The Long Mars

by Pratchett, Terry; Baxter, Stephen

  ‘That indeed is the idea, Doctor.’

  Maggie asked, ‘Can partial gravity really reverse ageing?’

  Mac grinned. ‘It’s one of the oldest space-buff dreams, Captain.’

  ‘Yeah, but I thought low gravity was bad for you – leaching away the calcium from your bones, wasting your muscles, messing with your body’s fluid balance . . .’

  Black said, ‘That’s true for zero gravity, Captain. Partial gravity is different. Surely this world’s pull will be sufficient to keep the muscles strong, the juices flowing as they should, with appropriate diets, exercise regimes and so forth. But by allowing the body to spend less energy just fighting gravity – the cells will oxidize more slowly, the joints, the ligaments, the dubious architecture of the spine will all be stressed significantly less – there is a strong argument that life spans could be significantly extended.’

  Maggie turned to her chief surgeon. ‘Mac?’

  He spread his hands. ‘There’s an argument, maybe. But not a shred of hard evidence. Very little research has been done on the effects of partial gravity, and won’t be until the day we have data from long-duration stays on Mars or the moon. However, it’s Mr Black’s choice, his money.’

  ‘Oh, come, Doctor; at my age, my position in my life, don’t you think it’s a gamble worth taking? And it’s not just my money by the way. I’m representing a consortium of backers – none of them adventurous enough to take this trip with me, but all willing to follow, in the next year or two. They will come with their staff, their own doctors . . .’ He smiled. ‘Now do you see the vision, Captain? Among my backers are Americans, Europeans, Chinese, politicians and industrialists and investors, some, frankly, closer to the dark edge of the law than others. Old money and new – some indeed who made a fortune out of the Yellowstone aftermath, for every disaster is an opportunity for somebody. Some people, you know, got rich even out of the fall of the Roman Empire. The Long Earth is still young, and we are very wealthy indeed; with time we’ll find ways to wield our influence even from this remote world. Now if you’ll excuse me – come, Philip, we need to find a location for our first settlement and get established before the airships leave. . .’

  Maggie stared after him. ‘A community of the fabulously rich, Mac. Rich and ageless, if this all works out as he dreams.’

  ‘Well, it might. Oxygen and low gravity – that’s quackery, probably. But they’ll be bringing in teams of researchers who’ll have nothing else to do but find something that does work.’

  ‘And if so it really will be a Shangri-La. Without the monks.’

  Mac grunted sceptically. ‘Or a community of struldbrugs, like Gulliver’s Travels – undying but ageing, and growing more and more bitter. A gang for whom even death will no longer bring an end to their clinging to wealth and power. Think of all the monsters of history who you wouldn’t want to see still around today, from Alexander through Genghis Khan to Napoleon . . .’

  ‘It might not be like that. Maybe they will give us a longer perspective.’

  ‘Hell of a gamble if you ask me. So are you going to allow this, Captain?’

  ‘I don’t see I’m in a position to stop him. He’s not crew, Mac.’

  ‘I guess. Well, I’m glad I won’t live long enough to see what grows from the seed you planted today.’

  ‘You old cynic. Come on, let’s get back to the ship and go home.’

  36

  THE GALILEO CREW had left behind the world of the sand-whalers and the monoliths with, as far as Frank Wood was concerned, a sigh of relief.

  And it was only when they were safely in the air, passing over yet more clones of dead Mars, one every second, that Frank began to relax, that the military man inside him began, grudgingly, to release his hold on events. How they had got away from ferocious fire-spitting land-dragons and harpoon-hurling sand-whalers – not to mention some kind of monstrous unseen Martian tyrannosaur – without harm to themselves or their equipment, he had no idea. And he kept remembering that crustacean prince, as Frank had labelled him (or her) in his head, humiliated by his leader with one of Willis’s Stepper boxes. What kind of consequence was that going to have? But, he supposed, that was a problem for the future, not for right here, right now.

  In the days that followed, while Willis paged through the screeds of images the whalers had retrieved for him from the monoliths, and Sally sank back into her own default mode of wary silence, Frank spent a lot of time asleep, nerves slowly recovering. He wasn’t as young as he used to be.

  And he was only peripherally aware of the new Jokers the expedition came upon, and paused to study.

  A flooded Mars, where, it looked like, the whole of the northern hemisphere was drowned by an ocean. Here beasts not unlike the sand whales roamed the land, while what looked like cities floated on tremendous rafts on the sea. ‘Fishermen’, crustacean types, came ashore in land-yachts to hunt the whales, just as on Earth land-dwellers harvested the fruit of the sea . . .

  A drier Mars, whose copy of Mangala Vallis was nevertheless covered by forests, of tough, low, needle-leaved trees. Willis was tempted to linger here because he thought he saw two forest clumps in slow-motion conflict with each other: a war waged at the speed a flower grew. ‘Birnam Wood besieging Dunsinane!’ he said. But they could not afford a long enough stay to study this slow encounter properly . . .

  A plain covered in rocky coils, like heaps of rope. Willis’s first guess was that these were some kind of volcanic extrusion. But when he took Thor down for a closer look the coils unwound into pillars of basalt, gaping mouths opened, and gouts of flame shot out at the hastily retreating glider: another variation on the theme of sand whale . . .

  Once, Sally swore, on a moist but chill Mars, a glacial Mars, she saw a herd of reindeer, off in the northern mist, coats shaggy, antlers held high, animals much larger than their terrestrial equivalent. But the others could not see it, and the cameras could not penetrate the mist for a clear image. None of them understood what this vision, like a race memory of the Ice Age, might mean . . .

  And, every so often, Frank thought he saw flickering forms in the valleys of Mangala, far below. Translucent sacs, like survival bubbles; gaunt forms like landed sand-yachts. As if they were being followed. Probably the product of paranoid dreams, he thought.

  Finally, eleven weeks since the landing and nearly three million steps from the Gap, Willis Linsay said he thought he had found what he was looking for.

  37

  TO SALLY, PILOTING Frank in Woden, it was just another dead Mars. As seen from a high altitude the basic shape of the landscape, the tangle of Mangala Vallis below, the great rise of the Tharsis uplands to the north-east, looked much as she remembered it from spacecraft images of the Datum-Earth Mars, taken decades ago in a reality all of three million steps away.

  Behind her, Frank, sleepy, grumpy since they had run out of caffeinated coffee a week back, was also unimpressed. ‘What the hell can he have found, if even a new set of Commandments from God on those damn monoliths wasn’t good enough?’

  ‘It’s not visible to the naked eye,’ said Willis from Thor, his voice crackling over the comms. ‘I’ve had optical and other scanners searching for it, from both gliders.’

  Sally said, ‘Tell us where to look, Dad.’

  ‘More or less east. You won’t see it, not from here. Use your screens . . .’

  Sally fooled with her screen, looking in the direction he’d told her, exploring the bulging Tharsis province landscape under the usual featureless toffee-coloured sky. She saw a lot of horizontals, the uneven horizon itself, craters reduced to shallow ellipses by perspectives, gullies on the uplifted flanks of the volcanoes, all painted a monotonous brown by the ever-present dust. No odd shapes, no unusual colours. Then she allowed the software to scan the image for anomalies.

  ‘Oh, my,’ said Frank. Evidently he had done the same thing, about the same time. ‘I was looking at the ground, the landscape. The horizontals.’

  ‘Yeah.
When all the time . . .’

  There was a vertical line, a scratch of very un-Martian powder blue, so fine and straight and true it looked like an artefact of the imaging system, a glitch. It rose up out of the landscape from some hidden root. Sally let the image pan, following the line upwards. What was this, some kind of mast, an antenna? But it rose on up into the sky – up until the imaging system reached the limit of its resolution, and the line broke up into a scatter of pixels, still dead straight, fading out like an unfinished Morse code message.

  Frank said reverently, ‘Arthur C. Clarke, you should be seeing this. And, Willis Linsay – respect to you, sir. You found what you were looking for, all this time. I get it now.’

  Willis said, only a little impatiently, ‘OK, let’s get the fan-boy stuff out of the way. I take it you understand what you’re looking at.’

  ‘A beanstalk,’ Frank said immediately. ‘Jacob’s ladder. The world tree. A stairway to heaven—’

  ‘What about you, Sally?’

  Sally closed her eyes, trying to remember. ‘A space elevator. Straight out of those wonders-of-the-future books you used to give me as a kid.’

  ‘Yeah. Future wonders of my own childhood, actually. Well, here it is. A cheap way of getting to orbit, basically. You put a satellite in orbit to be the upper terminus of your elevator string. You need it to hover permanently over the lower terminus, which is on the ground. So you put it over the equator, or close to, at an orbit high enough that its period matches the rotation of the planet.’

  ‘Where they station the communications satellites.’

  ‘Right. Mars has about the same day as Earth, so a twenty-four-hour orbit does the trick here too. Then you just drop a cable down through the atmosphere—’

  ‘The engineering details of that,’ Frank said dryly, ‘are left as an exercise for the reader.’

  ‘Then you fix it to the ground station, and you’re in business,’ Willis said. ‘Once it’s in place, no more expensive, messy rockets to get off the planet. You get a cable-car ride to the sky, fast, cheap, clean. In principle this technology will work on any world. Any Mars. This Mars is better than our own, in fact, because it doesn’t have any pesky low-orbit moons to get in the way.’

  Sally was plodding through the logic of this situation. ‘Let me get this straight, Dad. You predicted you were going to find a space elevator on Mars – I mean, somewhere in the Long Mars. How did you know? Who built it? How old is it? And why do you want it?’

  ‘How did I know? It was a logical necessity, Sally. Any advanced society on a Joker Mars is going to strive to reach space, before the window of habitability closes, as close it must. And if a spacegoing culture does arise, then a space elevator is going to be something they’re going to reach for, because it’s so much easier to build here on Mars, than on Earth. Who built it? Irrelevant. Somebody was bound to, given enough time – enough chances, in the worlds of this Long Mars.

  ‘As to why I want it – look, we need this back on Earth.

  ‘The big challenge for a space elevator is getting hold of a cable material strong enough. On Earth, you’d need a cable twenty-two thousand miles long, and said cable has to hold up its own weight, against the pull of gravity. If you used fine-grade drawn steel wire, say, you’d only be able to raise your cable through thirty miles or so before it would pull itself apart like taffy. That’s a long way short of twenty thousand miles. In the old days there was much fancy talk of special materials with a much higher tensile strength – graphite whiskers and monomolecular filaments and nanotubes.’

  ‘You understand this was all before Step Day,’ Frank said. ‘When because of you, Willis, everybody got distracted by travelling stepwise instead of up and out, and the dreams of opening up space were abandoned.’

  ‘OK, my bad. But, Sally, the point is that building an elevator on Mars is much easier than on Earth. The lower gravity, a third of Earth’s, is the key. Satellites orbit a lot slower than around Earth, at a given altitude. So the twenty-four-hour synchronous orbit is only eleven thousand miles up, not twenty-two. And you can use materials of much less tensile strength to make your cable. You see? That’s why space elevators are a much more accessible technology on Mars than on Earth. But if we can take this cable stuff home – learn its lessons, retro-engineer it to find out how it works, enhance its performance for Earth’s conditions – we’ll skip decades of development and investment.

  ‘Think about it. What a gift for humanity, just when we need it. Once you have an elevator, access to space is so easy and cheap that everything takes off. Exploration. Huge developments like orbital power plants. Resource extraction, asteroid mining, on a vast scale. Some of the Low Earths have populations of tens of millions now, since the Yellowstone evacuations. And as they industrialize, if they start with easy access to space, they’ll be able to keep it clean and safe and green from the beginning. We could have a million-fold industrial revolution across the Long Earth, on worlds as clean as my garden in Wyoming West 1, Sally, where you used to walk me as a kid. And as for the Datum itself, given the depletion of oil and coal and mineral ores there, this is the only way the old world can ever recover.’

  ‘You are playing Daedalus again, aren’t you?’ Frank said. ‘I guess the historians will call it Beanstalk Day this time.’

  ‘Things have a way of working out. Stepping did, didn’t it?’

  ‘Sure. After a slew of social disruption, economic chaos—’

  ‘And a billion lives saved during Yellowstone. Whatever. Anyhow this conversation is irrelevant because—’

  Sally said, ‘Because you’re going to do this anyhow.’

  ‘Yep. Come on, let’s head over; I want to find the root station before it’s dark. Then we’ll need to figure out how to acquire some kind of samples to take back. The cable is the thing; if we get pieces of that material the rest is detail.’

  Sally pushed at her joystick; the glider climbed higher, banking to the east. ‘One more question, Dad. So you figured that somebody would have come up with the space elevator idea, somewhere on the Long Mars. All you had to do was keep stepping until you found it. But how did you know it would be here? I mean, geographically. If I understand it right you could grow a beanstalk anywhere along the Martian equator.’

  Frank said, ‘Let me try to answer that one. We’ve been tracking the big Tharsis volcanoes. Right, Willis? Stick a beanstalk on top of Olympus Mons and you’re already thirteen miles up towards your goal, and above eighty per cent of the atmosphere, thus avoiding such hazards as dust storms.’

  ‘Actually Pavonis Mons would be a better choice,’ Willis said. ‘Not as big but slap on the equator. Yes, Frank, that was how I figured it; Tharsis had to be a site, if not the only one . . . Hmm.’

  ‘What?’

  ‘I’m getting better visuals now. Up here, out of the dusty air. As it happens the cable line doesn’t quite line up with the summit of Pavonis. Engineering details. Soon we’ll know for sure. Come on.’

  They flew on, Sally tracking Willis, heading steadily east, away from the setting sun, over slowly uplifting land. The shadows speared out from the rocks and pooled deep in the craters, where Sally imagined she saw mist gather.

  At last she thought she could see the cable itself with her naked eye, a baby blue scrape down a sky turning a bruised purple. She tilted her head, watching it spear up, up out of her vision, impossibly tall.

  ‘Like a crack in the sky,’ Frank said. ‘What’s that old song?’

  ‘It makes me feel kind of giddy,’ Sally said. ‘In an inverted way. I’m glad I can’t see the anchor satellite, poised up there. What if this thing broke and fell?’

  ‘Well, the cable would wrap around the planet as it rotated, and cause a hell of a lot of damage. There was a novel called Red Mars—’

  ‘It’s not going to fall,’ Willis said.

  ‘How do you know?’ Sally snapped.

  ‘Because it’s very ancient. If it was going to break and fall, it would
have done so by now. Ancient, and lacking maintenance for a long time.’

  ‘And how do you know that?’

  ‘Look at the ground below.’

  The featureless plain was scattered with meaningless shadows. No structure, Sally realized. No sign even of a relic.

  Willis said, ‘Think where we are. At the foot of a space elevator, this should be the hinterland of a port that serves a major chunk of the planet. Where are the warehouses, the rail lines, the airports? Where’s the city to house the travellers and the workers? Where’s the farmland to feed them all? Oh, I know whatever race built this probably had totally different ways from the human of solving those problems. But you don’t build a space elevator unless you want to bring materials down from space, or ship goods back up into space, and you don’t do that without some kind of facility to handle stuff on the ground.’

  ‘And there’s nothing down there,’ Sally said. ‘How much time, Dad? How much time to erode everything to invisibility?’

  ‘I can only guess. Millions of years? But the elevator survived all that time, the dust storms and the meteor impacts – and its own exotic hazards, such as solar storms and cable-snipping meteors further up. Whoever built that built it well . . .’

  Suddenly the wonder of it hit her, the strangeness of the situation. Here was the product of a long-vanished indigenous civilization, about which Willis could have known nothing. Nothing about their nature, the detail of their lives – their rise, their fall, their evident extinction. And yet, from the sheer planetary geometry of Mars, he had deduced they must exist, or must have existed, and they must have built a space elevator. And he was right, here was that final monument, their last legacy, with everything else about them worn to dust. As if they had only ever existed for this one purpose, to fulfil Willis’s ambition. And he, in turn, had crossed two million Earths, the Gap, and three million copies of Mars, in the utter certainty of what he would eventually find. Not for the first time in her life she wondered what it must be like to live inside her father’s head.