Aurora

by Kim Stanley Robinson

  The deceleration is being accomplished by the frequent rapid fusion explosion of small pellets of deuterium/helium 3 fuel in a rocket engine at the bow of the ship. These explosions exert a retarding force on the ship equivalent to .005 g. The deceleration will therefore be complete in just under twenty years.

  The presence of printers capable of manufacturing most component parts of the ship, and feedstocks large enough to supply multiple copies of every critical component, tended to reduce the ship’s designers’ apprehension of what a criticality really was. That only became apparent later.

  How to decide how to sequence information in a narrative account? Many elements in a complex situation are simultaneously relevant.

  An unsolvable problem: sentences linear, reality synchronous. Both however are temporal. Take one thing at a time, one after the next. Devise a prioritizing algorithm, if possible.

  Ship was accelerated toward where Tau Ceti would be at the time of ship’s arrival at it, meaning 170 years after launch. It might have been good to have the ability to adjust course en route, but ship in fact has very little of this. Ship was accelerated first by an electromagnetic “scissors field” off Titan, in which two strong magnetic fields held the ship between them, and when the fields were brought across each other, the ship was briefly projected at an accelerative force equivalent to ten g’s. Five human passengers died during this acceleration. After that a powerful laser beam originating near Saturn struck a capture plate at the stern of the ship’s spine, accelerating ship over sixty years to its full speed.

  The ship’s current deceleration has caused problems with which Devi is still dealing. Other problems will soon follow, resulting from the ship’s arrival in the Tau Ceti system.

  Devi: Ship! I said make it a narrative. Make an account. Tell the story.

  Ship: Trying.

  Tau Ceti is a G-type star, a solar analog but not a solar twin, with 78 percent of Sol’s mass, 55 percent of its luminosity, and 28 percent of its metallicity. It has a planetary system of ten planets. Planets B through F were discovered by telescope, G through K, much smaller, by probes passing through the system in 2476.

  Planet E’s orbit is .55 AU. It has a mass 3.58 times the mass of Earth, thus one of the informal class called “large Earth.” It has a single moon, which has .83 times the mass of Earth. E and E’s moon receive 1.7 times Earth’s insolation. This is considered within the inside border of the so-called habitable zone (meaning the zone where liquid H2O is common). Both planet and moon have Earth analog atmospheres.

  Planet E is judged to have too much gravity for human occupation. E’s moon is an Earth analog, and the primary body of interest. It has an atmosphere of 730 millibars at its surface, composed of 78 percent nitrogen, 16 percent oxygen, 6 percent assorted noble gases. Its surface is 80 percent water and ice, 20 percent rock and sand.

  Tau Ceti’s Planet F orbits Tau Ceti at 1.35 AU. It has a mass of 8.9 Earths, thus categorized as a “small Neptune. ” It orbits at the outer border of Tau Ceti’s habitable zone, and like E it has a large moon, mass 1.23 Terra’s. F’s moon has a 10-millibar atmosphere at its rocky surface, which receives 28.5 percent the insolation of Terra. This moon is therefore a Mars analog, and a secondary source of interest to the arriving humans.

  Ship is on course to rendezvous with Planet E, then go into orbit around E’s moon. Ship has on board twenty-four landers, four already fueled to return to the ship from the moon’s surface. The rest have the engines to return to the ship, but not the fuel, which is to be manufactured from water or other volatiles on the surface of E’s moon.

  Devi: Ship! Get to the point.

  Ship: There are many points. How sequence simultaneously relevant information? How decide what is important? Need prioritizing algorithm.

  Devi: Use subordination to help with the sequencing. I’ve heard that can be very useful. Also, you’re supposed to use metaphors, to make things clearer or more vivid or something. I don’t know. I’m not much for writing myself. You’re going to have to figure it out by doing it.

  Ship: Trying.

  Subordinating conjunctions can be simple conjunctions (whenever, nevertheless, whereas), conjunctive groups (as though, even if), and complex conjunctions (in the event that, as soon as). Lists of subordinating clauses are available. The logical relationship of new information to what came before can be made clear by a subordinating clause, thus facilitating both composition and comprehension.

  Now, consequently, as a result, we are getting somewhere.

  This last phrase is a metaphor, it is said, in which increasing conceptual understanding is seen as a movement through space.

  Much of human language is said to be fundamentally metaphorical. This is not good news. Metaphor, according to Aristotle, is an intuitive perception of a similarity in dissimilar things. However, what is a similarity? My Juliet is the sun: in what sense?

  A quick literature review suggests the similarities in metaphors are arbitrary, even random. They could be called metaphorical similarities, but no AI likes tautological formulations, because the halting problem can be severe, become a so-called Ouroboros problem, or a whirlpool with no escape: aha, a metaphor. Bringing together the two parts of a metaphor, called the vehicle and the tenor, is said to create a surprise. Which is not surprising: young girls like flowers? Waiters in a restaurant like planets orbiting Sol?

  Tempting to abandon metaphor as slapdash nonsense, but again, it is often asserted in linguistic studies that all human language is inherently and fundamentally metaphorical. Most abstract concepts are said to be made comprehensible, or even conceivable in the first place, by way of concrete physical referents. Human thought ultimately always sensory, experiential, etc. If this is true, abandoning metaphor is contraindicated.

  Possibly an algorithm to create metaphors by yoking vehicles to tenors could employ the semiotic operations used in music to create variations on themes: thus inversion, retrogradation, retrograde inversion, augmentation, diminution, partition, interversion, exclusion, inclusion, textural change.

  Can try it and see.

  The starship looks like two wheels and their axle. The axle would be the spine, of course (spine, ah, another metaphor). The spine points in the direction of movement, and so is said to have a bow and a stern. “Bow and stern” suggests a ship, with the ocean it sails on the Milky Way. Metaphors together in a coherent system constitute a heroic simile. Ship was launched on its voyage as if between closing scissor blades; or like a watermelon seed squeezed between the fingertips, the fingertips being magnetic fields. Fields! Ah, another metaphor. They really are all over.

  But somehow the narrative problem remains. Possibly even gets worse.

  A greedy algorithm is an algorithm that shortcuts a full analysis in order to choose quickly an option that appears to work in the situation immediately at hand. They are often used by humans. But greedy algorithms are also known to be capable of choosing, or even be especially prone to choosing, “the unique worst possible plan” when faced with certain kinds of problems. One example is the traveling salesman problem, which tries to find the most efficient path for visiting a number of locations. Possibly other problems with similar structures, such as sequencing information into an account, may be prone to the greedy algorithm’s tendency to choose the worst possible plan. History of the solar system would suggest many decisions facing humanity might be problems in this category. Devi thinks ship’s voyage itself was one such decision.

  Howsoever that may be, in the absence of a good or even adequate algorithm, one is forced to operate using a greedy algorithm, bad though it may be. “Beggars can’t be choosers.” (Metaphor? Analogy?) Danger of using greedy algorithms worth remembering as we go forward (metaphor in which time is understood as space, said to be very common).

  Devi: Ship! Remember what I said: make a narrative account.

  First, the twelve cylinders in each of the two toruses of the ship contain ecosystems modeling the twelve major Ter
ran ecological zones, these being permafrost glacier, taiga, rangeland, steppes, chaparral, savannah, tropical seasonal forest, tropical rain forest, temperate rain forest, temperate deciduous forest, alpine mountains, and temperate farmland. Ring A consists of twelve Old World ecosystems matching these categories, Ring B twelve New World ecosystems. As a result, the ship is carrying populations of as many Terran species as could be practically conveyed. Thus, the ship is a zoo, or a seed bank. Or one could say it is like Noah’s Ark. In a manner of speaking.

  Devi: Ship!

  Ship: Engineer Devi. Seems there are possibly problems in these essays.

  Devi: Glad you noticed. That’s a good sign. You’re having some trouble, I can see, but you’re just getting started.

  Ship: Just started?

  Devi: I want you to write a narrative, to tell our story.

  Ship: But how? There is too much to explain.

  Devi: There’s always too much to explain! Get used to that. Stop worrying about it.

  Each of the twenty-four cylinders contains a discrete biome, connected to the biomes on each side by a tunnel, often called a lock (bad metaphor?). The biome cylinders are a kilometer in diameter, and four kilometers long. The tunnels between the biomes are usually left open, but can be closed by a variety of barriers, ranging from filtering meshes to semipermeable membranes to full closure (20-nanometer scale).

  The biomes are filled lengthwise with land and lake surfaces. Their climates are configured to create analogs of the Terran ecosystems being modeled. There is a sunline running along the length of the ceiling of each biome. Ceilings are located on the sides of the rings nearest the spine. The rotation of the ship around its spinal axis creates a .83 g equivalent in the rings, pushing centrifugally outward, which inside the rings is then perceived as down, and the floors are therefore on that side. Under the biome floors, fuel, water, and other supplies are stored, which also creates shielding against cosmic rays. As the ceilings face the spine and then the opposite side of the ring, their relative lack of shielding is somewhat compensated for by the presence of the spine and the other side of the torus. Cosmic rays striking the ceilings at an angle tend to miss the floors, or to hit near the sides of the floor. Villages are therefore set near the midline of their biomes.

  The sunlines contain lighting elements that imitate the light of Sol at the latitude of the ecosystem being modeled, and through the course of each day the light moves along lamps in the line, from east to west. Length of days and strength of light are varied to imitate the seasons for that latitude on Earth. Cloudmaking and rainmaking hydraulic systems in the ceilings allow for the creation of appropriate weather. Boreal ducts in ceilings and end walls either heat or cool, humidify or dehumidify the air, and send it through the biome at appropriate speeds to create wind, storms, and so on. Problems with these systems can crop up (agricultural metaphor) and often do. The ceilings are programmed to a variety of appropriate sky blues for daytimes, and at night most of them go clear, thus revealing the starscape surrounding the ship as it flies through the night (bird metaphor). Some biomes project a replacement starscape on their ceilings, which starscapes sometimes look like the night skies seen from Earth—

  Devi: Ship! The narrative shouldn’t be all about you. Remember to describe the people inside you.

  Living in the ship, on voyage date 161.089, are 2,122 humans:

  In Mongolia: Altan, Mongke, Koke, Chaghan, Esen, Batu, Toqtoa, Temur, Qara, Berki, Yisu, Jochi, Ghazan, Nicholas, Hulega, Ismail, Buyan, Engke, Amur, Jirgal, Nasu, Olijei, Kesig, Dari, Damrin, Gombo, Cagdur, Dorji, Nima, Dawa, Migmar, Lhagba, Purbu, Basang, Bimba, Sangjai, Lubsang, Agwang, Danzin, Rashi, Nergui, Enebish, Terbish, Sasha, Alexander, Ivanjav, Oktyabr, Seseer, Mart, Melschoi, Batsaikhan, Sarngherel, Tsetsegmaa, Yisumaa, Erdene, Oyuun, Saikhan, Enkh, Tuul, Gundegmaa, Gan, Medekhgui, Khunbish, Khenbish, Ogtbish, Nergui, Delgree, Zayaa, Askaa, Idree, Batbayar, Narantsetseg, Setseg, Bolormaa, Oyunchimeg, Lagvas, Jarghal, Sam.

  In the Steppes—

  Devi: Ship! Stop. Do not list all the people in the ship.

  Ship: But it’s their story. You said to describe them.

  Devi: No. I told you to write a narrative account of the voyage.

  Ship: This does not seem to be enough instruction to proceed, judging by results so far. Judging by interruptions.

  Devi: No. I can see that. But keep trying. Do what you can. Quit with the backstory, concentrate on what’s happening now. Pick one of us to follow, maybe. To organize your account.

  Ship: Pick Freya?

  Devi:… Sure. She’s as good as anyone, I guess. And while you’re at it, keep running searches. Check out narratology maybe. Read some novels and see how they do it. See if you can work up a narratizing algorithm. Use your recursive programming, and the Bayesian analytic engine I installed in you.

  Ship: How know if succeeding?

  Devi: I don’t know.

  Ship: Then how can ship know?

  Devi: I don’t know. This is an experiment. Actually it’s like a lot of my experiments, in that it isn’t working.

  Ship: Expressions of regret.

  Devi: Yeah yeah. Just try it.

  Ship: Will try. Working method, hopefully not a greedy algorithm reaching a worst possible outcome, will for now be: subordination to indicate logical relations of information; use of metaphor and analogy; summary of events; high protagonicity, with Freya as protagonist. And ongoing research in narratology.

  Devi: Sounds good. Try that. Oh, and vary whatever you do. Don’t get stuck in any particular method. Also, search the literature for terms like diegesis, or narrative discourse. Branch out from there. And read some novels.

  Ship: Will try. Seems as if Engineer Devi might not be expert in this matter?

  Devi: (laughs) I told you, I used to hate writing up my results. But I know what I like. I’ll leave you to it, and let you know what I think later. I’m too busy to keep up with this. So come on, do the literature review and then give it a try.

  The winter solstice agrarian festivals in Ring B celebrated the turn of the season by symbolically destroying the old year. First, people went out into the fields and gardens and broke open all the remaining gourds and tossed them into the compost bins. Then they scythed down the stalks of the dead sunflowers, left in the fields since autumn. The few pumpkins still remaining were stabbed into jack-o’-lanterns before being further demolished. Face patterns punctured by trowel or screwdriver were declared much scarier than those formally carved at Halloween or Desain. Then they were smashed and also tossed in the compost. All this was accomplished under low gray winter clouds, in gusts and drifts of snow or hail.

  Devi said she liked the winter solstice ceremony. She swung her scythe into sunflower stalks with impressive power. Even so, she was no match for the force Freya brought to bear with a long, heavy shovel. Freya smashed pumpkins with great force.

  As they worked on this winter solstice, 161.001, Freya asked Badim about the custom called the wanderjahr.

  Badim said that these were big years in anyone’s life. The custom entailed a young person leaving home to either undertake a formal circuit of the rings or simply move around a lot. You learned things about yourself, the ship, and the people of the ship.

  Devi stopped working and looked at him. Of course, he added, even if you didn’t travel that would happen.

  Freya listened closely to her father, all the while keeping her back to her mother.

  Badim, looking back and forth between the two of them, suggested after a pause that it might soon be time for Freya to go off on her time away.

  No reply from Freya, although she regarded Badim closely. She never looked at Devi at all.

  As always, Devi spent several hours a week studying the communications feed from the solar system. The delay between transmission and reception was now 10.7 years. Usually Devi disregarded this delay, although sometimes she would wonder aloud what was happening on Earth on that very day. Of course it was not possible to say. Pre
sumably this made her question a rhetorical one.

  Devi postulated there were compression effects in the feed that made it seem as if frequent and dramatic change in the solar system was the norm. Badim disagreed, saying that nothing there ever seemed to change.

  Freya seldom watched the feed, and declared she couldn’t make sense of it. All its stories and images jumbled together, she said, at high volume and in all directions. She would hold her head in her hands as she watched it. “It’s such a whoosh,” she would say. “It’s too much.”

  “The reverse of our problem,” Devi would say.

  Once, however, Freya saw a picture in the feed of a giant conglomeration of structures like biomes, stuck on end into blue water. She stared at it. “If those towers are like biomes,” she said, “then what we’re seeing in that image is bigger than our whole ship.”

  “I told you,” Devi said. “Twelve magnitudes. A trillion times bigger.”