; Enrico Fermi, creator of the nuclear chain reaction, from his laboratory in Chicago; Paul A. M. Dirac, the British theorist whose famous equation for the electron had helped set the stage for the present crisis. It went without saying that they were Nobel laureates; apart from Oppenheimer almost everyone in the room either had won or would win this honor. A few Europeans were absent, as was Albert

Einstein, settling into his statesmanlike retirement, but with these exceptions the Pocono conclave represented the whole priesthood of modern physics.

Night fel and Feynman spoke. Chairs shifted. The priesthood had trouble fol owing this brash young man.

They had spent most of the day listening to an extraordinary virtuoso presentation by Feynman’s exact contemporary, Julian Schwinger of Harvard University. This had been difficult to fol ow (when published, Schwinger’s work would violate the Physical Review ’s guidelines limiting the sprawl of equations across the width of the page) but convincing nonetheless. Feynman was offering fewer and less meticulous equations. These men knew him from Los Alamos, for better and for worse. Oppenheimer himself had privately noted that Feynman was the most bril iant young physicist at the atomic bomb project. Why he had acquired such a reputation none of them could say precisely. A few knew of his contribution to the key equation for the efficiency of a nuclear explosion (stil classified forty years later, although the spy Klaus Fuchs had transmitted it promptly to his incredulous masters in the Soviet Union) or his theory of predetonation, measuring the probability that a lump of uranium might explode too soon. If they could not describe his actual scientific work, nevertheless they had absorbed an intense image of an original mind. They remembered him organizing the world’s first large-scale computing system, a hybrid of new electro-mechanical business calculators and teams of women with color-coded cards; or delivering a hypnotic lecture on, of al things,

elementary arithmetic; or frenetical y twisting a control knob in a game whose object was to crash together a pair of electric trains; or sitting defiantly upright, for once motionless, in an army weapons carrier lighted by the purple-white glare of the century’s paradigmatic explosion.

Facing his elders in the Pocono Manor sitting room, Feynman realized that he was drifting deeper and deeper into confusion. Uncharacteristical y, he was nervous. He had not been able to sleep. He, too, had heard Schwinger’s elegant lecture and feared that his own presentation seemed unfinished by comparison. He was trying to put across a new program for making the more exact calculations that physics now required—more than a program, a vision, a dancing, shaking picture of particles, symbols, arrows, and fields. The ideas were unfamiliar, and his slightly reckless style irritated some of the Europeans.

His vowels were a raucous urban growl. His consonants slurred in a way that struck them as lower-class. He shifted his weight back and forth and twirled a piece of chalk rapidly between his fingers, around and around and end over end. He was a few weeks shy of his thirtieth birthday, too old now to pass for a boy wonder. He was trying to skip some details that would seem controversial—but too late.

Edward Tel er, the contentious Hungarian physicist, on his way to heading the postwar project to build the Super, the hydrogen bomb, interrupted with a question about basic quantum physics: “What about the exclusion principle?”

Feynman had hoped to avoid this. The exclusion principle meant that only one electron could inhabit a

particular quantum state; Tel er thought he had caught him pul ing two rabbits from a single hat. Indeed, in Feynman’s scheme particles did seem to violate this cherished principle by coming into existence for a ghostly instant. “It doesn’t make any difference—” he started to reply.

“How do you know?

“I know, I worked from a—”

“How could it be!” Tel er said.

Feynman was drawing unfamiliar diagrams on the blackboard. He showed a particle of antimatter going backward in time. This mystified Dirac, the man who had first predicted the existence of antimatter. Dirac now asked a question about causality: “Is it unitary?” Unitary! What on earth did he mean?

“I’l explain it to you,” Feynman said, “and then you can see how it works, then you can tel me if it’s unitary.” He went on, and from time to time he thought he could stil hear Dirac muttering, “Is it unitary?”

Feynman—mystifyingly bril iant at calculating, strangely ignorant of the literature, passionate about physics, reckless about proof—had for once overestimated his ability to charm and persuade these great physicists. Yet in truth he had now found what had eluded al of his elders, a way to carry physics forward into a new era. He had created a private new science that brought past and future together in a starkly majestic tapestry. His new friend Dyson at Cornel had glimpsed it—“this wonderful vision of the world as a woven texture of world lines in space and time, with everything moving freely,” as Dyson described it.

“It was a unifying principle that would either explain everything or explain nothing.” Twentieth-century physics had reached an edge. Older men were looking for a way beyond an obstacle to their calculations. Feynman’s listeners were eager for the new ideas of young physicists, but they were wedded to a certain view of the atomic world

—or rather, a series of different views, each freighted with private confusion. Some were thinking mostly about waves

—mathematical waves carrying the past into the present.

Often, of course, the waves behaved as particles, like the particles whose trajectories Feynman sketched and erased on the blackboard. Some merely took refuge in the mathematics, chains of difficult calculations using symbols as stepping stones on a march through fog. Their systems of equations represented a submicroscopic world defying the logic of everyday objects like basebal s and water waves, ordinary objects with, “thank God,” as W. H. Auden put it (in a poem Feynman detested):

sufficient mass

To be altogether there,

Not an indeterminate gruel

Which is partly somewhere else.

The objects of quantum mechanics were always partly somewhere else. The chicken-wire diagrams that Feynman had etched on the blackboard seemed, by contrast, quite definite. Those trajectories looked classical in their precision. Niels Bohr stood up. He knew this young