Maverick Genius

by Phillip F. Schewe

  Freeman left Los Alamos and, along with a few of his colleagues, flew to Aspen, Colorado. There he would be joined by Verena for some skiing. Imme, establishing herself in the Dyson home, would take care of Katarina, Esther, and George.

  Georg Kreisel drove Verena to the airport in Newark. On the way they spent a night together in a hotel.

  Years later, in a volume of reminiscences by colleagues published in honor of Kreisel, Verena openly spoke of the affair that was now unfolding. With Dyson she was trapped in an “iron cage of Princeton domesticity,” she said, whereas Kreisel represented freedom, or at least a return to intellectual rigor. Furthermore, one reason Kreisel had been attracted to her, Verena suspected, was that he might be exacting some kind of revenge on Freeman Dyson, who was seen by Kreisel as a great rival from their time together at Cambridge when they vied for preeminence in the mathematical tripos competition.25

  Verena went ahead to Aspen. A few days later, and after an exhilarating day of fine outdoor activity, Verena told Freeman of her night spent with Kreisel. His first reaction was to laugh. Then he was angry, then ruthlessly practical. He insisted that she repeat her confession in the form of a written statement—“My wife informed me, Freeman J. Dyson, that on January 21, 1957 she committed adultery. I in no way condone this, and will have no further conjugal…”—which she should sign before a notary public. At that hour, with no notary available, they went to dinner. There, in the presence of his colleagues, Freeman amusedly announced that soon he would have some news for them. In the meantime, he and Verena would be leaving early.

  The next day they followed through with the notary public. At Verena’s insistence, Kreisel’s name was left out.26 They left for Denver the following morning, got a plane for New York City, then the last train to Princeton, and took a cab to their home. On the threshold Freeman turned to Verena: “Of course you understand,” he said, “this is no longer your home any more, but you can spend the night here. In the morning you will leave.”27

  The standards of the 1950s being what they were, it was not incongruous that the husband should enjoy a fling and justify this as a heroic action out of a poem by Blake, whereas when the wife does the same thing it results in a notarized statement and her being ejected from the home.

  Kicked out, Verena found a run-down house to rent in the nearby town of Hightstown. She borrowed some bedding and kitchen utensils. In March she moved to Philadelphia and began a job at Remington Rand UNIVAC. This was close to Princeton so that she could easily see the children on the weekends.

  Kicked out: this was Verena’s side of the story. Imme insists that Verena, frequently moody, left of her own accord. Freeman was devastated by Verena’s departure, Imme insists.28

  On one of Verena’s weekend visits in late spring, Freeman led Verena over to the Oppenheimers’ home for brunch. This was something of an honor; many Institute members came to the director’s residence for parties, but few came for breakfast in the kitchen. On the way in Verena saw a four-leaf clover. She stooped to pluck the thing and has kept it to this day. Inside, Freeman, with a laugh, declared that he and his wife did not live like other people, and that their marriage was ending (paraphrasing from the poetry of T. S. Eliot) “with a bang, not a whimper.”29

  That summer Verena Huber-Dyson, as she would call herself from then on, and Georg Kreisel traveled to a mathematics conference at Cornell University, where their appearance as a couple created a stir.30 After that they left for Britain, where Kreisel had an appointment at the University of Reading. This was, Verena thought, a new start for her, as a woman and as a mathematician. Some of this was her doing and some of it she credits to Kreisel. He was a difficult personality, but conversations with him were helping her to think analytically again. “Being with Kreisel was not fun,” she had to admit, “but it was meaningful.”31

  In June, Freeman drove with Esther, George, and Imme west to California, where again he would be working with Charles Kittel in Berkeley. But once there Freeman found that he couldn’t concentrate. “While I was supposed to be thinking about ferromagnets, my head was full of conservation laws and high energy experiments. Kittel and I agreed that I should not come back until I had a summer free of competing distractions. This never happened.”32

  8. Space Traveler’s Manifesto

  Dyson as Rocketeer

  (1957–1959)

  As a boy of nine Freeman Dyson visited the Moon. He wrote a story, “Sir Phillip Roberts’s Erolunar Collision,” about a wandering celestial object called Eros on a collision course with Earth’s Moon. The hero of the story is an explorer and scientist in the manner of Indiana Jones who wants to put himself in the path of danger. He journeys to the Moon to see the collision close-up. The rest of Dyson’s juvenile sketch described the vehicle for shooting Sir Phillip from a huge barrel in Jules Verne fashion. Dyson, who just then was being bullied by bigger boys, had retreated to the school library and escaped into fiction. He gave loving attention to calculating the necessary dimensions for the lunar projectile-craft.1

  The nine-year-old Dyson didn’t have enough fortitude, and the story petered out before the Erolunar plans were complete. Now, a quarter century later, the adult Dyson was about to get a second chance. He would attempt to finish what Sir Phillip had started.

  THE RIGHT STUFF

  The year is 1957 and there isn’t any Moon-impacting comet in sight. But there is something nearly as bad. The menace isn’t out there beyond Neptune but right here on Earth, at the horizon, stretching itself across half a dozen time zones. The Soviet Union, and not some inert celestial object, was coming in our direction, threatening Western civilization. Actually, part of the threat was in space. The Russians had just done what American engineers were not yet able to do: place a small radio transmitter into orbit around the Earth. The Soviets referred to Sputnik as a scientific experiment, but many in the West viewed the tiny satellite as a menacing portent. Its mere radio ping, given off as it looped overhead, could be taken as an affront to American know-how.

  Suddenly space was hot. Space, the gigantic empty ocean above us, wasn’t just a void stretching between Earth and Moon or the planets and stars. It could be viewed as a potential theater of war where weapons might be deployed. Worse; the Soviets wanted to make it their private lake. Dyson was not among those caught off guard. He had long been interested in Russia, and he knew people who knew what the Soviets were up to. But for most of the American public, in and out of government, Sputnik had come as a shock. Naturally there had to be an American response.

  The U.S. Army was aiming to send a craft to the Moon. The first step was getting something, anything, into orbit. After a humiliating failure or two, orbital altitude and velocity were finally accomplished using vehicles designed by Wernher von Braun, formerly Hitler’s master of rocketry and now a resident of Alabama. Indeed, the army rockets were a modified version of the V-2 missiles that had rained down on Freeman Dyson and his countrymen during the Blitz.

  Generally the progression here was from propeller to jet to rocket. All three produce propulsion by the combustion of fuel in an engine. The propeller moves the craft by twirling about and pushing masses of air to the rear. The jet scoops up air as the craft flies, burns the air with fuel, and then develops thrust by forceful backward ejection of the combustion products. Jet vehicles are much faster than propeller vehicles. Faster still is a rocket, which like the jet produces thrust by chemical combustion. The key difference: rockets carry all their own oxygen; they don’t need to scoop up air as they go. Recognizing no boundary, they can zoom into space, where air-breathing jets may not go.

  Were other forms of propulsion possible, better and faster than jets? Ted Taylor had the answer. The very night of the Sputnik launch, an idea had come to him, and he shared it with his General Atomic colleague Freddie de Hoffmann.2 In due course Dyson would be informed.

  Other branches of the U.S. government were also interested in attaining high velocity in space. The air force was lookin
g for orbital opportunities. The Advanced Research Projects Agency—ARPA, the predecessor of the modern DARPA, the Defense Department program for developing high-tech equipment—showed definite interest and had seed money available. Things were moving quickly. Just as the Atomic Energy Commission had taken over civilian control of nuclear research and custodianship of nuclear weapons, so too a new civilian government entity in charge of operations in space would make its debut the following year. Its name was the National Aeronautics and Space Administration—NASA.

  Somewhere among these mighty conglomerates an upstart alternative space venture would struggle for survival, and Dyson would be at the heart of it. Chemical rockets, von Braun–style rockets, were getting all the attention, but no final decision had yet been made about the kind of missile to be used to carry America into space. Maybe chemical wasn’t the best way to go. Taylor and a few others wanted to build a new kind of ship, something much grander than what von Braun had in mind.

  General Atomic would again provide the institutional home. “Give me a roomful of theoretical physicists,” Freddie de Hoffmann said, “and I will conquer the world.”3 The odds of defeating chemical rockets were slim, but de Hoffmann felt there was a period of opportunity, maybe only one or two years, for demonstrating a better plan for getting into space and out there among the planets. Like a movie producer who had just hired himself a hotshot director (Taylor), de Hoffmann now wanted to procure a hotshot actor for the lead role. He hinted at the creation of an immense project and was offering Dyson the chance to get in at the beginning.

  Because of the radical nature of the propulsion being contemplated, national security was going to be an issue. A full clearance would be needed, and de Hoffmann therefore wasn’t able to tell Dyson more than a few of the details. What seemed to be in prospect, however, was the engineering equivalent of the Manhattan Project, a project potentially just as big and just as important, but without the killing. Take the TRIGA reactor project, multiply by a thousand or a million, and that’s what the new thing might turn out to be. It was that big.

  Dyson was just then on another one of his tours into mathematical physics, the kind of work that concerned the representation of quantum fields and, like number theory, involved detailed and rigorous proofs. Having submitted his conclusions to Physical Review, he discovered to his horror that he’d made a mistake. Perhaps still somewhat distracted by general events in this life, he’d slipped up and now had to do what every scientist hates to do—submit a retraction. Dyson told a friend of his humiliation at having presented a nonrigorous proof. The friend’s reply: “What do you mean non-rigorous proof? There is no such thing as a non-rigorous proof. Either it is a proof, or it is not a proof.”4

  Dyson accepted de Hoffmann’s offer and in January 1958 began occasional consulting visits to General Atomic. He asked his boss at the Institute, J. Robert Oppenheimer, for a leave of absence. Oppie, who himself had once taken leave from an important position at the University of California to take up a gamesome nuclear design project in the desert, could hardly say no. Besides, Hans Bethe had endorsed the project, which was to be called Orion.5

  Freeman left the children behind in Princeton in the care of Imme Jung. Katarina had spent the 1957–58 school year boarding in the home of her ballet teacher nearby. Verena would now be returning from Europe and would live in the home on Battle Road Circle while Freeman was away. She had spent the fall months with Georg Kreisel in Britain and several more months alone in Zurich, where she’d been doing mathematics research again.

  On the day before Freeman’s departure for San Diego, Verena arrived in the United States and asked Freeman if she could live again as his wife. According to her, his answer was no.6

  DARWIN ON MARS

  Much is made of the mountain-and-plateau New Mexico setting for the Manhattan Project. You could think of its location on that isolated mesa as if it were a giant anvil on which the first nuclear bomb was forged. It was off by itself. By contrast, the seacoast-and-palm-tree setting and jaunty shirtsleeve insouciance of Project Orion would be typical of the whole aerospace industry that was sprouting up around suburban Southern California. Before long Dyson himself would own a 1957 Chevrolet Bel Air, which with its pastel shading and signature tail fins would become associated with the iconic look of the 1950s, especially emblematic of California surfer culture. He joined a glider club.

  If anything it was a bit too sunny there. Dyson was having eye problems and had to wear dark glasses to keep out the glare. But he was there to work and not to sunbathe. He was determined to get it right this time. In 1943, freshly out of college at the age of nineteen, Dyson had joined Bomber Command, whose mission was to defeat Fascism. In practice, however, this meant maximizing the number of killed Germans. Now, in 1958, as an eminent scientist, he was joining a new sort of Bomber Command, only this time the goal was not to kill civilians but to reach planets. The new work required the explosion of nuclear bombs, lots of them.

  Basically Orion was a nuclear-powered spaceship, and it worked like this: An atom bomb is shoved out the back of the craft. At a certain distance, a hundred feet or so, it explodes. Part of the blast slams into the back of the ship. The explosion pushes a gigantic disk coated with a thin layer of sacrificial material. The layer is vaporized into fiery plasma, a cloud of hot atoms from which electrons have been stripped off. This plasma, in turn, pushes violently on the disk, propelling it away from the blast. The disk is attached to a manned spacecraft through an elaborate system of shock absorbers that cushion the riders from the immense forward jerk.

  Let’s stop right there. Having heard scarcely the merest description of Orion, many will have been quickly brought to incredulity. Cinematically it might be easy to visualize a series of nuclear explosions but not so easy to believe that anything nearby could survive intact. A dozen urgent questions scream out: Where do the bombs come from? How big is the craft and how does it get off the ground? Why doesn’t it melt from the effect of the bomb? Where are the astronauts? Why aren’t they incinerated or at least irradiated into a state of blue glow?

  First, the disk does not melt if it has a proper coating sprayed on just before detonation. This coating, thin as it is, makes all the difference. Tests of actual nuclear bomb blasts showed that certain nearby metal objects, properly sheathed, could survive. The highest heat during the explosion lasts a mere fraction of a second. The sacrificial layer not only takes the brunt of the blast but provides the actual propulsive force. The rest of the ship, starting with the disk, is pushed away from the explosion by the plasma cloud. The craft does not so much gain thrust by sending exhaust out the back, the way rockets do, as it is pushed ahead by the plasma action of the cloud. Much of the blast and radiation is left behind and does not penetrate the disk and other parts of the craft situated further along.

  The ship, in effect, would be surfing through space on a hot plasma plume triggered by and flung outward from a nuclear detonation. The process is repeated many times. A new sacrificial layer is deposited across the back of the pusher plate, another bomb is brought out of the storehouse at the center of the ship and ejected out the back, another explosion occurs, another plasma cloud envelops and pushes the craft, and still more speed is achieved.

  Isn’t this going to be a bumpy ride? Yes, the blast-created plasma impinging on the craft does impart a violent kick, but this is smoothed out by the stacked shock absorbers. The timing of the blasts, every few seconds or so, at least at first, and the coordinated working of the springs would average out to something like an acceleration equivalent to about 3 or 4 g’s, no more than what the Apollo astronauts later put up with on their journey into space.7

  Still incredible? They’ve got the bombs loaded on the ship from the beginning? Yes, thousands of them, lined up on an inside rack. They descend a chute one at a time like cans in a soda machine. In fact, the Coca-Cola Company was consulted on this issue.8 The astronauts on board aren’t affected by the bombs going off only a hundred fe
et away? No, because the thick pusher plate sits in between. Furthermore, the expanding plasma shoves the ship away from the bomb blast. How would you ever get used to an acceleration of several times that of Earth’s gravity? This acceleration wouldn’t be there all the time, but only when you were in a boost phase.

  Boost phase? How does the whole thing get off the ground at all? Well, it blasts off from a tall tower. As you might imagine, a takeoff on top of an exploding atom bomb would make an Apollo launch, even with its roar and billowing smoke, look sedate. The early blasts would be small at first, enough to get Orion up off the ground and into space. Later explosions, the ones needed to gain really high speed, would be larger and come less often. For much of the time during a long mission there would be no explosions at all. The craft would be coasting.

  Does the mind still reel at the audacity and the improbability of the whole scheme? Suspend for a moment your disbelief, along with arguments about the political, environmental, and budgeting impracticalities, and consider the plan’s virtues. Consider Orion from Freeman Dyson’s point of view. The energy density in U-235 is so large that even when you take into account the fact that much of the effect of any nuclear explosion would wastefully shoot off in a direction away from the ship, the conversion ratio for the nuclear rocket scenario used in Orion is still far superior to that for the chemical rocket scenario contemplated for the Apollo mission.*

  Payloads and destinations are what motivated the people who had dreamed up Orion. This mad scheme of using bomb blasts to propel a ship first came to Stanislaw Ulam, the scientist who along with Edward Teller had been the chief creator of the first hydrogen bomb. Now Ted Taylor had commandeered the idea. Freddie de Hoffmann, with the organization of General Atomic behind him, provided the infrastructure. An ARPA grant allowed the project to grow quickly. With such an ambitious goal in mind, a proliferation of problems needed solving. That was where Dyson came in. If de Hoffmann was to be Orion’s equivalent of General Leslie Groves, and if Taylor was to be the Oppenheimer for the project, then Dyson would be its Hans Bethe, the chief theoretician.