Hidden Variables

by Charles Sheffield

  "Is it one of the Arks that has turned back?"

  He shook his head. "No. They're still on their way. Target star is Tau Ceti. They won't get there for another three hundred years."

  "Well, why pick them out? What's so special about the Ark of Massingham?" I had a sudden thought. "Are they having some problem that we could help with?"

  We had saved two of the Arks in the past twenty years. For one of them we had been able to diagnose a recessive genetic element that was appearing in the children, and pass the test information and sperm filter technique over the communications link. The other had needed the use of an unmanned high-acceleration probe, to carry a couple of tons of cadmium out to them. They had been unlucky enough to choose a freak asteroid, one that apparently lacked the element even in the tiniest traces.

  "They don't report any problem," said Mac. "We've never had a response to any messages we've sent to them, so far as the records on Triton Station are concerned. But we know that they are doing all right, because every three or four years a message has come in from them. Never anything about the Ark itself, it has always been . . . scientific information."

  McAndrew had hesitated as he said that last phrase. That was the lure, no doubt about it.

  "What kind of information?" I said. "Surely we know everything that they know. We have hundreds of thousands of scientists in the System, they can't have more than a few hundred of them."

  "I'm sure you're right on the numbers." Professor Limperis spoke when McAndrew showed no inclination to do so. "I'm not sure it's relevant. How many scientists does it require to produce the work of one Einstein, or one McAndrew? You can't just sit down and count numbers, as though you were dealing with—with bars of soap, or poker chips. You have to deal with individuals."

  "There's a genius on the Ark of Massingham," said McAndrew suddenly. His eyes were gleaming. "A man or woman who has been cut off from most of physics for a whole lifetime, working alone. It's worse than Ramanujan."

  "How do you know that?" I had seldom seen McAndrew so filled with feeling. "Maybe they've been getting messages from somebody in the System here."

  McAndrew laughed, a humorless bark. "I'll tell you why, Jeanie. You flew the Merganser. Tell me how the drive worked."

  "Well, the mass plate at the front balanced the acceleration, so we didn't get any sensation of fifty gee." I shrugged. "I didn't work out the math for myself, but I'm sure I could have if I felt like it."

  I could have, too. I was a bit rusty, but you never lose the basics once you have them planted deep enough in your head.

  "I don't mean the balancing mechanism, that was just common sense." He shook his head. "I mean the drive. Didn't it occur to you that we were accelerating a mass of trillions of tons at fifty gee? If you work out the mass conversion rate you will need, you find that even with an ideal photon drive you'll consume the whole mass in a few days. The Merganser got its drive by accelerating charged particles up to within millimeters a second of light speed. That was the reaction mass. But how did it get the energy to do it?"

  I felt like telling him that when I had been on Merganser there had been other details—such as survival—on my mind. I thought for a few moments, then shook my head.

  "You can't get more energy out of matter than the rest mass energy, I know that. But you're telling me that the drives on Merganser and Hoatzin do it. That Einstein was wrong."

  "No!" McAndrew looked horrified at the thought that he might have been criticizing one of his senior idols. "All I've done is build on what Einstein did. Look, you've done a fair amount of quantum mechanics. You know that when you calculate the energy for the vacuum state of a system you don't get zero. You get a positive value."

  I had a hazy recollection of a formula swimming back across the years. What was it? hw/2, said a distant voice.

  "But you can set that to zero!" I was proud at remembering so much. "The zero point of energy is arbitrary."

  "In quantum theory it is. But not in general relativity." McAndrew was beating back my mental defenses. As usual when I spoke with him on theoretical subjects, I began to feel I would know less at the end of the conversation than I did at the beginning.

  "In general relativity," he went on, "energy implies space-time curvature. If the zero-point energy is not zero, the vacuum self-energy is real. It can be tapped, if you know what you are doing. That's where Hoatzin draws its energy. The reaction mass it needs is very small. You can get that by scooping up matter as you go along, or if you prefer it you can use a fraction—a very small fraction—of the mass plate."

  "All right." I knew McAndrew. If I let him get going he would talk all day about physical principles. "But I don't see how that has anything to do with the Ark of Massingham. It has an old-fashioned drive, surely. You said it was launched seventy-five years ago."

  "It was." This was Limperis again, gently insistent. "But you see, Captain Roker, nobody outside the Penrose Institute knows how Professor McAndrew has been able to tap the vacuum self-energy. We have been very careful not to broadcast that information until we were ready. The potential for destructive use is enormous. It destroys the old idea that you cannot create more energy at a point than the rest mass of the matter residing there. There was nothing known in the rest of the System about this use until two weeks ago."

  "And then you released the information?" I was beginning to feel dizzy.

  "No. The basic equations for accessing the vacuum self-energy were received by laser communication. They were sent, with no other message, from the Ark of Massingham."

  Suddenly it made sense. It wasn't just McAndrew who was itching to get in and find out what there was on the Ark—it was everyone at the Penrose Institute. I could sense the excitement in Limperis, and he was the most guarded and politically astute of all the Members. If some physicist, working out there alone two light-years from Sol, had managed to parallel McAndrew's development, that was a momentous event. It implied a level of genius that was difficult to imagine.

  I knew Hoatzin would be on the way in a few days, whether I wanted to go or stay. But there was one more key question.

  "I can't believe that the Ark of Massingham was started by a bunch of physicists. What was the original composition of the group that colonized it?"

  "Not physicists." Limperis had suddenly sobered. "By no means physicists. That is why I am glad you will be accompanying Professor McAndrew. The leader of the original group was Jules Massingham. In the past few days I have taken the time to obtain all the System records on him. He was a man of great personal drive and convictions. His ambition was to apply the old principles of eugenics to a whole society. Two themes run through all his writings: the creation of the superior human, and the idea of that superior being as an integrated part of a whole society. He was ruthless in his pursuit of those ends."

  He looked at me, black face impassive. "From the evidence available, Captain, one might suggest that he succeeded in his aims."

  * * *

  Hoatzin was a step up from Merganser and Dotterel. Maximum acceleration was a hundred and ten gees, and the living-capsule was a four-meter sphere. I had cursed the staff of the Institute, publicly and privately, but I had got nowhere. They were obsessed with the idea of the lonely genius out there in the void, and no one would consider any other first trip for Hoatzin. So at least I would check out every aspect of the system before we went, while McAndrew was looking at the rendezvous problem and making a final flight plan. We sent a message to the Ark, telling them of our trip and estimated arrival time. It would take two years to get there, Earth-time, but we would take even longer. They would be able to prepare for our arrival however they chose, with garlands or gallows.

  On the trip out, McAndrew tried again to explain to me his methods for tapping the vacuum self-energy. The available energies made up a quasi-continuous "spectrum," corresponding to a large number of very high frequencies of vibration and associated wavelengths. Tuned resonators in the Hoatzin drive units selecte
d certain wavelengths which were excited by the corresponding components in the vacuum self energy. These "colors," as McAndrew thought of them, could feed vacuum energy to the drive system. The results that had come from the Ark of Massingham suggested that McAndrew's system for energy extraction could be generalized, so that all the "colors" of the vacuum self-energy should become available.

  If that were true, the potential acceleration produced by the drive could go up by a couple of orders of magnitude. He was still working out what the consequences of that would be. At speeds that approached within a nanometer per second of light speed, a single proton would mass enough to weigh its impact on a sensitive balance.

  I let him babble on to his heart's content. My own attention was mostly on the history of the Ark of Massingham. It was an oddity among oddities. Six of the Arks had disappeared without trace. They didn't respond to signals from Earth, and they didn't send signals of their own. Most people assumed that they had wiped themselves out, with accidents, wars, strange sexual practices, or all three. Four of the Arks had swung back towards normalcy and were heading in again for the System. Six were still heading out, but two of them were in deep trouble if the messages that came back to Triton Station were any guide. One was full of messianic ranting, a crusade of human folly propagating itself out to the stars (let's hope they never met anyone out there whose good opinion we would later desire). Another was quietly and peacefully insane, sending messages that spoke only of new rules for the interpretation of dreams. They were convinced that they would find the world of the Norse legends when they finally arrived at Eta Cassiopeia, complete with Jotunheim, Niflheim, and all the assembly of gods and heroes. It would be six hundred years before they arrived there, time enough for moves to rationality or to extinction.

  Among this set, the Ark of Massingham provided a bright mixture of sanity and strangeness. They had sent messages back since first they left, messages that assumed the Ark was the carrier of human hopes and a superior civilization. Nothing that we sent—questions, comments, information, or acknowledgements—ever stimulated a reply. And nothing that they sent ever discussed life aboard the Ark. We had no idea if they lived in poverty or plenty, if they were increasing or decreasing in numbers, if they were receiving our transmissions, if they had material problems of any kind. Everything that came back to the solar system was science, delivered in a smug and self-satisfied tone. From all that science, the recent transmission on physics was the only one to excite more than a mild curiosity from our own scientists. Usually the Ark sent "discoveries" that had been made here long ago.

  Once the drive of the Hoatzin was up to full thrust there was no way that we could see anything or communicate with anyone. The drive was fixed to the mass plate on the front of the ship, and the particles that streamed past us and out to the rear were visible only when they were in collision with the rare atoms of hydrogen drifting in free space. We had actually settled for less than a maximum drive and were using a slightly dispersed exhaust. A tightly focused and collimated beam wouldn't harm us any, but we didn't want to generate a death ray behind us that would disintegrate anything in its path for a few light-years.

  Six days into the trip, our journey out shared the most common feature of all long distance travel. It was boring. When McAndrew wasn't busy inside his head, staring at the wall in front of him and performing the mental acrobatics that he called theoretical physics, we talked, played and exercised. I was astonished again that a man who knew so much about so much could know nothing about some things.

  "You mean to tell me," he said once, as we lay in companionable darkness, with the side port showing the eldritch and unpredictable blue sparks of atomic collision. "You mean that Lungfish wasn't the first space station. All the books and records show it that way."

  "No, they don't. If they do, they're wrong. It's a common mistake. Like the idea back at the beginning of flight itself, that Lindbergh was the first man to fly across the Atlantic Ocean. He was more like the hundredth." I saw McAndrew turn his head towards me. "Yes, you heard me. A couple of airships had been over before him, and a couple of other people in aircraft. He was just the first person to fly alone. Lungfish was the first truly permanent space station, that's all. And I'll tell you something else. Did you know that in the earliest flights, even ones that lasted for months, the crews were usually all men? Think of that for a while."

  He was silent for a moment. "I don't see anything wrong with it. It would simplify some of the plumbing, maybe some other things, too."

  "You don't understand, Mac. That was at a time when it was regarded as morally wrong for men to form sexual relationships with men, or women with women."

  There was what I might describe as a startled silence.

  "Oh," said McAndrew at last. Then, after a few moments more, "My God. How much did they have to pay them? Or was coercion used?"

  "It was considered an honor to be chosen."

  He didn't say any more about it; but I don't think he believed me, either. Politeness is one of the first things you learn on long trips.

  We cut off the drive briefly at crossover, but there was nothing to be seen and there was still no way we could receive messages. We were crowding light speed so closely that anything from Triton Station would scarcely be catching up with us. The Institute's message was still on its way to the Ark of Massingham, and we would be there ourselves not long after it. The Hoatzin was behaving perfectly, with none of the problems that had almost done us in on the earlier test ships. The massive disc of dense matter at the front of the ship protected us from most of our collisions with stray dust and free hydrogen. If we didn't come back, the next ship out could follow our path exactly, tracking our swath of ionization.

  During deceleration I began to search the sky beyond the Hoatzin every day, with an all-frequency sweep that ought to pick up signals as soon as our drive went to reduced thrust. We didn't pick up the Ark until the final day and it was no more than a point on the microwave screen for most of that. The image we finally built up on the monitor showed a lumpy, uneven ball, pierced by black shafts. Spiky antennas and angled gantries stood up like spines on its dull grey surface. I had seen the images of the Ark before it left the Solar System, and all the surface structures were new. The colonists had been busy in the seventy-seven years since they accelerated away from Ganymede orbit.

  We moved in to five thousand kilometers, cut the drive, and sent a calling sequence. I don't remember a longer five seconds, waiting for their response. When it came it was an anti-climax. A pleasant-looking middle-aged woman appeared on our screen.

  "Hello," she said cheerfully. "We received a message that you were on your way here. My name is Kleeman. Link in your computer and we'll dock you. There will be a few formalities before you can come inside."

  I put the central computer into distributed mode and linked a navigation module through the com-net. She sounded friendly and normal but I didn't want her to have override control of all the Hoatzin's movements. We moved to a position about fifty kilometers away from the Ark, then Kleeman appeared again on the screen.

  "I didn't realize your ship had so much mass. We'll hold there, and you can come in on a pod. All right?"

  We usually called it a capsule these days, but I knew what she meant. I made McAndrew put on a suit, to his disgust, and we entered the small transfer vessel. It was just big enough for four people, with no air lock and a simple electric drive. We drifted in to the Ark, with the capsule's computer slaved through the Hoatzin. As we got nearer I had a better feel for size. Two kilometers is small for an asteroid, but it's awfully big compared with a human. We nosed into contact with a landing tower, like a fly landing on the side of a wasp's nest. I hoped that would prove to be a poor analogy.

  We left the capsule open and went hand-over-hand down the landing tower rather than wait for an electric lift. It was impossible to believe that we were moving at almost nine thousand kilometers a second away from Earth. The stars were in the same
familiar constellations, and it took a while to pick out the Sun. It was a bright star, but a good deal less bright than Sirius. I stood at the bottom of the tower for a few seconds, peering about me before entering the air lock that led to the interior of the Ark. It was a strange, alien landscape, with the few surface lights throwing black angular shadows across the uneven rock. My trips to Titan suddenly felt like local hops around the comfortable backyard of the Solar System.

  "Come on, Jeanie." That was McAndrew, all brisk efficiency and already standing in the air lock. He was much keener than I to penetrate that unfamiliar world of the interior.

  I took a last look at the stars, and fixed in my mind the position of the transfer capsule—an old habit that pays off once in a thousand times. Then I followed McAndrew down into the lock.

  * * *

  A few formalities before you can come inside. Kleeman had a gift for understatement. We found out what she meant when we stepped in through the inner lock, to an office-cum-schoolroom equipped with a couple of impressive consoles and displays. Kleeman met us there, as pleasant and rosy-faced in the flesh as she had seemed over the com-link.

  She waved us to the terminals. "This is an improved version of the equipment that was on the original ship, before it left your system. Please sit down. Before anyone can enter our main Home, they must take tests. It has been that way since Massingham first showed us how our society could be built."

  We sat at the terminals, back-to-back. McAndrew was frowning at the delay. "What's the test, then?" he grumbled.

  "Just watch the screen. I don't think that either of you will have any trouble."

  She smiled and left us to it. I wondered what the penalty was if you failed. We were a long way from home. It seemed clear that if they had been improving this equipment after they left Ganymede, they must apply it to their own people. We were certainly the first visitors they had seen for seventy-five years. How had they been able to accept our arrival so calmly?