Genius (24 page)
Authors: James Gleick
In the past eight years neither Dirac nor any other physicist had been able to follow up on the notion of a Lagrangian in quantum mechanics—a way of expressing a particle’s history in terms of the quantity of action. Now Dirac’s idea served as an explosive release in Feynman’s imagination. The uneasy elements of quantum mechanics broke loose and rearranged themselves into a radically new formulation. Where Dirac had pointed the way to calculating how the wave function would evolve in an infinitesimal slice of time, Feynman needed to carry the wave function farther, through finite time. A considerable barrier separated the infinitesimal from the finite. Making use of Dirac’s infinitesimal slice required a piling up of many steps—infinitely many of them. Each step required an integration, a summing of algebraic quantities. In Feynman’s mind a sequence of multiplications and compounded integrals took form. He considered the coordinates that specify a particle’s position. They churned through his compound integral. The quantity that emerged was, once again, a form of the action. To produce it, Feynman realized, he had to make a complex integral encompassing every possible coordinate through which a particle could move. The result was a kind of sum of probabilities—yet not quite probabilities, because quantum mechanics required a more abstract quantity called the probability amplitude. Feynman summed the contributions of every conceivable path from the starting position to the final position—though at first he saw more a haystack of coordinate positions than a set of distinct paths. Even so, he realized that he had burrowed back to first principles and found a new formulation of quantum mechanics. He could not see where it would lead. Already, however, his sense of paths in space-time seemed somehow cleaner—more direct. There seemed something quaint now about the peculiarly constrained oscillations of the post-ethereal field, the wavy inheritance of the 1920s.
Twentieth-century medicine was struggling for the scientific footing that physics began to achieve in the seventeenth century. Its practitioners wielded the authority granted to healers throughout human history; they spoke a specialized language and wore the mantle of professional schools and societies; but their knowledge was a pastiche of folk wisdom and quasi-scientific fads. Few medical researchers understood the rudiments of controlled statistical experimentation. Authorities argued for or against particular therapies roughly the way theologians argued for or against their theories, by employing a combination of personal experience, abstract reason, and aesthetic judgment. Mathematics played no role in a biologist’s education. The human body was still largely a black box, its contents accessible only by means of the surgeon’s knife or the crepuscular outlines of the early X rays. Researchers were stumbling toward the first rudimentary understanding of diet. The modern-sounding word
vitamin
had been coined and a few examples isolated in laboratories, but Feynman’s father, Melville, having been diagnosed with chronic high blood pressure, was being slowly poisoned with an enriched, salty diet of eggs, milk, and cheese. Immunology and genetics were nothing but wells of ignorance. The prevailing theory of the mind was less a science than a collection of literary conceits blended with the therapeutic palliative of the confessional. Cancers, viruses, and diseases of the heart and brain resisted even the first glimmers of understanding. They would continue to mock medical science throughout the century.
Yet medicine was within reach of its first planetwide triumphs against bacterial epidemics, with the twin weapons of vaccination and antibiotic drugs. The year Feynman entered graduate school, Jonas Salk became a medical doctor; his assault on polio was just a few years away. Still, the habits of large clinical trials and statistical thinking had yet to become engrained in medical research. Alexander Fleming had noticed the antibacterial effect of the mold
Penicillium notatum
a decade before and then failed to take what a later era would consider the obvious next steps. He published his observation in a paper titled “A Medium for the Isolation of Pfeiffer’s Bacillus.” He tried rubbing his mold onto the open wounds of a few patients, with unclear results, but it never occurred to him to attempt a systematic study of its effects. A full decade passed, while biologists (and Fleming himself) dreamed futilely of a magic antibacterial agent that would save millions of lives, before finally two researchers happened upon his paper, extracted penicillin, and in 1940 crossed the line separating anecdote from science: they injected it into four sick mice, leaving another four untreated. In the context of 1930s medical science the lost decade was hardly noteworthy. Fleming’s contemporaries did not deride him as a bungler. They hailed him as a hero and awarded him the Nobel Prize.
Tuberculosis—consumption, the wasting disease, scrofula, phthisis, the white plague—killed more people at its prime, in more parts of the globe, than any other disease. To novelists and poets it carried a romantic aura. It was a disease of pale aesthetes. It was a disease of rarefaction, of the body squandering itself. Its long, slow fevers gave the false impression of life intensified, the metabolism heightened, the processes of existence stimulated. Thomas Mann, allowing tuberculosis to inspire his most famous novel, associated the ruin and inflammation of the tubercles with sin, with the Fall, with the creation of life itself from cool inorganic molecules—“that pathologically luxuriant morbid growth, produced by the irritant of some unknown infiltration … an intoxication, a heightening and unlicensed accentuation of the physical state.” He wrote those words in 1924, when the
Magic Mountain
resort-style sanatoriums of Europe were already dinosaurs of the past. To American public-health authorities faced with the reality of the disease, even then tuberculosis was more simply a disease of the poor.
Tuberculosis had infected Arline Greenbaum’s lymphatic system, perhaps having been carried by unpasteurized milk. Swelling reappeared in the lymph nodes on her neck and elsewhere, the lumps rubbery and painless. She suffered fevers and fatigue. But an accurate diagnosis remained beyond the abilities of her doctors. Arline did not strike them as the typical tuberculosis victim; she was not poor enough or young enough. Nor was lymphatic tuberculosis as common as tuberculosis that began in the lung (it was twenty to thirty times rarer). When they abandoned the notion of typhoid fever and considered the other standard possibilities, they focused on cancerous outbreaks: lymphoma, lymphosarcoma, Hodgkin’s disease.
Feynman was back in the library at Princeton, reading everything he could find. One standard book listed the possibilities. First was local infection. This was out of the question because the swellings were traveling too far. Second was lymphatic tuberculosis. This was easy to diagnose, the book said. Then came the cancers, and these, he read to his horror, were almost invariably fatal. For a moment he mocked himself for jumping to the most morbid possibility. Everyone who reads such catalogues must start thinking about death, he thought. He went off to the Fine Hall tea, where the conversation seemed unnaturally normal.
Those months in 1941 were a blur of visits to hospitals, symptoms appearing and fading, consultations with more and more doctors. He hovered on the outside, hearing most news secondhand through Arline’s parents. He and Arline promised each other that they would face whatever came, bravely and honestly. Arline insisted, as she had when less was at stake, that honesty was the bedrock of their love and that what she treasured in Richard was his eagerness to confront the truth, his unwillingness to be embarrassed or evasive. She said she did not want euphemisms or pretense about her illness. Few patients did, but the weight of medical practice opposed forthrightness in the face of terminal illness. Honest bad news was considered antitherapeutic. Richard faced a dilemma, because the doctors were finally settling on a grim diagnosis of Hodgkin’s disease. There would be periods of remission, they said, but the course of the illness could not be reversed.
For Arline’s benefit they proposed a camouflage diagnosis of “glandular fever.” Richard refused to go along with it. He explained that he and Arline had a pact—no lies, not even white ones. How would he be able to face her with this biggest lie of all?
His parents, Arline’s parents, and the doctors all urged him not to be so cruel as to tell a young woman she was dying. His sister, Joan, sobbing, told him he was stubborn and heartless. He broke down and bowed to tradition. In her room at Farmingdale Hospital, with her parents at her side, he confirmed that she had glandular fever. Meanwhile, he started carrying around a letter—a “goodbye love letter,” as he called it—that he planned to give her when she discovered the truth. He was sure she would never forgive the unforgivable lie.
He did not have long to wait. Soon after Arline returned home from the hospital she crept to the top of the stairs and overheard her mother weeping with a neighbor down in the kitchen. When she confronted Richard—his letter snug in his pocket—he told her the truth, handed her the letter, and asked her to marry him.
Marriage was not so simple. It had not occurred to universities like Princeton to leave such matters to their students’ discretion. The financial and emotional responsibilities were considered grave in the best of circumstances. He was supporting himself as a graduate student with fellowships—he was the Queen Junior Fellow and then the Charlotte Elizabeth Proctor Fellow, entitling him to earn two hundred dollars a year as a research assistant. When he told a university dean that his fiancée was dying and that he wanted to marry her, the dean refused to permit it and warned him that his fellowship would be revoked. There would be no compromise. He was dismayed at the response. He considered leaving graduate school for a while to find work. Before he made his decision, more news came from the hospital.
A test had found tuberculosis in Arline’s lymph glands. She did not have Hodgkin’s disease after all. Tuberculosis was not treatable—or rather it was treatable by any of dozens of equally ineffectual methods—but its onslaught was neither swift nor certain. Relief came over Richard in a flood. To his surprise the first note he heard in Arline’s voice was disappointment. Now they would have no reason to marry immediately.
As the spring of 1941 turned to summer, the prospect of war was everywhere. For scientists it seemed especially real. The fabric of their international community was already tearing. Refugees from Hitler’s Europe had been establishing themselves in American universities for more than half a decade, often in roles of leadership. The latest refugees, like Herbert Jehle, had increasingly grim stories to tell, of concentration camps and terror. War work began to swallow up scientists long before the Japanese attack on Pearl Harbor. A Canadian colleague of Feynman’s returned home to join the Royal Air Force. Others seemed to slip quietly away: the technologies of war were already drawing scientists into secret enterprises, as advisers, engineers, and members of technical subcommittees. It was going to be a physicists’ war. When scientists were covertly informed about the Battle of Britain, the critical details included the detection of aircraft by reflected radio pulses—“radar” did not yet have a name. A few even heard about the breaking of codes by advanced mathematical techniques and electromechanical devices. Alert physicists knew from the published record that nuclear fission had been discovered at the Kaiser Wilhelm Institutes outside Berlin; that great energies could be released by a reaction that would proceed in a neutron-spawning chain; that any bomb, however, would require large quantities of a rare uranium isotope. How large? A number in the air at Princeton was 100 kilograms, more than the weight of a man. That seemed forbidding. Not so much as a grain of uranium 235 existed in pure form. The world’s only experience in separating radioactive isotopes on a scale greater than the microscopic was in Norway—now a German colony—where a distilling plant tediously produced “heavy,” deuterium-enriched, water. And uranium was not water.
Scientists picked up tidbits from casual conversation or found themselves fortuitously introduced into inner circles of secret activity. While Feynman remained mostly oblivious, his senior professor Eugene Wigner had for two years been a part of “the Hungarian conspiracy,” with Leo Szilard and Edward Teller, conniving to alert Einstein and through him President Franklin D. Roosevelt to the possibility of a bomb. (“I never thought of that!” Einstein had told Wigner and Szilard.) Another Princeton instructor, Robert Wilson, had been drawn in by a sequence that began with a telegram from his old mentor at the Berkeley cyclotron, Ernest Lawrence. At MIT, under cover of a conventional scientific meeting, Wilson and several other physicists learned about the new Radiation Laboratory, already called the Rad Lab, formed to turn the nascent British experience with radar into a technology that would guide ships, aim guns, hunt submarines, and altogether transform the nature of war. The idea was to beam radio waves in pulses so strong that targets would send back detectable echoes. Radar had begun at wavelengths of more than thirty feet, which meant fuzzy resolution and huge antennae. Clearly a practical radar would need wavelengths measured in inches, down toward the microwave region. The laboratory would have to invent a new electronics combining higher intensities, higher frequencies, and smaller hardware than anything in their experience. The British had invented a “magnetron” producing a microwave beam so concentrated that it could light cigarettes—enough to confound the Americans. (“It’s simple—it’s just a kind of whistle,” I. I. Rabi told one of the first groups of physicists to gather uneasily around the British prototype. One of them snapped back, “Okay, Rabi, how does a whistle work?”) These scientists acted long before the American public accepted the inevitability of the conflict. Wilson agreed to join the Rad Lab, though he had considered himself a pacifist at Berkeley. But when he tried to leave Princeton, Wigner and the department chairman, Smyth, decided it was time for another initiation. They told Wilson that Princeton would soon take on a project to create a nuclear reactor, and they told him why.
