The Cusanus Game

  The horse had suddenly disappeared, and I was looking down from a helicopter at the delta of a river.

  The voice went on: “Since then the phenomenon has often been observed. It occurs primarily in funnel-shaped estuaries in connection with a large tidal range. These waves, known as tidal bores in hydrodynamics, can surge upstream unflaggingly for hours and wreak considerable destruction; examples are the mascaret in the Seine, the pororoca in the Amazon, and the enormous bore in the Qiantang near Hangzhou. Aerodynamics too is acquainted with solitons; around the beginning of summer a powerful bore regularly forms in the atmosphere of Mars over the Tharsis ridge in the early morning hours.

  “From the perspective of particle physics or quantum physics, the soliton is an energy packet that can travel but cannot disperse in space, because its vacuum states are arranged topologically such that its field cannot be extended to a single vacuum value consistent everywhere in space. The result is a stable field perturbation. Understood in these terms, it has the character of a particle.

  “In the year 2024, the concept of the soliton was also applied for the first time to boundary layer or brane physics by the Burmese mathematician Hla Thilawuntha. He used the term to designate disturbances of the flow of time that had not been detected up to that point, because they can only be demonstrated indirectly. Only on the basis of his theoretical work and predictions did Folkert Jensma and Koos van Laere the following year at the Christiaan Huygens Institute in The Hague prove the existence of so-called time solitons, which Thilawuntha had predicted. These disturbances traverse the flow of time in both directions, that is, they bring about with their passage momentary damming and acceleration in the temporal dimension. They thereby deform the structure of space-time, but are eo ipso not directly detectable by an observer situated within this structure—that is, within our universe. Their existence can, however, be indirectly demonstrated, because their passage is accompanied by gravitational waves of various strength.

  “What these disturbances are—whether a transformation by another, hidden temporal dimension or an artificial manipulation, possibly carried out through deliberate use of superstrings—is a matter of controversy. According to calculations, the passage of every soliton is associated with amounts of energy in the peta and exa-electron volt range. The mass equivalent is thus several times the mass of our universe.”

  * * *

  WHAT ARE THEY talking about? I wondered. It seemed to be a heated discussion, for I saw them intensely raising and lowering their hands. Why were they speaking so softly? They were murmuring and whispering. Did they not want me to hear? But damn it, this involved me too!

  What had happened to the horse? It was surely grazing somewhere nearby. I must have dozed off. It had gotten cool. Something was tickling my chin. I swiped at it. The audiovid had slipped off my face. Dazed, I sat up. No one was there. The heated discussion was being carried on by the Caprifoliacea, which was rooted in the flower box on my balcony and had covered the white plaster of the wall and ceiling with a confused pattern of dark formulas. The hand-shaped leaves, stirred by a breeze; their continuous rustling and scraping against the wall had led me to believe I heard whispering voices.

  The tiles on the balcony were cold. The sky had darkened. Clouds from the north lay like coal seams over the autumnal faded blue.

  … the passage of every soliton is associated with amounts of energy in the peta and exa-electron volt range. The mass equivalent is thus several times the mass of our universe.

  I shivered. I closed the balcony door.

  Was it Dottore Ercole Mondoloni’s language implants that so exhausted me? That fragmented and scattered my thinking? During the day, I was often dog-tired; lately I had also been sleeping poorly and having strange dreams. You have to eat a sufficient amount, the doctor had impressed on me. Your gray cells are working hard. There are billions of new links to install.

  Sometimes I felt as if at night unbidden guests were making themselves comfortable in my brain, shamelessly taking advantage of my absence to misuse it for their purposes. Was that part of our conditioning too? Or was it the countless nanos that you took in with each breath here in Venice, which unloaded their chemical instructions before they died? The air was heavy with that tiny mechanical pollen, which drove the sunlight from the surface of the lagoon and swirled up like fine dust. Frans laughed when I brought it up with him.

  “Think of the countless microorganisms in the biosphere, which infiltrate your respiratory passages every second,” he said.

  All right, but the oxygen breathers had had 250 million years’ time to come to terms with them. I thought of the little boy whose brain had within an hour turned into crumbly Stilton.

  Questions.

  * * *

  “CAN ONE IMAGINE these solitons as waves that flow along the temporal dimension or the space-time continuum, deforming it in the process? Please don’t look at me so condescendingly, Frans! I’m trying to grasp this phenomenon. I actually always got good grades in physics.”

  “I’m not looking at you condescendingly,” he replied.

  “So when this soliton comes closer, time passes faster—or slower? Fine, I understand that. I’m not unfamiliar with the feeling, depending whether I’m bored or in a hurry. Still, I know that my clock always runs at the same speed. Right? But that’s not what you mean.”

  Frans nodded with amusement.

  “Then tell me, how do you detect whether a soliton is coming? It must be with clocks somehow … atomic clocks or something,” I added helplessly.

  He made a face as if he had bitten down on a piece of shell in a nut croissant, and shook his head.

  “No, Domenica. Even with the most precise clock it could not be measured. Our space-time continuum is a closed system. We and all our clocks are situated on the inside. If time flows faster or slower, our clocks run correspondingly faster or slower, atoms vibrate faster or slower. You have no independent standard by which you can measure that. We would have to leave our universe and view it from the outside to detect those irregularities.”

  We sat in Il Cavallo on the south side of Campo Santi Giovanni e Paolo, at the feet of Colleoni, less than two hundred yards from the Ospedaletto where Heli Abret lived. She had traveled farther than anyone before or since. She had flown with the birds over the sea and had now finally come to rest in the arms of Abaelard.

  It had gotten cold. Only at Il Cavallo were there still tables and chairs outside. We were the only patrons; both of us had turned up the collars of our jackets and were defiantly holding out.

  “So then how do you know when a wave is approaching?”

  “There’s an indirect sign: We detect an increased presence of gravitons—a gradual and then an ever-steeper rise. Those are virtual particles; they indicate masses of quintillions of electron volts, which interact with the real gravitons.”

  “But the mass of a graviton is tiny, if I remember correctly.”

  “A thousandth of an electron volt.”

  “Then where, for heaven’s sake, are those gigantic masses?”

  Frans shrugged. “They are their twins in parallel universes, which come into contact with them. Gravitons seem to be the only particles for which the boundary layers of the universes do not constitute an obstacle. They can shift between the membranes in which the universes are embedded, appear in ours, and vanish again. That happens above all during the passage of solitons. Whether they are secondary effects or directly related to these waves, we don’t know.”

  “Hm. You don’t actually know much about the things you’re playing around with.”

  “We’re learning more. We can roughly estimate what amounts of energy are moving along the temporal dimension. They’re gigantic. They are powerful tsunamis, which suggest deeper underlying convulsions.”

  Frans pushed aside our cups as if he wanted to make room for one of those surges and added: “They have so much energy that they can obliterate whole universes.”

  “Or creat
e new ones.”

  He looked at me with surprise and nodded. “Or create new ones.”

  “And we don’t notice a thing, even though they pass through us?”

  “Some time travelers claim to sense when they’re coming,” he said.

  “Not you?”

  “I’m not sure, Domenica. Your perception can easily play tricks on you. They certainly flood through every atom of your body, through every neuron of your brain. But then I think: That’s utter nonsense. How can you sense what’s going on in the atoms of your body? Or even in the subatomic realm? That’s absurd. We have no sense organs for that. But still—” Frans sighed. “All this is nothing but speculation, my dear.”

  “But it works when you use them to transfer masses, to transport them through time.”

  “With their immense energy they deform the membrane that contains our universe, our space-time continuum,” Frans confirmed. “They open for a brief moment the here and now and allow access to other spaces and times.”

  I looked up at the tower of Santi Giovanni e Paolo.

  “I always thought that the edge of our universe was far out there, fourteen billion light-years away from us.”

  “Not at all, Domenica. It’s only a tiny fraction of a millimeter away.”

  “Where?”

  He spread his hands with a smile. “Everywhere. The membranes that form the multiverse are tightly packed like cells in an organism. Each is a world unto itself, but the exchange of messenger substances between them seems to be vital. The passage of solitons makes this exchange possible. To stick to the image, it makes the cell walls temporarily permeable.”

  I felt the coldness creeping into me. A coldness that wafted toward me as if from shadowy abysses.

  “The idea somehow frightens me,” I confessed.

  “Oh. The membranes protect us. We are safely ensconced in our dimensions.”

  “Let’s go,” I said. “I’m cold.”

  He paid via his ICom, and we stood up. I burrowed deep into my jacket. The sun was gone. From Rio Medicanti fog was coming in. The membrane of reality dissolved, and Colleoni rode through.

  VIII

  The Serenissima

  The Turing principle says that a universal virtual-reality generator can be built, and could be programmed to render any physically possible environment, so clearly it could be programmed to render any environment that did once exist physically … Accuracy, in virtual reality, means the closeness of the rendered behavior to that which the original environment would exhibit if the user were present in it. Only at the beginning of the rendering does the rendered environment’s state have to be faithful to the original. Thereafter it is not its state but its responses to the user’s actions that have to be faithful.

  DAVID DEUTSCH

  I remembered a dream that had often haunted me when I was a teenager. It was a passionate sexual dream in which a lover visited me in the darkness. His body was familiar to me, his voice, his touches, his caresses, with which he brought me to climax—all this suggested an extremely intimate familiarity. But I never saw his face. He entered my room in the dark, came into my bed and embraced me … And when I awoke, he was gone.

  Those nighttime experiences were so realistic that in the morning I checked my body and the bed for traces of my amorous adventure—without finding anything, of course. But sometimes I doubted my sanity and caught myself eyeing men on the street or in a café who might have been secret nightly visitors.

  A typical young-girl dream, certainly—teenage longings, wishful sexual fantasies—but for me it was a highly unsettling experience that repeatedly made me feel ashamed. I had never told anyone about it. It felt eerie to me that I was so naturally intimate with a man about whom I knew nothing—not what he looked like, what his name was, or where he lived. Sometimes I had the suspicion that he crept in from a parallel world and after our secret tryst stole away from my reality to lead his life in his world, perhaps by the side of a woman with whom he lived or to whom he was married.

  Or did a different version of me live in his universe, with whom I occasionally exchanged selves? Who let me participate in her life, in her happiness? Did she, this other self, do that knowingly? Or was I a sort of nocturnal vampire, secretly battening on her pleasure, only to creep back into my world in the morning—sated and full?

  That feeling, which I thought I had overcome many years earlier, that at once cozy and scary feeling of familiarity, which should not actually have been possible, was suddenly back the first time I slept with Frans. He was, in an eerie way, physically familiar to me, as if I had known him for years. He had unexpectedly behaved so familiarly toward me when we had met on the piazzetta. Had that been the trigger for the return of that strange, unsettling feeling? And that familiarity had increased frighteningly the first time we were intimate.

  Did that feeling emanate from him? Was I so familiar to him? My body? But how was something like that possible?

  “You puzzle me, my dear,” I said to him.

  He furrowed his brow questioningly.

  “You act with me as if you’d known me for years. But we saw each other for the first time only recently.”

  He looked at me for a long time, then stroked my hair.

  “I don’t know,” he said. “Sometimes that’s the way it is.”

  * * *

  “DO YOU FEEL like going for a ride on the vaporetto?” he asked me casually one morning. I had spent the night with him, and we were putting the breakfast dishes in the dishwasher.

  “Where?”

  “Canal Grande,” he said. “I have to pay a visit. To a woman.”

  “Then you’d better go alone.”

  “First of all, it’s an old woman; secondly, a sick woman; and thirdly, it could be interesting and enlightening for you.”

  “If you insist,” I replied.

  I quickly went home, and we met half an hour later in his office at the institute. He wore an elegant, light gray jacket and a tie with a red paisley pattern. Over the back of his chair hung a dark blue cashmere coat.

  “Hey!” I exclaimed. “You should have said something. Look at me! Can I even go like this?”

  I looked down at myself: gray sweater, black corduroys, my old green anorak.

  He was about to spray his face and hands with smartdust.

  “Why not?” he asked with surprise.

  “You’ve gotten so dressed up.”

  “That’s part of our routine. The woman expects that from me.”

  “Not from me?”

  “Hm,” he said uncertainly. “No.”

  He handed me the spray bottle with the red-gold liquid and nodded encouragingly.

  “Is that necessary?”

  “It would be better. At least your palms. As a precaution.”

  “Precaution?”

  “Yes. It’s safer. If you touch something.”

  Shaking my head, I sprayed my palms. The cool feeling on the skin disappeared in an instant. It iridesced and looked as if it were lightly oiled, but didn’t feel greasy. It was more as if it had tautened and had become more sensitive to touch.

  “Are you ready?”

  I nodded.

  We walked through the studio toward a side door. A technician sitting next to the exit had directed his eyes to a monitor on which Frans and I could be seen. I saw Kazuichi sitting behind the glass pane in the control room at the main console. He gave a thumbs-up. Frans waved to him.

  “One moment,” said the technician next to the door, raising his hand. According to the sticker on his breast pocket, his name was Kenichiro Akabane. The young man did not look at us but kept his eyes fixed on his monitor. Then he reached for a pair of data glasses and put them on.

  The light over the door turned from red to green.

  “Okay,” he said, lowering his hand. “Ready to go.”

  We went through the door and walked along a dim corridor illuminated only by emergency lighting. A heavy steel door opened automatically and we s
tepped outside.

  It was a hazy winter day. Not really cold, but damp and unpleasant. I plunged my hands into the pockets of my anorak and tramped alongside Frans. Heading down Calle Sagredo, past ugly gray apartment buildings, which were largely unoccupied and would soon have to make way for an additional complex of the institute, we reached the station—a light blue box on a pontoon at the end of a floating dock, rolling on the standing waves. ACTV CELESTIA was written in black on a yellow background over the large, smeared windows. The vaporetto approached and moored with a terrible grating noise. The boat woman looped the rope around the H-shaped iron bars and slid open the railing made of metal tubing. A woman in a fur coat with a shopping bag waddled off the boat, and three boys wearing garishly colored school bags on their backs ran across the dock, jostling each other.

  We went aboard. Frans made no move to enter the passenger cabin and stayed outside. All right, I thought with a sigh, pushing my fists even deeper into my jacket pockets and involuntarily rubbing the coating off my palms.

  The rope was unfastened, the electric motor whined, and we rode along the long blackened brick wall of the Arsenale. A stiff north wind drove the waves forward, which slapped against the foundations. Strangely, it could scarcely be felt, though we were standing outside. Nonetheless, Frans turned up his coat collar.