Genius: The Life and Science of Richard Feynman

  Genius

  The Life and Science of Richard Feynman

  James Gleick

  For my mother and father,

  Beth and Donen

  I was born not knowing

  and have only had a little time to change that here and there.

  —Richard Feynman

  CONTENTS

  PROLOGUE

  FAR ROCKAWAY

  •Neither Country nor City •A Birth and a Death •It’s Worth It •At School •All Things Are Made of Atoms •A Century of Progress •Richard and Julian

  MIT

  • The Best Path • Socializing the Engineer • The Newest Physics • Shop Men • Feynman of Course Is Jewish • Forces in Molecules • Is He Good Enough?

  PRINCETON

  • A Quaint Ceremonious Village • Folds and Rhythms • Forward or Backward? • The Reasonable Man • Mr. X and the Nature of Time • Least Action in Quantum Mechanics • The Aura • The White Plague • Preparing for War • The Manhattan Project • Finishing Up

  LOS ALAMOS

  • The Man Comes In with His Briefcase • Chain Reactions • The Battleship and the Mosquito Boat • Diffusion • Computing by Brain • Computing by Machine • Fenced In • The Last Springtime • False Hopes • Nuclear Fear • I Will Bide My Time • We Scientists Are Clever

  CORNELL

  • The University at Peace • Phenomena Complex—Laws Simple • They All Seem Ashes • Around a Mental Block • Shrinking the Infinities • Dyson • A Half-Assedly Thought-Out Pictorial Semi-Vision Thing • Schwinger’s Glory • My Machines Came from Too Far Away • There Was Also Presented (by Feynman) … • Cross-Country with Freeman Dyson • Oppenheimer’s Surrender • Dyson Graphs, Feynman Diagrams • Away to a Fabulous Land

  CALTECH

  • Faker from Copacabana • Alas, the Love of Women! • Onward with Physics • A Quantum Liquid • New Particles, New Language • Murray • In Search of Genius • Weak Interactions • Toward a Domestic Life • From QED to Genetics • Ghosts and Worms • Room at the Bottom • All His Knowledge • The Explorers and the Tourists • The Swedish Prize • Quarks and Partons • Teaching the Young • Do You Think You Can Last On Forever? • Surely You’re Joking! • A Disaster of Technology

  EPILOGUE

  ACKNOWLEDGMENTS

  NOTES

  A FEYNMAN BIBLIOGRAPHY

  BIBLIOGRAPHY

  INDEX

  ILLUSTRATION CREDITS

  PROLOGUE

  Nothing is certain. This hopeful message went to an Albuquerque sanatorium from the secret world at Los Alamos. We lead a charmed life.

  Afterward demons afflicted the bomb makers. J. Robert Oppenheimer made speeches about his shadowed soul, and other physicists began to feel his uneasiness at having handed humanity the power of self-destruction. Richard Feynman, younger and not so responsible, suffered a more private grief. He felt he possessed knowledge that set him alone and apart. It gnawed at him that ordinary people were living their ordinary lives oblivious to the nuclear doom that science had prepared for them. Why build roads and bridges meant to last a century? If only they knew what he knew, they surely would not bother. The war was over, a new era of science was beginning, and he was not at ease. For a while he could hardly work—by day a boyish and excitable professor at Cornell University, by night wild in love, veering from freshman mixers (where women sidled away from this rubber-legged dancer claiming to be a scientist who had made the atomic bomb) to bars and brothels. Meanwhile new colleagues, young physicists and mathematicians of his own age, were seeing him for the first time and forming their quick impressions. “Half genius and half buffoon,” Freeman Dyson, himself a rising prodigy, wrote his parents back in England. Feynman struck him as uproariously American—unbuttoned and burning with physical energy. It took him a while to realize how obsessively his new friend was tunneling into the very bedrock of modern science.

  In the spring of 1948, still in the shadow of the bomb they had made, twenty-seven physicists assembled at a resort hotel in the Pocono Mountains of northern Pennsylvania to confront a crisis in their understanding of the atom. With Oppenheimer’s help (he was now more than ever their spiritual leader) they had scraped together the thousand-odd dollars needed to cover their rooms and train fare, along with a small outlay for liquor. In the annals of science it was the last time but one that such men would meet in such circumstances, without ceremony or publicity. They were indulging a fantasy, that their work could remain a small, personal, academic enterprise, invisible to most of the public, as it had been a decade before, when a modest building in Copenhagen served as the hub of their science. They were not yet conscious of how effectively they had persuaded the public and the military to make physics a mission of high technology and expense. This meeting was closed to all but the few invited participants, the elite of physics. No transcript was kept. Next year most of these men would meet once more, hauling their two blackboards and eighty-two cocktail and brandy glasses in Oppenheimer’s station wagon, but by then the modern era of physics had begun in earnest, science conducted on a scale the world had not seen, and never again would its chiefs come together privately, just to work.

  The bomb had shown the aptness of physics. The scientists had found enough sinew behind their penciled abstractions to change history. Yet in the cooler days after the war’s end, they realized how fragile their theory was. They thought that quantum mechanics gave a crude, perhaps temporary, but at least workable way to make calculations about light and matter. When pressed, however, the theory gave wrong results. And not merely wrong—they were senseless. Who could love a theory that worked so neatly at first approximation and then, when a scientist tried to make the results more exact, broke down so grotesquely? The Europeans who had invented quantum physics had tried everything they could imagine to shore up the theory, without success.

  How were these men to know anything? The mass of the electron? Up for grabs: a quick glance gave a reasonable number, a hard look gave infinity—nonsense. The very idea of mass was unsettled: mass was not exactly stuff, but not exactly energy, either. Feynman toyed with an extreme view. On the last page of his tiny olive-green dime-store address book, mostly for phone numbers of women (annotated dancer beauty or call when her nose is not red), he scrawled a near haiku.

  Principles

  You can’t say A is made of B

  or vice versa.

  All 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 successfully. 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 fallen 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 fell and Feynman spoke. Chairs shifted. The priesthood had trouble following 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 follow (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 brilliant 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 (still 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 all things, elementary arithmetic; or frenetically 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. Uncharacteristically, 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 Teller, 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; Teller thought he had caught him pulling 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!” Teller 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’ll explain it to you,” Feynman said, “and then you can see how it works, then you can tell me if it’s unitary.” He went on, and from time to time he thought he could still hear Dirac muttering, “Is it unitary?”

  Feynman—mystifyingly brilliant 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 all 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 Cornell 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 baseballs 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 physicist from Los Alamos—Feynman had argued freely and vehemently with Bohr. Bohr had sought Feynman’s private counsel there, valuing his frankness, but now he was disturbed by the evident implications of those crisp lines. Feynman’s particles seemed to be following paths neatly fixed in space and time. This they could not do. The uncertainty principle said so.

  “Already we know that the classical idea of the trajectory in a path is not a legitimate idea in quantum mechanics,” he said, or so Feynman thought—Bohr’s soft voice and notoriously vague Danish tones kept his listeners straining to understand. He stepped forward and for many minutes, with Feynman standing unhappily to the side, delivered a humiliating lecture on the uncertainty principle. Afterward Feynman kept his despair to himself. At Pocono a generation of physics was melting into the next, and the passing of generations was neither as clean nor as inevitable as it later seemed.

  Architect of quantum theories, brash young group leader on the atomic bomb project, inventor of the ubiquitous Feynman diagram, ebullient bongo player and storyteller, Richard Phillips Feynman was the most brilliant, iconoclastic, and influential physicist of modern times. He took the half-made conceptions of waves and particles in the 1940s and shaped them into tools that ordinary physicists could use and understand. He had a lightning ability to see into the heart of the problems nature posed. Within the community of physicists, an organized, tradition-bound culture that needs heroes as much as it sometimes mistrusts them, his name took on a special luster. It was permitted in connection with Feynman to use the word genius. He took center stage and remained there for forty years, dominating the science of the postwar era—forty years that turned the study of matter and energy down an unexpectedly dark and spectral road. The work that made its faltering appearance at Pocono tied together in an experimentally perfect package all the varied phenomena at work in light, radio, magnetism, and electricity. It won Feynman a Nobel Prize. At least three of his later achievements might also have done so: a theory of superfluidity, the strange, frictionless behavior of l
iquid helium; a theory of weak interactions, the force at work in radioactive decay; and a theory of partons, hypothetical hard particles inside the atom’s nucleus, that helped produce the modern understanding of quarks. His vision of particle interaction kept returning to the forefront of physics as younger scientists explored esoteric new domains. He continued to find new puzzles. He could not, or would not, distinguish between the prestigious problems of elementary particle physics and the apparently humbler everyday questions that seemed to belong to an earlier era. No other physicist since Einstein so ecumenically accepted the challenge of all nature’s riddles. Feynman studied friction on highly polished surfaces, hoping—and mostly failing—to understand how friction worked. He tried to make a theory of how wind makes ocean waves grow; as he said later, “We put our foot in a swamp and we pulled it up muddy.” He explored the connection between the forces of atoms and the elastic properties of the crystals they form. He assembled experimental data and theoretical ideas on the folding of strips of paper into peculiar shapes called flexagons. He made influential progress—but not enough to satisfy himself—on the quantum theory of gravitation that had eluded Einstein. He struggled for years, in vain, to penetrate the problem of turbulence in gases and liquids.

  Feynman developed a stature among physicists that transcended any raw sum of his actual contributions to the field. Even in his twenties, when his published work amounted to no more than a doctoral thesis (profoundly original but little understood) and a few secret papers in the Los Alamos archives, his legend was growing. He was a master calculator: in a group of scientists he could create a dramatic impression by slashing his way through a difficult problem. Thus scientists—believing themselves to be unforgiving meritocrats—found quick opportunities to compare themselves unfavorably to Feynman. His mystique might have belonged to a gladiator or a champion arm-wrestler. His personality, unencumbered by dignity or decorum, seemed to announce: Here is an unconventional mind. The English writer C. P. Snow, observing the community of physicists, thought Feynman lacked the “gravitas” of his seniors. “A little bizarre … He would grin at himself if guilty of stately behaviour. He is a showman and enjoys it … rather as though Groucho Marx was suddenly standing in for a great scientist.” It made Snow think of Einstein, now so shaded and dignified that few remembered the “merry boy” he had been in his creative time. Perhaps Feynman, too, would grow into a stately personage. Perhaps not. Snow predicted, “It will be interesting for young men to meet Feynman in his later years.”