Richard Feynman was the Michael Jordan of physics. His intellectual leaps, seemingly weightless, defied explanation. One of his teammates on the high school math team in Far Rockaway, Long Island, recalls that Feynman “would get this unstudied insight while the problem was still being read out, and his opponents, before they could begin to compute, would see him ostentatiously write down a single number and draw a circle around it. Then he would let out a loud sigh.” At twenty-three, he amazed a Princeton colleague when he worked out at the blackboard a proof of an important proposition of physics that had been only loosely conjectured eight years earlier by the Nobel Prize winner Paul Dirac. In 1960, in his early forties, restless and unable to find a physics problem worth working on, Feynman taught himself enough biology to make an original discovery of how mutations work in genes.
Feynman rarely read the scientific literature. When he did, he would read only far enough into an article to see what the problem was, fold up the journal, and then derive the results on his own. When a colleague, after perhaps months of calculations, walked into Feynman’s office with a new result, he would often discover that Feynman already knew not only that result, but a more sweeping one, which he had kept in his file drawer and regarded as not worth publishing. The mathematician Mark Kac has said that “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.” But for the second kind, “even after we understand what they have done, the process by which they have done it is completely dark….” He called Feynman “a magician of the highest caliber.”
Scientific genius alone would not have explained Feynman’s legend. It was also his style. He was stubborn, irreverent, unrefined, uncultured, proud, playful, intensely curious, and highly original in practically everything he did. He had a mystique. There are hundreds of “Feynman stories,” some told by Feynman himself in his popular book Surely You’re Joking, Mr. Feynman, and others passed along by word of mouth from one physicist to another, like beheld visitations passed from one disciple to another. As a graduate student at Princeton, for example, Feynman would spend long afternoons leading ants to a box of sugar suspended by a string, in an attempt to learn how ants communicate. When Feynman noticed that his Ph.D. thesis adviser, John Wheeler, pointedly placed his pocket watch down on a table during their first meeting, Feynman came to their second meeting with a cheap pocket watch of his own and placed it on the table next to Wheeler’s. At Los Alamos, when he was working on the Manhattan Project, the young Feynman continually alarmed other scientists and the military brass by cracking their safes, which were filled with atomic secrets.
When he was preparing to accept the Nobel Prize in the presence of the king of Sweden, Feynman worried that it was forbidden to turn one’s back on a king; he might, he was told, have to back up a flight of stairs. He then practiced jumping up steps backward, using both feet at once. Feynman hated pomp and authority of all kinds. After being elected to the prestigious and highly selective National Academy of Sciences, he withdrew from the organization, saying that its main function was only to elevate people to its exalted ranks.
There was something almost uncanny about the way Feynman could get to the heart of a question. On February 10, 1986, during the public hearings on the Challenger shuttle disaster, as a member of the committee of inquiry, he performed an experiment of deadly simplicity. He dropped one of the shuttle’s O-ring seals into a glass of ice water, the temperature of the air on the day of the launch, and showed that the rubber when squeezed did not stretch back under such cold. I cannot resist telling my own story about Feynman, one of the three professors who conducted the oral examination for my Ph.D. in physics at the California Institute of Technology. Wearing, as usual, a white shirt without a tie, he began the examination by asking me two questions. The first question I answered without much trouble. The second I struggled with. His two questions had precisely marked the limits of my knowledge, like artillery shells fired at a small boat, one landing just short, one long. During the following three hours, he asked no further questions.
James Gleick, the author of the widely read book Chaos, has taken on the difficult task of writing about Feynman as both a scientist and a human being. Gleick never met Feynman. But he has interviewed over a hundred people, including Feynman’s family and many of the world’s leading physicists; he has read unpublished letters and notes by Feynman and others, talked to a number of Feynman’s girl-friends (who remain discreetly unidentified in the book), reviewed documents about Feynman obtained from the FBI and CIA under the Freedom of Information Act as well as hundreds of pages of unpublished interviews by the science historian Charles Weiner. The result is a thorough and masterful portrait of one of the great minds of the century. In describing not only Feynman but the physicists around him, Gleick also succeeds in giving us a rare insight into the scientific community, its values, and its mentality.
Feynman was born in New York on May 11, 1918. His father, Melville, a Jewish immigrant from Minsk, Byelorussia, had a practical, vivid appreciation of science; he once explained to his son Richard that a dinosaur twenty-five feet high with a head six feet across, if standing in the front yard, would almost be able to get his head through the second-floor window. Melville Feynman sold police uniforms and automobile polish, among other ventures, without notable success. Gleick tells us that Feynman’s mother, Lucille, had a gift for humor and a love of storytelling.
As a child in Far Rockaway, Feynman tinkered with radio sets, gathering spare parts from around the neighborhood. Many theoretical physicists like Feynman have spent their childhoods building things, but Feynman retained throughout his life an immediate, tactile sense of physical phenomena. Even his mathematical calculations have a certain unfussy and muscular style. Feynman rigged a motor to rock his sister’s crib, freeing himself to read the Encyclopaedia Britannica. But he was intimidated by athletics, by stronger boys, and by girls, and was afraid that he would be regarded as an intellectual sissy. Like so many other socially fragile, budding scientists he sought refuge in an intense concentration on math and science, but he was particularly interested in their practical side. His manliness, he saw, lay in his ability to do things with his hands.
Correspondingly, he avoided all pursuits that seemed to him “delicate,” such as poetry, drawing, literature, and music. In fact, Feynman had little respect for the humanities, which he regarded as slippery and inferior to science, and even less respect for humanists. When he was in his early thirties, he wrote that “the theoretical broadening which comes from having many humanities subjects on the campus is offset by the general dopiness of the people who study these things.” Yet Feynman had an appreciation of the workings of human psychology in science. In his brilliant little book The Character of Physical Law he places great value on seeking different formulations of the same physical law, even if they are exactly equivalent mathematically, because different versions bring to mind different mental pictures and thus help in making discoveries. “Psychologically they are different because they are completely unequivalent when you are trying to guess new laws.”
In the fall of 1935, Feynman entered MIT, where he found that virtually everyone else was socially and athletically inept, and obsessed by science. He easily skipped first-year calculus and taught himself quantum mechanics before his sophomore year. He joined a fraternity, one of the two that took in Jews. He met another precocious physics student, T. A. Welton, and together they rederived for their own satisfaction the basic results of quantum physics, which they wrote down in a notebook that they passed back and forth to each other. Feynman briefly read Descartes and decided that philosophy was soft and that philosophers were incompetent logicians. It was in his junior year at MIT that he became engaged to Arline Greenbaum, whom he had met a few years earlier in Far Rockaway, and who became, besides physics, the love of his life.
Where MIT was working-class in tone and unbuttoned in manner, Princeton was patrician and genteel. The afternoon Feynman arrived there as a graduate student, in the fall of 1939, he was invited to a tea with Dean Eisenhart. As he stood uneasily in the suit he hardly ever wore, the dean’s wife, a lioness of Princeton society, said to him, “Would you like cream or lemon in your tea, sir?” “Both please,” Feynman blurted out. “Surely you’re joking, Mr. Feynman,” said Mrs. Eisenhart, thus supplying the title for the memoir Feynman published fifty years later. Feynman hated people who, he felt used manners and culture to make him feel small. He became aggressively unrefined.
Feynman and his thesis adviser at Princeton, John Wheeler, worked on the nature of time. Einstein had already shown, at the beginning of the century, that time is not absolute, that the rate at which clocks tick depends on the motion of the observer. But what determines the direction of time? Why is the future so distinct from the past? It was well known that, at the microscopic level, the laws of physics were indifferent to the direction of time: they gave the same results whether time flowed forward or backward. Feynman and Wheeler solved a difficult problem concerning electricity by assuming that, in the way electrons emit radiation, time flows both forward and backward. It seemed a crazy idea, but it was the kind of deep and important crazy idea that caused physicists to skip meals and stay at the blackboard. By the time the young Feynman presented his calculations to a departmental seminar in early 1941, his audience had come to include the great mathematician John von Neumann, the physicist Wolfgang Pauli, who was soon to win the Nobel Prize and was visiting from Zurich, and the sixty-two-year-old Einstein, who seldom came to colloquia. After listening to Feynman’s talk, Einstein commented, in his soft voice, that the theory seemed possible.
Around this time, Arline, who had been suffering from fevers and fatigue, was diagnosed as having tuberculosis. She was to spend much of the rest of her short life in sanatoriums. Against his parents’ strong objections, Feynman married her. The only witnesses to the wedding, in a city office on Staten Island, were two strangers.
In 1942, many of the physicists at Princeton began fanning out to work on military projects at, among other places, MIT’s Radiation Laboratory (the “Rad Lab”), the University of Chicago, Berkeley, and Oak Ridge, Tennessee. While still at Princeton, Feynman collaborated with Paul Olum and Robert Wilson on a device for culling the fissionable form of uranium from the nonfissionable. This was the beginning of the Manhattan Project. In March of 1943, Feynman and Arline took the train to Los Alamos. Arline entered Presbyterian Sanatorium in Sante Fe while Feynman lived in the barracks at Los Alamos, driving the twenty-five miles over rutted roads to see her every weekend.
At Los Alamos, Hans Bethe, the great nuclear physicist from Cornell, was in charge of all theoretical work. Where Bethe was calm, careful, and professorial, Feynman was quick, fearless, intuitive, and irreverent. Feynman was just what Bethe was looking for. He made the twenty-five-year-old Feynman a group leader, promoting him over older and more senior physicists. Feynman was able to solve a critical problem on how neutrons bounce around among uranium atoms and start a chain reaction.
Arline died in the summer of 1945. Two years later, when he was at Cornell during a frustrating impasse in his theoretical work, the twenty-nine-year-old Feynman wrote a letter to his dead wife, placed it in a box, and never read it again. After Feynman’s death, Gleick discovered the letter, which reads in part:
I adore you, sweetheart.
It is such a terribly long time since I last wrote to you—almost two years but I know you’ll excuse me because you understand how I am, stubborn and realistic; & I thought there was no sense to writing.
But now I know my darling wife that it is right to do what I have delayed in doing….I want to tell you I love you. I want to love you. I always will love you.
I find it hard to understand in my mind what it means to love you after you are dead—but I still want to comfort and take care of you—and I want you to love me and care for me. I want to have problems to discuss with you….
P.S. Please excuse my not mailing this—but I don’t know your new address.
Arline’s death was the great tragedy of Feynman’s life. Gleick suggests that he never let anyone get close to him again, although he had many affairs, a second brief and unpleasant marriage, and a third, apparently satisfying, one to Gweneth Howarth, with whom he had two children. Gleick also suggests that Feynman may have treated many women as sex objects because he felt no one measured up to his first wife. For the rest of his life, Feynman pursued only beautiful women, some of them the wives of his friends and colleagues, but he had no interest in their intellectual companionship. His attitude toward women is suggested by the conclusion of his Nobel address in 1965:
So what happened to the old theory that I fell in love with as a youth? Well, I would say it’s become an old lady, that has very little attractive left in her and the young today will not have their hearts pound when they look at her anymore. But, we can say the best we can for any old woman, that she has been a good mother and she has given birth to some very good children.
Beginning in his late twenties, Feynman started to be followed around by Feynman stories. He heard the stories, polished and embellished them, and retold them. He relished his image as a rough-hewn, philistine hero. Gleick writes that after Arline’s death, “The Feynman who could be wracked by strong emotion, the man stung by shyness, insecurity, anger, worry or grief—no one got close enough any more to see him.”
Feynman eventually emerged from his depression at Cornell and, in the late 1940s, did the work that won him the Nobel Prize, showing how electrons interact with electromagnetic radiation—e.g., radio waves—and other charged particles. His theory, called quantum electrodynamics, has been confirmed by experiments to greater accuracy than any other theory of nature. (Quantum electrodynamics predicts that the magnetic strength of the electron is 1.00115965246; the measured value is 1.00115965221.) Quantum electrodynamics explains all electrical and magnetic phenomena, which include everything we experience in daily life except gravity.
Feynman shared his prize with Shin’ichiro Tomonaga of Japan and with Julian Schwinger of the US, who had both independently derived their own formulations of quantum electrodynamics. These alternative formulations were, however, much harder to work with than Feynman’s. Schwinger was in many ways the antiparticle of Feynman. He dressed expensively and meticulously, drove a black Cadillac, spoke elegantly in long sentences with subordinate clauses, lectured without notes, and prided himself on arriving at the end of complex mathematical calculations with no dust on his shoes from taking an occasional blind alley.
Feynman made two other major contributions to physics, both worthy of a Nobel Prize. He developed a theoretical explanation for superfluids—fluids that are totally frictionless and that will spontaneously glide over the walls of a beaker and will pass through holes so tiny that even gas could not get through. He also worked out a theory for the weak nuclear force, one of the two kinds of nuclear forces. Both theories were developed at the California Institute of Technology, where he spent the second half of his life. Murray Gell-Mann, Feynman’s rival at Caltech, had independently arrived at the weak-force theory, and the department chairman judiciously arranged for both Feynman and Gell-Mann to publish their important work in a joint paper. Like Schwinger, Gell-Mann was very different from Feynman. His interests in science were narrow, but he had broad interests outside science, while Feynman was engrossed with virtually all of science, but with almost nothing outside it.
At Caltech, Feynman became more concerned with education, although he did not have the patience to supervise students preparing theses. In 1961, Caltech decided to revise its physics curriculum and asked Feynman to help. Lecturing at the blackboard to freshmen and later to sophomores, he began with atoms, moving up to larger phenomena like clouds and colors on ponds and down to the smaller, like electrons and the quantum world. Without consulting books, he slowly built up the entire edifice of physics as he understood it, the physical world as he saw it. Soon graduate students and other professors came to listen. Feynman’s Caltech lectures eventually became the three-volume Feynman Lectures on Physics, which can be found on the bookshelves of almost every professional physicist in the world. The lectures ultimately failed to accomplish their intended purpose. Apparently simple on the surface, they were in fact deeply sophisticated. But they are a triumph of human thought, and deserve a place in the history of Western culture, along with Aristotle’s collected works, Descartes’s Principles of Philosophy, and Newton’s Principia.
Feynman won the Nobel Prize for his work in quantum electrodynamics, the quantum theory of how electrons interact with radiation and other electrically charged particles. Electrons are the simplest electrical particles. Normally found in the outer parts of atoms, they produce light and other forms of electromagnetic radiation as well as most of the interactions between atoms and molecules. Quantum physics, one of the two pillars of twentieth-century physics along with Einstein’s relativity, is the physics of the subatomic world. The theoretical foundations of quantum physics were laid in the 1920s, principally by Erwin Schrödinger, Werner Heisenberg, and Paul Dirac. A basic idea of quantum physics is that particles of matter sometimes behave as if they were in several places at once. This uncertainty about the location of things is negligible for macroscopic objects like people, but it is extremely important for subatomic particles like electrons, where the phenomenon has been repeatedly observed and has immense consequences. Another important idea, also derived from experiment, is that physical quantities like energy are not indefinitely divisible into smaller amounts, but instead have a smallest, indivisible unit, called the quantum (as US currency has a smallest unit, the penny). Both ideas run counter not only to intuition but to the Newtonian theoretical conception of the world before 1900. In order to mathematically describe these two basic ideas of quantum physics the theories of Schrödinger, Heisenberg, and Dirac had to represent matter and energy not by certainties but by probabilities (or, technically speaking, amplitudes, which are closely related to probabilities). Thus, while in the Newtonian scheme a physical law would show how a particle moves from A to B under the action of a force, in the quantum scheme a physical law would show how the probabilities for a particle to be at various places evolve under the action of a force.
The quantum theory of the 1920s gave a good description of isolated particles, but it did not accurately describe the interactions of particles. Experiments began to turn up small discrepancies in particle behavior. For example, in the strange quantum world subatomic particles are constantly appearing out of nothing and then disappearing again. Each particle, such as the electron, surrounds itself with a cloud of other, ghost-like particles, called “virtual particles,” which fleetingly come into existence and then slip away into oblivion. Electrons interact with the ghost-like particles around them, and those interactions alter the properties of the electron, such as its mass and electrical charge. In reality, the physicists found, there are no isolated electrons. The quantum ghosts are everywhere. Their shadows have been seen in experiments. When physicists in the late 1930s and early 1940s tried to modify the quantum theory of Schrödinger, Heisenberg, and Dirac so as to accurately describe particle interactions, they ran into technical difficulties with the ghosts. Once the ghosts began popping up in the mathematics, the equations couldn’t be solved.
One of the triumphs of Feynman’s quantum electrodynamics was that it provided a method for dealing with the ghosts. Roughly speaking, the method involves treating the ghosts as part of the electron. Experiments on electrons do not penetrate inside the cloud of ghost-particles around them; we never observe the “bare” electron at the center of the cloud. What we observe is the electron and its cloud. When the thing we call an electron is redefined to include the virtual particles around it, the technical difficulties go away.
Other scientists in addition to Feynman contributed to this redefinition of the electron (and its subatomic cousins). However, Feynman’s own version of quantum electrodynamics had two further, and unique, features. First, it made use of mathematical methods that were much easier to work with than the methods of other versions, particularly the version of Schwinger. This was Feynman at his practical best. Second, Feynman’s quantum electrodynamics provided a new picture of the world. In other descriptions of quantum physics, even after certainties are replaced by probabilities, a particle advances from A to B in tiny increments, with forces acting to move the particle (or the probability of the particle) from one increment to the next. But Feynman’s mathematical description of quantum electrodynamics is global, not incremental. It considers every possible route from A to B, assigns a single number to the entire route, then adds up the numbers from all the different routes to arrive at the probability of getting from A to B.
The descriptions of other physicists could be compared to observing how a car speeds up and slows every few feet along a highway from New York to Los Angeles, whereas Feynman’s description looked only at the total gas consumption for the trip. Furthermore, in Feynman’s description, the car travels simultaneously on all routes from New York to Los Angeles, even on such crazy but possible routes as New York to Chicago to Miami to Los Angeles. Such a description leads to a strange picture of the world, where all the different ways in which something can happen are happening, at the same time. What we human beings, grossly insensitive, macroscopic objects that we are, conceive of as a single reality is actually a tapestry of many simultaneous realities. It is ironic that Feynman, who considered philosophy a waste of time, should have come up with ideas philosophically so rich. But all deep theories of nature since Lucretius’ atomism have had broad philosophical implications.
As with his previous book, Chaos, which described the new science of nonlinear physical phenomena and the people involved in it, James Gleick brings to Genius high intelligence, a strong sense of narrative, a commitment to thoroughness in ascertaining facts, and excellent prose. Many of his analogies and metaphors are memorable. For example, in describing Feynman’s concept of least-time trajectories, he makes an analogy to a lifeguard trying to reach a drowning swimmer. The lifeguard, who begins his rescue mission on the beach, travels faster on land than in water. Therefore, the fastest path to the swimmer is not necessarily along a straight line, which might include a short stretch on land but a long stretch in water. Guided by one of Feynman’s articles in the Physical Review, Gleick gives a beautiful and vivid description of how Feynman visualized superfluids while lying in bed one night. What Gleick does most brilliantly is to tell us with honesty and insight who Feynman was.
Where Genius falls short, in my opinion, is in its presentation of Feynman’s science. There are too many untranslated technical words, like “matrices,” “spin,” “momentum variables,” and “imaginary numbers.” (“One prescription was to take all the momentum variables and replace them with certain more complicated expressions.”) Perhaps more importantly, some of the scientific concepts are not clearly explained—for example, quantum physics, handedness, the difference between numerical and analytical solutions, space-time diagrams. To be sure, a great deal of science is presented skilfully, but many of the scientific explanations are facile and vague. Reading the science portions, one has the sensation of trying to see through a veil.
Many nonscientists are fascinated and puzzled by the scientific mentality. How does it differ from the thinking of musicians or writers? How do scientists make discoveries? What do scientists mean when they say that a theory or an equation is aesthetically attractive? In my view, few books explain this mentality better than Feynman’s own book The Character of Physical Law and the mathematician G.H. Hardy’s A Mathematician’s Apology. But, of course, the scientific mentality is only a part of the scientist. It does not include his personality, the life he leads, his world. Some of the scientific biographies of recent years try to bring together the mentality and the life; in doing so the scientific biographer, perhaps more than others, faces a formidable challenge, requiring not only the skills of a scholar and writer but also a technical grasp of the science.
How much of the actual scientific work of a great scientist do we have to understand in a scientific biography? The answer is only partly a matter of taste. We cannot understand a genius like Feynman, who spent sixteen hours a day thinking physics, if we do not also appreciate some of his work. Yet this is never enough. Two other recent scientific biographies, Abraham Pais’s “Subtle is the Lord,” about Einstein, and Walter Moore’s Schrödinger, both splendid books in their own ways, give accurate technical descriptions, but they are not accessible to the general reader, and the accounts of the lives of their subjects lack the richness and power of Genius: The Life and Science of Richard Feynman. Gleick has written a monumental work, a lasting scientific biography. Even the book’s shortcomings make one appreciate both the difficulties of the genre and the extent of Gleick’s accomplishment.
In February 1988, after a gruesome series of illnesses and complications from cancer, Feynman entered the UCLA Medical Center for the last time. He was sixty-nine. Across the city, on a corner of his blackboard, he had written in chalk, “What I cannot create I do not understand.” As he lay in his hospital bed, with his strength ebbing, Feynman whispered his last words: “I’d hate to die twice. It’s so boring.”
December 17, 1992