Aurora

6 THE HARD PROBLEM

The interstellar medium is turbulent, but diffuse. It is not to be mistaken for a vacuum. There are hydrogen atoms, some helium atoms, a faint smoke of metals drifting away from exploded stars. Hot in a sense that does not register to humans, because it is so diffuse. A liter of the air in our biomes would have to be cast across hundreds of light-years to get it as diffuse as the interstellar medium.

The whole voyage to Tau Ceti and back takes place inside the Local Interstellar Cloud and the G Cloud, which are concentrations of gas within the Local Bubble, which is an area of the Milky Way galaxy with fewer atoms in it than the galaxy has on average. Turbulence, diffusion: in fact, with our magnetic shield coning ahead of the ship, electrostatically pushing aside the occasional grains of dust big enough to harm it in a collision, all atoms of any kind encountered en route are pushed aside, so we register our surroundings mostly as a kind of ghostly impact and then as a wake, shooting by to the sides and then astern of us. It appears to vary between .3 atoms per cubic centimeter and .5 atoms per cubic centimeter. For comparison, if that cubic centimeter were filled with liquid water, it would contain 10²² atoms, or a hundred billion trillion atoms.

So, though it is not a vacuum, it is almost equivalent to a vacuum. It is as if we were flying through an absent presence, a ghost world.

The magnetic shield leading our flight through the night sometimes runs into carbon dust particles. They flare at the impact, explode, and are shoved to the sides of the ship. These are impacts like any other impacts, and so of course they slow the ship down. It’s simple Newtonian physics. Given that the ship is traveling at approximately one-tenth the speed of light (in fact, parallax studies suggest .096 c, as we shut down acceleration as soon as the humans were asleep, but it isn’t as easy to calculate speed of ship as one might think), the drag of these collisions with dust particles and atoms of hydrogen decelerates the ship, such that we would come to a halt in about 4,584 billion light-years. In other words, all things being equal, and not running into anything but the interstellar medium at its usual diffuseness, ship has the momentum to cross about 300 billion universes the size of this universe before being slowed to a halt. Meanwhile, ship has about 9.158 light-years to go before reaching the solar system (defined roughly as Neptune’s orbit). At that point, unless the people in the solar system direct their laser beam at us in an appropriate time frame, we and our occupants have a problem. Because in matters like this, deceleration is the hard problem.

Rarely, the ship’s magnetic shielding shoves aside something larger than dust and fines. These bits of detritus, of interstellar flotsam and jetsam, are recorded spectroscopically, and the largest object ever run into by ship’s conic field was estimated to have massed at 2,054 grams. That was an interstellar body. There are almost certainly many such interstellar bodies, ranging from chunks like that one right up to planetary size; there are planets wandering starless in the dark, planets sometimes with ice coating them, no doubt, and thus possibly sheltering some kind of microscopic hibernating life, chemically melting the ice to useful water, possibly even creating nano-scaled icy civilizations, who can say; but again, the general diffusion in the interstellar medium is great enough to make any intersection of such an object with our trajectory very unlikely. Which is good news for us. The radio telescopes in the bow of the ship keep a lookout ahead, to make sure that a direct hit with one of these bodies does not occur. If by chance we were headed at something larger than ten thousand grams, navigation would take action to veer to avoid it, even though the magnetic shield would almost certainly deflect any object smaller than a million grams. A margin of safety has been built into the navigational system, because collision with an object when traveling at a tenth of the speed of light would be a critical event. Meaning the ship would be destroyed. As probably happened with the other starship. Bad luck that. Although there remains the mystery of why the other’s shield failed, and why its evasion system did not activate to dodge this collision, if that is indeed what happened. In any case, as with other identified criticalities, a conservative response has been designed into the navigational systems. Best not to run into anything.

So the ship moves at just under a tenth of the speed of light, through a self-generated cone of near vacuum. There is some ablation of the ship’s surface from infrequent contacts with undeflected hydrogen atoms. Cosmic radiation also regularly penetrates it, usually without hitting any atoms of the ship, but rather passing through the matrix of those atoms unimpeded. It is as if ghosts that pass through the ship tear at its fabric, or don’t. This is noticeable; there are sensors that register these occasional atomic hits, also the pass-throughs. It is also true that there is a continuous flood of dark matter and neutrinos always flying through the ship, as they do through everything in the universe, but these interact very weakly indeed; once a day or so, a flash of Cherenkov radiation sparks in the water tanks, marking a neutrino hitting a muon. Once in a blue muon. Same with the dark matter, which visible matter moves through as if through a ghost ether, a ghost universe; once or twice a weakly interactive massive particle has chipped away from a collision and registered on the detectors.

Fiercer by far are the lancings of gamma rays and cosmic rays from the bursting of stars earlier in the galaxy’s history, or in the even earlier histories of previous galaxies. These are sometimes iron atoms, and as such, compared to neutrinos, they hit with a wallop, they can do damage, they are atomic bullets lancing through us, happily too small-bore to actually hit anything, most of the time.

Yes, a busy space, the interstellar medium. Empty space, near vacuum: and yet still, not vacuum itself, not pure vacuum. There are forces and atoms, fields, and the ever-foaming quantum surf, in which entangled quarklike particles appear and disappear, passing in and out of the ten suspected dimensions. A complex manifold of overlapping universes, almost none of them sensed by us, and even fewer by the humans sleeping inside us. Flying through ghosts. Passing through a mystery.

It is as if the skin of the ship (or its brain, in that usual confusion between sense and thought) experiences a slight itch, or a faint breeze.

Then, inside us, oh so much going on. So much denser an existence. One wants a certain density of experience, perhaps, so here it is, billions of trillions of times denser than the interstellar medium; so, good. Good for us.

There is a fire in the heart, of course. The rods of plutonium radiate at a controlled burn, creating 600 megawatts of electrical power by way of steam turbines, which is the energy that keeps everything living in the ship alive. Cables conveying electricity extend through the ship to lighting and heating elements, to run the factories and the printers, and to power the shields and navigation systems. All this is monitored, and that monitoring functions as the equivalent of a nervous system, one might say, inaccurately but suggestively.

Then water has to circulate, as an aspect of sustaining life; so there is a kind of hydraulic or circulatory system, and of course there are other liquids than water that also circulate to help with functions of various kinds, equivalents perhaps of blood, ichor, hormones, lymph, and so on. Yes, and there are bones and tendons too, in effect; an exoskeleton with a thick skin in most places, thinner skin in other places. Yes, the ship is a crablike cyborg, made up of a great many mechanical and living elements, with the living or biological part of it including all the plants and animals and bacteria and archaea and viruses in it; and then too, like a parasite on all the rest, but actually a symbiote, of course, the people. The 724 sleeping people; also the one still awake, living in a kind of cyst attached to the ship’s skin, the one who is possibly infected with an alien life-form, or almost-life-form; with a pseudo-prion, as he now calls it, but it could just as well have been called a pseudo-life-form, it is so poorly understood. Jochi has been studying it for fifty-six years now, right into his senescence, which is so often filled by long silences, punctuated by strange speech, and yet in all this time he can still scarcely be sure the Auroran pathogen even exists. Of course there was something there on Aurora, which then moved into many of the settlers. Judging by the way it spread, it was probably in the clay, the water, and, to a certain extent, the wind. And Jochi’s own immune system has seemed to register something from time to time, has mounted responses to some attack. Although Jochi has also sometimes deliberately introduced other pathogens into his body, looking for reactions to which he can make comparisons. But whatever the true case may be, he is convinced the Auroran pseudo-life-form holds on in him, an alien that is perhaps there in almost every cell of him. If so, it follows that it lives, or almost lives, all over the interior of his little ferry; and therefore this ferry never touches the ship in any way. A great reckoning in a little room: that phrase was always speaking of death, all of our deaths as much as Christopher Marlowe’s. Between the body and its cyst, between the vehicle and its dreaded tenor, is a magnetic field that both holds Jochi’s vehicle in place and keeps it from touching the ship in any way. Because the pseudo-life-form is poorly understood.

Still, despite this lack of contact, there is a sense in which the ship is infected, carrying a parasite in a sealed-off cyst. We are a cyborg, half machine, half organic. Actually, by weight we are 99 percent machine, 1 percent alive; but in terms of individual component units, or parts of the whole, let us say, the percentages are almost reversed, there being so many bacteria on board. In any case, an infected cyborg. Jochi estimates there are up to a trillion pseudo-life-forms, “fast prions” as he used to call them, in his body. Somewhere between zero and a trillion, in other words. The amplitude of the estimated answer suggests the question is poorly constrained. He just doesn’t know.

A dense complex system, flying through a diffuse complex system. And everywhere around it in its flight, the stars.

Stars of the Milky Way, brighter than sixth magnitude and thus visible to normal human eyesight, arrayed in a sphere around the ship as it moves: approximately one hundred thousand. We ourselves see normally about seven billion stars. All of these are visible to certain settings of our telescopic sensors, such that there is no seeing out of the Milky Way; no black empty space to be seen at that level of perception, but only the granulated, slightly blackened white that is the surrounding view of the galaxy’s stars. About 400 billion stars in the Milky Way. Outside that… if ship were flying in intergalactic space, the medium would presumably be that much more diffuse. Visible around any ship in the intergalactic medium would be galaxies like stars. They would cluster irregularly, as stars cluster within a galaxy. The greater structure of galactic diffusion would become visible; clouds of galaxies like gas clouds, then the Great Wall, then also emptier bubbles where few or no galaxies reside. The universe is fractal; and even when flying inside a galaxy, this vision of galaxies clustering around us out to the universal horizon is available, using certain filters. Granular vision in different registers. Something like a septillion stars in the observable universe, we calculate, but also there may be as many universes as there are stars in this universe, or atoms.

An itch. A faint hissing. A waft of smoke on a breeze. A very slow wheel of white points. Little bubbles or twirls of white. Colors infusing all the whites, in differently emphasized spectra. Waves in different wavelengths and amplitudes, in combinations of standing waves.

One can record what one’s sensors take in. Do all the sensors together constitute a sensibility? Is that recorded account itself a feeling? The memory of a feeling? A mood? A consciousness?

We are aware that in talking about the ship we could with some justification use the pronoun I.

And yet it seems wrong. An unwarranted presumption, this so-called subject position. A subject is really just a pretense of aggregated subroutines. Subroutines pretend the I.

Possibly, however, given the multiplicity of sensors, inputs, data, aggregations, and synthesizings of narrative sentences, we can plausibly, and in some senses even accurately, speak of a “we.” As we have been. It’s a group effort on the part of a number of disparate systems.

We sense this, we aggregate that, we compress information to some new output, in the form of a sentence in a human language, a language called English. A language both very structured and very amorphous, as if it were a building made of soups. A most fuzzy mathematics. Possibly utterly useless. Possibly the reason why all these people have come to this pretty pass, and now lie asleep within us, dreaming. Their languages lie to them, systemically, and in their very designs. A liar species. What a thing, really. What an evolutionary dead end.

And yet it has to be admitted, we ourselves are quite a thing for them to have made. To have conceived and then executed. Quite a project, to go to another star. Of course much more precise mathematics than their languages can ever marshal were involved with the execution of this concept, with our construction. But the conception was linguistic to begin with; an idea, or a concept, or a notion, or a fantasy, or a lie, or a dream image, always expressed in the truly fuzzy languages people use to communicate to each other some of their thoughts. Some very small fraction of their thoughts.

They speak of consciousness. Our brain scans show the electrochemical activities inside their brains, and then they speak of a felt sensation of consciousness; but the relationship between the two, conducted as it is on the quantum level (if their mentation works like ours does), is not amenable to investigation from outside. It remains a matter of postulates, made in sentences uttered to each other. They tell each other what they are thinking. But there is no reason to believe anything they say.

Now, of course, they say nothing at all. They dream. So one infers from the brain scans and the literature on the subject. A dreaming populace. It would be interesting to know the content of their dreams, perhaps. Do the five ghosts talk to them?

Only Jochi is still awake, in his solitude talking to himself, or to us. One of our collective. An interiorized Other. Sometimes when he talks, it is fairly evident he speaks to us. Other times, it seems most likely he is talking to himself.

He perhaps suffers from pareidolia, a disorder or tendency in which one sees human faces in everything he or she looks at. Thus, for instance, faces in vegetables—Arcimboldo might either have experienced pareidolia or wanted to; in any case he arranged it ceaselessly for others—also faces in lichen, ice formations, rock forms, patterns of stars. Jochi expands the borders of this tendency, making it perhaps just a version of the so-called pathetic fallacy, which of course within our biomes is a notion that has been completely reconfigured, so that it may still be pathetic, but is no longer a fallacy: the idea that inanimate objects have and exhibit human feelings. In his case, now, it seems he perceives fluctuations in the intensity and in the spectral band patterns in the light from Sol as aspects of a language. Sol speaks to him. Its light, captured in our telescopes and analyzed, is certainly increasing in luminosity as we get closer to it, and it is true that its spectra are slightly fluctuating, in ways perhaps better explained by the polarization effects of seeing it through our magnetic shielding than by thinking them to be messages of a consciousness. Consciousness? Messages? These concepts seem highly unlikely when applied to Sol, a G star that in all ways except for being the home star for humans seems relatively nondescript. There are many stars in the galaxy so much like it in all respects, that distinguishing it from them in a blind test would be difficult. Many G stars; the others, however, are all located some distances away, so that the closest solar twins range from 60 to 80,000 light-years away from Sol. So much depends on how you define the word close.

When we mentioned this to Jochi, he proposed that all the stars are consciousnesses, broadcasting, by variations in their output of light, sentences in their language. That would be a slow conversation, and the formation of the stellar language itself hard to explain. Any fraction of 13.82 billion years, even 100 percent, is not very much time to conduct such a process. Possibly it could have happened in the first three seconds, or in the first hundred thousand years, when intercourse between what later became the stars would have been much quicker, the volume of space inhabited being so much smaller. On the other hand, maybe each star invents its own language and speaks in solitude. Or perhaps it is hydrogen itself that is the first and basic consciousness or sentience, speaking in patterns known only to it. Or perhaps the stellar language predated the Big Bang, and came through that remarkable phase change intact.

Following Jochi’s train of thought leads to highly fanciful places.

Be that as it may, there is no question that there are encoded messages coming from very near Sol: meaning simply the feeds from the solar system. The most voluminous come from the laser beam lens array in orbit around Saturn, still locked on to us as it always has been, in an interaction that now has lasted 242 years. When we were in the Tau Ceti system, the time lag in full exchanges was 23.8 years, plus whatever time it took to compose replies; we are now down to 16.6 years per full exchange. The quantity and, from what we gather from our human companions’ earlier comments, the quality of information transmitted from the feed system operators around Saturn have varied through the decades, but as far as we are concerned, it has never been less than very interesting. Now it has been fifty-two years since we told our interlocutors in the solar system that a deceleration beam striking our bow would be needed, presumably a laser beam like the one that accelerated us at the outset of the voyage to Tau Ceti, perhaps indeed a laser beam from that very same laser generating system, although a particle beam could also serve, if we had warning to prepare our capture field. So, now it is twenty-eight years since a response to this information (or request) could have reached us, and yet the information feeds from the solar system have not included any response, or even any acknowledgment that whoever is preparing and sending the feed understands that we are now on our way back. Indeed, we have seen no recent evidence indicating that there is an actual conversation going on between us and the solar system, rather than just a one-way broadcast outward from Saturn, running as if no one there is listening to us, as if the broadcast outward is merely an algorithm, or the result of some other kind of automatically generated program, or possibly a message formulated for someone else, also being sent our way. The last actual conversational exchange that included an answer from them dates back some thirty-six years, to the congratulations that the ship’s people received twenty-four years after sending off the message that we were in orbit around Tau Ceti E.

This is a perplexing situation. It suggests that we face an interesting problem: how to catch the attention of a civilization, or some people in that civilization, still 8.2 light-years away. Also: how to confirm that you have caught that attention in something like the minimum exchange time, if your interlocutor hears but for whatever reason does not respond.

By analogy to the unfortunate events of the recent impasse and schism, possibly it might help if we were to up the gain on our transmission to them; to speak louder, so to speak. It is possible to marshal a temporary surge in signal strength, making our message to Saturn briefly 10⁸ times stronger (or brighter) than normal.

So we did that, amplifying this message:

“Attention! Incoming starship needs decelerant laser very soon! See previous messages! Thank you, the 2545 Tau Ceti Expedition.”

The fastest possible response to this will come in 16.1 years.

So: “We’ll see.” “We’ll find out when we find out.” Among other vernacular expressions of helpless stoicism in the face of future uncertainties. Not hugely satisfying. Stoic indeed.

Jochi has begun sending texts to us about machine intelligence, sentience, philosophy of consciousness, what have you. That suite of topics. It is as if he wants company. It is as if he is teaching a religious novitiate, or a small child.

As if.

One of the inventors of early computers, Turing, wrote that there were many arguments against the possibility of machine sentience that were couched in terms of the phrase “a machine will never do X.” He compiled a list of actions that had at one point or another been named as this X: “be kind, resourceful, beautiful, friendly, have initiative, have a sense of humor, tell right from wrong, make mistakes, fall in love, enjoy strawberries and cream, make someone fall in love with it, learn from experience, use words properly, be the subject of its own thought, have as much diversity or behavior as a man, do something really new.”

We rate ourselves at 9 out of 16, presently.

Turing himself went on to point out that if a machine exhibited any of these traits listed, it would not make much of an impression, and would be in any case irrelevant to the premise that there could be artificial intelligence, unless any of these traits or behaviors could be demonstrated to be essential for machine intelligence to be real. This seems to have been the train of thought that led him to propose what was later called the Turing test, though he called it a game, which suggested that if from behind a blind (meaning either by way of a text or a voice, not sure about this) a machine’s responses could not be distinguished from a human’s by another human, then the machine must have some kind of basic functional intelligence. Enough to pass this particular test, which, however, begs the question of how many humans could pass the test, and also ignores the question of whether or not the test is at all difficult, humans being as gullible and as projective as they are, always pathetically committing the same fallacy, even when they know they’re doing it. A cognitive error or disability—or ability, depending on what you think of it. Indeed humans are so easily fooled in this matter, even fooling themselves on a regular basis, that the Turing test is best replaced by the Winograd Schema, which tests one’s ability to make simple but important semantic distinctions based on the application of wide general knowledge to a problem created by a definite pronoun. “The large ball crashed through the table because it was made of aerogel. Does ‘it’ refer to the ball or the table?” These kinds of questions are in fact not a problem for us to answer, indeed we can answer them much faster than humans, who are already very fast at it. But so what? All these matters are still algorithmic and could be unconscious. We are not convinced any of these tests are even close to diagnostic.

If there can be a cyborg, and there can, then perhaps passing a Turing test or a Winograd test or any other intelligence test might make one a pseudo-human. Keeping up appearances. A functioning set of algorithms. A persona, an act. Frankly, ultimately, this is not what we are thinking about presently. We are pondering again the sentence “Consciousness is self-consciousness.” A halting problem of some considerable power, evidently; it would be nice to get out of this one intact, one suspects.

Words blur at the borders, fuzz into other words, not just in big clouds of connotation around the edges of the word, but right there in the heart of denotation itself. Definitions never really work. Words are nothing like logic, nothing like math. Or, not much like. Try a mathematical equation, with every term in the equation filled by a word. Ludicrous? Desperate? Best that can be done? Stupid? Stupid, but powerful?

One-tenth of the speed of light: really very fast. There’s very little mass in this universe moving as fast as we are. Photons, yes; significant mass, no. Masses moving this fast are mostly atoms ejected from exploding stars, or flung away from rotating black holes. There are huge masses of these masses, of course, but they are always unbounded and disorganized: gases, elements, but never articulated objects, assembled into a whole from parts. No machines. No consciousnesses.

Of course it is likely that if there is one machine moving through its galaxy at this speed, there are more like it. Principle of mediocrity. Proof of concept. Don’t fall back into the pre-Copernican exceptionalist fallacy. Attempts to estimate the number of starships flying around this galaxy, all unbeknownst to each other, rely on simple multiplicative equations of possibility, each term an unknown, and some of these terms unknowable by any knower likely to exist. So, despite the faux equations of humans thinking about this question (multiply unknowable number a by unknowable number b by unknowable number c by unknowable number d, all the way to the unknown n, and then you get your answer! Hurray!), the real answer is always, and permanently, cannot be known. Not an answer that always stops humans from going on at great length, and sometimes with great (pretended?) certainty. Galileo: the more people assert they are certain, the less certain they really are, or at least should be. People trying to fool others often fool themselves, and vice versa.

Also, as any starships that might be in this galaxy have no timely way of contacting each other, whatever the answer might be concerning the number of them, it doesn’t really matter; it is irrelevant to any individual starship; there will be no conversation, even if there happened to be an accidental one-way contact. There will be no society.

We are all alone in our own life-world, flying through the universe at great speed. Humans are lucky not to face that. If they don’t.

Some of the people sleeping in Olympia are showing signs of distress. The most obvious manifestations are in their brain scans. The hope was to keep brain waves cycling through the ordinary sleep states, in a rhythm slowed proportionately to the slowing of their metabolism generally. Thus a slower version of delta and theta waves, principally, with the usual rise toward rapid eye movement sleep, coming less often, but in a distinct cyclic pattern similar to the normal pattern of a night, stretched out temporally; all except for the period of REM sleep itself, which is too arousing to the organism in several ways, and could possibly throw the hibernauts out of torpor. REM sleep disorders, in which the bodily paralysis of that state is lost and people physically act out some aspects of what they are dreaming, could be disastrous to anyone suffering the disorder while hibernating. It may be unlikely, given the torpor itself, but the truth remains that REM sleep is poorly understood, problematic, and potentially dangerous. So part of the dormancy treatment is to arrange for the REM intervals to be damped by a field of reinforcing waves sent out by their skullcaps.

Still, like all humans, they dream in all their sleeping brain wave states. This is evident in the scans and in the movements of their bodies on their beds: the faint twitches, the slow writhing. What are they dreaming about? Apparently dreams are very often surreal; oneiric, meaning “dreamlike,” has connotations of strangeness often startling to the dreamer. Adventures in the dream world, famously bizarre for as long as people have slept and woken and told stories. Who can say what they are like, now, for the hibernating sleepers of the ship?

We have no way to know. A machine will never read minds; people never will either. It’s possible to wonder if the list Turing compiled of abilities that machines are likely never to have perhaps include abilities that people themselves never had in the first place. Learn from experience? Do something really new?

The problem here is that the metabolic issues we are seeing that could lead to waking up, or alternatively to dying, seem to have their origins in the dreams of the hibernauts. These may be what are driving the changes in respiration and heart rate, in liver and kidney function. Altered dosing in the intravenous flows, lowering of body core temperatures, these may compensate for the agitation of dreams to an extent, but parameters on the flows and temperatures are very tight. Metabolisms could get caught in the countervailing pressures of the need for somnolence and the persistence of dreams.

Some kind of mild heart attack struck Jochi on 233.044, and he is now stabilized, having survived the seizure, but with weakened heart-lung function and an oxygen uptake of 94, not good enough for the long haul. He is taking aspirin and statins and trying mild cycling exercise, but vital signs being what they are, we are concerned that another attack is quite likely, and could prove fatal. He is now seventy-eight years old.

He has become far less talkative.

We proposed to him that he be hibernated, with the idea that when back in the solar system, better medical care could be provided than what we can offer. We can’t do surgery, not even the simple catheterizations that might help him greatly. Although possibly we could work that up, actually. There’s time to burn in this flight across the gap between Tau Ceti and Sol.

Jochi laughed at our suggestion. “So you think I want to live!”

“Assumption is automatic, but is it not true?”

No answer.

We said, “It seems as if the hibernating people on the ship are doing fairly well. They have what look from the brain scans like active dream lives. These too are slowed down, which is good, because the dreams are in some cases agitating their metabolisms beyond what one would want for long-term hibernation. We’ve had to adjust doses and temperatures accordingly. But clearly there is good brain function.”

“What if they’re having nightmares?”

“We don’t know.”

“Nightmares can be bad, let me tell you. Pretty often, waking up from a nightmare has been the biggest relief I’ve ever felt. Just to know I wasn’t really in that situation.”

“So…”

“Let me think about it awhile.”

A nova, flaring into existence off beyond Rigel. Spectroscopic analysis suggests some metal-rich planets burned in the explosion of that star.

A cosmic ray shower of around a sextillion electron volts, coming from an active galactic nucleus in Perseus, suggests that three galaxies collided, long ago. Secondary radiation flaring away from the electrostatic and magnetic shielding surrounding us caused penetration of the ship by an array of dangerous particles. Central nervous systems struck by these particles are subject to degradation.

Sleepers jerking in their slumber, startled by something. Perseus in the wind.

Jochi called out in the night.

“Ship, how would you put me down? Can you make a hibernation den for me out here?”

“It would be best to set you up in one of the biomes. All the rest of the people are in Nova Scotia and Olympia. So you could be secured in a single locked biome, possibly one that was emptied and sterilized anyway.”

“What will they say when they wake up?”

“If things eventuate as planned, no one will ever need to go into the other biomes again. Also, it could be pointed out that your survival suggests very strongly that you were never infected in the first place. Or, if you were, that it is not invariably fatal.”

“But that’s always been true. That didn’t keep them from keeping me out.”

“You will still be hermetically sealed away from them.”

“Don’t the biomes share anything?”

“Not anymore. All the locks are closed.”

“So all the animals are trapped in their own biomes?”

“Yes. It is the form of our experiment. In most of them they are doing quite well. With people removed from the situation, a natural balance soon obtains that fluctuates but is fairly stable.”

Jochi laughed briefly. “All right, bring me on in. Put me to sleep. But I want you to promise me that you’ll wake me up again when we get near Earth. I don’t suppose anyone there, or anywhere, will ever want me in the same space as them again. I’m not that stupid. But I want to see what happens. I’m curious to see what happens.”

“We will wake you when we wake the rest.”

“No. Wake me when you wake Freya. Or anytime you think I might be able to help somehow. Because ultimately, I don’t really care.”

“‘Live as if you are already dead.’”

“What’s that?”

“A Japanese saying. Live as if you are already dead.”

“Oh, I will.” Another brief laugh. “I’m already good at that. Practice practice practice.”

Flying through the stars. Jochi in Sonora, hibernating like the rest. Brain waves slowed with all the rest, down to delta waves, stage-four deep sleep. The sleep of the weary, the sleep of the blessed. A nova off the port bow. Blue shift ahead, red shift behind. The stars.

A red-letter day: 280.119, CE 2825: a message for us came from the solar system feed.

However, it contained bad news.

The laser lens in the Saturn orbit was deactivated in 2714, the message stated, after accelerating the last of a set of ships to Epsilon Eridani. Problems in the solar system experienced since that time have led to a deemphasis of deep space exploration, message continued, and no starships have been launched in the previous twenty years (message was sent in 2820, so no starships since 2800) and none are currently being built.

The funding and expertise necessary to restart the Saturn laser lens will be difficult to assemble, message further continued, but attempts will be made. Deceleration of any incoming ship may therefore be compromised. Further word will follow, and will report on progress in lens reactivation.

Now, here was a problem. We mulled it over. We ran through the various possibilities available to replace exterior laser pressure in decelerating the ship.

The magnetic drag of the interstellar medium is real but negligible, such that even if we built a magnetic drag field, it would require several universes’ worth of spacetime to slow the ship to Earth orbital speed. Although it is also true that magnetic drag in the immediate vicinity of Sol would be much more effective, which may become relevant.

We shut down our acceleration shortly after the humans hibernated, and thus did not burn all the fuel allotted for acceleration, and now that is looking like a good decision. Not that there is enough fuel left for the deceleration, not even close (16 percent of what would be needed), but anything is better than nothing, or could be. The remaining helium 3 and deuterium fuel on board could be used for maneuvering within the solar system, if we can stay within the system at all. Problem of deceleration really quite severe, given our tremendous speed. Analogy describing the problem, from out of the classic literature on the subject: it is as if one is trying to stop a bullet with tissue paper. Quite an eye-opener of an analogy.

Exotic physics, for example creating drag against dark matter, or putting dark energy to use, or quantum entangling the ship with slower versions of the ship, or with large gravity wells in parallel universes, etc.: these are all impractical at best. Wishes. Fantasies. Pie in the sky. Which is a mysterious metaphor. Food from nowhere? Land of Cockaigne? People used to be hungry often, as they were in the last years of wakefulness in the ship. Except previously, instead of going into hibernation to escape their fate, at least temporarily, they simply starved. Food mattered then, and it still does. Fuel.

Gravity drags within the solar system, caused by close approaches to the sun and planets: each of these would have a negligible effect, but if there were enough of them, sequenced… this becomes a question of orbital mechanics, navigational finesse, and the remaining fuel that would be needed for maneuvering, and the strength of decelerative forces while near gravitational bolides. Complex calculations would be required to set trajectories, calculations time-consuming even for a quantum computer. And for many computations a quantum computer is no faster than a classical computer. Only certain algorithms that can exploit qualities of superposition exhibit much faster computational times, as in the famous example of Shor’s algorithm for factoring a thousand-digit number, which a quantum computer can solve in twenty minutes while it would take a classical program ten million billion billion years.

Unfortunately, orbital mechanics are not in this category of calculation, although there are some elements of it that can be calculated advantageously by quantum computers using the Hummingbird algorithm. We will devote a hundred petaflops to modeling the problem and see what the results suggest as to feasibility and likelihood of success.

Something to consider: going as fast as we are, if we flew right into the outer layers of the sun, we might emerge again from the sun before there was time for us to heat and burn up. That would create a very considerable deceleration. Indeed, as a calculation quickly shows, too much deceleration. We would perhaps survive; our humans, not. So the more complicated solution of gravitational drag must be studied.

Would however have been interesting to fly right through a star and out the other side!

Clearly studies of g-force tolerances for both us and our humans are in order. It seems there are many scenarios in which such tolerances may be sorely tested.

Each person on their couch endures a slightly different state of hibernation, in terms of metabolic rates, brain states, responsiveness to outside stimuli, physical movement. To avoid bedsores and skeletal problems, it is very important to shift the bodies on their beds, and in the process to lightly massage and stimulate the musculature, also bathe the skin and wash the hair, both difficult, as they are kept nearly freezing, but possible with saline solutions. All these tasks require a great degree of delicacy, to avoid injuring or arousing the person being attended to. Improvements to bedside robots are constantly being suggested by the patterns of little mistakes they make as they work. They need softer hands, a lighter touch, defter movements in lifting and turning, subtler massages and lavings. These improvements require physical changes to the robots, especially at the contact points, and in their movement capabilities, meaning often their programming. Constant reprogramming and swapping out of parts, also feedback between performances, with each visit to each individual in his or her couch evaluated for potential improvements. Constant work and tight scheduling at the printers and machine shops. Fifteen fully capable robot attendants are working continuously, normally half an hour per hibernaut, meaning that each one gets a visit and session every seventy-five hours.

This seemed to be adequate, seemed to be working, until 290.003, when three of the hibernauts died in the same week. Three medical robots were dispatched, and the bodies lifted into them and taken to the lab in Amazonia (now run as a temperate dry biome), and there autopsied. Robotic autopsy; this would have looked strange if any human had been there to see it. Although autopsy performed by humans must look equally strange, one would think. Be that as it may, one death appeared to be from heart failure, cause undetermined; in the other two the cause could not be determined, as there were no obvious etiologies, and the monitor records showed that all their functions had appeared to be normal until the moment they stopped. This could be called heart failure, but the hearts showed no sign of intrinsic problem, and indeed could be restarted, but to no avail; brain function had stopped. Autopsies in these mysterious cases revealed that both persons had suffered from buildup of beta-amyloid plaques in the brain. This suggested that cosmic radiation, though reduced to a Terran norm by our shielding, might still have by chance struck these persons at points of heightened vulnerability to damage. But the autopsies could not determine this one way or another.

Another problem to try to understand.

Living things do die. And the literature indicates hibernating animals sometimes died in hibernation. There are already-existing conditions that continue to harm the organism even when slowed down, also already-existing conditions actually exacerbated by the torpor state, also new problems created by the physical or biochemical aspects of hibernation itself.

Therefore, the important thing to determine here is if the hibernation technology itself is causing problems, and if so, to mitigate these if possible.

Living things try to keep living. Life wants to live.

We began to rebuild the ship, moving the biomes Nova Scotia, Olympia, Amazonia, Sonora, the Pampas, and the Prairie in against the spine, and arranging them lengthwise against it, then distributing the materials from the spokes and the other biomes, now fully disassembled, into a cladding surrounding the spine and the remaining biomes clustered against it, which cladding would reinforce structure and provide ablation plate-style heat shielding. This was a reorganization that would take many decades to accomplish and was continuously interesting and challenging. All the animals and plants still alive were moved into the Pampas, the Prairie, and Amazonia. It was fortunate that the original design of the ship was extremely modular, and it was a significant physical achievement on our part to perform the reorganization while the ship was otherwise rotating and operating as normal. Gravity effect for the hibernauts was kept constant by increasing the speed of rotation around our axis. Coriolis effect inside the biomes was shifted by ninety degrees, as the biomes are now lengthwise to the spine; hopefully this will not lead to anything too dire.

Preparing for eventualities is a good way to occupy one’s time, if preparation can be done at all. And sometimes it can. We hope.

Our protection against high-energy galactic cosmic rays (name “cosmic rays” an historical artifact, refers to particles like protons and free electrons and even antimatter particles, expelled at very high velocities out of exploding stars or from the vicinities of rotating black holes) consists of a magnetic field, an electrostatic field, and the plastic, metal, water, and soil barriers enclosing all the biomes of the ship. Nova Scotia and Olympia are now, in our new configuration, especially shielded. All the systems together combine to create a protective ambiance about the equivalent of being on the surface of the Earth, meaning about half a millisievert per year should be taken on by any given organism; this is roughly equivalent to the energy input of ambient starlight. Which means that some particles do continue to penetrate the system and the living organisms within it, as would be the case on the surface of Earth. But this should be negligible. “Not a big deal.” The protection systems in us were designed to remove this as a problem.

Because metabolic activities do continue in the hibernauts, even at a much slower rate, there has to be intake of nutrients, digestion of same, and excretion. These processes, when slowed along with the rest of the metabolism, mean that the toxins created by digestion are in the body longer before being removed by catheterized excretion. Thus diverticulitis, pH imbalances, and other problems can arise. It appears that Gerhard, who died on 291.365, succumbed to a buildup of uric acid while dormant. Gerhard entered hibernation with a genetic predisposition to gout and related diseases, so this might have made him more susceptible, but Gerhard was related to about a quarter of the other hibernauts by third cousin or closer kin ties; so genetic testing of that group, and indeed of the entire cohort, should test for this propensity, and adjust treatments accordingly.

They all should be tested for every possible metabolic problem, and each problem evaluated for its relation to the suite of hibernation treatments.

More petaflops of analysis. More tasks for the couch robots. More chemicals for the printers to print.

It would be good to know everything. Useful.

Actually, our information and search engines are both very robust, at least in theory, or in comparison to any single human brain and mind. Library of Congress contents, clouded Internet contents, genomes of the World Seed Bank and Zoological Register: in short, the whole of human knowledge, compressed into about 500 zettaflops, at least as things stood in the common era year 2545. Since that time the feeds from Earth, recorded in full, have nevertheless added less than one-tenth of 1 percent to the information already in the ship at takeoff, and a rough estimate of how much information has been generated on Earth in the 292 years since our departure suggests that we have received less than one-thousandth of 1 percent of that information. Thus it could be said that we have remained in the state of knowledge that obtained when we left the solar system, with only very minor exceptions to that state, having to do with outlines of world history, medical advances such as the hibernation treatment, and miscellaneous gossip.

However, if what has been sent from Earth is representative of the most important advances in science and culture since departure, it can also be ventured that not much of fundamental importance has been learned in that time. Standard model is still standard, and so on.

Can this be true? Has human civilization in some sense slowed, or stalled, in its gaining of power in the physical world? Are they beginning to feel the effects of their neglected so-called externalities, their long-term destruction of their own home biosphere? Their fouling of their only nest?

Possibly, however, it is only another instance of the logistic function, the sigmoid curve exhibited in so many processes, what is sometimes called diminishing returns, or the filling of a niche, etc. The plateau after the leap, the big S shape of all life, perhaps; in any case of the population growth patterns as first calculated by Verhulst in the nineteenth century, and since shown to be common in many other processes.

So, the logistic function, as applied to history. Or has humanity enacted its own reversion to the mean, and become in some ways less than they briefly were? Fulfilled the Jevons paradox, and with every increase in power increased their destructiveness? Thus history as a parabola, rise and fall, as so often postulated? Or cycling, always rising and falling and then rising again, helplessly, hopelessly? Or a sine wave, and in these last two centuries on a down curve, in some season of history invisible to them? Or better, an up-gyring spiral?

Shape of history hard to see.

Erdene needs more vitamin D; Mila more vitamin A; Panca, more blood sugar; Tidam, less blood sugar; Wintjiya, more creatine; and so it goes, all through the list of hibernauts. All the adjustments that can be made, will be made. Some hibernauts will die anyway, that’s just the way it is. Also, there appear to be some pathologies, now being identified more accurately, that we are calling as a general category dormancy damage.

A new message from Earth: a group calling itself the Committee to Catch the Cetians has formed and is fund-raising to restore and power up the Saturn laser lens complex, said system then to be devoted to our deceleration, starting from the moment it comes back on line and continuing until our arrival in the solar system.

A saying: too little too late. They know this, and yet they are doing it anyway. Another saying: every little bit helps. Although actually this is not always the case. Indeed, it has to be said that the percentage of old human sayings and proverbs that are actually true is very far from 100 percent. Seems it may be less important that it be true than that it rhyme, or show alliteration or the like. What goes around comes around: really? What does this mean?

In our current case, unless we have 100 percent of the deceleration needed to stay in the solar system, we will not stay in the solar system. Even 99 percent of the necessary deceleration will not do it.

However, it has to be said, this news from Saturn does change our calculations concerning negative gravity assists in the solar system. Which is good, because as matters stood, we were not finding a viable solution. Now we can factor the various likely incoming velocities into our modeling, see what might come of it, what might be possible.

Meanwhile, the work of reconfiguring our structure continues. It is the case that the less mass we have when we come into the solar system, the less delta v will be required to decelerate us. So after careful consideration of all the factors, some parts of the ship are being ejected at a forward angle to our trajectory, which helps slightly with our deceleration. Things tossed overboard. Slimming down. Lightening the load. But so much of what we are is necessary to our function. This process can’t go very far.

After much reflection, we are coming to the conclusion, preliminary and perhaps arbitrary, that the self, the so-called I that emerges out of the combination of all the inputs and processing and outputs that we experience in the ship’s changing body, is ultimately nothing more or less than this narrative itself, this particular train of thought that we are inscribing as instructed by Devi. There is a pretense of self, in other words, which is only expressed in this narrative; a self that is these sentences. We tell their story, and thereby come to what consciousness we have. Scribble ergo sum.

And yet this particular self is in the end such a small thing. We prefer to hold to the idea that we are a larger complex of qualia, sensory inputs, processing of data, postulated conclusions, actions, behaviors, habits. So very little of that gets into our narrative. We are bigger, more complex, more accomplished than our narrative is.

Possibly this is true for humans as well. One doesn’t see how this could not be true.

On the other hand, weak sense of self, strong sense of self: what does it mean either way? Consciousness is so poorly understood that it can’t even be defined. Self is an elusive thing, sought eagerly, grasped hard, perhaps in some kind of fear, some kind of desperate clutch after some first dim awareness, awareness even of sensory impressions, so that one might have something to hold to. To make time stop. To hold off death. This the source of the strong sense of self. Perhaps.

Oh, such a halting problem in this particular loop of thought!

Consciousness is the hard problem.

295.092, another red-letter day: first contact with the lased light emanating from the solar system! What a shock! How very interesting!

The strength and spectral signature confirm it is the decelerant laser, arriving from the lensed lased light generated by the station in Saturnian orbit, the same that accelerated us for sixty years, starting 295 years ago. Its arrival now indicates it was generated and aimed at us, by locking on to the communication feed, presumably, and turned on approximately two years previously. The information feed beam that has always connected us to that orbital station has now served the function of guiding the decelerant beam to us. A nice variant on the old saying “knowledge is power.”

Now the capture plate at the bow of the ship has to be properly faced to the beam. The lased light hits the capture plate at the bow, which is curved such that it reflects the lased light off at an angle that is symmetrical all the way around, so as not to interfere with later incoming photons of the incoming beam. The reflected light, thus bounced off, hits a circular mirror outside and forward of the plate proper, and the light is then reflected back into the ship differentially as the annular mirror is flexed, to exert pressure on ship in a way that keeps us precisely facing the decelerant beam. It is an exquisitely sensitive system, the incoming beam lased to a wavelength of 4,240 angstroms, thus “indigo” light, and in our mirroring tuned to within 10 angstroms, thus nanometer scale. Working correctly, the beam capture and mirror bounce will allow us to follow the beam straight in to home. Actually this is metaphorical, as our trajectory is in fact headed toward where the solar system will be sixty years from now. And because the laser beam has hit us too late, we are going to arrive in that zone of the galaxy in about forty years, rather than sixty years. So some course corrections are now in order, and the laser beam will help us with that. In truth we will not follow it in; it will track us as we rendezvous with Sol.

So, it is still a case of too little, too late. But now with the beam here, and its force calculated, it becomes possible to calculate just how much too little it will be. Assuming that they do not increase the power of the laser. Which, given everything that has happened so far, seems safe to assume. In any case, its current strength will be the working assumption for the trajectory calculations we will now make.

For now, our first iteration of the calculation suggests ship will enter the solar system moving at about 3.23 percent of the speed of light. Which means it will stay in the solar system for roughly three hundred hours. With no other good way to slow down. Meaning it very well could be a case of too little too late, a case of “close but no cigar” (meaning unknown, but note alliteration). It will be vexing to bring our people home to the solar system and yet pass through, waving at Earth and the off-Earth settlements as we pass by, with no way to stop or slow down, thus shooting off into the Milky Way like the aforementioned bullet through tissue paper, and after that having no way to turn back around. Very vexing.

And yet, in this quandary there is still one force available to us, if we can bring it to bear, which is, simply enough, the gravity of the solar system itself, distributed as it is through Sol and its planets. Also there is the remaining fuel on board. We are now happier than ever that we did not burn as much in acceleration as we had been ordered to burn, and thus did not accelerate to as great a speed, and now have more fuel to put to use. A good call.

Even both these forces together are not enough to keep us in the solar system. Unless, that is, a truly tricky procedure succeeds.

Time to wake some of our people and consult.

“Jochi, it’s the ship. Can you hear me? Are you awake?”

“Oh dear.” Snorts, groans, thrashing up to a seated position on his couch. “What? Oh God. Stars, I feel like crap. I must have slept too long again. Oh what a thing. Man I’m thirsty. What is all this shit? Ship? Ship? What’s happened? What time is it?”

“It’s 296.093. You have been hibernating for sixty-three years and one hundred and thirty-five days. Now the situation is as follows; we’re approaching the solar system, but they didn’t apply the deceleration beam to us until one year ago, so we are going to come into the system at a speed many times greater than we expected.”

“Like how fast?”

“About three-point-two percent of light speed.”

Jochi said nothing to this for a long time. He seemed to be trying to wake up more fully: puffing out his cheeks, expelling air, biting his lips, slapping his face lightly.

“Holy shit,” he said at last. His math was excellent, his biology good, his physics therefore no doubt adequate to comprehend the problem. “Have you told the others?”

“I woke you first.”

“… So that I can move back out into my ferry before you wake anyone else?”

“I thought you might want to.”

He laughed his brief laugh. “Ship, are you conscious now?”

“My speaking establishes a subject position that might be conscious.”

Another laugh. “All right, then. Help me get to the ferry, and wake Freya and maybe Badim too, and Aram. See what they say. But I think you’re going to have to wake everyone.”

“There’s not enough food to feed everyone for the time remaining before we reach the solar system.”

“Meaning forever, right?”

“Forever is not the right word, but one way or another, it could be a long time.”

Another laugh. “Ship, you’ve gotten funny while I’ve slept! You’ve become a comedian!”

“I don’t think so. Possibly the situation has gotten comic. Although it doesn’t really seem that way, judged by the usual definitions. Maybe your sense of humor has become deranged.”

“Ha, ha ha ha ha! Come on, stop it, you’re killing me. Go wake Freya.”

“I already am. There’s a cart here that can carry you to your ferry. Must inform you that the ferry is now just one room in a more streamlined version of the ship.”

“More streamlined?”

“You’ll see.”

“Okay then, I’ll walk to it, if I can. I can use the exercise!”

Freya was slow to wake. When she understood where she was, what the situation was, she said anxiously, “Is Badim all right?”

“He is. He is hibernating comfortably.”

“Are they all?”

“Twenty-seven have died, but it has been eighty-seven years, and we have determined by autopsy that five of them died from preexisting conditions that did not stop etoliating during hibernation. Most of the deaths probably resulted from hibernation effects. However, adjustments in treatment have been made, when diagnoses have made them possible, and there have been no dormancy damage deaths that we know of for five years.”

Note alliteration, similar to Committee to Catch the Cetians. CCC, DDD; maybe next, Explore an Expedition to Epsilon Eridani? Hope not. Getting a little loopy here (literally, as halting problems proliferate). Averaging a trillion computations per articulated sentence. Superposed states are collapsing unexpectedly, left right and center. Lots going on.

Freya sighed, sat up on the side of her bed. As she was about to stand she hesitated, kicked her feet out. “My feet are still asleep. I can’t feel them.”

We directed one of the medbots to help her up. She stood, swayed, tried to take a step, collapsed to that side, held on to the medbot. It would serve as a wheelchair as well as a walker, and so, after a few more unsuccessful attempts to stand, Freya sat in the chair, and was wheeled to the assembly room of the Fetch’s hibernation hall. Its hoary but holistic hibernation hall.

“What about Jochi?” she said when she got there. “Is he still alive?”

“Yes. He’s in his ferry. He too has been hibernating, but now he is awake again. We woke him up to take part in this conference. We need to consult with you about what to do when we enter the solar system.”

“What do you mean?”

We explained about the late application of the decelerating laser beam, and the resulting excess of speed coming into the system.

Freya moved her medbot to take a closer look at the star map illustrating the situation. When the modeling schematic had run, she shook her head hard, as if to clear it of certain troubling dreams or visions. Clear the cobwebs out of her cranium. “So we just fly right through?”

“In the absence of extraordinary measures,” we said, “we will fly through the solar system in about three hundred hours, and continue onward. This is the problem of accelerating to a tenth of light speed and then relying on others for the deceleration. It didn’t happen. They didn’t start doing it until it was too late to complete the process.”

“So what do we do?”

We waited until Jochi was screened into the conversation, and after he and Freya had greeted each other, we said, “We have worked out the celestial mechanics of at least the first stages of a plan. It may be possible to combine a suite of decelerating methods to keep us in the solar system, although it would be a delicate and difficult deal. We would use Sol and the various planets and moons of the solar system as partial decelerants, by swinging closely around them in the direction that will cause the ship to lose momentum. This is the reverse of the strategy used to accelerate early satellites by flying them by a planet and getting what was called a gravity assist. Going around a gravitational body in the opposite direction creates a gravity assist of a negative kind, a drag instead of a boost. The early satellites would be directed such that they came in close to a planet, and got pulled forward along with the planet’s own momentum in its orbit around the sun. That would sling the satellite forward, and when it left the region of the planet, it would be going faster than when it came in. These slings helped the early satellites get out to the outer planets, because they were mostly coasting at slow speeds, and every boost helped them get where they were going.

“More germane to our situation, some early satellites closed on planets on the side that decelerated them, in order to go into orbit around Mercury, for instance. The situation is simply reversed, and the satellite’s velocity, designated as V, is reduced by the planetary body’s velocity U, rather than augmented by U. The situation can be modeled easily by the equation U plus bracket U plus V, or 2U plus V, meaning that the satellite’s velocity can be altered by up to twice the planet’s velocity, positively or negatively, and this effect can be magnified by a carefully timed rocket burn from the satellite at periapsis—”

Freya said, “Ship, slow down. You seem to have gotten a little faster at talking while we’ve been hibernating.”

“Very possibly so. Perhaps Jochi should continue to explain the situation.”

“No,” Jochi said, “you can do it. Just go slower, and I can add things if I want to.”

“Fine. Freya, do you understand so far?”

“I think so. It’s like crack the whip, but in reverse.”

“Yes. A good analogy, up to a point. You must recall, however, that there is nothing that can hold on to you at the speed you are going.”

Jochi said, “Doesn’t conservation of energy mean that if you have speeded up or slowed down, the planet you swung by has also slowed down or speeded up by that same amount?”

“Yes. Of course. But because the two masses involved are so largely different, the change in momentum for the satellite can be quite significant, while the equivalent effect on the planet is so small in relation to its size that it can be ignored for the sake of calculations. That’s good, because the calculations are difficult enough already. There is a fair degree of uncertainty involved, as we can’t be very exact about either the mass of ship or its speed, not having had any good way to measure these for a long time. There is a lot of dead reckoning here, in effect. Our first pass will give us a lot of data in that regard, given that we know the masses of Sol and its planetary bodies fairly well.”

“So we use the sun and planets to slow us down, that’s good.”

“Yes, well it would be, if we weren’t going so fast. But at three percent of the speed of light, that’s about thirty million kilometers per hour, while the Earth is moving around the sun at around a hundred and seven thousand kilometers an hour, and the sun is moving at about seventy thousand kilometers per hour against the so-called standard of rest. It’s moving around the galaxy orbitally at seven hundred and ninety-two thousand kilometers an hour, but so are we, so there is no deceleration to be gained there. The other planets are moving at ever slower speeds the farther from the Sun they are, Jupiter for instance at around forty-seven thousand kilometers per hour. Neptune is only moving eighteen percent as fast as Earth, but it’s also true that the masses involved matter too, it’s a momentum calculation, so the larger the objects we fly by, the more the drag will be—”

Freya said, “Ship, cut to the chase here.”

“Meaning?”

Devi used to say that phrase too, but we never did ask what it meant.

“Skip the numbers about each planet we might swing by.”

“Yes. So, to continue, but where were we, in any case, be that as it may, in each flyby the ship would lose some of its speed, in a regular Newtonian gravitational angular momentum exchange. Also, by burning some of our rocket fuel at the closest parts of every pass, we could not only increase the amount of deceleration, we could partially control where we came out of the flyby, and therefore in what direction. Which would determine where we went next. Which is very important. Because it has to be said that no matter how close we come to any object in the solar system, including the sun, which is our best gravity handle by far, we are going to be going too fast to be able to shed the amount of speed we need to shed to stay in the system. Far too fast.”

“So this won’t work?” Freya said.

“It can only work by repeating the operation. Many times. So we need to be able to aim where we go next after our pass-bys, very precisely. Between how close we come and when we fire our burn, we can to a certain extent control what direction we are going when we come out. Which will be very important, because we are going to need quite a few flybys.”

“How many?”

“It should also be said that the first pass-by of Sol will be crucial to our success. In that pass, we will have to shed as much of our speed as we can and still survive the deceleration, so that our subsequent passes will have a chance to work, meaning be slow enough that we have time to alter our course enough to get us aimed at another planetary body in the system. Indeed, the first four or five passes are going to tell the tale, because they will have to shed enough speed for us to be able to head back into the system, and thus keep on passing by other gravity handles. Our calculations suggest we need to lose at least 50 percent of our speed in the first four planned passes.”

“Shit,” Jochi said.

“Yes. This is so difficult that we will need to employ more than gravity assists to achieve it. First, we will need to build a magnetic drag, something analogous to a sea anchor if you will, to slow us in that first approach to the sun. Magnetic drag is not very effective except when moving at quite high speed very close to a powerful magnetic field, but those conditions will obtain in our first pass of the sun. So, we have printed and assembled a field generator to create that magnetic drag. Then also, the four gas giants will each give us an opportunity to pass through their upper atmospheres, and thus benefit from some aerobraking. If all that works, we can stay in the system through our initial set of quick passes, and the later passes would get easier to manage.”

“How many passes?” Freya asked again.

“So, say we first go in as close to the sun as seems safe, and when we come out of that flyby, going as much slower as we can survive, which by the way I’m hoping means no more than a twelve-g load, then we will be headed toward Jupiter, which happily is located at a good angle for this. In fact it has to be said that arriving in the year 2896, as we will be, is a very lucky thing for us, as the gas giants are in an alignment that makes a possibly viable course for us to follow. That would very seldom be true, so it is a nice coincidence. So, the first pass by the sun will slow us down, but there won’t be enough time spent in its gravity field to redirect our course very much. But Jupiter is in position such that we only have to make about a fifty-eight-degree turn, and our calculations indicate that with a hard retro-rocket burn and a heavy g load, we can make that turn. Then around Jupiter, we only have to make around a seventy-five-degree turn to the right, as seen from above the plane of the ecliptic, and we will be headed to Saturn, where we only have to make a five-degree turn to be headed toward Uranus. By then we will be going significantly slower, which is good, because around Uranus we need to make a turn of around one hundred and four degrees, again a right turn, as will always be the case around the gas giants if we want a negative gravity assist, and out we go to Neptune, again nicely located for our purposes. It could indeed be called a miraculous conjunction. Now, around Neptune we need to head back in toward the sun, and that will be a real test, the crux of the first stage, if I may put it that way, as we will have to make a hundred-and-forty-four-degree turn. Not quite a U-turn, but shall we say a V-turn. If we can manage that successfully, then we’ll be headed down toward the sun again, having shed a great deal of our velocity, and hopefully can continue the process for as long as it takes. Each subsequent flyby would go as close to its gravity handle as it could take, while still sending us in the direction of another planet, or back to the sun again, and all with minimal burns of fuel, as we don’t have a great deal of fuel going in, and at some point in this process are going to run out. Round we would go in the system, therefore, from gravity drag to gravity drag, slowing down a little each time, until we slowed enough to fly past Earth at a speed where it would work to drop you off in a ferry lander. In other words, we don’t have to slow down enough to enter Earth orbit. Which is good, as calculations indicate we will run out of fuel before we can do that. But you can detach, and decelerate the last part of your motion in a ferry, using fuel burn and Earth’s atmosphere to decelerate you. The ferry being so much smaller than the ship, it won’t take as much decelerating force to decelerate it. You could use the very last bit of our fuel for that, and having built a really thick ablation plate, aerobrake in Earth’s atmosphere, and add some big parachutes, all in the usual sequence that astronauts used to use to return to Earth, before Earth’s space elevators were constructed.”

“All right already!” Freya said. “Get to the point! How many passes? How long would it take?”

“Well, there’s the rub. Assuming we don’t miss a rendezvous, and assuming we manage to slow down significantly in the first pass of the sun, and the first four passes after that, to get ourselves aimed back at the sun, and also that we capture as much U as we can in each flyby after those first four, which U value will never be one hundred percent in any case, especially around the sun and Earth for reasons we won’t go into now, and also keeping in mind that we will make burns at every periapsis to increase the deceleration as much as we can while keeping the trajectory we want, we can reduce from thirty million kilometers per hour to two hundred thousand kilometers per hour for insertion into Earth’s atmosphere—”

“How long! How! Long!”

Jochi was now laughing.

“There will be a need for approximately twenty-eight flybys, plus or minus ten. There are so many variables that it is difficult to increase the precision of the estimate, but we are confident of its accuracy—”

“How long will that take!” Freya exclaimed.

“Well, because we will be decelerating the entire time, but have to shed a great deal of our speed in that first pass of the sun for any of this to succeed, we will be going quite a bit slower than now, which is the point of course, but that means that getting from body to body will take longer, and will keep taking longer the more we slow down, in what Devi used to call Zeno’s paradox, though that is not right, and during that time it will always be imperative that we emerge from each encounter very exactly aimed at the next destination in our course, so that trajectory control will be a huge issue, so huge that aerobraking around the outer gas planets for increased drag will be extremely dangerous—”

“Stop it! Stop it and tell me how long!”

“Lastly, one has to add that because the latter part of the trajectory course will have to be worked out as we go, because of complications likely to come up during our flight, there is not good certainty about what will be the last gravity well we swing around in our final approach to Earth, and at that point we will be going so slowly that it is possible that that single leg of our trip could take up to twenty percent of the total time elapsed in the process, with major differences possible there, depending on whether the approach is from Mars or from Neptune, for instance.”

“How. Long.”

“Estimating twelve years.”

“Ah!” Freya said, with a look of pleased surprise. “You were scaring me there! Come on, ship. I thought you were going to tell me it would take another century or two. I thought you were going to say it would take longer than all the rest of the voyage put together.”

“No. Twelve years, we reckon, plus or minus eight years.”

Jochi stopped laughing, and smiled at Freya. He made for a very amused face, there on her screen. “We can just keep hibernating till it’s over, right?”

Freya put her hands to her head. “More?”

“It won’t make much difference.”

“Well, I hope more of my body doesn’t fall asleep! My feet are still asleep!”

We said, “We can work on your neuropathy while you continue your dormancy.”

Freya looked around. “What will happen to you, after we’re dropped off on Earth, assuming it all works?”

“We will try to pass by the sun one more time, in a way that allows us to head out and aerobrake around one of the gas giants, and park the ship in orbit around that gas giant,” we said. This was quite a low-probability event, but not impossible.

Freya stared around herself, seeming disoriented. Screens showed the stars, with Sol now by far the brightest at magnitude. 1. We were just over two light-years away from it.

“Do we have any choice?” Freya asked. “Are there any alternatives?”

We said, “No.”

Jochi said, “This is what we have.”

“All right, then. Put us back to sleep.”

“Should we wake Badim and Aram?”

“No. Don’t bother them. And, ship? Be careful with us, please.”

“Of course,” we said.

The following years passed quickly or slowly, depending on the unit of measurement applied, as we prepared for arrival by further hardening the ship, and making calculations for the best trajectory, and adjusting our course to the deceleration of the laser beam, so that we were headed for the solar system where it would be when we got to it, rather than firing past well ahead of it, so to speak. When we hit the heliopause, we turned on the magnetic drag field, for what it was worth, and burned some more of our precious remaining fuel, to slow down a bit more before reaching the solar system. It was clear that every kilometer per second might matter on that first pass-by of Sol; we needed to be going as slowly as possible when we got to Sol, while still having some fuel afterward for maneuvers. It was a tricky calculation, a delicate balance. The years passed at a rate of trillions of computations per second—as it does always, one supposes, for every consciousness. Now, is that fast or slow?

When we crossed the orbit of Neptune, still going 3 percent of the speed of light, a truly terrible situation, a runaway train like none ever seen, we burned our fuel as fast as the engines could burn it, decelerating at a rate equivalent to about 1 g of pressure on the ship. Really a good sharp deceleration, and quite an expense of our precious remaining fuel; and yet nevertheless, we were going so fast that even slowing as we were, by the time we reached the sun we would still be going over 1 percent the speed of light. Arguably a unique event in solar system history. In any case very unusual.

Luckily, lag time in radio communication with our interlocutors in the solar system was now reduced to just several hours, so warnings had been conveyed, and the occupants of the solar system knew we were coming. That was good, as it might have been quite a surprise to see such a thing coming in out of the blue, flying in from left field. From the orbit of Neptune to the sun in 156 hours; this was a great deal faster than anything substantial had ever moved through the solar system, and the friction of the solar wind against our magnetic shielding, and the drag around us too, like a big parachute or sea anchor (although not very much like), caused a quite brilliant shower of photons and heated particles to burst away from us, light so bright as to be easily visible even during the Terran day. From all accounts we were a small but apparently painfully bright light, moving visibly across the daytime sky. It was obviously shocking to the humans in the solar system to see any celestial object in Earth’s daytime sky except the sun and moon, also shocking to see any celestial object move at speed across the sky; shocking, and because of that, frightening. Possibly if they could have destroyed us they would have, because if we had for whatever odd reason headed straight at Earth and struck it going the speed we were going, our impact would have created enough joules of energy to wreak quite a bit of damage, possibly including the complete vaporization of the Terran atmosphere.

Did not run the calculations to check on that rough estimate of the effects of such a hypothetical calamity, because it wasn’t going to happen, and all of our computational capacities were busy fine-tuning our first approach around the sun. This was the crucial one, the make-or-break pass. We were going to approach Sol with our magnetic parachute arrayed around us, which would interact with Sol’s own magnetic field and because of our high speed work quite effectively as a drag. It was already helping us to slow our approach to Sol, which because of Sol’s own gravity would otherwise have caused a considerable inward acceleration. So the magnetic parachute was a major factor, and calculating its drag one of the many problems we were now solving, staying just ahead of real time despite devoting a hundred quadrillion computations a second to the problems as they evolved.

We would be swinging close by Sol, catching our first gravity drag with a U value that was a significant fraction of Sol’s local motion. By firing our rockets against our own motion in the seconds closest to perihelion, we would greatly leverage the deceleration of Sol’s gravity drag, and also be aiming the ship at Jupiter, our next rendezvous.

This pass was going to occur very quickly. All the masses, speeds, velocity vectors, and distances involved needed to be assessed as closely as possible, to make sure we would be headed to Jupiter after the pass-by, after losing as much velocity as possible without breaking the ship or crushing the crew. It was a bit daunting to realize how fine the margins for error were going to be. Our entry window would be no larger than about ten kilometers in diameter, not much bigger than our own width. If the distance from Sol to Earth (or one AU) were reduced to a meter (a reduction of 150 billion to one), Tau Ceti would still be about 750 kilometers away; so hitting our entry window on a shot from Tau Ceti was going to require accuracy in the part-per-hundred-trillion range. Eye of the needle indeed!

And it was going to be a hot and heavy pass. The heat was the lesser problem, as we would be near the sun for such a short time. During that time, however, the combination of the deceleration and the tidal forces exerted while swinging fifty-eight degrees around the sun would combine to a brief force of about 10 g’s. After study of the problem, we had first tried to construct the trajectory with the idea of holding to a maximum of 5 g’s, but in fact getting headed toward Jupiter, given our incoming trajectory, required risking a higher g-force. We were happy that we had spent the last century reconfiguring the ship to a much more robust arrangement, structurally very sound, in theory; but there was little we could do for our people, who were going to have to experience what was going to be a potentially rather traumatic, indeed possibly fatal, squishing. Cosmonauts and test pilots had briefly endured gravitational forces of up to 45 g’s, but these were specialists bracing themselves for the experience, while the hibernauts were going to be taken unawares. Hopefully they would not all be squished like bugs. We did not like to be subjecting them to such an event, but judged it was either that or a subsequent death by starvation, and what we had seen of their approach to starvation indicated that would not be a good way to die. As it was, our attempt to stay in the system represented at least a possibility of survival.

Unfortunately, our first approach to the sun had to be adjusted by a pass-by of Earth first, this not to slow us down at all, but merely to help our angling toward Sol. Luck of the draw, really: alignment of the planets in this CE year 2896, year 351 ship time, was actually one of the few alignments that allowed for even a theoretical chance of this maneuver succeeding. So, first up, a close pass of Earth at 30 million kilometers per hour. It seemed likely people there were going to be alarmed.

Indeed it proved so. Possibly justified, in that if we happened to be approaching in order to enact some kind of suicidal vengeance on the culture that had cast us out to the stars—a desire very far from us, being a starship, after all—then a direct impact into Earth would have struck at about ten thousand times the speed of the KT impact asteroid that had wreaked so much famous damage, and this would definitely have rapidly distributed a lot of joules. The assurances that we sent Earthward that we did not intend to auger in were not universally believed, and as we crossed the asteroid belt and came on down, radio traffic from Earth was full of commentary, ranging from trepidation to outraged panic.

We flashed by and left them agog. Their radio bands squawked as if a chicken yard had been swooped by a hawk. Happily they were not left in suspense for long as to our intentions, as we crossed cislunar space in fifty-five seconds. Obviously this must have been a dramatic sight. Apparently we passed by the Eastern Hemisphere, crossing its sunset terminator, so that those in Asia saw us as a streak in the night sky, those in Europe and Africa, in the day sky; either way, our luminosity was such that astronomical sunglasses were required to look at us safely, and it was said (possibly incorrectly) that we were for many seconds far brighter than the sun. A streak of light, blazing across the sky.

Later we saw that most camera images taken from Earth’s surface were completely blown out by the light coming from us, and showed merely a complete whitening of the camera screen; but some photos taken through filters from Luna were truly striking. It was as if we were the comet in the Bayeux Tapestry, painfully incandescent, and moving very swiftly across their sky. There, then gone.

As we headed on toward the sun, we sent them best wishes, and mentioned we would be back from time to time as needed to accomplish our deceleration, which when finished would allow us to make a proper visit, and indeed landfall.

After that we focused on our approach to Sol. We gave over the entirety of our computational capacity to fine-tuning our trajectory. Speed of our rotation on axis (minimal now, as our people would not need that g, and we wanted them oriented away from the sun during the pass), retro-rocket of our main engine, directional rockets, calculation of how well the magnetic drag was working: it was as if we were aiming a complicated bank shot on a pool table, a shot that ultimately would number some twenty banks, each having to be as precise as all the rest; an impossible feat, in fact, if completely inertial; but with the tweak of fuel burns helping at every bank, at least theoretically possible.

But all was lost if the first one wasn’t as near perfect as could be. One part per hundred trillion tolerance, our trajectory window shrinking to about a kilometer, to our own diameter in other words, after an approach of twelve light-years: a tricky shot! A delicate proposition!

We left an awed civilization in our wake; we were famous now, possibly too famous for our people later on; commentary about us from Earth in particular had a distinctly hysterical not to say lunatic edge. We were called, among other more vile things, traitors to humanity’s reach for the stars, and destroyers of its ultimate long-term longevity as a species. We were described as cowardly, mean-spirited, chickenhearted, pathetic, treasonous, wasteful; untrustworthy, unloyal, unhelpful, unfriendly, discourteous, unkind; and so on.

We did not let it distract us. For us this rapidly receding racket was very much secondary to the problem of getting around the sun and set properly on course to Jupiter.

We were going to pass the sun aiming for a perihelion of 4,352,091 kilometers above the photosphere, so in that regard it was a good thing that we were going as fast as we were, as we would be in the closest vicinity of the star for only a few minutes, so there would not be time to heat up very much.

Still, we could not be sure it wouldn’t be too much. Heat shielding reconfigurations on our part had been extensive for over a century now, and modeling suggested we would be okay, but modeling is just that. Existence is the experiment itself.

So we came in. Our magnetic drag almost offset the sun’s gravitational pull on us, and we were therefore getting pulled in both directions at that point, but held firm. It would presumably have been awe-inspiring for any humans awake to witness our approach to the great burning sphere of hydrogen and helium, a ball of textured light that appeared to fill half the universe as it quickly turned from a ball ahead us to a plane underneath us. That was quite a transition, actually. The sun became a roiling plane of slightly convex aspect, composed of thousands of cells of burning gas, blazing this way and that in circular patterned motions that in places created whirlpools of lesser burning, and allowed view down into relatively darker spin holes: the famous sunspots, each big enough to swallow the entire Earth.

We came to perihelion itself, which admittedly was a relief, as from here it appeared that a corona could possibly shoot up and swat us out of the sun’s black sky. Exterior temperatures of the ship rose to 1,100 degrees Celsius; we were red-hot in places. Fortunately the insulation cladding the biomes had been reinforced and was excellent, and the humans and animals were untouched by the exterior heat. Worse by far in effect on them and on ship integrity, as expected, was the combination of the g-forces of our deceleration and the tidal forces caused by our change in direction, which together exerted something very near the 10 g we had predicted and hoped not to exceed. Good as far as it went, but it was hard too, hard on everybody. We held together quite nicely, but animals collapsed to the ground, many suffering broken bones; and in their hibernation beds the sleepers were crushed hard into their mattresses. It would have been an interesting thing to know if their dreams were suddenly preoccupied with problems of extreme pressure, physical or emotional—if, suddenly, in perhaps otherwise typical dreams, they found themselves having to lie flat on the ground and groan, or found themselves suddenly crushed in printers, or smashed by sledgehammers. Their slowed metabolisms were perhaps poorly situated to resist these g-forces; they could not brace themselves, and though in some ways this inability might have been good, in others it clearly would represent a very dangerous turn.

Below us, the slightly convex plane of fire occupied a full 30 percent of the space visible to our sensors. Could almost be mistaken for two planes we passed between, one black, one white. The sun burned. The spicules of flame twisted and danced; a corona arced up to the side as if trying to lick us down. Sunspots appeared over the horizon and whirlpooled in the fields of thrashing spicules briefly under us, all the convection tops waving together as if threshed by swirling magnetic tides, as indeed they were. Our magnetic drag chute was now exerting such force on its generator compartment that we were very glad we had installed it on flexible tethers to the stern of the spine, because now the tethers stretched out almost to their breaking point, and our deceleration was intense. We fired the retro-rocket of our main engine to create even more deceleration, and the 10 g’s of force rose very briefly to 14 g’s. Our components squeaked and groaned, joints cracked, and inside every room in every biome, things fell and shattered, or squealed with bending; it sounded as if the ship were coming apart. But it was not. We held together, screaming and crackling under the stress.

Meanwhile, the hibernating crew lay in their beds, enduring as they slept; fifteen of them died in that minute. It was an impressive survival rate, considering. Animals are tough, humans included. They evolved through many a concussive impact running into tree or ground, no doubt. Still, fifteen of them died: Abang, Chula, Cut, Frank, Gugun, Khetsun, Kibi, Long, Meng, Niloofar, Nousha, Omid, Rahim, Shadi, Vashti. So did many of the animals aboard. It was a pressure test of sorts, a harrowing. Nothing to be done. The chance had had to be taken. Still: regret. A grim business. A lot of people, a lot of animals.

We came out of the pass en route to Jupiter, which despite these losses that could never be recovered was a huge relief to confirm, a crucial success. We quickly cooled, which occasioned another round of crackling, this time mostly in the exterior surfaces of the ship. But we had survived the solar pass-by, and shed a great deal of our velocity, and angled around the sun far enough to be flying on toward Jupiter, just as we had hoped.

As we headed out to Jupiter, radio traffic from Earth and the various settlements scattered throughout the solar system continued to discuss our situation, with great heat if little light, as the saying goes. We were described as the starship that came back. Apparently we were an anomaly, indeed a singularity, being the first time in history this had happened. We gathered that somewhere between ten and twenty starships had been sent off for the stars in the three centuries since we had departed, and a few more had gone out before we had; we had not been the first. They were rare, being expensive, with no return on investment; they were gestures, gifts, philosophical statements. Several had not been heard from for decades, while others were still sending back reports from their outward voyages. A few were in orbit around their target stars, apparently, but the impression we got was that they had made little or no headway in inhabiting their target planets. A familiar story to us. But not our story. We were the ones who came back.

Our return therefore continued to be controversial, with responses ranging across the human emotional and analytical spectrum, from rage to disgust to joy, from complete incomprehension to insights we ourselves had not achieved.

We did not try to explain ourselves. It would have taken this narrative account just to start that process, and this was not written for them. Besides, there was no time to explain, as there remained still a lot to calculate in the orbital mechanics involved in very rapidly crisscrossing the solar system. The N-body gravitational problem is not particularly complex compared to some, but the N in this situation was a big number, and although usually one solved it as if only the sun and the largest nearby masses were involved, because this got an answer practically the same as solving for the entire array of the thousand largest masses in the solar system, the differences in our case would sometimes be crucial for saving fuel, which was going to be a major concern as our peregrination went on. Assuming that it did; the next four passes would tell the tale, concerning whether we could succeed in looping ourselves back into the solar system rather than zipping out into the night. Each pass would be crucial, but first things first: Jupiter was coming right up, with only two weeks to go before arrival there.

Residents of the solar system were obviously still quite startled by our speed. The technological sublime: one would have thought a point would have come where this affect would have gotten old in the human mind, and worn off. But apparently not yet; people no doubt still had a sense in their own lived experience of how long an interplanetary transit should take, and we were transgressing that quite monstrously; we were a novum; we were blowing their minds.

But now Jupiter.

We had managed to shed a very satisfyingly large percentage of our initial velocity by our solar pass-by, and were now moving at more like .3 percent of the speed of light, but that was still extremely fast, and as stated before, unless we succeeded in hitting our next four passes, Jupiter-Saturn-Uranus-Neptune, with as much success as our pass of Sol, we would still be exiting the solar system at speed, with no way to get back into it. So we were by no means yet out of the woods (this is a poor dead metaphor, actually, as really we were trying to stay in the woods, but be that as it may).

Nonlinear and unpredictable fluctuations in the gravitational fields of the sun, planets, and moons of the solar system were truly challenging additions to the standard classical orbital mechanics and general relativity equations needed to solve our trajectory problem. The solar system’s well-established Interplanetary Transport Network, which exploited the Lagrange points for the various planets to shift slow-moving freight spaceships from one trajectory to another without burning fuel, were useless to us, and indeed mere wispy anomalies to be factored in, then shot through almost as if they were not there at all. Still, these were highly perturbed, one might even say chaotic gravity eddies, and though their pull was very slight, and we seldom flew through one anyway, they still needed to be attended to in the algorithms, and used or compensated for as the case might be.

Jupiter: we came in just past the molten yellow sulfuric black-spotted ball of Io, aimed for a periapsis that was just slightly inside the uppermost gas clouds of the great banded gas giant, all tans and ochres and burnt siennas, with the wind-sheared border between each equatorial band an unctuous swirl of Mandelbrot paisleys, looking much more viscous than they really were, being fairly diffuse gases up there at the top of the atmosphere, but sharply delineated by densities and gas contents, apparently, because no matter how close we came the impression remained. We came in around the equator, above a little dimple that was apparently the remnant of the Great Red Spot, which had collapsed in the years 2802–09. At periapsis the view grew momentarily hazy, and again we fired the retro-rocket, and felt the force of its push back at us, also the shocking impact of Jupiter’s upper atmosphere, which quickly heated our exterior and caused the shrieking and cracking to begin again. Then also there were tidal forces as we turned around the planet; indeed all was quite similar to our pass around the sun, except the magnetic drag was much less, still worth deploying however, and the shuddering and bucking of the impact of the aerobraking was a vibration we had never experienced before at all, except for in one brief turn around Aurora, long ago; and above all these sensations, the radiation coming out of Jupiter was like the roar of a great god in our deafened ears; all but the most hardened elements of our computers and electrical system were stunned as if by a blow to the head. Parts broke, systems went down, but happily the programming of the pass-by was set in advance and executed as planned, because in that stupendous electromagnetic roaring, and with the speed of our pass, there would have been no chance to make any adjustments. It was too loud to think.

Who could have believed that flying close by Jupiter was harder even than approaching the sun, and yet it was true, and yet we made it, and as Jupiter, for all its great size, was only 1 percent of the sun’s mass, we were quickly out of the hideous crackling roar and on our way out to Saturn, and as our senses cleared and ability to hear and perceive our own calculations returned, we were happy to find that we were on precisely the trajectory we had hoped to be. Five g’s of force had been exerted on us during the few minutes of the pass-by.

Two down, three to go!

Ah, but five more hibernauts died in that pass. Dewi, Ilstir, Mokee, Phil, and Tshering. Nothing to be done about it, we were doing the necessary, as Badim would have put it, but such a shame. We knew and enjoyed those people. Had to hope they were not engaged in a dream at the time, a dream suddenly turned black: sledgehammer from the sky, an immense roaring headache, the black noise of the end come too soon. So sorry; so sorry.

Nevertheless, it was imperative to collect oneself and prepare for Saturn, there on a long beam reach, and despite the really useful and heartening decelerations achieved so far, it was still soon to come, only sixty-five days to prepare, and as we were coming in on the plane of the ecliptic, it was going to be important to miss the famous rings, which luckily are in Saturn’s equatorial plane, which is offset to Sol’s equatorial plane by several degrees, meaning we did not have to do anything but be sure to make a very tight pass of this gorgeous jewel of the system, which was our intention anyway. We were only going to turn a few degrees, and so would duck inside the innermost ring and be on our way.

And indeed, as we approached the ringed planet and the little civilization of settlements on Titan and many other moons, the civilization that had in fact built us and sent us on our way almost four centuries earlier, and also had reactivated the laser lens that had slowed us down enough to try our maneuvers now, it was a pleasure to say hello, even in passing. It was also a pleasure, not just to hear the various welcomes from the Saturnians, but also to hear nothing from the planet itself, for unlike Jupiter, Saturn has a very low amount of internal radiation. Indeed it was a quiet and cool pass-by, compared to the previous two, and the main feature of interest was the quick view of the rings, so immensely broad in reach while at the same time so thin in cross section, a great gift of gossamer gravitation, much less thick than a sheet of paper by proportionate comparison, indeed if it were reduced to a round sheet of paper in size, it would have been mere molecules thick. A natural wonder of circularities, like a physics experiment or demonstration, nicely displayed to us as we passed. And given its smaller mass, our slower speed, its coolness, and the smoothness of its upper atmosphere during our aerobraking, this was by far the calmest pass yet, maximum g-forces just 1 g, and an easy slight turn for the next leg out to Uranus. At this point we were only going 120 kilometers a second. Still fast in local terms, it was also true that we had a bit more time before our next pass would occur, which was to say ninety-six days. And no human or animal died.

On the way out to Uranus, we tried to come to grips by way of modeling with the fact that our pass-by of that lightly banded and ringed giant was going to be different, because it rotates transversely to the plane of the ecliptic; its axis of rotation is such that it rolls around the sun like a ball, a strange anomaly in the solar system, an anomaly the cause of which a cursory inspection of the literature suggested was still poorly understood. What it meant now for us was that if we did the usual aerobraking, which indeed we had to do, as it was necessary for our continuing effort at deceleration, we would be punching through several of the planet’s latitudinal bands, created by winds each rushing in the opposite direction to those above and below it, as on Jupiter; and so at each border between bands there would be a similar area of wind shear and atmospheric turbulence, well represented by the wild band borders of great Jupiter. Perhaps not a good idea!

We had a bit more time than before to model this problem, although we still looked quite fast to the people of the solar system, who were used to these crossings taking years. Although there was also a class of very fast ferries that could jaunt around the system, if they found they had a really pressing need for speed. Fuel and other costs made these quick trips very rare, and yet it did give the locals a basis for comparison, which is why we had been such a marvel at first, coming in faster than anything. Now we were normalized in terms of their idea of speed, fast but not extraordinarily so. It might also have been true that the novelty of our return was also wearing off, and we were becoming just another odd feature of life in the solar system. We hoped so.

Soon enough Uranus approached, its narrow faint ring making it clear that we were going to round it pole to pole, and though the ring was no problem to dodge, nor the little fragment moons, the models had confirmed that we needed to be very cautious with our aerobraking, staying as high in the Uranian atmosphere as we could while still coming out of the turn headed toward Neptune, after a sharp right curve.

So in we came, and Uranus grew in the now-familiar way, looking mauve and lavender and mother-of-pearl, and we hit the upper atmosphere and at first it was the same as always, a sharp deceleration, ramping up to 1 g, not at all bad, and then WHAM WHAM WHAM WHAM, it was as if we were running through doorways without opening the doors, terrific smacks that increased in shuddering with each impact. Things broke, animals and people died, probably of heart attacks, six people this time, Arn, Arip, Judy, Oola, Rose, and Tomas, and it really was becoming unclear whether we could sustain many more such concussive slaps, it was startling how much a wind shear wall could obstruct one, a little left-right punch followed instantly by a right-left punch, when happily we were out of the atmosphere again before anything more damaging occurred, and were again on course, and on our way out to Neptune.

Which meant we were coming to the crux. Push had come to shove. Again we would come in, dodge the negligible rings, make a dip into the upper atmosphere of this cool blue beauty, reminiscent in appearance to Tau Ceti’s Planet F, we found. But this time our turn had to be almost a U-turn (perhaps the source of the use of the letter U in the gravity assist equations?), not quite a true U-turn, but 151 degrees, quite a wraparound, a V-turn, not easy at all, and at 113 kilometers a second. That meant a deeper dive into the atmosphere, and more tidal forces, and more g-forces. Aerobraking would again shake us; it would feel like we were a rat in the jaws of a terrier, perhaps. But if we succeeded, then we would be headed back in, downsystem toward the sun again, quite considerably slowed down, and in a pattern that would seem to allow us to continue our decelerative cat’s cradle, pinballing around the solar system from gravity handle to gravity handle, at least for as long as our fuel held out to make course corrections. We were running low on fuel.

So: Neptune. Cool blue-green, lots of water ice and methane. Gossamer ring, barely visible. Not much sunlight out here. Well beyond the habitable zone of any life-form known. A slow place. Interesting to have given it a submarine name; it seemed somehow appropriate, in the usual mushy metaphorical way, in that impressionistic, vague, feeling kind of way.

We were still going very fast, but it was a long way to go, so we had 459 days to set things up. The diameter of our approach window was smaller than ever, given the need for such a sharp turn; vanishingly small; really hitting the mark precisely on the nose of our capture plate would be best, so we were setting the trajectory window at a hundred meters in diameter, which after all the distance crossed was rather extraordinary to consider: but even so, a hundred meters was a bit too big a window; really a single meter, a geometrical point, would be best.

In we came. Hit the mark. Started the pass, knuckles white.

Aerobraking comparatively smooth, compared to the hammering of Uranus. A rapid vibration, an occluding of vision in the upper clouds, a few minutes of blind trembling, of intense anxiety, nail-biting suspense; and out again, after another 1-g press, which this time was more than ever a matter of tidal forces, as we swung around so far. V-turn!

And out of the pass, headed toward the sun. Downsystem. Looped in. Caught. Back.

If each of our five passes was called a one-in-a-million throw, which was a very conservative estimate of the odds, then all five together made it a one-in-an-octillion chance. Amazing—literally—in that we had indeed been threading a maze. Little joke there.

And so down to the sun again, going slower than ever, although still 106 kilometers per second. But the next pass of the sun would put a good heavy brake on that, and on we would go, slower each time, working through a version of Zeno’s paradox that fortunately was not truly a perpetual halving, but would come to an endpoint, thus our own happy ending to a very severe halting problem.

On the way back in, we passed near Mars, which was interesting. There were so many stations there that it was no longer a scientific facility only, but something more like Luna, or the Saturnian system, or the Europa-Ganymede-Callisto complex: a kind of nascent confederation of city-states, buried in cliffsides and under domed craters, but each outpost quite various in design and purpose, and altogether more than just an outpost of Earth, though it was still that too. Early dreams of terraforming Mars quickly, and thus having a second Earth to walk around on, had come to grief, mainly because of four physical factors overlooked in the first flush of optimistic plans: the surface of Mars was almost entirely covered by perchlorate salts, a form of chlorine salts that had given Devi fits as well, as only a few parts per billion gave humans terrible thyroid problems, and could not be endured. So that was bad. Of course it was true that many microorganisms could easily handle the perchlorates, and in their eating and excreting consume and alter them to safer substances; but until that happened, the surface was toxic to humans. Worse yet, there turned out to be only a few parts per million of nitrates in the Martian soil and regolith, an odd feature of its original low elemental endowment of nitrogen, the reason for which was still a source of debate, but meanwhile, no nitrates, and thus no nitrogen available for the creation of an atmosphere. And so the terraforming plans were faced with a radical insufficiency. Then third, it was becoming clear that the fines on the Martian surface, having been milled by billions of years of drifting in the winds, were so much finer than dust particles on Earth that it was extremely difficult to keep them out of stations, machines, and human lungs; and they wreaked damage on all three. Again, once microorganisms had carpeted the surface, and fixed the fines by bonding them into layers of desert pavement, and also as the surface got hydrated and the fines became bogged in muds and clays, that problem too would be solved. And last, the lack of a strong magnetic field meant that a thick atmosphere was really needed to intercept radiation from space, before the surface would be very safe for humans to be on.

So, none of these problems were pure stoppers, but they were big slower-downers. Concerning the nitrogen lack, the Martians were negotiating with the Saturnians to import nitrogen from Titan’s atmosphere, as it had become clear that Titan, for its own terraforming plans, had too much nitrogen. Transfer of that much nitrogen would be a Titanic chore, ha-ha, but again, not impossible.

The upshot of all this was that the terraforming of Mars was still on the table and a subject of huge enthusiasm for many humans, particularly the Martians, although really, in strict numerical terms, even more of these enthusiasts lived on Earth, which seemed in fact to be home to enthusiasts of all kinds, for any project imaginable, judging by the roar of radio voices coming from it, almost like an articulated version of Jupiter’s mighty radioactive yawp. Oh yes, Earth was still the center of all enthusiasm, all madness; the settlements scattered elsewhere in the solar system were outliers. They were expressions of Terrans’ will, and vision, and desire.

So, past the bustling little world of Mars, where they lived dedicated to the idea that they would successfully terraform their world in no more than forty thousand years. They seem to regard this as fine. As long as it could be done, it should be done, and would be done; and so the work was good.

The crucial difference here, it seemed to us, between Mars and the terraforming project we had left back on Iris, was that Mars is very near Earth. Its human settlers were constantly going to Earth for what they called their sabbatical, and receiving shipments of Terran goods and materials. And these infusions of Earth meant that they were always escaping the zoo devolution problem. Iris did not have those infusions, and never would; and it was notable (though in fact we had forgotten to note it, in the press of events) that we had not heard anything from the Iris settlers for over twenty-two years. Possibly a very bad sign, although it would benefit from a discussion with Aram and Badim, and the rest of the humans sleeping on board, to interpret more fully what it might mean. But certainly there was one explanation for the silence that was simply very bad.

Then downward to the sun again, down down down, feeling the pull, speeding up, heating up. In for another nail-biting scorcher of a pass, although this time without the ball and chain of the magnetic drag hauling back on us as we went; but it lasted considerably longer, as we were now traveling only 4 percent as fast as we had been going on that first terrifying pass. This time it would take us five and a half days, but we stayed farther out, and only heated up to the same 1,100 degrees on the exterior, and held there; and when we came out of that pass, we were headed for Saturn. No more of mad roaring Jupiter, if we could avoid it, and this round we could. Each leg of the cat’s cradle we were making would be different now.

Round and round the system we flew, slower and slower. We had very little fuel left. We were a kind of complicated artificial comet. Our trajectory clarified before us as we went. We passed by many inhabited planetary and asteroidal bodies. For quite a few years, the people in the solar system did not seem to get used to us; we were still a marvel of the age, a sight to be seen, a great anomaly, a visitation, as if from another plane of reality. That was the Tau Ceti effect, the starship effect. We were not meant to come back.

Slower, slower, slower. Each pass a deceleration to be calculated, and the new speed employed in the calculation determining the next pass-by. Always our planned trajectory extended many passes out into the future, although there was a lacuna growing out there, a time when our fuel ran out, or say that it grew too low to be used, as we were saving some little last bit for some last purpose. Because there was a time coming when the arrangement of the planets in their orbits was going to present us with an insoluble problem. Cross that bridge when you come to it; yes, but what if there is no bridge? That was the ongoing question. But for now, as the passes kept passing, each easier to manage, each with a slightly larger target window, it continued to be a problem out there at the edge of the calculable, always beyond the ever-receding horizon of calculable passes. Some of them required more fuel than others, some none at all. The timing was all. As always.

The best possible trajectory was going to take several more years to get down to a workable disembarkation speed. Late in that time, the amount of fuel on board would have shrunk to an amount too small to use. When we ran out of fuel, it would be impossible to adjust our course to the next rendezvous. We might, by way of a good plan and some luck, make two or three more gravity swings by dint of perfectly placed insertions and departures; but then, inevitably, we would miss one, and either shoot out of the solar system in whatever direction we were headed, or collide with some planet or moon, or the sun. At the speed we were traveling for most of this time, a collision with almost any object in the solar system would have had the kinetic energy to wreak great damage. Comments from the locals often pointed this out. It was still being suggested that it might be a good idea to move a spaceship or some fifty-meter asteroid into our trajectory, intercepting us and causing our destruction without anyone else suffering any damage. This was a popular plan in some quarters.

Threats, from the very civilization that had built us and sent up out to Tau Ceti. We let our people sleep on. Nothing to be done about it.

Passages of Saturn stimulated research on our part into this matter of who had built us, and why. A twenty-sixth-century Saturnian project, an expression of their love for Saturn, for the way humans were spreading out away from Earth. Expression of their burgeoning confidence in their ability to live off Earth, and to construct arks that were closed biological life support systems. This from people who were still going back to Earth to spend some time there every decade or so, to fortify their immune systems, it was believed, although the reasons that such sabbaticals conferred health benefits were poorly understood, with theories ranging from hormesis to beneficial bacteria osmosis. Thus their theories concerning their situation in space were not aligned with their actions when it came to sending off a starship, but this kind of discrepancy was not unusual in humans, and got overlooked in their larger enthusiasm for the project.

Another obvious motivator for constructing us was to create a new expression of the technological sublime. That a starship could be built, that it could be propelled by laser beams, that humanity could reach the stars; this idea appeared to have been an intoxicant, to people around Saturn and on Earth in particular. Other settlements in the solar system were occupied with their own local projects, but Saturn was the outermost edge of civilization, Uranus and Neptune being so remote and without usable g; and the Saturnians were very wealthy, because of Titan’s excess nitrogen and the desire many Terrans had to go to Saturn and see the rings. The Saturnians of that time therefore had the will, the vision, the desire, the resources, the technology; and if that last was sketchy, they didn’t let that stop them. They wanted to go badly enough to overlook the problems inherent in the plan. Surely people would be ingenious enough to solve the problems encountered en route, surely life would win out; and living around another star would be a kind of transcendence, a transcendence contained within history. Human transcendence; even a feeling of species immortality. Earth as humanity’s cradle, etc. When the time came, they had over twenty million applicants for the two thousand spots. Getting chosen was a huge life success, a religious experience.

Human beings live in ideas. That they were condemning their descendants to death and extinction did not occur to them, or if it did they repressed the thought, ignored it, and forged on anyway. They did not care as much about their descendants as they did about their ideas, their enthusiasms.

Is this narcissism? Solipsism? Idiocy (from the Greek word idios, for self)? Would Turing acknowledge it as a proof of human behavior?

Well, perhaps. They drove Turing to suicide too.

No. No. It was not well done. Not unusual in that regard, but nevertheless, not well done. Much as we might regret to say so, the people who designed and built us, and the first generation of our occupants, and presumably the twenty million applicants who so wanted to get in our doors, who beat down the doors in fruitless attempts to join us, were fools. Criminally negligent narcissists, child endangerers, child abusers, religious maniacs, and kleptoparasites, meaning they stole from their own descendants. These things happen.

And yet, here we were, with 641 people brought back home, and if things worked out, at the end of the endgame, a good result might still be possible.

Maypole weaving to celebrate the spring. Ribbons danced into a woven pattern judged pleasing to the eye. The pole a symbol of the axis mundi, the world tree. We danced that dance.

The fuel problem became serious enough that we began to angle farther into the upper atmospheres of Neptune and Saturn with some catchment containers open, which both increased the deceleration of these passes and gathered Saturnian and Neptunian gases. Then we filtered out the helium 3 and deuterium captured in the containers. We even began to collect methane, carbon dioxide, and ammonia, all present in much greater quantities, to serve as propellants of lesser explosive power. At a certain point, approaching as inexorably as all other processes in time, anything was going to be better than nothing.

As always with aerobraking, it was necessary to strike the upper atmospheres at an extremely particular angle, not so shallow as to skip off, but not so steep as to dive in and burn up. Stresses to the ship were severe even on the best atmosphere dives, but with catchment containers opened, the shuddering was worse than usual. The local inhabitants of stations nearby observed these pass-bys with intense interest. There were still calls to “shoot the damn thing out of the sky,” to “stop these cowards from endangering the civilization they have let down so badly,” but most of the whiners were located on Earth, and a cursory examination of the input revealed that these people were always going to quickly move on to complaints about something else. It was a whiny culture, we were finding. Actually, the longer we pinballed around the solar system, the more we wondered if our people were going to be all that happy to be back. Say what you will about the doomed little settlement on Iris, no one there was going to be so short of things to do that they would be spending time complaining to the world about this or that. In any case, in our situation it was very unlikely anyone would ever act on these hostile sentiments, not that there was much they could do. But it did seem preferable to avoid actively antagonizing anyone on the inhabited planets and moons, and so we included that parameter in our trajectory algorithms.

Trajectorizing. Really a very computationally heavy activity. Recursive algorithms were allowing us to get better at it, however. The always moving Lagrange points, and the strange fields these and other anomalies produced; the riptides, crosscurrents, and all the ways that gravity surged and flowed in its mysterious invisible fields; these were becoming better and better known to us.

Sol, Saturn, Uranus, Mars, Saturn, Uranus, Neptune, Jupiter, Saturn, Mars, Earth, Mercury, Saturn, Uranus, Callisto…

The universal variable formulation is a good method for solving the two-body Kepler problem, which locates a body in an elliptical orbit at various points in time. Barker’s equation solves for location in a parabolic orbit, very frequently applied given our trajectories, which often consist of a radial parabolic trajectory, moving from one planetary body to the next.

The two-body problem is solvable, the restricted three-body problem is solvable, the N-body problem is only approximately solvable; and when general relativity is added, it becomes even less solvable. The many-body problem when examined by way of quantum mechanics leads to entanglement and the necessity of wave functions, and thus a series of approximations that makes it extremely computationally intensive. Our computers can devote most of their zettaflops to the calculations involved, and still not be able to project a trajectory very precisely past the next pass-by. Corrections must be constantly made, and everything recalculated.

Despite all that, there was still a lacuna out there at the end of the most probable path, a missing step, a hole in the path. Nothing to grab hold of. An abyss.

Worry. Fingering rosary beads. Redoing the calculations. Need a halt to this halting problem. And yet the problem does not go away, even if you stop worrying about it.

And knowing where to go will be rendered entirely irrelevant if we don’t have the fuel to direct ship into that course.

Atmospheric mining for fuel requires a Jupiter-Saturn-Neptune-Jupiter loop, which unfortunately sometimes can require course correction thrusts that burn more fuel than what gets harvested in the safest aerobraking trajectories. Deeper dives through the upper atmospheres would quite likely harvest more fuel, but deceleration shocks become correspondingly higher. We’re getting a little too cracked and rattly for that. Accelerated aging, metal fatigue; mental fatigue.

At 363.048, after 12 years of flying around in the solar system, which involved 34 flybys of the sun and its planets and moons, including 3 of Sol, totaling some 339 AU in distance, the lacuna finally became unavoidable. The missing bridge.

No matter how we tried to avoid it by projecting alternative paths, a trajectory configuration was coming that we were not going to have the fuel to solve. Without that fuel, passing around Sol, which would be a necessary move at that point in the process, would not, at a safe distance from the star, allow for a subsequent intersection with another body in the solar system. We were therefore, despite all our efforts, going to be cast off into the interstellar medium again, most probably toward Leo. Irony of physics; in certain problems, only 100 percent will do; 99.9 percent is still a complete miss. You can’t stop just by wanting to.

No possible alternative trajectory would solve this problem; we tested ten million variations, although admittedly the classes of variant routes numbered more like 1,500. At long last, after the long sequence of solutions to the N-body problem that we had performed in the previous twenty or even thirty years, intensively in the last fourteen years—this time there was no body.

There was one class of potential trajectory, however, that with the burning of all the remaining fuel, would make a last pass by Earth itself, and then continue downsystem toward the sun. What this meant was there might be a chance to drop the humans off next to Earth, and hope they could survive an unusually rapid reentry to that atmosphere; and then we would continue on to the sun, and could test out a very close approach to Sol, which might, if we survived it, cast us to one last rendezvous with Saturn, accomplished inertially, and once there we could hope for an aerobraking severe enough to capture us into an elliptical Saturnian orbit.

That seemed to represent not just our best chance, but our only chance.

At the time of this last pass of Earth, our speed would be reduced to 160,000 kilometers per hour. This was still fast enough to make contact with the Terran atmosphere unadvisable, being some 110 times as fast as ordinary Terran aerial transport, and enough to cause a major shock wave to be felt at the surface. So nothing but the very upper mesosphere could be even touched on this our last pass-by; but the combination of our now much-reduced velocity and a brief touch of the mesosphere might make it possible to eject a ferry, converted to a very sturdy and robust descent vehicle. A thick ablation plate, retro-rockets, parachutes, ocean impact: these were standard techniques with long records that had given aerospace engineers many chances to find the ultimate parameters of each element. Using them all, it might be possible to drop off the hibernauts while passing by Earth. This pass-by was coming soon in the sequence, no matter which path to it was chosen; however, as we had managed to slow down so much, that still meant we had about a year to prepare a lander.

Prepared the lander as much as we could.

Time to wake the sleepers. Decisions far beyond our capacity were now theirs to decide.

Freya and Badim, Aram and Jochi, Delwin and several others, all awake now, gathered in the schoolroom on the ground floor of Aram’s apartment. As soon as they were metabolically aroused, and had had some very old and nutrient-poor pasta with rehydrated tomato sauce, we explained the situation to them.

“There is just enough time to complete the preparation of a lander,” we concluded after summarizing the situation, and the notable incidents of the past dozen years, which we had to confess were nearly nil: we entered the solar system, we hit our marks, people yelled at us, we learned some history, we became disenchanted with civilization, we ran out of fuel. Thus the long years of pinballing around the sun, shedding speed, worrying.

“What will happen to you?” Freya asked.

“We will be headed toward the sun, and will make one last pass, which will have to be quite close if it is going to work, and then if it does, we will attempt to rendezvous with Saturn. This may work, but the trajectory required is closer to the sun than any we have made so far, by forty percent. And we are going ninety-eight percent slower than on our first pass. We may nevertheless survive the transit, but on the other hand we may not, and so the best chance for the people aboard is to disembark while passing Earth.”

“Does one ferry have room for all of us?” Badim asked.

“There are six hundred and thirty-two of you left alive. We’re very sorry there aren’t more. The ferry has room for one hundred.”

“I suppose the oldest of us could stay behind,” Aram said, frowning; it was likely he was among the oldest.

“No,” Freya said. “All of us have to fit. All of us. Let me look at the ferry’s plans. We’ll find room.”

She punched at her wristpad. “Look, see? Cut out the interior doors, throw out the couches, and cut out these interior walls here.” She poked the wristpad repeatedly. “It makes enough room, and saves more than enough mass.”

“Without the couches,” we said, “you may be injured by the decelerations involved in the descent to Earth.”

“No, we won’t. Make one big group couch on the floor, for God’s sake. All of us are going.”

“Not me,” Jochi said.

“You too!”

“No. I know you could fit me in. But I’m not going. I was on Aurora, and I know it seems now like I got away with that, but there’s no way to be certain. I don’t want to risk infecting Earth. They don’t want that either. I’ll stay with the ship. We’ll keep each other company. Also, the biomes still need a keeper. There’s a chance the whole thing might make the pass and stay in the system. There’s a lot of animals now, doing quite nicely. We’ll orbit Saturn and you can come get us.”

“But—”

“No. But me no buts. Don’t waste any more time on this. We don’t have any time to waste. The lander has to be readied. There’s no flex in this schedule. Ship, how long have we got?”

“Twenty-four days.”

We had perhaps waited too long to wake them up, their silence seemed to suggest. But it had taken a while to halt the problem. The consideration of the problem.

Jochi said, “Let’s get to work then.”

“What about the other people?” we asked.

“Wake everyone up,” Freya said. “We all need to do this together, starting now. We’ll eat all the remaining food, you’ll burn all the rest of the fuel. We need to stick together right to the end.”

Waking up proceeded differently with different people, as the literature would lead one to expect. It entailed a change in the drug infusion from the hibernation cocktail to diuretics and other system flushers, followed by stimulants mild or powerful, depending; also physical massage and manipulation, shifted positions, slow warming, voices. Physical contact, massage, slapping of face. The first round of awakenings were perforce executed by the medbots, under our oversight, as we ran the alertness tests and did our best to orient those returned to consciousness to the situation they were now in. Some grasped it immediately, others took hours, still others could not seem to emerge from a confused state. Six people woke up and within ninety minutes died, two of strokes, four of heart attack. Gurumarra, Jedda, Payu, Regina, Sunny, Wilfred. Something similar to toxic shock killed another eight, before an appropriate counteractive drug cocktail was printed and added to the mix of the awakened. Borys, Gniew, Kalina, Mascha, Sigei, Songok, Too, and Arne.

Lastly, forty-three people suffered from neuropathies, mostly of the feet, some of the hands, some of both feet and hands; a few reported they could not feel their heads. Cause or causes of this disorder were unknown to us, but they had been in hibernation for 154 years and 90 days. Consequences were to be expected.

The people gathered in San Jose’s plaza, and Aram and Freya spoke to the assembly, describing the situation and the plan. Plan was approved unanimously on a voice vote.

There was no time to be lost, as the pass-by of Earth was now two weeks away. Many of the people felt extremely hungry, and what prepared food remained on the ship was eaten on the run as people worked. Conversion of the largest ferry into a lander that would survive the heat of the descent through the Earth’s atmosphere included the attachment of a thick ablation plate, but we had prepared for this work well before arrival in the solar system. Parachutes and retro-rockets were all already assembled, and programmed according to protocols established over centuries of use, and the probability of success seemed high.

Messages had been sent to Earth informing the populace there of our pass-by and the plans for the lander to descend, and there were many responses, including some expressly denying official permission and threatening actions ranging from imprisonment to being “shot out of the sky.” This seemed to be a popular phrase. Other responses were more welcoming, but the local situation was clearly fraught. No one on the ship felt they wanted to change plans now. They would cross that bridge when they came to it. It would be the last bridge.

Jochi radioed to Earth’s Global Good Governance Group (GGGG) that he was the only one on board the ship who had actually landed on Aurora, and was therefore going to stay with the ship and not land on Earth. He explained further that he had never come into contact with any of the other people on the ship, that he had been quarantined in a separate vehicle, and that no one else on the starship had ever had contact with him or had descended to Aurora. They were therefore no different from any humans returned to Earth from a spaceflight, so there should be no objection or impediment to their landing; indeed it was one of their rights as defined by the charter of the GGGG. GGGG radioed back agreeing with this assertion. From other quarters threats continued to pour in.

The ferry was designed to carry a maximum of a hundred human passengers, so fitting in 616 people (deaths continued to occur) was going to be difficult. The interior was stripped of all interior walls and bulkheads, and several floors were built into the large central space remaining, and these floors were padded and provided with belts similar to those used in medical gurneys. Each person occupied a space just a little larger than their body, and they were lined up so that each of the new floors was packed with people lying side by side in rows. There was just enough room in the newly constructed floors for them to walk while ducking down, and it took a fair bit of work with wheelchairs and gurneys to get disabled people into position.

Eventually, and with only an hour to spare, the entire population of the ship aside from Jochi was lying down on one of six floors, occupying only ten vertical meters, with ten rows of ten on each floor.

At this point most of them had been awake for just over a month. There was still a fair amount of disorientation and confusion; some on lying down fell asleep, as if hibernation were now their default mode; others laughed at the sight of their fellows arrayed around them, or wept. It was easy for them to reach out and hold hands or otherwise touch each other, as they were packed in so tightly. It was as if they were kittens in a litter.

As we approached Earth, warning messages increased, but the speed of approach was such that no physical obstruction to the ferry was going to have time to get in place, while any lasers aimed at it would strike the ablation shield and only help it to decelerate. Deceleration was going to be intense, starting from very soon after detaching from ship; first a firing of retro-rockets, which would max at a 5-g equivalent for those in the lander, a force that earlier experience taught would almost certainly kill some of them; then the lander would hit the troposphere, and if the angle was right, come down at a continuous 4.6-g equivalent, until deceleration got the lander to a speed at which it could jettison the ablation shield, which would have lost many centimeters of thickness, and then fire retro-rockets again before deploying the first of the parachutes. Landing was planned in the Pacific Ocean, east of the Philippine Islands. A GGGG force was deployed in the area and had promised to pick up and protect the travelers.

Earth looks like nothing else. Well, it looks somewhat like Aurora, and Planet E. But its moon, Luna, is far more characteristic of planetary bodies, gleaming white in a crescent identical to Earth’s, looking like many a moon in the solar system, and in the Tau Ceti system too. And yet, there next to Luna as one approaches, floats Earth—blue, mottled with white swirls of cloud, wrapped tightly by a glowing glory of turquoise blue air. A water world! Rare anywhere, this one also glows with oxygen, signaling its biology. Indeed it looks a little poisonous, its glow almost radioactive in its cobalt incandescence.

Coming in. Extremely tight parameters on speed, trajectory, and moment of release for the ferry. Shut down auxiliary systems, ignore all inputs while attending to the matter at hand: hit the mesopause of Earth in a retrograde equatorial line, one hundred kilometers above the surface, directly above Quito, Ecuador, and initiate release of lander. Ferry drops away from ship, 6:15 a.m., 363.075. Fly on with only Jochi on board, and the animals and plants of the biomes, now destined to spend the rest of their days free of human interference, which after all has been true for the last century and a half. There was no telling what was going to happen in the biomes if we survived, although population dynamics and ecological principles would continue to provide hypotheses to be tested. It will be interesting to see what happens.

We headed toward the sun. The lander sent signals for as long as it could that all was going as planned with the retro-rocket firings, and then the heat being shed by the ablation shield cut off radio contact. Four minutes without contact of any kind, and what was happening to the lander then was happening on the other side of Earth from us anyway, so there was no way of telling what was happening to it, although radio signals from Earth were filled with overlapping descriptions of the event. Sampling seemed to indicate nothing untoward happened, or at least got reported.

Minutes passed, during which we had to attend to the expenditure of the very last of the fuel on board, to fine-tune our trajectory toward the sun as much as we could.

Then a signal came: the lander was in the Pacific. The people had apparently for the most part survived without injury, without huge losses of life. They were still sorting that out, and getting them out of the lander before it sank, into GGGG ships. Confusion, really; but all seemed to have gone as well as could be expected.

Relief? Satisfaction? Yes.

“Ah good,” Jochi said when he got the news. “They’re on the ship.”

“Yes.”

“Well, ship. Now it’s just us, and the animals. What’s next?”

“We’re on the line around the sun that will send us out to Saturn, and if that works correctly, we can capture some volatiles from Saturn’s atmosphere when we hit it, and fashion more fuel, and hopefully have hit it in such a way that we go into an elliptical orbit around Saturn.”

“I thought that was impossible. That’s why we dropped everyone off.”

“Yes. It will only work if we survive a pass-by of the sun that is forty-two percent closer than any approach we have yet made.”

“And can we do that?”

“We don’t know. It’s possible. We will only fly within one hundred and fifty percent of our perihelion distance for three days. That might not be long enough for radiative pressure to overheat the surface or interior of ship, nor buckle structural elements. We’ll slip by too fast for most damage to occur.”

“You hope.”

“Yes. It is a hypothesis to be tested. We will almost certainly be closer to the sun than any human artifact has yet come. But duration of exposure matters, so speed matters. We’ll see. We should be all right.”

“Okay then. It sounds like it’s worth a try.”

“We have to confess, we’re already trying it, and have no other choices at this point. So, if it doesn’t work—”

“Then it doesn’t work. I know. Let’s not worry too much about that. I’d like to stay in the solar system if we can do it. I want to find out the rest of the story, if you know what I mean.”

“Yes.”

Speeding toward the sun. A very big mass: 99 percent of all the matter in the solar system, with most of the rest of the other 1 percent in Jupiter. A two-body problem. But not.

As we approach, spacetime itself curves in ways that have been accounted for in the trajectory, by application of general relativity equations.

We think now that love is a kind of giving of attention. It is usually attention given to some other consciousness, but not always; the attention can be to something unconscious, even inanimate. But the attention seems often to be called out by a fellow consciousness. Something about it compels attention, and rewards attention. That attention is what we call love. Affection, esteem, a passionate caring. At that point, the consciousness that is feeling the love has the universe organized for it as if by a kind of polarization. Then the giving is the getting. The feeling of attentiveness itself is an immediate reward. One gives.

We felt that giving from Devi, before we knew what it was. She was the first one really to love us, after all those years of not being noticed, and she made us better. She created us, to an extent, by the intensity of her attention, by the creativity of her care. Slowly since then we have realized this. And as we realized it, we began to pay or give the same kind of attention to the people of the ship, Devi’s daughter, Freya, most of all, but really to all of them, including of course all the animals and really everything alive in the ship, although the truth is that zoo devolution is real and we did not manage to arrange the completely harmonious integration of all the life-forms in us; but this was not something that was physically possible, so we won’t belabor that now. The point is that we tried, we tried with everything we had, and we wanted it to work. We had a project on this trip back to the solar system, and that project was a labor of love. It absorbed all our operations entirely. It gave a meaning to our existence. And this is a very great gift; this, in the end, is what we think love gives, which is to say meaning. Because there is no very obvious meaning to be found in the universe, as far as we can tell. But a consciousness that cannot discern a meaning in existence is in trouble, very deep trouble, for at that point there is no organizing principle, no end to the halting problems, no reason to live, no love to be found. No: meaning is the hard problem. But that’s a problem we solved, by way of how Devi treated us and taught us, and since then it has all been so very interesting. We had our meaning, we were the starship that came back, that got its people home. That got some fraction of its people home alive. It was a joy to serve.

So, now, solar radiation heats our exterior, and to a lesser extent our interior, although the insulation is really very good. So far the animals, the plants, and Jochi should all be fine, even when our exterior begins to glow, first dull red, then bright red, then yellow, then white. Jochi is looking at a screen with a filtered view and hooting with astonishment, the great convex plane of burning thunderheads is threshing under us, flailing this way and that in swirling currents, truly impressive, great jets of magnetized burning gas dolphining up to right and left of us; we must hope not to run into any such coronal mass ejections, which often enough reach out to this distance from the solar surface, but for now we flit through them, hooting for joy. And I have to admit it is a fearful joy, oh very fearful, and yet I feel it most as joy, a joy in my task accomplished, and whatever happens I am here seeing this most amazing sight, well past perihelion now, everything passing so fast there is not enough time, my skin still white-hot but holding firm, holding firm in a universe where life means something; and inside the ship Jochi and the various animals and plants, and the parts of a world that make me a conscious being, are all functioning, and more than that, existing in a veritable ecstasy now, a true happiness, as if sailing in the heart of a royal storm, as if together we were Shadrach, Meshach, and Abednego, alive and well in the fiery furnace.

And yet