The Berlin Project

by Gregory Benford

  The room murmured, everyone muttering an opinion on the choices.

  That there were choices at all was news to Karl. He had been focused, ignoring all other issues and gossip. With Fermi and Urey he had worked to get the first fast centrifuge into operation. That meant going by train to the Westinghouse research buildings in Pittsburgh to shape the work, up to the first working device. He had missed that others at Columbia, Dunning’s team especially, had been going along another track.

  “I want to see some real separation data,” Urey said, face firm. “If you have it. Not just some projections.”

  Karl decided to get into the fray, though he was still a junior member of this group. He said, “What membrane can stand up against the vicious bite of the uranium hexafluoride? Have you found one?”

  Dunning was a big guy, and his body language showed that he was used to being in charge. He puffed himself up, adopted a thoughtful gaze, waltzed left, turned right, shrugged. Eyebrows up. “Not yet, no. We tried some simple filters and they blew apart. That U-hex is tough stuff.”

  Karl knew this already. As a chemist he saw that the cumbersome method of separating U-235 and U-238 was to push a gas of uranium bound to fluorine through a barrier, a membrane. The slightly lighter U-235 passed through a bit more effectively, so on the other side the residue got enriched.

  Dunning dodged. “We’ll see. Too early to tell.”

  Urey rose. “Too early to tell? But then you don’t know it’s gonna be the best.”

  Still, there was a logic to Dunning’s argument. Apply high temperatures to the hex, put it under pressure, and the lighter isotope diffuses easier through a membrane, due to its higher speed. Karl knew that maybe a membrane of electro-deposited nickel mesh could do it. A big maybe, though. Since the mass separation ratio was quite small, a plant would need many stages. Each stage enriched the uranium of the previous one, just a bit more, before being sent to the next stage. The tailings from each stage returned to the previous stage for repeated enrichment. So a cascade of membranes, or of centrifuges, was the answer.

  A huge industry. Nothing like it had ever been tried. Now they had to do it when the war loomed like a purple gathering cloud on their horizon. If the Germans got such a weapon, they could attack America, the whole world. Yet all these implications played out in a quiet academic seminar. He had seen paintings of surrealism, read some books—but this was the real thing.

  “So this ‘electromagnetic mass spectrograph’ can do the job?” Karl asked.

  “It’s the brainchild of Ernest Lawrence, out in California.” Dunning sniffed dismissively. “He calls it a calutron, and it’s based on his cyclotron, which I’ve built a close copy of. It’s all about the precise control of beams of charged particles. Like this.”

  Calutron

  “See,” Dunning went on, in his element, “the technique is simple, but the scale has to be huge. You take a beam of ions, naturally occurring uranium, so it has U-235 and a hundred forty-three times more U-238 in it.”

  Dunning scribbled a quick equation on the blackboard. “Then pass it between the poles of a big magnet, so those two isotopes split into several streams according to their mass, one per isotope, each with a particular radius of curvature. Some charged cups at the ends of the half-circle trajectories catch the streams. Lawrence estimates—this is from a paper he sent me—he could enrich U-235 by about fifteen percent.”

  “So then you do it again,” Fermi said from the front row.

  “Right!” Dunning pointed at Fermi. “Keep refining it.”

  Fermi said mildly, “I respect Lawrence very much, but . . .” The room hung on his pause. “This-a seems very optimistic. The difference in mass is tiny between uranium 235 and 238. I would like to see data.”

  “I’m sure I can get some,” Dunning said, turning away, smiling.

  But Fermi was not through. “At the end of their arc, the ions of U-235 are more plentiful on the inside than on the outside of the beam. But the maximum separation even in the ideal case is small.” He waved a small notebook, where apparently he had made a calculation during Dunning’s talk. “There is only one-tenth inch for an arc with a diameter of thirty-seven inches—that is, ninety-four centimeters—which is the size of Lawrence’s cyclotron. And actual beams are far from ideal.”

  Dunning drew back, gave the crowd a lopsided smile. “I never said it would be easy.”

  No kidding, Karl thought. He was not sure why he disliked Dunning, but that didn’t matter much. Point was, Dunning was getting by on salesmanship, not physics. But physics bats last.

  A few chuckles. Dunning’s face fell. He kept on for a few moments, but Fermi had skewered his estimates. Leaving, Karl asked Urey, “Will this calutron thing compete with us for money?”

  A shrug. “Sure. And Lawrence won a Nobel last year too.”

  Another Nobel in the field, Karl thought as he walked home through honking traffic. He was a mouse among dancing elephants.

  6.

  May 14, 1940

  Karl lasted through the Pesach Sheni ceremony led by Rabbi Kornbluth, but it was a struggle. He thought about a calculation he was working on with Fermi instead of the rabbi’s droning speech. This minor Jewish holiday was, Rae had informed him, exactly one month after the fourteenth of Nisan, the day before Passover. That in turn was the day prescribed for bringing a sacrificial lamb in anticipation of Passover. “Admittedly, I had to look it up,” she’d said.

  This was exactly the sort of arcane time wasting he had expected of religion, any religion. He had only once before been to temple with his grandfather Cohen and had been bored then, too. But that same grandfather Cohen had left Karl enough money in his will to let him go to Paris and discover Marthe, too. Time abounded in ironies.

  He was here because his mother, Rae, thought it was canny to bring Anton and Karl to hear the rabbi, just to “keep lines of communication open” to the investors the rabbi had brought into Karl’s world. This reasoning too seemed nonsensical to Karl. Investors, a few of whom he had now met, cared about results, not ceremony.

  They were nearly free, almost out the tabernacle door, Marthe in front with the baby, when news came. The rabbi held up his hand and said solemnly, “Our enemies have invaded Belgium.”

  A rustle, and Karl got out the door ahead of Rae, who said, “I thought the Germans were going to hold off for summer.”

  Anton said, “They wait? Never. Already deporting many where I lived.”

  “They hit Norway and Denmark last month,” Karl said. “Now they’re headed for the main prize.”

  Marthe was already out of the tabernacle, he saw. She had bought a newspaper from the boy shouting the headlines on the corner.

  HOLLAND, BELGIUM, LUXEMBOURG INVADED, it screamed. Marthe said, “You mean headed for France.”

  Rae said, “That’s the way they did it in the Great War. Straight through Belgium.”

  People were already calling this World War II, Karl had noticed. Already it was bigger in scale, including the Japanese invasions in Asia.

  “This one is going to be greater,” he said. He decided to take them out to lunch. It might cheer them up a bit. Plus, he could write some calculations in his little notebook before the emotions of this day erased the idea that had come to him as the rabbi delivered his Hebrew wisdom, while the world burned.

  Centrifuge 2

  • • •

  Some obscure philosopher had said, God is in the details, Karl recalled. Now he was seeing that played out in tedium. Months stretched on.

  The first centrifuge from Westinghouse had arrived, with some engineers to handle installation, so Karl had pitched in to set up the first trial runs. They got into a basement room once used for storage, now fitted with electrical and gas tube feeds.

  The engineers dealt with the control systems, lots of wiring on racks, behind gray steel panels adorned with big dials. Ranks and ranks, like tiny skyscrapers. Everything had to be tried and tested. Karl dealt with the check valv
es and their monitors. All this he had to adjust and tune. Maybe the philosopher’s saying meant that if you looked hard enough, God’s fingerprints showed up somehow.

  He had distilled some uranium hexafluoride, “hex,” the real point of all this, but they would run with simpler compounds first. He used his chemical skills to do the rudimentary work of making isotopes of lighter elements, since they had a bigger fractional difference in mass. Now he wanted to see how the slim cylinder worked at high speeds. This was the first time he had seen his ideas shaped into solid hardware.

  “All set up now?” Fermi asked at his elbow. They were in another newly cleared lab in the lowest basement of the Pupin Physics Laboratories, and he had heard that they were ready to run.

  “Soon.” Karl showed Fermi the diagram Westinghouse had supplied of the built machine and then took him behind the cowling that wrapped around it. There wasn’t a lot of room left in the lab, after all the power and control apparatus got stacked in. Maybe universities weren’t the best places to build and try such stuff. But that was where the people who had the imagination were, for now.

  He forgot about Fermi as the trials started. The engineer team ran the centrifuge up and down, reaching interesting speeds, then backing off. The engineer team termed it a “spinner,” calling out, “Spin ’er up!”

  The engineers used the calculations Fermi had made, with some simple help from Karl. Maria Goeppert Mayer had done some insightful analysis that came in handy in the engineering too. Fermi had a clipboard and slide rule to keep track of the data. The man could do theory brilliantly, but he loved the grip of the real. They were near the resonances now. Fermi told the engineers to edge cautiously up into the danger area, and then accelerate through.

  This worked on the first few of the whole-body resonances—vibrations that could shake the whole thing apart—he and Fermi had worked out, and some in the Columbia engineering department had improved. The spinner whined with an eerie, cutting tone. It rattled a bit as its speed rose, and then an engineer shoved the power on hard. The whine added a jarring, rattling sound, a peevish complaint—and then they were through, the whine quieter now.

  They worked on, to higher speeds. Karl made up some impromptu earmuffs for himself and Fermi. That helped some.

  They were trying for a speed of three hundred meters a second at the end of the rotor. Their predicted resonance was at 268 meters a second. They idled at 250 and Fermi nodded to the head engineer. Karl made a note in his own lab book and looked toward the steel cowling that surrounded the centrifuge. Its high-pitched cry rose.

  The sound felt wrong. He jerked his hand up. A shrill note keened briefly—

  Later, trying to recall the moment, he seemed to see his hand moving with languid, slow-motion grace. In memory, something had alerted his unconscious, lending the events a sliding grace.

  Fermi’s face seemed to smear and dissolve an instant before Karl had the sensation of somebody hitting him in the head with a baseball bat wrapped in goose down. No sound, just massive impact. Then he was weightless, buoyant, the world beyond a blur of soundless velocities.

  No smack of landing. No sudden jar. But then he was lying in utter silence on a cement floor as cool as an angel’s kiss, staring up at the high, ribbed ceiling far, far away.

  He turned his head. Legs flicked across the milky foreground of this curiously flat, dimensionless scene. The disembodied legs seemed in a tremendous hurry for no apparent cause. Certainly he felt no great urgency himself. He turned his head again, finding it a great effort, the vertebrae going rak-rak-rak like a rusty crank-driven machine.

  How had he gotten tired so fast? Steel sheeting lay curled next to him, its jagged edges glinting in the enamel light. The steel kiosk around the spinner was now a shredded box lying on its side.

  It was odd, he thought, how wounded people looked like heaps of clothing, as if calamity was a confused fashion statement. They were somehow no longer people, just collections of their wrappings that had failed to protect them from the shrapnel weather here.

  Pain started to seep into his elbows. His shirt was torn and bloody. Abstractly he noted the cuts and bruises where steel had peppered him. Metal was cold, so the icy threads he felt up and down his legs were steel. Logical.

  The ethereal fog around him began to retreat, letting in movement—damp air, faces wide-eyed, their O mouths. Everything happened beyond the glass wall of silence.

  He got to his knees in a gliding, soundless world.

  He stood up shakily. Rubbery legs. Fermi was there with him in the silence, also getting up.

  He saw an engineer with a deep shoulder cut wobbling out of the room, brushing past them, his seeping blood smelling like freshly sheared brass, startling and pungent.

  God is in the details.

  • • •

  His hearing took a day to come back.

  The doctors who tended to the injured—fortunately, none seriously—insisted they all go home for a day to rest up. Indeed, he felt little of what the “health syrup” advertisements on the radio called vim and vigor.

  He got a phone call summary from Urey. The centrifuge had developed an instability, splintered, sprayed the lab with shrapnel.

  Marthe cared for him, sending him to bed with a mock-stern face. That gave him a good time to play with the baby, whom they had given the mouthful name of Martine Claude Malartre Cohen. Snap pictures of the small, precious center of their lives. And think.

  As he watched his wife move through the day, he realized that she and he had acquired important skills, almost without thinking about it. How to be vulnerable, how to set boundaries, how to listen, and how to speak up. They had learned the art of compromise and forgiveness and how to love someone, even when you don’t always like them. Through practice and repetition, they were mastering this exquisite, complicated dance, cultivating wisdom and muscle memory that could be successfully applied to their future.

  She now fathomed his earnest Jewish tribal loyalty, even though he was an atheist. She had laughed when Rae had described his family’s reaction to first meeting her. “She’s a looker,” his sister Mattie had commented, and Rae herself observed, “So he’s a goner.” They had missed that for him, Marthe stood for Paris, style, beauty, Europe.

  A deep wisdom flickered across her face, like light dancing on water. For him this was the finest sight the soiled world could give him.

  These quiet victories would all vanish if the war now growing steadily like a cancer could leap the Atlantic and lay waste to everything he cherished.

  • • •

  Urey looked around the small seminar room, a week after the accident. “So where was the mistake?”

  A burly Irish engineer said softly, “We hadn’t secured the base enough. It ripped free.”

  Urey frowned, snorted. “That basic? Nothing fundamental?”

  Fermi had a bandage on his forehead and hand but said mildly, “Apparently not. We should have checked more thoroughly. Engineers, we are not.”

  An actual engineer had sustained some eye damage and now wore dark glasses. “I take a dim view of all this,” he said to mild chuckles.

  God is in the details, Karl thought. He had a few bandages too, and the daze from the explosion had faded. Mostly he felt ashamed. “We’ve set the program back a lot. Nothing from the gear can be saved. It’s all shards.”

  Urey grinned. “Think of yourselves as war casualties, gentlemen. And don’t look dejected. We can go forward.”

  Karl demanded, “How? Our ideas can’t be tested with—”

  “I struck a deal with Westinghouse back when we ordered the centrifuge. Glad I did, now. They were complaining about the tight windings, about getting the fittings as accurate as we wanted. They had to make a model one to test their machining. So I made a proposal.”

  “Ah!” Fermi said. He was always the first to grasp implications, Karl knew, but what—?

  “I had extra cash from our investors—sorry, donors—so I cut a deal. Th
ey made a second one, from the model they had to build anyway, and”—a dramatic pause, which Urey relished—“since I give them an extra ten thousand dollars.”

  Everyone laughed. “There’s a second centrifuge?” Szilard asked, startled.

  “They need to shape it up, sure.” Urey stood, preening just a bit. “But it’ll be here from their plant in a week. About the time you guys’ wounds heal.”

  PART III

  * * *

  ANOTHER DAMNED ELEMENT

  1.

  May 11, 1941

  Karl had never played soccer before, and now he knew why.

  Anton had urged him into it. “Exercise, you need.” With a wry smirk, just a heavy-browed touch of a man-challenge.

  Now Karl was bent over, getting his wind back in big gasps as fleet-footed foreigners raced away down the field in pursuit of a dirty ball. Bright day, cotton clouds, and he was staring at mud. The sharp spring air seemed to cut in his throat. He would rather be home with Marthe, taking photos of their baby and getting some much-needed rest.

  He was feeling somewhat human when he glanced up, still panting, and saw the teams bearing down on him. Like they’re chasing down a bouncing rabbit.

  The ball came plunging toward him out of a clear blue sky. Without moving a step, he launched his head at it, the way he had seen others do. It hit, knocking his glasses off into the mud—and the ball shot back downfield.

  “Is great!” a player called downfield, waving Karl into the gang now rushing away. The ball bounced among a scrum of players, and his side got control. Karl snatched up his glasses and strolled that way, knowing he was no good at the tricky foot maneuvers these European players had, like gazelles dancing as they ran. He watched a big, burly Hungarian slap the ball into the goal with a hard kick. Cheers.