On (50 page)

Tighe digested this. ‘The wall goes on for ever,’ he said. Somehow that sounded somehow right, somehow appropriate to the mystery of the wall. ‘But how can you know it is endless?’ he asked. ‘You cannot have travelled
up the wall for ever. And’, a second objection occurred to him, ‘if the wall has no top and no bottom, then where does God reside?’

‘Ah,’ said the Wizard. ‘God. But I think we are all three of us hungry.’

He pulled out a parcel from a pouch by his belly and unwrapped some more of his delicious meat-cake, followed by a metal flask identical to the one Tighe had discovered in the cupboard under the control panel. He swiftly divided the food three ways and handed the smallest portion to pashe. She munched it absently.

Tighe devoured his portion in a few mouthfuls and drank deep of the bitter tingly fluid in the flask. It made his thoughts blur a little, but he soon refocused himself. The Wizard himself picked at his food without energy, breaking off tiny fragments of meat-cake between thumb and forefinger and popping them delicately between his black leather lips.

‘What is wrong with my pashe, Master Wizard?’ Tighe asked, reverting to Imperial again, to express deference. ‘She is not herself.’

‘You speak more truth than you know,’ said the Wizard. ‘There has been a – shall we say, a cortical diminishment. Unfortunate, but necessary. She does not suffer, that is the important thing; but it would take me too long to explain to you the precise nature of the cerebellar microplaque operation that obtains in her skull.’ He lifted the flask to his own lips and let a tiny dribble pour into his mouth. ‘Where was I?’ he asked, picking again at his food.

‘I do not know, Master Wizard,’ said Tighe. ‘I find it difficult to follow your explanations.’ He was speaking the Imperial tongue, thinking this would find favour with the Wizard, but his leather face creased momentarily.

‘Don’t chatter so in Imperial,’ he said, crossly in the village tongue. ‘It’s hard enough explaining these things to you in the first place, without your having to translate them into a foreign language in your head! Speak your native tongue, boy!’

He nibbled another morsel.

‘Let us talk about gravity, my son,’ he said. ‘Gravity. What else is it that makes the world so precarious a place? And precariousness is, after all, the condition of existence. It has been my struggle to escape the precariousness that defines the rest of humanity. Most of the rest of humanity, I should say, for neither I nor my Lover are defined by our precariousness.’

Tighe looked up. The thought of so grotesque an individual having a lover made him queasy in his stomach. ‘Your Lover, Mister Wizard?’ he asked.

The Wizard nodded. ‘You are surprised because you find my face hideous. Your failing, my pretty one, not mine. I have several Lovers and
they are all myself. We go to the East Pole because that is the best place to hide from them. From one in particular, who has devoted himself to destroying me. As if he can destroy me! It would be destroying himself. We are the same. But’, he said, waggling his head with annoyance, ‘we are not talking about my Lover, fascinating though I find the topic. We are talking, my dear boy, about gravity.’

‘Gravity,’ said Tighe.

‘You understand gravity?’ prompted the Wizard.

Tighe swallowed. The taste of the meat-cake was fading from his tongue and he mourned its passing. ‘I understand the word, Wizard,’ he replied.

The Wizard seemed to find this amusing; he scraped out his dry laugh and nodded. ‘An excellent answer, my young monkey,’ he said. ‘Worth a philosopher’s salary. Yes, human beings have spent their lives trying to understand gravity. And yet it defines us. Who built the wall?’

Tighe thought at first that this was a rhetorical question, so he didn’t answer. He was busy running his tongue into the coign of his mouth, where the last crumbs of meat lurked behind his teeth. When the Wizard stopped, and Tighe realised that he had directed the question at him, he looked up.

‘I’m sorry, Wizard?’

‘Who built the wall, boy?’

‘God,’ said Tighe, automatically.

‘Man,’ returned the Wizard. ‘Man built the wall. We built it.’

Tighe thought about this. ‘Not possible, though, Mister Wizard,’ he returned. ‘How can man build something so high that it goes on for ever?’ He had, none the less, a sudden, piercing sense of the enormity of such an undertaking. Hundreds of people, hauling enormous blocks of stone together one after the other, building a wall on such a scale. Hundreds and hundreds. How many generations would it take? What now-lost skills of engineering? But it was a false image; it was nonsense.

‘I never said’, replied the Wizard, ‘that the wall was infinite in proportions. That was your contribution. I said that the wall has no top, nor bottom; and neither has it.’

‘I do not understand,’ said Tighe.

‘When I say that man built the wall,’ said the Wizard in gentle tones, ‘I mean that he altered his world and turned it into the worldwall. It is gravity, do you understand?’

‘No, Wizard.’

‘Of course not. Let me explain. Gravity changed. You know what gravity is – it pulls us down. If we step off a ladder, it pulls us down to the floor. If we step off a ledge, it pulls us down through the sky. I hardly need to tell you this! You fell!’

‘I fell,’ said Tighe.

‘Gravity pulled you down. Do you see? Gravity runs parallel to the world and that is what defines the world we live in. But it used not to be that way. Once, and it was some hundreds of years ago, gravity pulled in a different direction.’

Tighe pondered. ‘What other direction could there be?’ he asked.

‘Not parallel to the world, but at a ninety-degree angle to it. Imagine that!’

But Tighe could not imagine it. ‘I don’t understand,’ he said.

‘Before worldwall there was flat-earth,’ said the Wizard. ‘Try to enter imaginatively into such a place, my bright boy. The wall was not up, nor down, but a huge shelf, a never-ending shelf that stretched flat on all sides. That was because gravity in those days ran at ninety degrees to its way now. This is, in fact, the way gravity runs most elsewhere in the Universe; on other worlds, on other stars. And our world, that we call the worldwall – our world still orbits around the sun, and the sun still pulls us inwards with perpendicular gravitational attraction, or we would not so orbit. This is physics, my sweet-smelling child; please pay attention.’

‘Yes, Wizard,’ replied Tighe, baffled.

‘Once, our world was a sort of sun; it shone with the light made by its people and glittered out into the void. Like the sun it had its own planet, orbiting the world, which was called moon. After the gravity changed we lost the moon, which ran its own way. These days the place of turbulence, the point at which gravity starts to angle away from its universal direction, is only a few thousand yards out. But it seems that immediately after gravity changed this boundary fluctuated; it spooled and whirled, like water that is unruly, and the boundary whirled outwards in a great Van Eder pattern. It caught the moon, and the moon fell suddenly and sped away. But, according to my Lover – who has many interesting theories about this time of change – it was the vastness of the impulse required to accelerate the moon out of its orbit, the orbit it had maintained for so many millennia, that reined the Van Eder pattern back towards the earth. Instead of spreading ever outwards in every-weakening spirals, the pattern of changed gravity shrank back to this world. It might have shrunk wholly to the centre of the planet and we would have had the old world restored to us. But this was not the way things happened. Instead it settled into its current pattern.

‘This’, said Tighe, with a hazy sense of what the Wizard was talking about,‘ – you mean, the Pause.’

‘The Pause,’ said the Wizard. ‘Is that what you call it?’

‘Kite-pilots know this,’ said Tighe. ‘You can fly only so far from the wall before you reach the Pause. Then you can fly no further.’

‘Well, exactly,’ said the Wizard. ‘That is the Pause, then. A good name
for the phenomenon. How exciting, my witty adventurer! You bring tales from the boundary of the world. This is the boundary between the spiral of gravity that surrounds our world and the perpendicular force that applies elsewhere. As for the moon, it fell away from us, and in the vacuum of space there is none to slow its fall and it sped so fast it ran clear free of its onetime owner. Now it is out there on its own, and my Lover – who has examined it – says that its orbit is erratic, sunwards. Like as not, it will become a moon for another world, for Venus most say; and Venus is a foul world, acid and hot. Perhaps our moon will calm the world of Venus. Ah, the telescopic view of it makes it seem severely beautiful, fine and silver, etched with delicate patterns and designs like art-ware! I can imagine that having the moon will shake up the stagnant acid of Venus’s world and maybe bring about a better place. Maybe a place for a new life, so perhaps the changing of gravity will bring great good in the universe.’

The Wizard stopped, as if musing. But Tighe had lost track of what he was saying. ‘Master Wizard,’ he said, in Imperial, and then stopped himself. ‘Mister Wizard,’ he said in his native tongue. ‘I do not understand. How can gravity change? How was the world before?’

‘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?’