Genius: The Life and Science of Richard Feynman

by James Gleick

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

Feynman’s particles seemed to be following paths neatly fixed in space and time. This they could not do. The uncertainty principle said so.

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.

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.

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.

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.

He was the enemy of pomp, convention, quackery, and hypocrisy. He was the boy who saw the emperor with no clothes.

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.

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.

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.

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.

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.

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.

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.

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.

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.

He accumulated tube sets and an old storage battery from around the neighborhood. He assembled transformers, switches, and coils. A coil salvaged from a Ford automobile made showy sparks that burned brown-black holes in newspaper. When he found a leftover rheostat, he pushed 110-volt electricity through it until it overloaded and burned. He held the stinking, smoking thing outside his second-floor window, as the ashes drifted down to the grassy rear yard. This was standard emergency procedure. When a pungent odor drifted in downstairs during his mother’s bridge game, it meant that Ritty was dangling his metal wastebasket out the window, waiting for the flames to die out after an abortive experiment

Children and scientists share an outlook on life. If I do this, what will happen? is both the motto of the child at play and the defining refrain of the physical scientist. Every child is observer, analyst, and taxonomist, building a mental life through a sequence of intellectual revolutions, constructing theories and promptly shedding them when they no longer fit. The unfamiliar and the strange—these are the domain of all children and scientists.

A jury-rigged motor rocked his baby sister’s crib.

Recognizing some illogic in the customary notation for trigonometric functions, Feynman invented a new notation of his own: for sin for cos (x), for tan (x). He was free, but he was also extremely methodical. He memorized tables of logarithms and practiced mentally deriving values in between. He began to fill notebooks with formulas, continued fractions whose sums produced the constants π and e.

He made sure the knowledge was practical. His notebooks contained not just the principles of these subjects but also extensive tables of trigonometric functions and integrals—not copied but calculated, often by original techniques that he devised for the purpose. For his calculus notebook he borrowed a title from the primers he had studied so avidly, Calculus for the Practical Man. When his classmates handed out yearbook sobriquets, Feynman was not in contention for the genuinely desirable Most Likely to Succeed and Most Intellectual. The consensus was Mad Genius.

As late as 1922 Bohr, delivering his Nobel Prize address, felt compelled to remind his listeners that scientists “believe the existence of atoms to be proved beyond a doubt.”

When a primer on mathematical methods baffled him, he worked through it formula by formula, filling a notebook with self-imposed exercises.

The currency of scientific information had not yet been devalued by excess.

They would not meet for another decade; not until Los Alamos. Long afterward, when they were old men, after they had shared a Nobel Prize for work done as rivals, they amazed a dinner party by competing to see who could most quickly recite from memory the alphabetical headings on the spines of their half-century-old edition of the Encyclopaedia Britannica.

American professional mathematics of the thirties was enforcing its rigor and abstraction as never before, disdaining what outsiders would call “applications.” To Feynman—having finally reached a place where he was surrounded by fellow tinkerers and radio buffs—mathematics began to seem too abstract and too far removed.

In the stories modern physicists have made of their own lives, a fateful moment is often the one in which they realize that their interest no longer lies in mathematics. Mathematics is always where they begin, for no other school course shows off their gifts so clearly. Yet a crisis comes: they experience an epiphany, or endure a slowly building disgruntlement, and plunge or drift into this other, hybrid field.

in preparing for the New York State Regents Examination, he chose Treasure Island. (But he outscored all of them, even in English, when he wrote an essay on “the importance of science in aviation” and padded his sentences with what he knew to be redundant but authoritative phrases like “eddies, vortices, and whirlpools formed in the atmosphere behind the aircraft ...”)

Meanwhile in physics itself Feynman took two courses in mechanics (particles, rigid bodies, liquids, stresses, heat, the laws of thermodynamics), two in electricity (electrostatics, magnetism, ...), one in experimental physics (students were expected to design original experiments and show that they understood many different sorts of instruments), a lecture course and a laboratory course in optics (geometrical, physical, and physiological), a lecture course and a laboratory course in electronics (devices, thermionics, photoemission), a course in X rays and crystals, a course and a laboratory in atomic structure (spectra, radioactivity, and a physicist’s view of the periodic table), a special seminar on the new nuclear theory, Slater’s advanced theory course, a special seminar on quantum theory, and a course on heat and thermodynamics that worked toward statistical mechanics both classical and quantum; and then, his docket full, he listened in on five more advanced courses, including relativity and advanced mechanics. When he wanted to round out his course selection with something different, he took metallography.

People like Descartes were stupid, Richard told Arline, relishing his own boldness in defying the authority of the great names. Arline replied that she supposed there were two sides to everything. Richard gleefully contradicted even that. He took a strip of paper, gave it a half twist, and pasted the ends together: he had produced a surface with one side.

“Not from positions of philosophers but from the fabric of nature”—William Harvey three centuries earlier had declared a division between science and philosophy.

It also had what seemed to Dirac a painful logical flaw. It implied that the probability of certain events must be negative, less than zero. Negative probabilities, Dirac said, “are of course quite absurd.”

Morse put them to work calculating the properties of different atoms, using a method of his own devising. It computed energies by varying the parameters in equations known as hydrogenic radial functions—Feynman insisted on calling them hygienic functions—and it required more plain, plodding arithmetic than either boy had ever encountered. Fortunately they had calculators, a new kind that replaced the old hand cranks with electric motors. Not only could the calculators add, multiply, and subtract; they could divide, though it took time. They would enter numbers by turning metal dials. They would turn on the motor and watch the dials spin toward zero. A bell would ring. The chug-chug-ding-ding rang in their ears for hours.

Harvard sounded him out about the scholarship, but he told them he had already decided to go elsewhere: to Princeton.

A crystal, with its molecules in a regular geometrical array, can expand more along one axis than another. Typically scientists would represent a crystalline structure with a Tinkertoy model, balls stuck on rods, but real matter is not so rigid.

Those habits in turn depend on the forces at work within a substance—forces both classical and quantum mechanical—and when Feynman began his thesis work those forces were not well understood, even in quartz, the most common mineral on earth.

He had never thought about molecular structure in such detail before. He taught himself everything he could about crystals, their standard arrangements, the geometries and the symmetries, the angles between atoms. It all came down to one unknown, he realized: the nature of the forces pressing the molecules into particular alignments.

Substance itself would vanish. Matter would crumple in on itself. Only in terms of quantum mechanics was that impossible, because it would give the electron a definite pointlike position. Quantum-mechanical uncertainty was the air that saved the bubble from collapse. Schrödinger’s equation showed where the electron clouds would find their minimum energy, and on those clouds depended all that was solid in the world.

Eventually he could draw a curve representing the change in energy. The slope of that curve represented the sharpness of the change—the force. Each varied configuration had to be computed afresh. To Feynman this seemed wasteful and ugly. It took him a few pages to demonstrate a better method. He showed that one could calculate the force directly for a given configuration, without having to look at nearby configurations at all.

The force on an atom’s nucleus is no more or less than the electrical force from the surrounding field of charged electrons—the electrostatic force. Once the distribution of charge has been calculated quantum mechanically, then from that point forward quantum mechanics disappears from the picture. The problem becomes classical; the nuclei can be treated as static points of mass and charge. Feynman’s approach applies to all chemical bonds. If two nuclei act as though strongly attracted to each other, as the hydrogen nuclei do when they bond to form a water molecule, it is because the nuclei are each drawn toward the electrical charge concentrated quantum mechanically between them.

John Archibald Wheeler

In any field find the strangest thing and then explore it.

Through quantum mechanics, physics had established a primacy over chemistry—itself formerly the most fundamental of sciences, if the most fundamental was the one responsible for nature’s basic constituents.

At MIT Feynman had read Dirac’s 1935 text as a cliffhanger with the most thrilling possible conclusion: “It seems that some essentially new physical ideas are here needed.” Dirac and the other pioneers had taken their quantum electrodynamics—the theory of the interplay of electricity, magnetism, light, and matter—as far as they could. Yet it remained incomplete, as Dirac well knew.

As its size diminished, the electron’s energy grew, just as the pressure transmitted by a carpenter’s hammer becomes thousands of pounds per square inch when concentrated at the point of a nail. Furthermore, if the electron was to be imagined as a little ball of finite size, then what force or glue kept it from bursting from its own charge? Physicists found themselves manipulating a quantity called the “classical electron radius.” Classical in this context came to mean something like make-believe. The problem was that the alternative—a vanishingly small, pointlike electron—left the equations of electrodynamics plagued with divisions by zero: infinities. Infinitely small nails, infinitely energetic hammers.

The wave equation of quantum mechanics only made the infinities more complicated. Instead of the grade-school horror of a division by zero, physicists now contemplated equations that grew out of bounds because they summed infinitely many wavelengths, infinitely many oscillations in the field

Feynman quietly nursed an attachment to a solution so radical and straightforward that it could only have appealed to someone ignorant of the literature. He proposed—to himself—that electrons not be allowed to act on themselves at all. The idea seemed circular and silly. As he recognized, however, eliminating self-action meant eliminating the field itself. It was the field, the totality of the charges of all electrons, that served as the agent of self-action. An electron contributed its charge to the field and was influenced by the field in turn. Suppose there was no field. Then perhaps the circularity could be broken. Each electron would act directly on another. Only the direct interaction between charges would be permitted. One would have to build a time delay into the equations, for whatever form this interaction took, it could hardly surpass the speed of light. The interaction was light, in the form of radio waves, visible light, X rays, or any of the other manifestations of electromagnetic radiation. “Shake this one, that one shakes later,” Feynman said later. “The sun atom shakes; my eye electron shakes eight minutes later because of a direct interaction across.”

Implicit in Feynman’s attitude was a sense that the laws of nature were not to be discovered so much as constructed. Although language blurred the distinction, Feynman was asking not whether an electron acted on itself but whether the theorist could plausibly discard the concept; not whether the field existed in nature but whether it had to exist in the physicist’s mind. When Einstein banished the ether, he was reporting the absence of something real—at least something that might have been—like a surgeon who opened a chest and reported that the bloody, pulsing heart was not to be found. The field was different. It had begun as an artifice, not an entity.