Michael. Poole’s invisible ghost-touch evaporated. Spinner-of-Rope lifted her hands from the waldoes.
Her job was done, then. She pulled her fingers inside the body of her gloves and balled her stiff hands into fists, digging her nails into the palms of her hands. She felt herself shudder, from fear and exhaustion. There was a stabbing in the small of her back, and across her shoulder blades, just below her neck; she twisted in her couch and flexed her spine, trying to work out the stiffness.
Then she looked out, beyond the construction-material cage, for the first time.
31
‘Dr Uvarov. Dr Garry Uvarov.’
The voice, flat and mechanical, roused him from a broken sleep.
He opened his mouth to reply, and ropy saliva looped across his lips. ‘What is it now?’
‘Is there anything you require?’ The voice, generated by the pod’s limited processors, didn’t even bear a semblance of humanity, and it came - maddeningly! - from all around him.
‘Yes,’ he said. He felt himself shivering, distantly; he felt cold. Was the power in here failing already?
How long had it been, since his abrupt abandonment by Lieserl and Mark Wu?
‘Yes,’ he told the pod again. ‘Yes, there is something I require. Take me back to the Northern.’
The pod paused, for long seconds.
Uvarov felt the cold settle over his bones. Was this how he was to die, suspended in the thoughts of an idiot mechanical? Was he to suffer a final betrayal at the hands of technology, just as the AS nanobots had been slowly killing him for years?
Well, if he was to die, he would take with him one deep and intense regret: that he had not lived to see the conclusion of his grand design, his experiment at extending the natural longevity of his race. He knew how others had seen him: as obsessed with his eugenics objectives, as a monomaniac perhaps. But - ah! What an achievement it would have been! What a monument . . .
Ambition burned within him still, intense, almost all-consuming, betrayed by the failure of his body.
His thoughts softened, and he felt himself grow more diffuse, his awareness drifting off into the warm, comfortable caverns of his memory.
The pod spoke again. ‘I’m unable to comply with your request, Doctor. I can’t obtain a fix on the Northern. I’m sorry. Would you like me to—’
‘Then kill me.’ He twisted his head from side to side, relishing the stabs of pain in his neck. ‘I’m stranded here. I’m going to die, as soon as my supplies run out. Kill me now. Turn off the damn power.’
‘I can’t comply with that, either, Dr Uvarov.’
But Uvarov was no longer listening. Once more he felt himself falling into a troubled - perhaps final - sleep, and his ruined lips moved slowly.
‘Kill me, you damn mechanical . . .’
32
The torus of ragged, fragmented string loops was gone. Now, cosmic string crossed the cavity: great, wild, triumphant whorls of it, shining a false electric blue in the skydome’s imager.
This one, tremendous, complex, multiple loop of string filled the cavity at the bottom of the gravity well. This was - astonishingly, unbearably - a single object, an artifact, at least ten million light-years across.
Louise Ye Armonk - with Mark, Lieserl and Morrow - hovered on zero-gee scooters, suspended beneath the crown of the skydome. Beneath Louise - she was distantly aware - the layers of forest were filled with the rich, comforting noises: the calls of birds and monkeys and the soft burps of frogs, sounds of busy life which persisted even here at the end of time . . .
Beyond the clear dome, string filled the Universe.
Here, a hundred thousand years into the past, the galaxies still fell, fragmenting and blue-shifted, into the deepest gravity well in the Universe. And the Northern had emerged from its jaunts through the string loop’s spacetime defects to find itself once more inside a star-walled cavity, at the bottom of this Universal well.
There the similarity ended, though, Louise thought. The cavity walls were much smoother than in the future, containing rather fewer of the ragged holes she’d noted . . . The walls looked almost artificially smooth here, she thought uneasily.
And, of course, there was the Ring, whole and magnificent.
The Ring was a hoop woven from a billion-light-year length of cosmic string. The Northern was positioned somewhere above the plane of the Ring. The near side of the artifact formed a tangled, impenetrable fence over the lifedome, twisted exuberantly into arcs and cusps, with shards of galaxy images glittering through the morass of spacetime defects. And the far side of the object was visible as a pale, hard band, remote across the blue-shifted sky.
The rough disc of space enclosed by the Ring - a disc no less than ten million light-years across, Louise reminded herself - seemed virtually empty. Perhaps, she mused, in this era the Xeelee were actively working to keep that central region clear.
. . . Clear, Louise saw as she looked more carefully, save for a single, glowing point of light, right at the geometric centre of the Ring. She saw how Lieserl was staring into that point of light, her mouth half-open.
Spinner-of-Rope’s precipitate action had delivered them, back through time, to another snapshot-timeslice of this war in Heaven . . . and this was, it seemed, an era not far removed from the Ring’s final fall.
She was aware of their eyes - Mark’s, Lieserl’s, Morrow’s - resting on her, expectantly. On her.
Remember what Lieserl said, she told herself. I’m a survival mechanism. That’s all. I have to keep functioning, for just a little while longer . . . She reached deep inside her.
She clapped her hands. ‘All right, people - Mark, Lieserl. Let’s do some work. I think it’s obvious we’ve delivered ourselves right into the middle of a war zone. We know that, at this moment, the photino birds must be hitting this Ring from all sides - because, within a hundred thousand years, we know that the Ring is going to be destroyed. That gives me the feeling that we don’t have much time, before one side or other notices we’re here . . .’
‘I think you’re right, Louise,’ Mark said. Both the Virtuals, on high-capacity data links to the central processors, were working on different aspects of the situation. ‘I don’t think we should be fooled by the fact that most of the action in this incredible war seems to be occurring at sublight velocities, so that - on this scale - it has all the pace of an ant column crossing the Sahara. Let’s not forget the Xeelee have a hyperdrive - which we’ve stolen - and, for all we know, so do the photino birds. We could be discovered at any time.’
‘So give me a summary of the environment.’
Mark nodded. ‘First of all, our position in time: Spinner-of-Rope constructed enough closed timelike paths for us to have travelled a hundred thousand years into the past, back from the era to which our first journey brought us.’ He raised his face to the skydome and rose into the air by a few feet, absently forgetting to take his Virtual-scooter with him. ‘The Ring is complete in this era, as far as we can tell. Its mass is immense - in fact we’re suffering inertial drag from it. Kind of a lot of drag, in fact . . . We’re being hauled around, through space, by the Ring. Spinner-of-Rope seems to be compensating . . .’
‘Lieserl. Tell me what you have.’
Lieserl seemed to have to tear her eyes away from that tantalizing point of light at the heart of the Ring. She looked down at Louise.
‘I have the Ring, Louise. We have been restored to an era before its destruction. Bolder’s Ring is a single loop of cosmic string . . . but an immense one, no less than ten million light-years across and with the mass of tens of thousands of galaxies, united into one seamless whole. The string is twisted over on itself like wool wrapped around a skein; the Ring’s topography is made up of string arcs moving at close to lightspeed, and cusps which actually reach lightspeed. The motion is complex, but - as far as I can tell - it’s non-intersecting. The Ring could persist forever.
‘Louise, there is no way this monster could have formed natural
ly. Our best theories say that any natural string loops should be a mere thousand light-years across.’ She looked up, and the blue false colour of the string images caught her profile, picking out the lines around her eyes. ‘Somehow—’ she laughed briefly ‘—somehow the Xeelee found a way to drag cosmic string across space - or else to manufacture it on a truly heroic scale - and then to knit it up into this immense artifact.’
Louise stared up at the Ring, tracing the tangle of string around the sky, letting Lieserl’s statistics pour through her head. And I might have died without seeing this. Thank you. Oh, thank you . . .
‘The cosmology here is . . . spectacular,’ Lieserl said, smiling. ‘We have, essentially, an extremely massive torus, rotating very rapidly. And it’s devastating the structure of spacetime. The sheer mass of the Ring has generated a gravity well so deep that matter - galaxies - is being drawn in, towards this point, across hundreds of millions of light-years. Even our original Galaxy, the Galaxy of mankind, was drawn by the Ring’s mass. So we know that the Ring was indeed the “Great Attractor” identified by human astronomers.
‘And the rotation has significant effects. Louise, we’re on the fringe of a Kerr metric - the classic relativistic solution to the gravitational field of a rotating mass. In fact, this is what’s called a maximal Kerr metric: because the torus is spinning so fast the angular momentum far exceeds the mass, in gravitational units . . .
‘As Mark said, the Ring’s rotation is exerting a large torque on the ship. This is inertial drag: the twisting of spacetime around the rotating Ring.’
Morrow frowned. ‘Inertial drag?’
Lieserl said, ‘Morrow, naive ideas of gravity predicted that the spin of an object wouldn’t affect its gravitational field. No matter how fast a star rotated, you’d be attracted simply towards its centre, just as if it wasn’t rotating at all.
‘But relativity tells us that isn’t true. There are nonlinear terms in the equations which couple the rotating mass to the external field. In other words, a spinning object drags space around with it,’ she said. ‘Inertial drag. And that’s the torque the Northern is experiencing now.’
‘What else?’ Louise asked. ‘Mark?’
He nodded. ‘The first point is, we’re drowning in radio-wavelength photons—’
That was unexpected. ‘What are you talking about?’
‘I mean it,’ he said seriously, turning to face her. ‘That’s the single most significant difference in our gross physical environment, compared to the era we came from: we’re now immersed in a dense mush of radio waves.’ He looked absent for a moment. ‘And the intensity of it is increasing. There’s an amplification going on, slow, but significant on the timescales of this war; the doubling time is around a thousand years. Louise, none of this shows up in the future era. By then, the radio photons will be gone.’
Louise shook her head. ‘I can’t make sense of this. What’s causing the amplification?’
He shrugged, theatrically. ‘Beats me.’ He glanced around the sky. ‘But look around. The Ring is contained in a shell of galactic material, Louise. The frequencies of the radio waves are below the plasma frequency of the interstellar medium. So the waves are trapped in this galaxy-walled box. We’re inside an immense resonant cavity, ten million light-years across, with reflecting walls.’
Morrow looked beyond the skydome uncertainly. ‘Trapped? But what happens when—’
Lieserl cut in, ‘Mark, I think I’ve figured it out. The cause of the radio-wave amplification.’
He glanced at her. ‘What?’
‘It’s the inertial drag. We’re seeing superradiant scattering from the gravitational field. A photon, falling into the Ring’s gravity well, is coupled to the Ring by the inertial drag, and is then thrown out with additional energy—’
‘Ah. Right.’ Mark nodded, looking distant. ‘That would give an amplification of a few tenths of one per cent each traverse . . . just about fitting my observations.’
Morrow frowned. ‘Did I understand that? It sounds as if the photons are doing gravitational slingshots around this Ring.’
Louise smiled at him, sensing his fear. ‘That’s right. The inertial drag is letting each photon extract a little energy from the Ring; the radiation is amplified, and the Ring is left spinning just a fraction slower . . .
‘Lieserl. Tell us more about the spacetime metric.’ She looked up, at the point of light at the heart of the Ring. ‘What do we see, there, at the centre?’
Lieserl looked up, her face composed. ‘I think you know, Louise. It is a singularity, at the centre of the Ring itself. The singularity is hoop-shaped, a circular flaw in space: a rip, caused by the rotation of the immense mass of the Ring. The singularity is about three hundred light-years across - obviously a lot smaller than the diameter of the material Ring . . .
‘If the Ring were spinning more slowly, the Kerr metric would be quite well-behaved. The singularity would be cloaked in two event horizons - one-way membranes into the centre - and, beyond them, by an ergosphere: a region in which the inertial drag is so strong that nothing sublight can resist it. If we were in an ergosphere, we’d have no choice but to rotate with the Ring. In fact, if it weren’t rotating at all, the Kerr field would collapse into a simple, stationary black hole, with a point singularity, a single event horizon and no ergosphere.
‘But the Ring is spinning . . . and too rapidly to permit the formation of an event horizon, or an ergosphere. And so . . .’
Louise prompted, ‘Yes, Lieserl?’
‘And so, the singularity is naked.’
Michael Poole sat with his legs crossed comfortably on the shoulder of the nightfighter. His gaze was on Spinner’s face, steady, direct.
The Ring is a machine, whose sole purpose is to manufacture that naked singularity. Don’t you see? The Xeelee constructed this huge Ring and set it spinning in order to tear a hole in the Universe.
Spinner-of-Rope enhanced the false-colour of the central singularity in her faceplate imager. The flaw looked like a solid disc - a coin, perhaps - almost on edge towards her, but tipped slightly so that she could see its upper surface.
In that surface, white starlight swam. (White?)
She said to Poole, ‘The Xeelee built all of this - they modified history, disrupted spacetime, drew in galaxies to their destruction across hundreds of millions of light-years - just for this?’
Poole lifted his eyebrows. It is the greatest baryonic artifact, Spinner-of-Rope. The greatest achievement of the Xeelee . . .
The singularity was like a jewel, surrounded by the undisciplined string-scribble of the Ring itself.
‘It’s very beautiful,’ she conceded.
Poole smiled. Ah, but its beauty lies in what it does . . .
He turned his gaunt, tired face up to the singularity. Spinner-of-Rope, humans have imputed many purposes to this artifact. But the Ring is not a fortress, or a last redoubt, or a battleship, or a base from which the Xeelee can reclaim their baryonic Universe, he said sadly. Spinner, the Xeelee know they have lost this war in Heaven. Perhaps they have always known that, even from the dawn of their history.
‘I don’t understand.’
Spinner, the singularity is an escape hatch.
Lieserl and Mark turned to each other, inhumanly quickly. They stared into each other’s eyes, as if exchanging data by some means invisible to humans, their blank expressions like mirror images.
‘What is it?’ Louise asked. ‘What’s happened?’
Pixels, defects in the Virtual projection, crawled across Mark’s cheek. ‘We need Spinner-of-Rope,’ he snapped. ‘We can’t wait for the repairs to the data links. We’re trying to find bypasses - working quickly—’
Louise frowned. ‘Why?’
Mark turned to her, his face expressionless. ‘We’re in trouble, Louise. The cops are here.’
Spinner-of-Rope asked, ‘How do you destroy a loop of cosmic string ten million light-years across?’
It isn’t so diffic
ult . . . if you have the resources of a universe, and a billion years, to play with, Spinner-of-Rope. Poole, perched on the shoulder of the nightfighter, pointed at a hail of infalling galaxies swamping a nearby section of the Ring. If the Ring tangles - if cosmic string self-intersects - it cuts itself, he said. It intercommutes. And a new subloop is formed, budding off the old. And perhaps that subloop, too, will self-intersect, and split into still smaller loops . . . and so on.
Spinner nodded. ‘I think I understand. It would be an exponential process, once started. Pretty soon, the Ring would decay into the torus of debris we found - will find - a hundred thousand years from now . . .’
Yes. No doubt the motion of the Ring has been designed by the Xeelee so that it does not cut itself. But all one need do is start the process, by disrupting the Ring’s periodic behaviour. And that is evidently what the photino birds are endeavouring to do, by hurling galaxies - like thrown rocks - at the Ring.
Spinner sniffed. ‘Seems kind of a crude technique.’
Poole laughed. Baryonic chauvinism, Spinner-of-Rope? Besides, the birds have other mechanisms. I—
‘ . . . Spinner. Spinner-of-Rope. Can you hear me?’
Spinner sat bolt upright in her couch and clutched at her helmet. ‘Lieserl? Is that you?’
‘Listen to me. We don’t have much time.’
‘Oh, Lieserl, I was beginning to think I’d never—’
‘Spinner! Shut up, damn you, and listen.’
Spinner subsided. She’d never heard Lieserl use a tone like that before.
‘Use the waldoes, Spinner. You have to get us out of here. Take us straight up, with the hyperdrive, over the plane of the Ring. Have you got that? Use the longest jump distance you can find. We’ll try to patch subroutines into the waldoes, but—’
‘Lieserl, you’re scaring the pants off me. Can’t you tell me what’s wrong?’
‘No time, Spinner. Please. Just do it . . .’
The Universe darkened.
For a bleak, heart-stopping instant Spinner thought she was going blind. But the telltales on the waldoes still gleamed at her, as brightly as ever.
Xeelee: An Omnibus: Raft, Timelike Infinity, Flux, Ring Page 130