Genius: The Life and Science of Richard Feynman - James Gleick (1993)

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 liquid 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.”

One team of physicists, assembled for the Manhattan Project, met him for the first time in Chicago, where he solved a problem that had baffled them for a month. It was “a shallow way to judge a superb mind,” one of them admitted later, but they had to be impressed, by the unprofessorial manner as much as the feat itself: “Feynman was patently not struck in the prewar mold of most young academics. He had the flowing, expressive postures of a dancer, the quick speech we thought of as Broadway, the pat phrases of the hustler and the conversational energy of a finger snapper.” Physicists quickly got to know his bounding theatrical style, his way of bobbing sidelong from one foot to the other when he lectured. They knew that he could never sit still for long and that when he did sit he would slouch comically before leaping up with a sharp question. To Europeans like Bohr his voice was as American as any they had heard, a sort of musical sandpaper; to the Americans it was raw, unregenerate New York. No matter. “We got the indelible impression of a star,” another young physicist noted. “He may have emitted light as well as words… . Isn’t areté the Greek word for that shining quality? He had it.”

Originality was his obsession. He had to create from first principles—a dangerous virtue that sometimes led to waste and failure. He had the cast of mind that often produces cranks and misfits: a willingness, even eagerness, to consider silly ideas and plunge down wrong alleys. This strength could have been a crippling weakness had it not been redeemed, time and again, by a powerful intelligence. “Dick could get away with a lot because he was so goddamn smart,” a theorist said. “He really could climb Mont Blanc barefoot.” Isaac Newton spoke of having stood on the shoulders of giants. Feynman tried to stand on his own, through various acts of contortion, or so it seemed to the mathematician Mark Kac, who was watching Feynman at Cornell:

There are two kinds of geniuses, the “ordinary” and the “magicians.” An ordinary genius is a fellow that you and I would be just as good as, if we were only many times better. There is no mystery as to how his mind works. Once we understand what they have done, we feel certain that we, too, could have done it. It is different with the magicians. They are, to use mathematical jargon, in the orthogonal complement of where we are and the working of their minds is for all intents and purposes incomprehensible. Even after we understand what they have done, the process by which they have done it is completely dark. They seldom, if ever, have students because they cannot be emulated and it must be terribly frustrating for a brilliant young mind to cope with the mysterious ways in which the magician’s mind works. Richard Feynman is a magician of the highest caliber.

Feynman resented the polished myths of most scientific history, submerging the false steps and halting uncertainties under a surface of orderly intellectual progress, but he created a myth of his own. When he had ascended to the top of the physicists’ mental pantheon of heroes, stories of his genius and his adventures became a sort of art form within the community. Feynman stories were clever and comic. They gradually created a legend from which their subject (and chief purveyor) seldom emerged. Many of them were transcribed and published in the eighties in two books with idiosyncratic titles, Surely You’re Joking, Mr. Feynman! and What Do You Care What Other People Think? To the surprise of their publisher these became popular best-sellers. After his death in 1988 his sometime friend, collaborator, office neighbor, foil, competitor, and antagonist, the acerbic Murray Gell-Mann, angered his family at a memorial service by asserting, “He surrounded himself with a cloud of myth, and he spent a great deal of time and energy generating anecdotes about himself.” These were stories, Gell-Mann added, “in which he had to come out, if possible, looking smarter than anyone else.” In these stories Feynman was a gadfly, a rake, a clown, and a naïf. At the atomic bomb project he was the thorn in the side of the military censors. On the commission investigating the 1986 space-shuttle explosion he was the outsider who pushed aside red tape to uncover the true cause. He was the enemy of pomp, convention, quackery, and hypocrisy. He was the boy who saw the emperor with no clothes. So he was in life. Yet Gell-Mann spoke the truth, too. Amid the legend were misconceptions about Feynman’s accomplishments, his working style, and his deepest beliefs. His own view of himself worked less to illuminate than to hide the nature of his genius.

The reputation, apart from the person, became an edifice standing monumentally amid the rest of the scenery of modern science. Feynman diagrams, Feynman integrals, and Feynman rules joined Feynman stories in the language that physicists share. They would say of a promising young colleague, “He’s no Feynman, but …” When he entered a room where physicists had gathered—the student cafeteria at the California Institute of Technology, or the auditorium at any scientific meeting—with him would come a shift in the noise level, a disturbance of the field, that seemed to radiate from where he was carrying his tray or taking his front-row seat. Even his senior colleagues tried to look without looking. Younger physicists were drawn to Feynman’s rough glamour. They practiced imitating his handwriting and his manner of throwing equations onto the blackboard. One group held a half-serious debate on the question, Is Feynman human? They envied the inspiration that came (so it seemed to them) in flashes. They admired him for other qualities as well: a faith in nature’s simple truths, a skepticism about official wisdom, and an impatience with mediocrity.

He was widely considered a great educator. In fact few physicists of even the middle ranks left behind so small a cadre of students, or so assiduously shirked ordinary teaching duties. Although science remained one of the few domains of true apprenticeship, with students learning their craft at the master’s side, few learned this way from Feynman. He did not have the patience to guide a student through a research problem, and he raised high barriers against students who sought him as a thesis adviser. Nevertheless when Feynman did teach he left a deep imprint on the subject. Although he never actually wrote a book, books bearing his name began to appear in the sixties—Theory of Fundamental Processes and Quantum Electrodynamics, lightly edited versions of lectures transcribed by students and colleagues. They became influential. For years he offered a mysterious noncredit course called Physics X, for undergraduates only, in a small basement room. Some physicists years later remembered this unpredictable free-form seminar as the most intense intellectual experience of their education. Above all in 1961 he took on the task of reorganizing and teaching the introductory physics course at Caltech. For two years the freshmen and sophomores, along with a team of graduate-student teaching assistants, struggled to follow a tour de force, the universe according to Feynman. The result was published and became famous as “the red books”—The Feynman Lectures on Physics. They reconceived the subject from the bottom up. Colleges that adopted the red books dropped them a few years later: the texts proved too difficult for their intended readers. Instead, professors and working physicists found Feynman’s three volumes reshaping their own conception of their subject. They were more than just authoritative. A physicist, citing one of many celebrated passages, would dryly pay homage to “Book II, Chapter 41, Verse 6.”

Authoritative, too, were Feynman’s views of quantum mechanics, of the scientific method, of the relations between science and religion, of the role of beauty and uncertainty in the creation of knowledge. His comments on such subjects were mostly expressed offhand in technical contexts, but also in two slim models of science writing, again distilled from lectures: The Character of Physical Law and QED: The Strange Theory of Light and Matter. Feynman was widely quoted by scientists and science writers (although he seldom submitted to interviews). He despised philosophy as soft and unverifiable. Philosophers “are always on the outside making stupid remarks,” he said, and the word he pronounced philozawfigal was a mocking epithet, but his influence was philosophical anyway, particularly for younger physicists. They remembered, for example, his Gertrude Stein-like utterance on the continuing nervousness about quantum mechanics—or, more precisely, the “world view that quantum mechanics represents”:

It has not yet become obvious to me that there’s no real problem. I cannot define the real problem, therefore I suspect there’s no real problem, but I’m not sure there’s no real problem.

or, similarly, what may have been the literature’s most quoted mixed metaphor:

Do not keep saying to yourself, if you can possibly avoid it, “But how can it be like that?” because you will get “down the drain,” into a blind alley from which nobody has yet escaped. Nobody knows how it can be like that.

In private, with pencil on scratch paper, he labored over aphorisms that he later delivered in spontaneous-seeming lectures:

Nature uses only the longest threads to weave her patterns, so each small piece of her fabric reveals the organization of the entire tapestry.

Why is the world the way it is? Why is science the way it is? How do we discover new rules for the flowering complexity around us? Are we reaching toward nature’s simple heart, or are we merely peeling away layers of an infinitely deep onion? Although he sometimes retreated to a stance of pure practicality, Feynman gave answers to these questions, philosophical and unscientific though he knew they were. Few noticed, but his answer to the starkest of science’s metaphysical questions—Is there a meaning, a simplicity, a comprehensibility at the core of things?—underwent a profound change in his lifetime.

Feynman’s reinvention of quantum mechanics did not so much explain how the world was, or why it was that way, as tell how to confront the world. It was not knowledge of or knowledge about. It was knowledge how to. How to compute the emission of light from an excited atom. How to judge experimental data, how to make predictions, how to construct new tool kits for the new families of particles that were about to proliferate through physics with embarrassing fecundity.

There were other kinds of scientific knowledge, but pragmatic knowledge was Feynman’s specialty. For him knowledge did not describe; it acted and accomplished. Unlike many of his colleagues, educated scientists in a cultivated European tradition, Feynman did not look at paintings, did not listen to music, did not read books, even scientific books. He refused to let other scientists explain anything to him in detail, often to their immense frustration. He learned anyway. He pursued knowledge without prejudice. During a sabbatical he learned enough biology to make a small but genuine contribution to geneticists’ understanding of mutations in DNA. He once offered (and then awarded) a one-thousand-dollar prize for the first working electric motor less than one sixty-fourth of an inch long, and his musing on the possibilities of tiny machinery made him, a generation later, the intellectual father of a legion of self-described nanotechnologists. In his youth he experimented for months on end with trying to observe his unraveling stream of consciousness at the point of falling asleep. In his middle age he experimented with inducing out-of-body hallucinations in a sensory-deprivation tank, with and without marijuana. His lifetime saw a stratification of the branch of knowledge called physics. Those specializing in the understanding of elementary particles came to control much of the field’s financing and much of its public rhetoric. With the claim that particle physics was the most fundamental science, they scorned even subdisciplines like solid-state physics—“squalid-state” was Gell-Mann’s contemptuous phrase. Feynman embraced neither the inflating language of Grand Unified Theories nor the disdain for other sciences.

Democratically, as if he favored no skill above any other, he taught himself how to play drums, to give massages, to tell stories, to pick up women in bars, considering all these to be crafts with learnable rules. With the gleeful prodding of his Los Alamos mentor Hans Bethe (“Don’t you know how to take squares of numbers near 50?”) he taught himself the tricks of mental arithmetic, having long since mastered the more arcane arts of mental differentiation and integration. He taught himself how to make electroplated metal stick to plastic objects like radio knobs, how to keep track of time in his head, and how to make columns of ants march to his bidding. He had no difficulty learning to make an impromptu xylophone by filling water glasses; nor had he any shyness about playing them, all evening, at a dinner party for an astonished Niels Bohr. At the same time, when he was engrossed in the physicists’ ultimate how-to endeavor, the making of an atomic bomb, he digressed to learn how to defeat the iron clamp of an old-fashioned soda machine, how to pick Yale locks, and then how to open safes—a mental, not physical, skill, though his colleagues mistakenly supposed he could feel the vibrations of falling tumblers in his fingertips (as well they might, after watching him practice his twirling motion day after day on their office strongboxes). Meanwhile, dreamily wondering how to harness atomic power for rockets, he worked out a nuclear reactor thrust motor, not quite practical but still plausible enough to be seized by the government, patented, and immediately buried under an official secrecy order. With no less diligence, much later, having settled into a domestic existence complete with garden and porch, he taught himself how to train dogs to do counterintuitive tricks—for example, to pick up a nearby sock not by the direct route but by the long way round, circling through the garden, in the porch door and back out again. (He did the training in stages, breaking the problem down until after a while it was perfectly obvious to the dog that one did not go directly to the sock.) Then he taught himself how to find people bloodhound-style, sensing the track of their body warmth and scent. He taught himself how to mimic foreign languages, mostly a matter of confidence, he found, combined with a relaxed willingness to let lips and tongue make silly sounds. (Why then, his friends wondered, could he never learn to soften his Far Rockaway accent?) He made islands of practical knowledge in the oceans of personal ignorance that remained: knowing nothing about drawing, he taught himself to make perfect freehand circles on the blackboard; knowing nothing about music, he bet his girlfriend that he could teach himself to play one piece, “The Flight of the Bumblebee,” and for once failed dismally; much later he learned to draw after all, after a fashion, specializing in sweetly romanticized female nudes and letting his friends know that a concomitant learned skill thrilled him even more—how to persuade a young woman to disrobe. In his entire life he could never quite teach himself to feel a difference between right and left, but his mother finally pointed out a mole on the back of his left hand, and even as an adult he checked the mole when he wanted to be sure. He taught himself how to hold a crowd with his not-jazz, not-ethnic improvisational drumming; and how to sustain a two-handed polyrhythm of not just the usual three against two and four against three but—astonishing to classically trained musicians—seven against six and thirteen against twelve. He taught himself how to write Chinese, a skill acquired specifically to annoy his sister and limited therefore to the characters for “elder brother also speaks.” In the era when high-energy particle accelerators came to dominate theoretical physics, he taught himself how to read the most modern of hieroglyphics, the lacy starburst photographs of particle collisions in cloud chambers and bubble chambers—how to read them not for new particles but for the subtler traces of experimental bias and self-deception. He taught himself how to discourage autograph seekers and refuse lecture invitations; how to hide from colleagues with administrative requests; how to force everything from his field of vision except for his research problem of the moment; how to hold off the special terrors of aging that shadow scientists; then how to live with cancer, and how to surrender to it.

After he died several colleagues tried to write his epitaph. One was Schwinger, in a certain time not just his colleague but his preeminent rival, who chose these words: “An honest man, the outstanding intuitionist of our age, and a prime example of what may lie in store for anyone who dares to follow the beat of a different drum.” The science he helped create was like nothing that had come before. It rose as his culture’s most powerful achievement, even as it sometimes sent physicists down the narrowing branches of an increasingly obscure tunnel. When Feynman was gone, he had left behind—perhaps his chief legacy—a lesson in what it meant to know something in this most uncertain of centuries.