Stephen Baxter - Coalescent

“A what?”

He hesitated. “Supercold matter. All the atoms line up, quantum-mechanically … It doesn’t matter. The point is, light can be slowed to below walking pace . I saw the trials in that lab in San Jose. It’s really quite remarkable.”

“And then you can make your black hole.”

“You can blow your slow-moving light around — even make it move backward. Photons, thrown around like paper planes in a Texas twister. To make a black hole you set up a vortex in your medium — a whirlpool. You just pull out the plug. And if the vortex walls are moving faster than your light stream, the light gets sucked into the center and can’t escape, and you have your black hole.”

“That’s what these Californians were doing?”

“They were getting there,” Peter said. “They hit practical problems. The condensate is a quantum structure, and it doesn’t respond well to being spun around … But all this was fixable, in principle.”

“Why would anybody want to do this?”

“That’s obvious. Quantum gravity,” he said.

“Of course,” I said. I actually had to keep from laughing. I was talking to a crack in the wall, watched by ten differently evolved hive-mind drones and my own long-lost sister. “You know, on any other day this conversation would seem bizarre.”

“Pay attention, double-oh seven,” he said wearily.

Quantum gravity, it seems, is the Next Big Thing in physics. The two great theories of twentieth-century physics were quantum mechanics, which describes the very small, like atomic structures, and general relativity, which describes the very large, like the universe itself. They are both successful, but they don’t fit together.

“The universe today is kind of separated out,” said Peter. “Large and small don’t interact too much — which is why quantum mechanics and relativity work so well. You don’t find many places in nature where they overlap, where you can study quantum gravity effects, the predictions of a unified theory. But the Black Hole Kit would be a tabletop gravity field. The San Jose people hoped, for instance, to explore whether space-time itself is quantized, broken into little packets, as light is, as matter is.”

I said heavily, “What I don’t understand is why all this should cost anybody her life. How do you justify it, Peter? Omelettes and eggs?”

“You know I don’t think like that, George.”

“Then tell me why that lab was destroyed.”

“You already know.”

“Tell me anyhow.”

“Because of the future. Humankind’s future. And because of the war in Heaven.”

All this was so like our bullshit sessions in the park by the Forum. I could imagine his earnest face as he spoke, that big jaw, the small mouth, the beads of sweat on his brow, the half-closed eyes. But Rosa was watching me, skeptical, drawing her own conclusions, no doubt, about Peter’s sanity. She twirled her finger. Hurry it up.

He reminded me of what he had told me, of SETI, the search for extraterrestrial life, and attempts to signal to it.

“Most of it was absurd,” he whispered. “Quixotic. Like the plaques stuck on the side of Pioneer space probes. They will fail through sheer statistics, because the chance of any sentient being picking up such objects is minuscule. We are surrounded by that tremendous unintentional ripple of radio noise, spreading out everywhere at lightspeed — nothing we can do about that now … But then, most perniciously, some signaling has been intentional, and designed to succeed. Such as using the big antenna at Arecibo to throw digital signals at the nearest stars …”

“Pernicious?”

“George, where was the debate? Were you consulted? Did you vote to have your whereabouts blasted to the universe? What right had these people to act on your behalf?”

“I can’t say it keeps me awake at night.”

“It does me,” he said hoarsely. “We know there is something out there waiting for us. The Kuiper Anomaly — long faded from the news — is still out there, orbiting silently. My seismic signals, the dark matter craft that decelerated and veered inside the Earth: more evidence. Signaling is dangerous. It must be. That is why the sky is so quiet. Whoever is out there has learned to keep quiet — or has been forced to be.”

“Peter, I don’t see what this has to do with the destruction of the black hole lab.”

He sighed again. “George, there are some SETI proponents who say that our feeble attempts to signal so far are futile. Plaques on clunky spacecraft, radio signals — all of this is laughably primitive technology. Jungle drums. It won’t attract the attention of anybody advanced enough to matter.”

“Right. And the kind of technology they will use—”

“Well, we don’t know, but we can speculate. For instance, about technologies based on quantum gravity. Or even the manipulation of space-time itself. If you could do that there is no limit to what you could achieve. Warp drive — faster than light. Antigravity. The control of inertia—”

I began to see where this was going. “The San Jose Black Hole Kit would be a manipulation of space- time.”

“That toy black hole would have stood out like a single campfire shining in the middle of a darkened landscape.”

“You think the San Jose people were trying to signal to aliens?”

“Oh, they didn’t mean to. All they were doing was trying to build a test bed for quantum gravity, just as advertised. I’m sure of that. But they wouldn’t listen to our warnings — the Slan(t)ers. They would have gone on, and on, until they lit that damn campfire …”

And then I understood what had been done. I rubbed my eyes. “What did you use, Peter?”

“Semtex-H,” he whispered. “Not difficult to get hold of if you know how. Before the fall of communism the Czechs shipped out a thousand tons of the stuff, mostly through Libya. My police background …”

He hadn’t set the thing off, he said, but he had designed the system. It turned out to be simple. He had used electronics parts he bought from RadioShack to build a simple radar-activated sensor. It was based on dashboard detectors supposed to warn drivers of the presence of a police radar gun. If attached to a detonator, such a sensor could be used to set off a bomb, in response to a signal from a radar gun — or even from something smaller, lighter. He had learned these techniques in Northern Ireland.

“You know, Semtex is remarkable. It’s brown, like putty. You can mold it to any shape. And it’s safe to handle. You can hold it over a naked flame and it won’t explode, not without a detonator. So easy.”

I held my breath.

“You see, it’s all about the future,” he said softly. “That’s what I’ve come to understand. We humans find ourselves on a curve of exponential growth, doubling in numbers and capability, and doubling again. We are wolflings now, but we are growing. We will become adults, we will become strong. Billions will flow from each of us, a torrent of minds, a great host of the future. This is our predestination. The future is ours. And that is what they perceive, I think.”

“Who?”

“Those beyond the Earth. They see our potential. Our threat. They would want to stop it now, while we are still weak, cut down the great tree while it is still a sapling.”

I tried to hold this extraordinary chain of logic in my head. “All right. I can see why you thought the San Jose lab should be stopped. But what are you doing here?”

“The hive is just as much of a threat to the future. Don’t you see that yet? It is an end point to our destiny. And we have to avoid it.”

I could see a glimmer of light in the rock cleft. He was holding something; it looked like a TV remote. “Peter, what’s that?”