“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 center?”
Lieserl looked up, her face composed. “I think you know, Louise. It is a singularity, at the center 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 center — 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-color of the central singularity in her faceplate imager. The flaw looked like a solid disc — a coin, perhaps — almost on edge toward 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 tike 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 difficult… 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 behavior. And that is evidently what the photino birds are endeavoring 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.
She looked up. There was something before the ship, occluding the blue-shifted galaxy fragments, hiding the Ring.
She saw night-dark wings, spread to their fullest extent, looming over the Northern.
Nightfighters.
She twisted in her seat. There were hundreds of them — impossibly many, dark lanterns hanging in the sky.
They were Xeelee. The Northern was surrounded.
Spinner screamed, and slammed her fists against the hyperdrive waldo.
The ’fighters moved through electric-blue cosmic string like birds through the branches of a forest. There were so many of them in this era. They were cool and magnificent, their nightdark forms arrayed deep into space all around her. Lieserl stared at the swooping, gliding forms, willing herself to see them more clearly. Had any humans ever been closer to Xeelee than this?
The Xeelee moved in tight formation, like bird-flocks, or schools of fish; they executed sudden changes of direction, their domain wall wings beating, in squads spanning millions of miles — absolutely in unison. Now Lieserl saw how ’fighters should be handled, in contrast to Spinner’s earnest, clumsy work. The nightfighters were sculptures of space-time, with a sleek beauty that made her shiver: this was baryonic technology raised to perfection, to a supreme art, she thought.
She was struck by the contrast between this era and the age of devastation — of victory for the photino birds — to which the Northern had first brought them. Here, the Ring was complete and magnificent, and the Xeelee, in their pomp, filled space. Already, she knew, the final defeat was inevitable, and the Xeelee were, in truth, huddling inside their final redoubt. But still, her heart beat harder inside her as she looked out over this, the supremacy of baryonic life.