At the Pocono conclave, Feynman’s approach didn’t go over well. Feynman, who would later be legendary for his sparkling self-assured, animated presentations, was on this occasion unclear and troubling. Questions kept coming. Teller wanted to know if Feynman’s theory took into account the exclusion principle, which insists that not more than one electron may occupy a specific quantum state at a time within an electron. Dirac wanted to know if the theory was unitary. Feynman was stumped. He had to be told what unitary meant: it referred to the fact that when you sum over all possible paths that the probability of something happening was somewhere between 0 and 1.
Bohr was particularly bothered. He wanted to know if Feynman’s theory was compatible with the uncertainty principle. It didn’t seem to be. Didn’t Feynman know even elementary quantum mechanics? Here, said Bohr, give me the chalk. And with that the elder statesman of quantum science took over. Feynman’s inexplicable ability (some called it magic) to glide over numerous tedious steps in a multistep disquisition—his supernatural power to arrive at the correct answer quicker than anyone else—here tripped him up.
In modern intellectual discourse we use words to convey ideas. In mathematical physics, words are supplemented with symbols, Greek letters, subscripts and superscripts, all packed into equations. Schwinger, difficult as he was to understand, at least used conventional-looking equations to describe electrons. He spoke a language, the equivalent of the church-approved Latin, the other quantum bishops could follow.
Feynman, by contrast, had invented a pictorial language of his own, a new form of hieroglyphs. He showed you how electrons interacted with each other using drawings covered with squiggles going every possible way. Feynman delivered his promotional pitch with the gusto of an auto salesman. But also like the salesman he didn’t seem to answer all the questions put to him.
His demanding audience, not to be swept aside, wanted precisely to see all the intermediate levels. If Schwinger could do it, why not Feynman? Schwinger had unpacked his version of reality and had not seen fit to violate any known laws of quantum reality. With Feynman you couldn’t be sure what had happened. In the battle of the theories he was clearly the loser.
The Pocono meeting was over. Feynman’s Princeton thesis advisor, John Wheeler, compiled and circulated detailed notes. Feynman, put in an awkward position, was asked to summarize the meeting for Physics Today magazine. In the modest sentence or two he devoted to his own brand of quantum electrodynamics he had to admit that it wasn’t as complete as Schwinger’s.16
THE THIRD MAN
In hindsight we can say that the prospective reformation of quantum science would have been faster if another man had been present. Two noninvited scientists should have been at the meeting. One, only a hundred miles away at Ithaca, was Freeman Dyson, who, having already formulated a worthy account of the Lamb shift, would soon have much more to say on the subject.
The other missing man was, through accident of birth and by the burden of world war, stranded on the other side of the world. Most Pocono participants had no idea that Japanese physicists were chasing the same quantum infinities bothering those in the West. Infinities know no boundaries. They do not stop for world wars. Electrons are the same whether they plunge out of the ubiquitous electron field in Tokyo or Quito or Helsinki.
Shin’ichiro Tomonaga, working with colleagues at the University of Tokyo, had formulated an infinity-neutralizing explanation very similar to Schwinger’s, except that the man in Japan seemed to have arrived at his model several years before the man at Harvard. Neither knew of the other’s work, and yet a splendid parallel achievement had come about, testifying to the common genius of human intelligence. Here you had several inquisitive minds pondering the same dilemma of matter at the most basic level, but working in different hemispheres and immersed in very different cultures.
Consider Tomonaga’s situation. Even after the U.S. Air Force stopped its bombing attacks at the end of the war, privations continued in Japan. It was hard to obtain food and shelter, much less scientific equipment or journals. It had been hard for Dyson and the rest of the British to restart the rhythms of life in postwar London. And they were the victors. In Tokyo rhythms were even harder to regenerate.
For several years after the war, ordinary Japanese were forbidden to travel or even to receive mail from abroad. The piece of news that so electrified the physicists gathered on Shelter Island, namely the Lamb shift, came circuitously to the physicists gathered in Tokyo. In Shelter Island they listened to Lamb himself. In Japan, Lamb arrived in the pages of Newsweek magazine, copies of which were placed on the shelves of the public libraries operated by the American Occupation forces.
Bethe in Cornell and Oppenheimer at Princeton had finally received copies of Tomonaga’s paper, and Oppie quickly made the Japanese work known to the Pocono attendees. He arranged to have it published in Physical Review. Dyson, pondering Tomonaga’s plight, considered such an outstanding paper coming from Tokyo to have been a voice from the deep.17 Thus was forged the beginnings of a true international theory of electrons and light.
ON THE ROAD
In the history of quantum electrodynamics, one of the most important friendships, if not exactly a collaboration, was the one between Richard Feynman and Freeman Dyson. Dyson felt that he stood in relation to Feynman as the playwright Ben Jonson had been to William Shakespeare.
The 1623 collection of Shakespeare’s plays features a effusive preface. Written by Jonson, Shakespeare’s protégé, friend, and sometime rival, this most famous of literary encomiums gives eyewitness tribute to Shakespeare’s good nature, his industry, and his superior talent: “He was not of an age, but for all time!” said Jonson. Not one given to easy charity, the otherwise boastful Jonson admitted that he admired the Swan of Avon (another of Jonson’s phrases for Shakespeare) “this side idolatry.”
Three and a half centuries later Freeman Dyson would play the same role for Richard Feynman. Writing the Preface to a collection of Feynman essays, Dyson embraced his idolatry.18 Calling him a sort of American Shakespeare, Dyson commended Feynman for his good cheer and his quicksilver ability to see through to the heart of physical problems.
Since arriving at Cornell months before, Dyson had, in many letters to his parents back in England, provided an apt portrait of his newfound friend. Feynman was not just smart. By his jovial presence he maintained morale. He was the life of every party. He loved to play on bongo drums and perpetually seemed to be in a good mood, but not necessarily in a sweet mood. Dyson, always ready to learn something, would frequently go around to Feynman’s office. If Feynman wanted to talk, they talked. If he didn’t want to talk, he told Dyson to go away.19 The first half of Dyson’s Cornell year had been spent extending Bethe’s work. The second half of the year was devoted to being Feynman’s sounding board,20 and Dyson considered this the best possible education. Feynman was the new Frank Thompson in Dyson’s life, an older brother to look up to.21
Feynman threw off good physics ideas as a meteor throws sparks. He was, Dyson wrote, part genius and part buffoon.22 The larger public fame of Feynman-as-Shakespeare did not emerge for some years, until in the 1980s the essence of the man was captured in Surely You’re Joking, Mr. Feynman! and other books filled with his aphorisms. But among physicists the man’s reputation for largeness of soul was already there in the 1940s at Cornell, and before that at Los Alamos.
If you were Ben Jonson and William Shakespeare invited you along on a car trip to Albuquerque you would surely accept. And so it was that starting in Cleveland in June 1948, Dyson found himself in the passenger seat of Feynman’s car on a cross-country journey. This would be a great chance for the young man (age thirty) from Queens, New York, and the even younger man (age twenty-four) from Winchester, England, to become better acquainted. They talked about physics, naturally, and many other things.
The war was over but new hostilities were blossoming. Thanks to the weapon that Richard Feynman had helped create in Los Alamos, the
world was again quickly becoming a dangerous place, and the overhang of the nuclear threat was preying on their minds. Coming into St. Louis, for instance, Feynman deduced with grim precision, at various mileposts approaching the city, the likely effects of a hypothetical Hiroshima-size bomb detonation. This mordant apocalyptic ritual was played out at several cities, and Dyson came to feel uneasy, as if he were with Lot making his way through Sodom and Gomorrah.23
The car glided along at high speed down Route 66, the signature pike of pre-Interstate America. For Dyson, the Englishman from a green isle, it was his first time in a really dry place. Not only did he enjoy the novel geography but also the human panorama. Feynman was fond of picking up hitchhikers, who added a stream of conversational topics. Dyson was amused to see Feynman adapt his speaking style to the successive backseat riders. The farther west they glided the folksier he got.
The automotive part of the trip went well until they hit Oklahoma, where drenching rains flooded the path. Nearby towns were disrupted and drownings were reported. At the town of Supulpa they reached a blockage. So the two scientists were forced to backtrack, and found themselves in the town of Vinita, where they spent the night. Owing to the storm, accommodations were scare, and so they shared the only available room, at fifty cents per man, in a brothel.
With rain beating down outside, a stifling stuffiness inside, and girlish noises coming from outside their door, the two men spent the whole night talking in the dark. Feynman spoke of his first wife, Arline, and of her struggle with cancer. He spoke of his loneliness in the years following her death. According to Feynman’s biographer James Gleick, “Feynman confided more in Dyson than he had done with any friend in his adult life,” at least up to that time.24
You can’t have Freeman Dyson and Richard Feynman in a room without talk of quantum physics. Feynman, with his pictorial approach, was attempting more than a solution to the infinity problem. He felt that his approach might be applicable to other areas of physics too, such as to the realm of gravity and also to the atomic nucleus. Dyson wasn’t sure about this. He mistrusted Feynman’s intuition, however valuable it might have been in leading Feynman to physics discoveries. Many all-inclusive physics theories had foundered before, he argued. Conversely, Feynman mistrusted Dyson’s reliance on mathematics. Math, to Feynman, was to be used but not to be treasured for its own sake.25
In Feynman’s account of this night, but not in Dyson’s, we learn that the Englishman found himself in need of a toilet. But he was reluctant to open the door, since this would mean having to run a gauntlet of prostitutes on the way to the lavatory at the end of the hall. “Use the sink,” said Feynman. “But it’s unsanitary,” responded Dyson. “Run the water,” said Feynman. To this sensible suggestion Dyson had no immediate response. But Feynman reports that later that night he could detect, from the other side of the room, a discreet movement toward the sink.26
The rain abated the next day and the men continued on through Texas to New Mexico. They came streaming into Albuquerque, going seventy miles per hour in a twenty-miles-per-hour zone, meriting the highest speeding fine ever issued by the local judge. Feynman, in high spirits, reminisced with the judge about wartime conditions in the town, and cajoled His Honor into reducing the fine. Feynman’s main reason for coming all this way had been love. Near the end of the war, Feynman had met a woman in town and was coming back to see how things stood between them. Dyson guessed, incorrectly as it turned out, that the attachment would turn to marriage.
Dyson was himself entangled with a female, at least slightly. He was receiving letters from Hilde Jacobs, one of the German girls he’d met the summer before in Münster. These letters were starting to increase in number.27 One was especially long and addressed in a roundabout way something on her mind. Her letters to Dyson were usually in German, but at the very end of this letter she quoted in English from “He Wishes for the Cloths of Heaven,” a poem by William Butler Yeats:
Had I the heavens’ embroidered cloths,
Enwrought with golden and silver light,
The blue and the dim and the dark cloths
Of night and light and the half-light,
I would spread the cloths under your feet:
But I, being poor, have only my dreams;
I have spread my dreams under your feet;
Tread softly because you tread on my dreams.
What was Hilde’s reason for quoting this passage, he asked himself. What was her dream? He decided he’d better be careful. In matters like this he would have to tread softly.
ON TO PRINCETON
The two buddies now split up. Feynman stayed in Albuquerque while Dyson got on a Greyhound bus. The terms of his fellowship encouraged him to gain wide experience. Dyson had traveled to Germany the previous summer and planned to go to Mexico to do manual labor. But now he decided to spend the summer soaking up still more physics at the Michigan Summer Symposium in Ann Arbor.28 He loved riding in buses and was eager to survey the geography of his adopted country. His method was to sightsee during the day and ride the bus at night. Not that he slept that much. He came to have a hankering for all-night talk, falling into Feynman-style conversation with the person sitting across the aisle. And so the miles sped by.29
Dyson liked Michigan and did some campaign work on behalf of Henry Wallace’s 1948 presidential campaign.30 But his primary purpose was to attend classes where he could hear Julian Schwinger lecture.31 At first sight Schwinger seemed formidable, but the stiff impression softened a bit when you got to know him privately. Still, his brand of mathematics seemed more difficult, more encumbered with details, than necessary. So thick a forest of equations, surely, could not be the best way of describing nature.32 When Schwinger came to submit his theory to the pages of Physical Review he had to obtain special dispensation from the editors, who for the first time allowed equations to spread out beyond the width of a page and to spill onto a second line.
Dyson did not return to Cornell in the fall term. True to his restless nature and to the expansive spirit of his fellowship, he was moving on to yet another institution. In their turn, London, Cambridge, and Ithaca had been useful but limited. At Cornell, especially under the watchful eye of Hans Bethe, Dyson had learned a lot. But he had officially signed up only as a master’s degree student, and Bethe now decided that Princeton would be a better place for Dyson.33 They agreed a year spent at the Institute for Advanced Study with J. Robert Oppenheimer would be a fine thing.
As usual, Dyson came highly recommended. Oppie could read for himself Dyson’s article on the Lamb shift in Physical Review, but if that wasn’t enough there was Bethe’s private letter to Oppenheimer describing Dyson as the best graduate student he’d ever seen.34
4. The Secret Signature of Things
Dyson as Artist
(1948–1949)
What is the most important week of your life? Its probably wrapped up with the birth of a child, a vacation in Hawaii, a wedding. It’s often hard to say. But for Freeman Dyson—restricting ourselves to his scientific career—his most important week was about to break out.
On top of an exhilarating year at Cornell, Dyson had just had a fulfilling summer. First by bus to Cleveland and by car with Feynman down to New Mexico. Then by bus up to Michigan to hear Schwinger. These were memorable events but they did not, by themselves, afford him his best week.
What his weary mind craved now were mountains and desert scenery. He went by bus out to the Pacific coast. Dyson, his head stuffed with Feynman’s diagrams and Schwinger’s fields, was on a well-earned holiday. What he now saw from his window passing through Utah gave him particular bliss. The Mormons, having set off on their own with a peculiar vision of the world, had marvelously planted towns up beautiful mountain valleys. Dyson, loving tidy arrangements, appreciated the pattern of their crop cultivation. It struck him as being almost Swiss.1 But this was not yet the week.
He went to Berkeley and roomed in the International House. The physics building was nearb
y, but he stayed away.2 Instead he diverted himself by reading James Joyce’s A Portrait of the Artist as a Young Man, which tells the story of a spiritual and aesthetic odyssey not unlike what Dyson was undertaking just then.3
Dyson’s thinking had actually been free of physics for two whole weeks, and still he couldn’t relax. Something was turning over in his mind. Restless, he got back on yet another bus and headed east. He had some of his best thoughts on buses. He was not yet twenty-five years old, and precisely now, without him knowing it, the week had begun.
NEBRASKA HAILSTORM
Although Dyson had written that article for Physical Review about the Lamb shift, he now yearned to provide a fuller explanation. He liked the feeling of adding to knowledge. He enjoyed calculating the behavior of particles at the submicroscopic level. In effect, he was telling electrons what to do. Would they obey? His effort to enunciate new physics rules, or at least to fashion some better version of Feynman’s and Schwinger’s rules, was to include physics and art: “It is like writing a novel where you as author have complete control over the characters,” Dyson said. “It is a self-contained world where you understand everything, the parts and the whole.” 4
This sounds like a formula right out of the book Dyson was reading. Here is Joyce’s description, in A Portrait, of the literary writer’s mission: “The artist, like the God of creation, remains within, or behind or beyond or above his handiwork, invisible, refined out of existence, indifferent, paring his fingernails.”5 Except in the case of Dyson the scientist-creator would be sitting at a desk, with his feet up, reading a newspaper. In Joyce’s novel, the artist-hero, Stephen Dedalus, looks for inspiration as he strides through the streets of Dublin. In Dyson’s saga, the scientist-hero rumbles across the High Plains in a Greyhound.
“Epiphany” was Joyce’s name for the intensest form of artistic apprehension. He borrowed this term from Christian observance where, for example, the nature of Christ is manifested in a sudden realization. In A Portrait Joyce uses epiphany as a literary term. It represented a shining forth, an aesthetic revelation by which an artist recognized “the secret signature of things.”
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