by Adam Roberts
‘Like,’ said the Wizard with a hush of irritation, ‘like a never-ending shelf that stretched flat on all sides. Do listen! Handsome, but not so bright, not so bright.’ He shook his leather head. ‘Now, I am telling you about the change in things, and they changed a little before I was born; but this is a true history none the less. The world stretched flat on all sides because gravity ran perpendicular, as is its way. Millions lived on the world – billions – and you cannot even imagine such a word. Your language does not even possess such a word because you have no call for numbers so large.’
‘Gravity,’ said Tighe. ‘Did it change often?’
‘No, no, you don’t understand. It changed once, catastrophically. That is the true history I am telling you. Please listen! This explains the world – no small-scale model, no mythical doors through the world, but the way things actually are. It is hard because you have never thought of these issues before.’
‘I have!’ retorted Tighe. He remembered his childhood on the sunny ledges, staring out at the sky, pondering the nature of things.
‘Be quiet, my dear one. Now: gravity. Think of gravity, I request you: think of a great fabric, which is the fabric of space. Bodies such as the sun, the planets, make dents in this cloth, and the lines of force of space-time run down towards the centre of these dips. In the rest of the universe this is the way; but on our world gravity twisted. The earth still makes the same dip in space-time, still orbits the sun in its old path. But a traveller from outside coming along those lines of force will find herself suddenly jolted to the side; in the heart of the gravity well the lines of force run circular about the bottom point. It is like water running down a plug-hole. Well, that is a crude analogy, but it is the best I can manage. If only you possessed a proper physical education.’
‘Physical education?’
‘An education in physics, my silk-haired young darling. It changed, suddenly. And the changing of gravity brought about great suffering on this world, on our world. There were billions living here. And that word means thousand of million, such that a million means thousand of thousand. Your mind rebels against such profusion of people, I can see, but think! If the wall were flattened and ran all the world about, would there not be space for billions? Those places where the wall is smoothest were the most populous, and those places where we now live, the bumps and crevasses, were the least. So it was that this event has turned the world upside down.’
‘Upside down?’ asked Tighe, genuinely confused now.
‘A figure of speech,’ snapped the Wizard. ‘Please don’t feel compelled to be so literal, sweet one. I meant: turned the world through ninety degrees.’
He leant forward to peer closely at Tighe and then settled back in his cradle, apparently satisfied with what he saw.
‘You want to know’, he said, softly, ‘how this great change happened?’
‘Yes,’ said Tighe hesitantly. He was uncertain what to say.
‘Human beings generate energies for their uses. In the more distant times, and mostly today, energy generation was mostly heat, mostly the burning of materials; sometimes heat is converted into electricity by underefficient means. Underefficient power-source is one where more power is fed into the system than is derived from it; and such was the way for many years. Overefficient power-source is one where more power is derived from the system than is fed into it. When overefficient power was lighted upon, the people blessed it. They called it Power-at-Zero, and it depended upon the oscillation of electrical current at high frequency to create electromagnetic harmonics that bled power from the fabric of space-time. Machines were converted, mostly to use the P-at-Z to take apart water into Oxygen and Hydrogen, and use the one to combust the other, and so were machines powered. It is a P-at-Z machine that powers my engines here, that moves my craft about. But there was a great danger in the ubiquity with which these machines were once used. For gravity is part of the space-time fabric; it is dents in that fabric – remember I explained that to you? Down-pulling dips and holes. When power is taken from the fabric of space-time for a small thing, the whole fabric distorts very minutely, to accommodate the loss. But with sudden large power drains the fabric can suddenly ripple, flex. This is what happened with us. The fabric was distorted, it rippled and shifted. The flow of gravity changed in the dip in space-time caused by the weight of our world. Before it had flowed from the outer boundaries of the dip, where it was weakest, to the middle of the dip, where it was strongest – do you see? The inverse square law? After, it flowed turnways, rotating around the dip as the world turned. All that had been down before became to-the-side; all that was then called west became upwall. That which used to be called east became downwall. The old North Pole and the old South Pole became the left-most and right-most reaches of the wall; became called east and west by many peoples. Now, am I reaching you at all with any of this? Am I getting through to you?’
Tighe paused. He didn’t want to offend the Wizard. ‘I think so,’ he said, slowly. ‘Only, I do not understand the fabric you are talking about. What is this cloth? How does it fit into the story?’
The Wizard whistled and span through three hundred and sixty degrees in his cradle. ‘No, no, no,’ he said. ‘You misunderstand. I apologise, the analogy with the fabric was ill judged. Let me try again. Have you ever wondered what gravity is?’
Tighe shut his eyes. ‘It pulls us down,’ he said.
‘Yes, yes, that is what it does. Shall I tell you what it is? Well, all things are made of atoms. You have heard of this fact?’
‘Of course,’ said Tighe. ‘Atoms are very small. The smallest thing.’
‘Not the very smallest, as it turns out, but yes, for our purposes. Mass is the accumulation of atoms. But even where there is no mass, even in the vacuum of space, there is subatomic activity. Particles even smaller than atoms come into being and wink out of existence in a turmoil of subatomic creation and cancellation; particles and anti-particles. This is the real nature of the universe at the most fundamental level, this seething and boiling of primal matter, creating and destroying.
‘Where does this happen?’ said Tighe. He didn’t like the sound of this description: it sounded violent, like the boiling of water over a fire. Scalding. Was this how the Wizard saw the universe?
‘All around us! All through the universe – it’s too small for you to see, you literal-minded beauty. But this is what space-time is, this constant seething of subatomic activity. The important thing to realise about this constant activity is that it is not random, not swirling around in no particular direction. It has a larger pattern to it, it has a grain, shall we say, like the grain in wood. These subatomic events all happen in a certain way following a certain grain, and this grain is what we call gravity. Where there are more atomic structures – which is to say, where there is greater mass – the trajectories of this subatomic foaming become shorter and passage along them becomes quicker, which is another way of saying that gravity becomes greater. Away from atomic massing, the trajectories become longer and gravity is weaker. Yes? Yes? Now, the point about Power-at-Zero technologies is that they derived their power from this quantum foam. Gravity is a weak force, but it accumulates; and it is possible to steal billions of quanta of energy from the foam and accumulate as much power as you like without much difficulty. But there is a price to pay in the long run; there always is. Humanity discovered this. Eventually the drain on the subatomic foam was so intense in one place, one concentration of atomic mass we call the world we live on, that it sheared the grain of the subatomic flux right around through ninety degrees.’
The Wizard sat back, looking pleased with himself. Then his leather face shifted expression minutely and he looked cross. ‘This means nothing to you, does it?’ he barked. ‘Nothing at all!’ He ran a hand over his leathern face. ‘Never mind. Never mind. It’s not your learning I want you for, not your education. It is your capacity for learning, well yes, that’s the truth, the truth. And for the sake of that, please tell
me that you understand something of what I’ve been telling you.’
Tighe swallowed. ‘Gravity changed,’ he said.
‘Yes. Hundreds of years ago now, that’s right.’
‘It used to be upside down, but the fabric was torn.’
‘Well,’ squeaked the Wizard. ‘In a manner of speaking. Ninety degrees, boy! Ninety degrees.’
‘Ninety degrees,’ gabbled Tighe quickly.
‘Well, anyway,’ said the Wizard. ‘I’m older than you can imagine, but I’m not old enough to remember those events exactly. Old enough to get tired; and on only ten hours’ sleep you can’t expect me to be the most cogent of teachers.’
‘No, sir,’ said Tighe.
‘Don’t call me sir,’ said the Wizard languidly. He stretched himself out, like a monkey stretching after a meal.
4
There was a silence for a long while. Tighe sat, motionless, overawed by the incomprehensible narrative the Wizard had just spun out.
‘Wizard?’ he asked, softly. ‘Wizard?’
But the Wizard seemed to have fallen asleep in the cradle. There was a faint snoring sound coming from his mouth.
Gingerly Tighe got to his feet. He had the feeling that this was some sort of opportunity, but he didn’t know what to do. Perhaps if he were able to bind the Wizard up somehow? To hold him hostage? Force him to fly them all back to the village. Yes, that was a plan.
He took a step towards the sleeping figure.
At once the Wizard woke up. ‘Where was I?’ he demanded immediately.
Tighe pulled his foot back and sat down. ‘Master?’
‘What was I saying before I fell asleep there?’
‘The world turned upside down,’ said Tighe, his heart hammering. ‘The catastrophe.’
‘Oh, yes,’ said the Wizard. ‘Oh yes! Oh, the terrors of days immediately after gravity changed! You must understand the world. It was flat – flat – it lay flat in all directions. It was mostly covered with water, water that lay as it were in pools, pools that stretched for thousands of square miles. Two-thirds of the world was covered by water, imagine that! After gravity changed, this water all went into the air and fell downways. It rained for years. Much more than rain at first; great shire-sized sheets of water falling, resolving itself eventually into a never-ending downpour of fat raindrops. People had built houses, built cars and machines, and all were resting flat on the ground. Most things went into the air and fell downways. Some people were out, doing their people-things, when the change happened: they were walking on the flat, or sleeping in houses that could not stay fixed to the wall after gravity changed. Most people went into the air and fell; they simply fell. They fell and crashed against the other flying debris, or were smashed against the wall like rubbish, or were simply plucked to pieces by the ferocity of the tempest winds. Most of all the rain fell; it was rain muddy with all the loose earth and sand that was also in the air. Rain that was heavy, falling as fast as it could fall round and around the world. Raindrops like bullets, rain that killed many of those who had managed to avoid falling by clinging to the new crags. Rain that shredded up those few up in the air in aircraft that were able to fly on and not crash into the wall. And the wind howling like a beast. The rain fell for years and the wind howled for years. Clouds that moved fast as falling boulders filled the sky and blocked out the sun. And it grew very cold.’
As if in response to his words, the floor of the craft shifted and trembled. The Wizard paused and checked his screens. They showed a slow passage of worldwall now, a stately procession of white-marked rock. They were moving much more slowly, still going east. He turned back to face Tighe again. ‘Nothing to worry about,’ he said. ‘There will be these hiccoughs, my young one.’
Tighe inched closer to his pashe and put his arm around her.
‘Catastrophe,’ said the Wizard, gesturing in the air with his arm. ‘Apocalypse. People believed it was the ending of things. And indeed it might all have ended there as many survivors thought it would. Many threw themselves into the void with prayers to their gods on their lips. Many starved, huddling in the caves formed by cellars from which the housetop had been ripped away. Some survived for a time, in subterranean tunnels living off ratmeat and micemeat, in government bunkers eating the metal-tinned food laid by for emergencies. Some found themselves somehow on one of the ledges, not fallen off or blown away, and were able to dig themselves into crevices. Sometimes food would fall against the wall and wedge there. Water was so plentiful people could drown breathing the air, but it was salt water and not drinkable. But then, as now, there were springs and spouts of water from the wall. By all accounts, the first year was the worst and the second year lessened the suffering. Rain and snow.’
‘Snow?’ Tighe asked. He was following few of the details of this latest narrative of the Wizard’s, except to glean a sense of terrible disaster and people falling off the world.
‘Oh, you won’t know that. It happens almost never towards the equator of the worldwall, where the winds are too warm – heated by the sun, sinking when they cool.’
‘Equator?’
‘The centre line of the worldwall,’ said the Wizard quickly. ‘It runs from bottom to top at the very centre. The fattest portion of our twisted globe. But out near the West and East Poles, where we are going, there are still squalls of snow. Snow is where frozen water falls in drops and flakes from the sky.’
‘Oh,’ said Tighe, little illuminated.
‘Well, anyway, it rained. Perhaps the rain would have fallen for ever; perhaps the wind would never have relented. But the water was slowly taken out of the atmosphere by freezing. It settled on the far-eastern and far-western ledges as snow and ice, and much water was held there; but more found its way to the graveyard of water at the Poles. Before gravity changed, the Poles had been frozen, the coldest parts of the world because those parts were furthest from the Sun. But before gravity changed the Poles had been flat, and gravity had worked there just the same as it worked all over the world, pulling people flat against the ground. Now, the nature of the Poles has changed. At the East Pole and the West Pole the flow of gravity is weakest. The downward flux is least. To begin with, this meant that snow and ice from the Poles were continually being ripped by the speed of the more equatorial winds and thrown into the atmosphere, but with time the system began to approach an equilibrium. Water settled at the Poles as snow and ice and accumulated there. Before gravity changed, our world was an almost perfect sphere, and indeed was a little flattened at the Poles. Now – as we shall see when we arrive there – there are two great Polar Promontories, oceans’ worth of water frozen into two massive mountains. There in the cold, where the pull of gravity is the least. Earth, which was orange-shaped before gravity changed, has become lemon-shaped now.’
‘Orange?’ asked Tighe, completely confused.
‘Orange is a fruit named for its colour, which is also perfectly spherical. It grows on the trees, you know. A lemon is another species of fruit, shaped like the world. But why am I telling you this? This means nothing to you. The important thing for you to realise is that the rain did stop. So much of the water in the atmosphere was frozen out that, although the rain fell for a decade, the air did eventually clear. Most of the animals had died, along with most people, but different ledges had preserved different livestock, a little here, a little there. Life started again. So many challenges! The atmosphere – that’s very different now.’
‘Is it?’
‘Yes, it tends to pull down with gravity. It used to rest on the ground, now it rests only on itself. But it heats in the day and starts to rise, or at least stops falling. But then it chills at night and falls faster. Where day and night meet – dawn, dusk – there are ferocious gales, very dangerous. Of course, those become less the further towards the Poles one travels. Life manages, somehow.’
5
Tighe scratched at his head. The story was so ornate, so full of inexplicable terms and so ungainly, that he had diff
iculty even remembering most of it, let alone believing it. Something bad had happened, that much was certain. It was a punishment, perhaps; God’s punishment for crimes committed by humanity. The world had been an enormous shelf, nothing but shelf all around; and now God had condemned everybody to the precariousness of the worldwall.
‘I think,’ he said, ‘I think I understand.’
‘I think you’re lying,’ said the Wizard, without heat, ‘but it matters very little, I’m afraid. The important thing to keep in mind is the fact that the world was once flat and might be again.’
‘Might be again?’
‘Oh, yes,’ said the Wizard. ‘We have to relinquish command to the laws of thermodynamics, to the essence of the universe. That is simply the way it is, my bright-toothed beauty. If a man were to fall from a ledge he might fall for ever, passing round and around the world. Well, he would probably be dashed against the wall into pieces, or torn apart by winds, but you see the point I’m trying to make. It violates the law of physics that a body might fall for ever; accordingly, logically, there must come a time in the future when gravity will change again. This will probably mean the wall tilting flat again and humankind resuming its old way of living. Things will again be flat. Or perhaps some farther change will come, something we cannot anticipate – a further twist in the contorted rag of space-time, something beyond our comprehension. When will this second apocalypse come? That is the biggest of questions. That is the question that my Lover is most centrally concerned with.’
‘Your Lover,’ said Tighe.
‘The chief amongst my Lovers,’ said the leathern man, ‘at any rate. He understands that every action of any mass in this system is draining energy from somewhere. Energy is not free, my pretty child. Every person who dips their cup into the never-ending flow of gravity that circles our world draws energy from the greater fabric of space-time. One theory of physics suggests that when this drain on the larger fabric becomes too great for its balance to be maintained, then, as before, change will flip our world into some new gravitational permutation. But this could happen in one hour’s time; or one year’s; or a thousand years from here. The calculations are rather ambiguous, I’m afraid to say.’