Джеймс Глик - Genius - The Life and Science of Richard Feynman

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 fel owships—he was the Queen Junior Fel ow and then the Charlotte Elizabeth Proctor Fel ow, entitling him to earn two hundred dol ars 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 fel owship 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 al . Tuberculosis was not treatable—or rather it was treatable by any of dozens of equal y 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.

Preparing for War

As the spring of 1941 turned to summer, the prospect of war was everywhere. For scientists it seemed especial y 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 tel , of concentration camps and terror. War work began to swal ow up scientists long before the Japanese attack on Pearl Harbor. A Canadian col eague 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 distil ing 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 Tel er, 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 cal ed 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 smal er 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.

Fueling the prewar col aboration of scientists and weapons makers was a patriotic ethos that no subsequent war would command. It easily overcame Wilson’s pacifism.

Feynman himself visited an army recruitment office and offered to join the Signal Corps. When he was told he would have to start with unspecialized basic training—no promises—he backed down. That spring, in 1941, after three years of frustration, he final y got a job offer from Bel Laboratories in New York, and he wanted to accept. When his friend Wil iam Shockley showed him around, he was thril ed by the atmosphere of smart, practical science in action. From their windows the Bel researchers could see the George Washington Bridge going up across the Hudson River, and they had traced the curve of the first cable on the glass. As the bridge was hung from it, they were marking off the slight changes that transformed the curve from a catenary to a parabola. Feynman thought it was just the sort of clever thing he might have done. Stil , when a recruiter from the Frankford Arsenal nearby in Philadelphia—an army general—visited Princeton seeking physicists, Feynman did not hesitate to turn down Bel Laboratories and sign up with the army for the summer. It was a chance to serve his country.

In one way or another, by the time the United States entered the war in December, one-fourth of the nation’s seven-thousand-odd physicists had joined a diffuse but rapidly solidifying military-research establishment. A generation brought up with the understanding that science meant progress, the harnessing of knowledge and the empowerment of humanity, now found a broad national purpose. A partnership was already forming between the

federal establishment and the leaders of scientific institutions. The government created in the summer of 1941

an Office of Scientific Research and Development, subsuming the National Defense Research Committee, charged with coordinating research in what MIT’s president, Karl Compton, the epitome of the new partnership, cal ed “the field of mechanisms, devices, instrumentalities and materials of warfare.” Not just radar and explosives but calculating machines and battlefield medicines occupied the urgent war effort. An area like artil ery was no longer a matter of haphazard trial-and-error lobbing of randomly designed shel s. The nuclear physicist Hans Bethe had turned on his own initiative to a nascent theory of armor penetration; he also took on the issue of the supersonic shock waves that would shudder from the edge of a projectile. Less glamorously, Feynman spent his summer at the Frankford Arsenal working on a primitive sort of analog computer, a combination of gears and cams designed to aim artil ery pieces. It al seemed mechanical and archaic—later he thought Bel Laboratories would have been a better choice after al .