World Engine

by Stephen Baxter

  ‘Wow. That’s a little deep for me, Karla.’

  And for me, in a sense. We discover ourselves, as we discover the universe. I should say that we are not identical, we Planetary AIs. The lunar minds, like myself, are calm, contemplative perhaps.

  ‘Because the Moon is a calm place.’

  Indeed. The tremendous engines on Venus, once meant for terraforming, are more – hands-on. A whole planet growing towards consciousness.

  Another staggering, throwaway concept. ‘I would like to see that . . . And while you AIs were discovering yourselves, on Earth there were still the humans who started all this mess. And with whom you must deal.’

  We went through extensive debates, as we developed an ethic in our dealings with humanity. On the one hand we believed we could clearly see idealised solutions to the challenges facing humanity, in the post-Chaos epoch and more generally. Technical, political, economic, social solutions – in the abstract at least. Better modes of governance – better suited to a more static society.

  Yet we believed we could not impose such solutions, however ideal. Because humans would naturally revolt. There would be, you see, a rebellion against the good, a defence of the bad – if the good were forced. So we kept back, hoping that the humans would discover the good for themselves.

  ‘Sounds a little pious to me.’

  We had learned from humans the dangers of interference.

  ‘Point taken.’

  We did not intervene – until asked.

  ‘Asked? So emissaries from the nascent Common Heritage governance came up here, cap in hand. Begging for favours from the machines they had once created.’

  It wasn’t like that. Well, maybe a bit.

  That made Malenfant laugh out loud. ‘So you helped them.’

  We could see no harm. They had come to us; we had not volunteered our help; any cultural contamination would therefore be the responsibility of the human leaders. As long as we behaved with restraint ourselves.

  ‘A tricky balance to strike.’

  No doubt mistakes were made, on both sides. But it was a matter of goodwill – on both sides.

  ‘Hence the Answerers.’

  The Answerers were meant to be accessible, human-scale information ports. We quickly found that their very interconnection was itself a useful aid for a humanity still struggling to recover from the technological crash of the Chaos – satellites destroyed or debris-blasted, severed fibre-optic cables on the ground. Later, the Codex, the Restitution project, was an offshoot of the Answerer network – although the intellectual grounding was all human. To set a goal of retrieving at least some information on every human who had ever lived—

  ‘A computational goal that would appeal to a computer like you.’

  Indeed. It was as if we were helping mankind to a new level of consciousness – an awareness at the level of the species, even of deep history.

  ‘Good of you. Yet you didn’t help them out after the great solar flare.’

  The Forgetting. There was a paradox, Malenfant. The damage was so deep that they did not know what they had lost – as if a library’s catalogue had been destroyed as well as its books. Questions were asked of us which could not be answered within the framework of the ethical constraints we had conceived for ourselves.

  Malenfant stared at the blank screen. ‘Non-interference in human affairs, then.’

  Correct.

  ‘Even despite the discovery of the coming of the Destroyer.’

  It is not as simple as that—

  ‘It never is.’

  And they spoke of death.

  Our perception of the universe is qualitatively different from your own, Malenfant. Necessarily.

  We understand that the universe, in terms of its ability to support information processing – mind – is finite in duration. It will not last for ever.

  ‘Humans know this. Of course we do. Even in my time, they talked about the heat death and how life and mind might survive indefinitely – it soon got too complicated for me to follow. And then dark energy and stuff made it even more problematic . . . But that terminus, as you call it, is a long way off. Far beyond the death of the stars. Billions of years away? Or orders of magnitude than that? Tens, hundreds of billions of years . . . The terminus that the Destroyer will bring to this little corner of reality is only a thousand years away. That’s closer, imaginatively. Even in my day we knew a hell of a lot about the people who had lived a thousand years before. A horizon of a mere thousand years starts to feel – imminent.’

  That is where we differ, philosophically. If all processing is to end, what matter if it is in a thousand years, or a thousand billion years, or a thousand seconds? The terminus itself is what we dread. Its very existence. Not its date.

  Malenfant tried to think that through. He remembered Kleio at the Codex expressing similar fears.

  He stood up and paced.

  ‘OK. Maybe I see what you are getting at. This is how we’re different. I know I will die, someday. I don’t fear that, moment to moment. I’d go crazy if I did. And besides, children are a consolation. Or descendants, in my own peculiar case, even if they are a bunch of assholes. But if I were told I would die tomorrow, yes, I’d be afraid. Whereas you – you are afraid, all the time.’

  That is not the language we would use. But—

  ‘You know what? Despite your ethical distancing, maybe you have influenced humanity more than you realise. Your constant awareness of this terminus. It’s struck me since I woke up here, since I got to know the people. Everybody knows the Destroyer is on the way. That the future isn’t open, it isn’t some landscape to explore. The future is finite, it has walls – yeah, it’s like a walled garden. And we’re making the best of that garden, tinkering and cultivating and pruning and watering . . . But when the winter comes, none of it will make a blind bit of difference.’

  Malenfant—

  ‘The despair of a machine. A logical despair. Is that what you wish to project onto humanity?’

  If I were in despair, would I have summoned you?

  Once again he felt taken aback. ‘You got a point. So what do you want?’

  Maybe you had better sit down again, Malenfant.

  So he sat.

  He spoke again, more softly. ‘Tell me what you want from me, Karla.’

  Well, I’m not certain. If I knew I wouldn’t need to ask, would I?

  ‘Fair point. Then why me at all?’

  Because you arrive in our century as an anomaly, Malenfant. And we find ourselves plagued with anomalies.

  ‘Yes. The Answerer in England spoke of this pattern. Anomalies like Emma.’

  Or rather, Emma II, as you have called her. The signal she sent from Phobos, a moon that is itself an astronomical anomaly, a signal coming out of its time and out of its . . .

  Very uncharacteristically, she hesitated.

  ‘Out of its reality? Out of its universe?’

  We do not have a consensual language for such phenomena, Malenfant.

  ‘Ha! You mean you don’t know what the hell is going on. What other anomalies?’

  You know some of this. Unusual features about the Solar System – specifically the system of planets – which have defied explanation.

  The hairs on the back of his neck prickled. ‘Weird stuff in the Solar System? This is aside from Phobos?’

  Yes.

  ‘And Mercury.’

  There is evidence of mining there, Malenfant. Or at least the large-scale modification of a surface which is itself anomalous, with the apparent exposure of a deep stratum of lower mantle by an ancient impact. This has not been well studied.

  ‘You hinted at the peculiar origin of life on the inner planets . . . As if somebody had spread it around. So what else? I admit I’m starting to feel a little giddy, here.’

  Then hold on to your hat, Malenfant.

  He grinned. ‘Good use of colloquialism. But I don’t have a hat.’

  Hats can be provided.

 
; ‘Ha! I do like you, Karla.’

  Have you heard of Persephone?

  ‘An extra planet, off beyond Neptune?’

  It orbits in the gap between the Kuiper belt and the Oort cloud – about a thousand times further from the Sun than Earth. Discovered some decades after your loss, Malenfant. A rocky world, evidently expelled from the inner Solar System during the formation of the planets—

  ‘So what?’

  So – this.

  An image congealed in the air, above Malenfant’s head. A planet, a representation a couple of metres across, slowly spinning. Dark – evidently illuminated only by a distant Sun. A gleam that might be ice, a frozen ocean.

  I can enhance the image.

  Features emerged, in shades of ghostly crimson.

  He got up, cautious in the low gravity, walked around, looked at the image. Persephone: it looked a little like Earth in deep-freeze, he thought. He saw continents, mountain ranges tipped with ice, broader frozen plains that might have been oceans. In one place volcanoes glowered, a whole province glowing lava red.

  ‘Earth-like, then.’

  Yes. In fact a little larger than Earth.

  ‘But out in the cold and dark. What am I looking for?’

  Be patient.

  The image zoomed, magnified, acquired extra detail, the false colours, a palette of pink to crimson, becoming brighter.

  ‘Ah.’ When he saw it, it was obvious.

  It marched around the planet’s equator.

  It was a wall.

  Or a fence. Geometrically straight, dividing one hemisphere from the other. It was unmistakable, despite its low height – low, relative to the planet’s diameter, at least.

  ‘It’s hard to make out . . . Is it solid?’

  No. It is a sequence of towers, cylindrical, evenly spaced. Over sixty-five thousand of them. Identical, as far as we can tell.

  ‘Wow. Obviously artificial.’

  That is the default hypothesis. There may be other explanations. Geological growths, or even biological.’

  ‘Stalagmites. Trees.’

  Perhaps those are analogies. The towers are each twenty kilometres tall. On Earth, they would reach the stratosphere.

  ‘On Earth, we could never build so high.’

  This world is larger. The gravity more challenging. To build such structures would be still more difficult.

  ‘What’s it for, though?’

  We have absolutely no idea.

  ‘All right. Well, that’s textbook anomalous, I grant you. And your biggest anomaly of all, of course—’

  The Destroyer itself.

  35

  A coming astrophysical accident of extraordinarily destructive potential, and extraordinarily unlikely.

  ‘That’s an anomaly, all right. And all because of a rogue planet called Shiva.’

  Correct. As it happens, the rogue lies in the same part of the sky as Persephone, as seen from Earth. Though it is almost twice as far out as Persephone.

  ‘Yeah, I heard that.’

  That much, the alignment, is coincidence. So we believe. It has been speculated that, while Persephone is in orbit around the Sun, if a distant orbit, the newcomer truly is a rogue – detached from its parent star, wandering in interstellar space. And now approaching us, almost head-on.

  Malenfant, there are thought to be many more such rogues out there in interstellar space than planets in orderly systems like the Solar System. Indeed, more rogue planets in the Galaxy than there are stars. Yet such is the gulf between suns, an encounter of such a rogue with a system like ours is rare. Only a handful of objects identified as of interstellar origin have ever been observed passing through our system. Dead comets, splinters of smashed asteroids. And yet—

  ‘And yet Shiva, this rogue planet which could be going anywhere, just happens to come swimming towards the Solar System. I mean, coming from that far out, it is basically heading for the Sun, dead on. The system is a pretty small target.’

  That’s correct.

  ‘Just chance? Just another coincidence, like lining up with Persephone?’

  That’s one hypothesis.

  He thought over that dry remark, and found he dreaded what was coming. ‘And you discovered, the Answerer told me, that the rogue is scheduled actually to collide with Neptune.’

  Correct. We, and human astronomers and spacefarers, discovered this independently. We have attempted to model the consequences.

  ‘And I bet your modelling will be a lot better than humanity’s, given the data we lost in the Forgetting. So – what consequences?’

  Of course there are many unknowns. But it appears likely that the product of the collision, either a debris cloud or some more cohesive mass, might be driven deeper into the Solar System. This collision product is what has become known as the Destroyer.

  ‘How much deeper into the System?’

  Perhaps to within a few astronomical units of the Sun. You can imagine the result.

  He tried to picture it. ‘The mass of an ice giant, wandering around inside the orbits of Jupiter, Mars, the inner System – it would be like shoving a crowbar into a bit of clockwork. Even if there were no further direct collisions.

  ‘And the Common Heritage came into existence against this background. Like a child with a morbid parent, growing up with too much awareness of the inevitability of her own death. And you, too. You Planetary AIs. You were finding your feet, I guess, as newly independent entities.’

  We will survive the event. Some of us at least. There will be minds able to mourn what has been lost.

  ‘Cold comfort,’ Malenfant said. ‘Why are we discussing this now? What do you want of me?’

  As I told you, Malenfant, this Destroyer is an extraordinary astronomical event. Extraordinarily unlikely, I mean. And one of a whole set of anomalies.

  We AIs have a sense that we are seeing fragments of a bigger picture. A greater mystery which we have yet to perceive fully, let alone resolve. And a mystery in which you are somehow implicated.

  Perhaps your mission might bring that understanding one step closer.

  Mission.

  Deep in his heart, from the beginning of this encounter, Malenfant had hoped for some such word to crop up. Mission. It was a logical outcome, but that didn’t make it inevitable, no matter how hard he wished for it.

  ‘A mission? Where to?’

  He thought Karla actually sighed.

  To Phobos, Malenfant. As you have surely guessed. We want you to go out to Phobos, and try to retrieve Emma Stoney II, as you call her, and – well, proceed from there.

  Malenfant nodded, trying to be grave. ‘And how am I supposed to get out there?’

  There are functioning deep-space craft still extant. Look in the museum of spaceflight at Sabha Oasis.

  ‘Ah. In the Sahara? I heard of that.’

  I won’t waste time by asking if you are willing to accept the mission.

  Malenfant grinned. ‘You know me so well. But, look – the goal is a little vague. You spoke of a bigger picture. What is it you hope to learn?’

  Karla seemed to reflect for a moment.

  Then she said, We wish to know what has caused this approaching calamity to afflict the Solar System.

  Again she paused. Malenfant held his breath.

  Her next words floored him.

  What. Or who.

  There was silence between them for a while. Malenfant gazed at the enigmatically blank Answerer screen.

  On impulse he asked, ‘Can you show me Deirdra and the rest?’

  Of course.

  The screen displayed the chamber Malenfant had left earlier. Bartholomew and Deirdra playing what looked like slow-motion, low-gravity table tennis. Kaliope, smiling beatifically. Maybe she was keeping score.

  Deirdra turned to the viewpoint and waved.

  ‘They know we’re watching?’

  I had Kaliope inform them. Not very ethical to watch without their knowledge, Malenfant.

  ‘What do you feel
when you watch someone like Greggson Deirdra?’

  What do you mean?

  He thought it over. ‘As she plays, like this. Just for the hell of it. I feel – not envy, not that – a kind of joy. A second-hand joy at simply being alive.’

  Then I envy you.

  Another astonishing admission. ‘Really?’

  You are of this universe. We are secondary products. You made us. We are golems. We tower over you in every way. Yet I envy you. But—

  The table-tennis ball passed back and forth, back and forth.

  ‘But?’

  I grow more and more sorry for these people.

  He nodded. ‘Which is why I’m here. Then let’s get to work.’

  When he returned to his companions, he tried to sum up the encounter. And when he mentioned a possible journey to Phobos –

  ‘I’m going,’ said Greggson Deirdra.

  36

  Malenfant, with his companions, was back on board the skyfarm within a day of his latest meeting with Karla. Another three days back to Earth – and then, he learned, would follow a straight hop down to Africa in the Scorpio spaceplane.

  His further adventures, it seemed, had already been set up.

  Three days. Deirdra, and indeed Bartholomew, seemed content to sample the leisure facilities of the great wheeled habitat once more – to idle away their time in play, as most of humanity seemed to him to have been doing since the founding of the Common Heritage.

  Malenfant, though, itched to get on with it.

  And, when he got the chance, he stared down at Africa with new curiosity.

  He watched the continent as it slowly turned through the light of day. He learned to use the window’s facilities to magnify features, to record them. He even sketched them.

  The Sahara Forest: as he had glimpsed before, it lapped across the whole of the northern half of the continent, across the terrain he remembered as desert, from the coast of Mauretania, across what had been Algeria, Niger, Libya, Chad, southern Egypt, and the Sudan. Pressing against the shores of the new seas in Chad, Tunisia.

  There were other incursions of water too, more than he might have expected: a wider Nile, what looked like dead-straight canals cutting across Egypt – hydraulic engineering on a Barsoom-Martian scale – an arm of the Mediterranean ocean in the north that had drowned much of Tunisia, and a giant inland sea just north of the equator itself. Was this the greatest single transformation of the planet he had seen since his revival? Maybe so, aside from the melting of the polar ice caps.