Space

by Stephen Baxter

  She had to descend to the level of the Lakshmi Planum, six kilometres below, to study Nemoto’s puzzle. They hadn’t anticipated any surface journey of such length and difficulty; she hadn’t brought a surface vehicle, and the lander had neither the fuel nor the capability to fly her deeper into the ocean of air. And so she had to walk.

  Nemoto had said she owed it to the human race to accept the risk, to complete her mission. Carole just thought she owed it to her mother, who would surely not have hesitated.

  ‘Of course Venus is closer to the sun; even wet Venus was not an identical twin of Earth. The air was dominated by carbon dioxide. The oceans were hot – perhaps as hot as two hundred degrees – and the atmosphere humid, laden with clouds. But, thanks to the water, plate tectonics operated, and much of the carbon dioxide was kept locked up in the carbonate rocks, which were periodically subducted into the mantle, just as on Earth.

  ‘Venus was a moist greenhouse, where life flourished …’

  She found talus slopes, rubble left by crumbled rocks. It would require care, but this type of climb wasn’t so unfamiliar to Carole. She had hiked in places in the Rocky Mountains that were rather like this, places where chemical weathering seemed to dominate, even on Earth. But the depth would push the envelope of her suit’s design. And, of course, there was nobody here to help her up. So she took care not to fall.

  After a couple of kilometres she paused for breath. She looked down, across kilometres of steeply sloping rock, to the Planum below.

  She thought she could see something new, emerging from the murk: a long dark line, oddly straight, that disappeared here and there among folds in the rock, only to emerge once more further along. As if somebody had reached down with a straight-edge and scoured a deep dark cut into these hot rocks.

  There was something beside the line, squat and dark, like a beetle. It seemed to her to be moving along the line. But perhaps that was her imagination.

  She continued her careful climb downwards.

  ‘… But then the visitors came in their drifting interstellar moonlets,’ Nemoto had said. ‘And they cared nothing for Venus or its life forms. They just wanted to steal the moon, to propagate their rocky spore. So they stopped Venus spinning.’

  At the base of the cliffs she paused for a few minutes, letting her heartbeat subside to something like normal, sipping water.

  The black line was a cable. It was maybe two metres thick, featureless and black, and it was held a metre from the ground by crude, sturdy pylons of rock.

  ‘How do you despin a planet?’ Nemoto whispered. ‘We can think of a number of ways. You could bombard it with asteroids, for instance. But I think Venus was turned into a giant Dyson engine. Carole, I have observed cables like this all over the planet, wrapped east to west. They are fragmentary, broken – after all they are eight hundred million years old – but they still exist in stretches hundreds of kilometres long. Once, I would wager, the surface of Venus was wrapped in a cage of cables that followed the lines of latitude, like geographical markings on a schoolroom globe …’

  She pressed her lab box against the cable. She even ran her hand along it, cautiously, but could feel nothing through the layers of her suit.

  She began to walk alongside the cable. Some of the pylons were missing, others badly eroded. It was remarkable any of this stuff had lasted so long, she thought; it must be strongly resistant to Venus’s corrosive air.

  ‘Electric currents would be passed through the cables,’ Nemoto whispered. ‘The circulating currents would generate an intense magnetic field. This field would be used to couple the planet to its moon – perhaps the moon was dragged within its Roche limit, deliberately broken apart by tides.

  ‘Thus they used the planet’s spin energy to break up its moon.

  ‘They rebuilt the fragments into their habitats, their rocky bubbles. The moonlets would be hurled out of the system, each of them robbing Venus of a little more of its spin. I wonder how long it took – thousands, millions of years? … And, as they worked, they waited for Venus to bake itself to death.

  ‘The climate of Venus was destabilized by the spin-down, you see,’ Nemoto said. ‘It got hotter. There must have been a paucity of rain, a terrible drought, at last no rain at all … And finally, the oceans themselves started to evaporate.

  ‘When all the oceans were gone – life must already have been extinguished – the water in the air started to drift to the top of the atmosphere. There, it was broken up by sunlight. The hydrogen escaped to space, and the oxygen and remnant water made sulphuric acid in the clouds.

  ‘And that was what the moonlet builders wanted, you see. The acid. They mined the acid out of the ruined air, perhaps with ships like our profac crawlers.

  ‘It’s an efficient scheme, if you think it over. All you need is a fat, fast-spinning planet with a moon, and you get a source of moonlet ships, a way to launch them, and even a sulphuric acid mine. Venus, despun, was ruined. But they didn’t care. They had what they wanted.

  ‘We are lucky they did not select Earth. Perhaps our Moon was too large, too distant; perhaps the sun was too far away …’

  But they didn’t finish the job, Carole thought. What great catastrophe, eight hundred million years ago, stopped them? Were some of Venus’s great impact craters the wounds left by remnants of that vanished moon falling from the sky, uncontrolled – or even the scars of some disastrous war? … For Venus, Nemoto said, things got worse still. When all its water was lost, plate tectonics halted. The shifting continents seized up, like an engine run out of oil. The planet’s interior heat was trapped, built up – until it was released catastrophically. ‘Mass volcanism erupted. There were immense lava floods, giant new volcanoes. Much of the surface fractured, crumpled, melted – and the carbon dioxide locked up in the rocks began to pump into the atmosphere, thickening it further …’

  Something was moving, directly ahead of her.

  It was the beetle-like thing that she had observed from the cliff. And it was working its way along the cable, gouging at it with complex tools she couldn’t make out, scoring it deeply.

  It was a grey-black form, the size of a small car. It was as tall as she was, its surface featureless, returning glinted highlights of Venus’s complex sky. And it was based on a dodecahedral core.

  ‘Hello,’ she said. ‘You haven’t been here for eight hundred million years.’

  ‘Gaijin technology,’ Nemoto whispered when she saw the image. ‘It is here to scavenge. Carole, this ancient cable is a superconductor, working at Venusian temperatures. Remarkable. Even the Gaijin have nothing like this. And what,’ she hissed, ‘do they intend to do with it? Which of our planets or moons will they wrap up, like a Christmas parcel?’

  An alarm chimed softly in Carole’s helmet. She must soon turn back, if she was to complete her long climb back to the lander in safety.

  From here she could see the lower plains, the true floor of Venus, the great basalt ocean that covered the planet, still kilometres below her altitude. She longed to go further, to climb down and explore. But she knew she must not. My mission is over, she realized. Here, at this moment; I have come as far as I can, and must turn back.

  She was surprised how disappointed she felt. Earth would seem very confining after this, despite the wealth she expected to claw in from her celebrity. She glanced up at the twisting, pulsing clouds, fifty kilometres up. But no matter how far I travel, she thought, I will always remember this: Venus, where I was first to set foot.

  This, and the immense crime I have witnessed here.

  ‘… If this happened once, it must have happened again and again,’ whispered Nemoto. ‘A wave of colonists come to a solar system like ours. They take what they want, ruinously mining out the resources, trashing what remains. And then they move on … or are somehow stopped. And then, later, when the planets have begun to heal, others follow, and the process begins again. Over and over.

  ‘I predict we will find this everywhere. We can’t assu
me that anything in the solar system is truly primordial. We don’t yet know how to look, and the scars will be buried deep in time. But here, it is unmistakable, the mark of their wasteful carelessness …’

  Carole stepped carefully behind the blindly toiling Gaijin beetle machine, and, peering patiently through the ruddy murk, sought scraps of superconductor.

  Chapter 13

  THE ROADS OF EMPIRE

  Different suns, a sheaf of worlds: Malenfant drifted among the stars, between flashes of blue teleport light.

  It was a strange thought that because the Saddle Point links were so long – in some cases spanning hundreds of light years, with transit times measured in centuries – there could be whole populations in transit at any moment, stored in Saddle Point transmissions: whole populations existing as frozen patterns of data arrowing between the stars, without thought or feeling, hope or fear.

  And he was slowly learning something of the nature of the Saddle Point system itself.

  A teleport interstellar transportation system made economic sense – of course, or else it wouldn’t have been built. Saddle Point signals were minimum strength. They seemed to be precisely directed, as if lased, and operated just above the background noise level, worked at frequencies designed to avoid photon quantization noise. And the gateways, of course, were placed at points of gravitational focussing, in order to exploit the billion-fold gain available there. He figured, with back-of-the-envelope calculations, that with such savings the cost of information transfer was at least a billion times less than the cost of equivalent physical transfer, by means of ships crawling between the stars.

  It was an interstellar transport system designed for creatures like the Gaijin, who relished the cold and dark at the rim of star systems, working at low temperatures and low energies and with virtually no leaked noise. No wonder we had such trouble detecting them, he thought.

  But the physics of the system imposed a number of constraints.

  Each receiver had to be quantum-entangled with a transmitter. What the Builders must have done was to haul receiver gates to the stars by some conventional means, slower-than-light craft like flower-ships. But it was a system with a limited life. Each gate’s stock of entangled states would be depleted every time a teleportation was completed – and so each link could only be used a finite number of times.

  Perhaps the Builders still existed, and had sustained the motivations that led them to build the gates in the first place, and so were maintaining the gates. If not, the system must be fragmenting, as the key, much-used links ceased to operate. Perhaps the oldest sections had already failed.

  It might be that the hubs, the oldest parts of the system, would be inaccessible to humans and Gaijin, the Builders isolated, forever unknowable.

  He wondered if that was important. It depended on how smart the Builders had been, he supposed, how much they understood about what the hell was going on in this cruel universe. He was getting the impression that the Gaijin knew little more than humanity did: that they too were picking their way through this Galaxy of ruins and battle scars, trying to figure out why this kept happening.

  Confined for most of his time to the habitats the Gaijin provided, Malenfant was a virtual prisoner. After a time – after years – he knew he was becoming institutionalized, a little stir crazy, too dependent on the small rituals that got him through the day.

  He became devoted, obsessively so, to his suit, his Shuttle EMU, his one possession. He spent hours repairing it and maintaining it and cleaning it. As much as possible he tried to leave his animated photo of Emma in the spacesuit pocket where it had lain for years. He already knew every grain of it, every scrap of motion and sound; he couldn’t bear the thought of wearing it out, of it fading to white blankness; it would be like losing his own existence.

  After a time it seemed to him he was getting ill. He sensed he was growing weaker. If he pinched his cheek – or even cut himself – it didn’t seem to hurt the way it should.

  It didn’t trouble him, cocooned as he was in the tight confines of his habitats.

  He did find out that the Gaijin didn’t suffer such problems.

  The very basis of their minds was different. His consciousness was based on quantum-mechanical processes going on in his brain, which was why his whole brain – and his body, his brain’s support system – had to be transported, and was therefore somewhat corrupted by every Saddle Point transition.

  Cassiopeia’s ‘mind’ was more like a computer program. It was composed purely of classical information, stuff you could copy and store at will, stuff that didn’t have to be destroyed to be transmitted by the Saddle Points. When she went ‘through’ a gateway, Cassiopeia’s program was simply halted. That way she used up fewer of the Saddle Point link’s stock of entangled states.

  He wasn’t enough of a philosopher to say if all this disqualified her from being conscious, from having a soul.

  There were other differences.

  Periodically he would watch the Gaijin swarming like locusts over the hull of a flower-ship, thousands of them. They would merge, in clattering, glistening sheets, as if melting into each other, and then separate, Gaijin coalescing one by one as if dripping out of a solute.

  The purpose of these great dissolved parliaments seemed to be a transfer of information, perhaps the making of decisions. If so it was an efficient system. The Gaijin did not need to talk to each other, as humans did, imperfectly striving to interpret for each other the contents of their minds. They certainly did not need to argue, or persuade; the shared data and interpretations of the merged state were either valid and valuable, or they were not.

  But how was it possible to say that this Gaijin, who came out of the cluster, was the same individual as had entered such a merge? Was it meaningful even to pose the question?

  To the Gaijin, mind and even identity were fluid, malleable things. To them, identity was something to be copied, broken up, shared, merged; it didn’t matter that the self was lost, it seemed to him, as long as continuity was maintained, so that each of the Gaijin, as currently manifested, could trace their memories back along a complex path to the remote place that had birthed the first of them.

  And, likewise, he supposed, they could anticipate an unbounded future, of sentience, if not identity. A cold mechanical immortality.

  He was less and less interested in the blizzard of worlds the Gaijin showed him. Even though, as it turned out, everywhere you looked there was life. Life and war and death. He strove to understand what the Gaijin were telling him – what they wanted him to do.

  Chapter 14

  DREAMS OF ANCESTRAL FISH

  Madeleine Meacher flew into Kourou from Florida.

  The plane door slid open, and hot, humid air washed over her. This was East Guiana, a chunk of the north-eastern coast of South America. All Madeleine could see, to the horizon, was greenery: an equatorial rainforest, thick, crowding trees, clouds of insects shimmering above mangrove swamps.

  Already she felt oppressed by this crowding layer of life, the dense, moist air. In fact she felt a stab of panic at the thought that this big, heavy biosphere was unmanaged. Nobody at the controls. Madeleine guessed she’d spent too long in spacecraft.

  Some kind of truck – good grief, it looked like it was running on gasoline – had dragged up a flight of steps to the plane. Madeleine was going to have to walk down herself, she realized. It was the year 2131, and, through the Saddle Points, Madeleine had travelled as far as twenty-seven light years from Sol. And here, seventy years out of her time, she was walking down airline steps, as if it was 1931.

  Not a good start to my new career, Madeleine thought bleakly.

  A man was waiting at the bottom of the steps. He looked about thirty, and he was a head shorter than Madeleine, with crisp black hair and a round face, the skin brown and leathery. He was wearing some kind of toga, white and cool.

  She wanted to touch that face, feel its texture.

  ‘Madeleine Meacher?’r />
  ‘Yes.’

  He stuck out his hand. ‘Ben Roach. I’m on the Triton project here. Welcome to South America’s spaceport.’ His accent was complex – multinational – but with an Australian root.

  She took his hand. It was broader than hers, the palm pink-pale; his flesh was warm, dry.

  They walked towards a beat-up terminal building. There was vegetation here: scrubby, yellowed grass, drooping palms. It was a contrast to the lush blanket she’d glimpsed from the air.

  ‘What happened to the jungle here?’

  He grinned. ‘Too many fizzers.’ He glanced down, then took her hand again. ‘Oh. You are hurt.’

  There was a deep cut on the index finger; a wound she’d somehow suffered on that creaky old staircase, probably. Madeleine studied the damaged finger, pulling it this way and that as if it were a piece of meat. ‘It’s my own fault; the plane was so hot I left off my biocomp gloves.’ The gloves, like the rest of the body suit Madeleine wore, were made of a semi-sentient mesh of sensors which warned her when she was damaging herself.

  ‘This is the Discontinuity,’ said Ben, curious.

  ‘Yeah. Too much teleportation is bad for you.’ Eventually, as she played with the finger, she reopened the drying cut.

  Ben stared curiously as fresh blood oozed.

  Madeleine’s employer had set up an office in the spaceport Technical Centre. This housed a run-down mission control centre, a press office, a hospitality area and a dusty, shut-down space museum: tinfoil models of forgotten satellites.

  The office itself was cool, light, airy. Too neat. There was rice straw matting on the floor, and scroll paintings on the wall, and flowers. It was all traditional Japanese, though Madeleine could see the ‘paintings’ were on some kind of softscreen, so configurable.

  The office had a view of the full-scale Ariane 5 mock-up that stood outside the entrance to the Technical Centre. Sitting on its mobile launch table, the Ariane looked a little like the old American Shuttles, with a fat liquid-propelled core booster (called the EPC, for Etage Principal Cryotechnique), flanked by two shorter strap-on solid boosters. The launch table itself was a lot more elegant than the Shuttle’s Apollo-era gantries, though; it was a slim curved tower of concrete and steel, like a piece of modern sculpture, dwarfed by the booster. This mock-up had to be a hundred and fifty years old, Madeleine figured; its paintwork was eroded away, the old ESA markings barely visible. Mould and creepers clawed at the sides of the rocket, a slow, irreversible vegetable onslaught; the booster was drowned in green, as ancient and meaningless as the ruins of a Mayan temple.