2312

by Kim Stanley Robinson

  No. Because the much more strict pseudoiterative of the tunnel still filled his mind, and overlaid the sensations of the present moment. And as Iapetus in the present was for the most part an Iapetus reenacted, much more vivid to him was that more recent past consisting of what he had just lived through with his so-mercurial friend. And he wondered about her. The mercurialities of Swan were infinite, but she had gone through quite a bit down there, and so had he. She had protected him at the elevator door, just as a matter of course, the obvious thing to do, with no time to think; just an animal response. And with far too much time to think, he had helped her through her radiation sickness.

  So when he thought he wasn’t thinking of anything, he found himself whistling snatches of Beethoven, and hearing over it a skylark filigree of inhuman virtuosity. He wondered what they had really sounded like, and if Pauline had recorded the entire time and could carve out and play back the music they had made—another kind of transcription. All those poor musicians… Maybe a record was always a distorter of memory, not to be sought. Better to hear it by way of reenactment. He would only really hear it again if they did it again.

  No. He needed to think about something else, and bring himself into the present. Possibly he would see Swan again somewhere, and they would whistle then, or not. Probably not, this being the world. So… recent or not, the past was the past; the present was the only reality. So really, it was necessary to start up a new pseudoiterative that did not rely so fully on his habits from three or four lives back. He needed a new Iapetus, with the memory of Swan properly encoded into it.

  So he would walk down High Street to the park with the best view of Saturn for an evening constitutional, for a communing with the great ringed god, and perhaps a chance to see Titan-his-true-home spangling over the giant like a jewel; and just the act of trudging to the park would bring a whole host of feelings to him; and in the park a small gathering of musicians would pass around the chance to start up a tune and have everyone join in, and he could either listen, or venture to whistle along—even to whistle the start of some movement when it was his turn—end of the Sixth, end of the Seventh—and they all would join in on their instruments and off they would go. With Saturn overhead, and some truly gifted musicians in the little band, he would be snagged by the moment, fully entangled, and Swan would be there with him in his mind. What a temper she had.

  Then on days when the council and various work groups weren’t meeting, he could tram around the city four degrees, and come to the gate for the ski boats, and get in one and take off down the gigantic side of the Iapetus bulge, in this region an undulant slope of black-tipped white billows, in some parts like a shaken sheet of snow, in others like frozen waves in a waterslide. There were moguls the size of big hills. Down the great hill of the bulge’s side the ski boats would slide, carving lines and performing jumps and rollers, if desired; but also one could simply cut a line and keep to it on a long traverse, or even fly straight down the slope, a forty-five-degree drop, and even at the highest speed the descent took all day. Rides went on so long that many people slid down on larger boats to have a party, and on some days Wahram tried that too. Then at the bottom they got into funiculars for a ride back up, during which everyone was in high spirits, often expressed in song. People shared schnapps and sang Schubert. Wahram had done these things long before, in the first year he had lived in Iapetus, but somehow they had dropped out of his habits and been forgotten. Now thinking of Swan had brought them back into his life.

  Even his work brought Swan to mind, as the council and its staff were discussing what to do about the light deal with the Vulcanoids now that Terminator had been destroyed. Wahram pointed out to his colleagues that Terminator would be quickly rebuilt and repopulated, and thus remain a treaty partner with whom they already had an agreement. Alex’s death did not change that agreement. He could see that while this was obviously the case, stating it aloud only tagged him among his colleagues as biased, which was true, so after that he went silent and only listened to what the others said about it, which really was nothing surprising: many of them had not liked the arrangement with Mercury in the first place, and now they reverted to these views and argued that they should be making their deals with some kind of Vulcanoid league, or even with individual Vulcanoids. These were not, after all, spaceships, but small asteroids located in the gravitationally stable orbit between .06 and .21 astronomical units from the sun—thirty-kilometer rocks, white-hot on their sunward surfaces, and just big enough to spin out their solettas and contain in their interiors the little habitats that their operators or votaries lived in. These were city-states just like any other city-states, some of Wahram’s colleagues insisted, and should not be represented by some exterior power like Terminator, no matter what Alex had asserted. How would the city-states of the Saturn League like it if some Jovian party claimed to represent them just because it orbited between Saturn and the rest of civilization? Wasn’t that ultimately the argument that Terminator had been making in this case? Wasn’t this in fact yet another move in what some had called the Alexandrine Integration, the offline effort to bypass the AIs and unify the entire system—under Alex?

  Not exactly, others had replied, to Wahram’s relief, as he had been working with Alex on precisely this project, which was not exactly as characterized by these colleagues but would be difficult to explain in the context of that accusation. Much better to observe silently and let the argument drag on in the long and leisurely way typical of the council, until it had moved on its own to something else. The councilors from Hyperion and Tethys were the main reasons this would take a while; they were both very long-winded, also maniacally focused on the minutiae of matters they took an interest in. The council was one of the many organizations in the Saturn League made up of drafted temporary workers, and the permanent staff there to assist them often had to Sir Humphrey the process along, guiding their employers invisibly through every decision. But some of the ministers, having been selected by lottery and assigned a year’s responsibility for the Saturn system’s welfare, intended to be in full command of their own decisions, and to make the best decisions they could by being fully informed. Admirable in theory, it was painfully slow in practice.

  So in this discussion the dispute kept on seesawing between the idea that Mercury was the legitimate, or in any case agreed-upon, broker in the matter, and furthermore could make things difficult—and besides had things to offer Saturn—and the idea that the Mercurials were interlopers who had succeeded in imposing a protection racket on the new little settlements inside it, and so should be finessed out of the deal in this their winter of discontent.

  Ultimately the council came to a conclusion Wahram had foreseen hours before: as Wahram himself was so sympathetic to the Mercurials, he was to return there and see what the situation was, talk to the lion cubs and find out who the next Lion would be, and then also go visit the Vulcanoids and see what they had to say for themselves—see what they thought of the arrangement Mercury had proposed to Saturn. He was instructed to revise Terminator out of the deal if he thought that would work.

  Probably he should have refused to do it based on his dislike for that last instruction, but it occurred to him that a different delegate might mean an even worse result for the Mercurials. And after all, the assignment meant he would very soon return sunward, which was interesting to contemplate. As for his instructions, he could see about that when he got there. In Alex’s realm in particular, an ambassador was again as of old, a diplomat at large, charged with making decisions as well as conveying them. By the time he got there it could very well be a different story. With a little forethought, he could be almost sure it would be a different story.

  So he said nothing beyond a simple acceptance of the assignment.

  At which point the Satyr of Pan stood to speak. “You must tell us if you think this effort will make trouble for the other projects Alex had going. Can you remind the council what’s at stake here, and how those pr
ojects are going in her absence?”

  Wahram nodded stiffly as he thought over his response. He and the other Alexandrines were attempting to keep a low profile, and some of the council members had not paid enough attention to notice their projects’ authorization and budgeting inside larger expenditures. “Alex kept things separate in her calculations, so that won’t be a problem for us. Some other matters are being dealt with by a group centered around Wang and Inspector Jean Genette. We would need to go under a cone of silence to discuss all this in detail, but suffice it to say, Alex was heavily involved with a Mondragon project to help Earth cope with its various problems by ecological means. A lot of the terraria in the Mondragon are working on that, it has its own momentum, and we’ve agreed to help them. Then also there is an investigation going on into the role of qubes in some questionable activities, on Mars, Venus, Io, and elsewhere. This also will proceed no matter what happens with the Vulcanoids, which is only an above and beyond, although admittedly an important one.”

  The council, not wanting to retire into the cone and be cut off from the cloud and radio, adjourned the meeting. Wahram returned to his room. His crèche kept an apartment in a little block of apartments, all clustered around a square that was occupied almost entirely by Titans, with Titanic shops and restaurants. There he lived among his crèchemates and enjoyed their support, which was so benign and understanding that life there much resembled living in complete solitude. As the days passed before the spaceliner that would take him downsystem arrived, he walked the city spine to the council meetings, he followed the work on Titan in daily consultations, and he did his share of Iapetus work in the kitchen of the dining hall on the ground floor of their building. He attended a concert series, joined the little group of musicians in the park, filled and emptied dishwashers. As he dodged diners and servers in the hall, the repeated minuscule navigational challenges reminded him of Proust’s comparison of a restaurant in action with the whirling planets of the solar system, which had struck him as fanciful (not to mention quite a scale shift between vehicle and tenor) until he had seen it for himself, in restaurant after restaurant: their affairs were elaborations of the second law of thermodynamics, Beckian diffusions of energy through the universe, and around they went in the great orrery of their lives. Soon he would descend sunward and seek out the Mercurial.

  But then she called him. She was coming to Saturn, with Jean Genette; they wanted to descend into the clouds of Saturn to look for a spaceship possibly adrift in the big beauty’s upper layers. She wanted him to arrange the dive into Saturn, if possible, and then join them in it.

  “That would be fine,” he replied; “I am at your disposal.” Which was certainly one way of putting it.

  Lists (8)

  Prometheus, Pandora, Janus, Epimetheus, and Mimas; these are the moons that shepherd Saturn’s rings.

  The rings are only 400 million years old, the result of a passing Kuiper belt ice asteroid being stripped to its core when it passed Saturn too closely.

  Mimas, the bull’s-eye moon, is 400 kilometers in diameter, while its crater Herschel is 140. The Herschel impact nearly blew Mimas apart.

  Hyperion is a fragment of a similar collision that did blow a moon apart; it is shaped like a hockey puck. The impact caused flash steam explosions across a plane and split the moon as if spalling granite. The facet left behind is pocked like a wasps’ nest by a field of rimless dust-filled craters.

  Pandora is shaped like a jelly bean.

  Tethys and Dione were both about 1,100 kilometers across (think France), both fractured all over their surfaces, etched by canyons with mile-high walls. Tethys’s Ithaca Chasma is twice as deep and four times as long as the Grand Canyon, and a thousand times older, very battered by Saturn’s everlasting civil wars.

  Dione, on the other hand, was disassembled by self-replicating ice cutters in the 2110s, and the Hector-sized segments were then directed downsystem to Venus. They struck Venus on a line parallel to the equator and provided Venus with a deep ocean bed and the water to fill it, while also knocking a good bit of the choking Venusian atmosphere off into space.

  Rhea is as wide as Alaska, with the usual plethora of craters, including fresh ones that throw bright ice rays out from their centers.

  Iapetus orbits seventeen degrees out of the plane of Saturn’s equator and thus has one of the best views of the rings; is therefore popular. The bulge is the biggest city in the Saturnian system.

  Epimetheus is a misshapen pile of loosely consolidated rubble. It switches orbits with the moon Janus every eight years; they are co-orbital moons, very rare—a sign of past impacts.

  Enceladus is covered by braided spills of ice. No craters—the ice surface is too new, as it is continuously resurfaced from the liquid-water ocean in the depths. Heat sources boil some of this carbonized water, creating geysers that shoot many kilometers into space. The water quickly freezes in its flight, and some of it makes it up to the slender E ring; the rest falls back down and under its own weight turns to firn and then back to ice again. A suite of microscopic life-forms was discovered in the Enceladan ocean in the year 2244, and scientific stations have been established on its surface, as well as a cult of votaries who ingest a suite of the alien life-forms, to unknown effect.

  There are twenty-six irregular small moons. These are all Kuiper belt objects, captured as they crossed Saturn’s earliest gas envelope. Phoebe, at 220 kilometers across, is the largest of these, and it has a retrograde and highly inclined orbit, twenty-six degrees out of the plane; thus another popular viewing platform.

  Titan, by far the largest Saturnian moon, is bigger than Mercury or Pluto. More about Titan later.

  Extracts (9)

  One question for computability: is the problem capable of producing a result

  If a finite number of steps will produce an answer, it is a problem that can be solved by a Turing machine

  Is the universe itself the equivalent of a Turing machine? This is not yet clear

  Turing machines can’t always tell when the result has been obtained. No oracle machine is capable of solving its own halting problem

  A Turing jump operator assigns to each problem X a successively harder problem, X prime. Setting a Turing machine the problem of making its own Turing jump creates a recursive effect called the Ouroboros

  All problems solvable by quantum computers are also solvable by classical computers. Making use of quantum mechanical phenomena only increases speed of operation

  two popular physical mechanisms, dots and liquids. Quantum dots are electrons trapped inside a cage of atoms, then excited by laser beams to superposed positions, then pushed to one state or the other. Quantum liquids (often caffeine molecules because of the many nuclei in them) are magnetically forced to spin all their nuclei in the same spin state; then NMR techniques detect and flip the spins

  Decoherence happens at the loss of superposition and the resulting either/or. Before that a quantum calculation performs in parallel every possible value that the register can represent

  Using superposition for computation requires avoiding decoherence for as long as possible. This has proved difficult and is still the limiting factor in the size and power of a quantum computer. Various physical and chemical means for building and connecting qubits have increased the number of qubits possible to connect before decoherence collapses the calculation, but

  Quantum computers are restricted to calculations that can be performed faster than decoherence occurs in the superposed wave functions. For over a century this restricted time for a quantum computing operation to less than ten seconds

  Qubes are room-temperature quantum computers with thirty qubits, the decoherence boundary limit for circuit-connected qubits, combined with a petaflop-speed classical computer to stabilize operations and provide a database. The most powerful qubes are theoretically capable of calculating the movements of all the atoms in the sun and its solar system out to the edge of the solar wind

  Qubes are
only faster than classical computers when they can exploit quantum parallelism. At multiplication they are no faster. But in factoring there is a difference: to factor a thousand-digit number would take a classical computer ten million billion billion years (lifetime of universe, 13.7 billion years); using Shor’s algorithm, a qube takes around twenty minutes

  Grover’s algorithm means that a yearlong search using a classical computer in a random walk of a billion searches a second would take a qube in its quantum walk 185 searches

  Shor’s algorithm, Grover’s algorithm, Perelman’s algorithm, Sikorski’s algorithm, Ngyuen’s algorithm, Wang’s algorithm, Wang’s other algorithm, the Cambridge algorithm, the Livermore algorithm,

  entanglement is also susceptible to decoherence. Physical linkage of quantum circuits is necessary to forestall decoherence to useful time frames. Premature or undesired decoherence sets a limit on how powerful qubes can become, but the limit is high

  it has proved easier to manipulate superposition than entanglement for computing purposes, and therein lies the explanation of many

  The quantum database is effectively distributed over a multitude of universes

  the two polarized particles decohere simultaneously no matter the physical distance between them, meaning the information jump can exceed the speed of light. The effect was confirmed by experiment in the late twentieth century. Any device that uses this phenomenon to communicate messages is called an ansible, and these devices have been constructed, but undesired decoherence has meant the maximum distance between ansibles has been nine centimeters, and this only when both were cooled to one millionth of a K above absolute zero. Physical limitations strongly suggest further progress will be asymptotic at best