Charles Stross - Singularity Sky

“You’re trying to be disruptive,” Ilya accused.

“Yes.” She nodded. “I make a career of it. I poke into corners and ask uncomfortable questions and stick my nose into other people’s business and find answers that nobody realized were there. So far, I’ve saved eight cities and seventy million lives. Would you like me to be less annoying?”

‘Tell me what you know. Then I’ll decide.“ He said the words carefully, as if making a great concession to her undisciplined refusal to stick to her place.

Rachel leaned back. “It’s a matter of deduction,” she said. “It helps to have a bit of context. For starters, this ship — this fleet — didn’t just accidentally embark on a spacelike trip four thousand years into the future. You are attempting a maneuver that nearly, but not quite, violates a number of treaties and a couple of laws of nature that are enforced by semidivine fiat. You’re not going to go into your own past light cone, but you’re going to come very close indeed — dive deep into the future to circumvent any watchers or eaters or mines the Festival might lay in your path, jump over to the target, then reel yourselves back into the past and accidentally come out not-quite-before the Festival arrives. You know what that suggests to me? It suggests extreme foolhardiness. Rule Three is there for a reason. You’re banging on the Eschaton’s door if you test it.”

“I had that much already,” Ilya acknowledged. “So?”

“Well, you should ask, what should we have expected to find here? We get here, and we’re looking for a buoy. A time capsule with detailed tactical notes from our own past light cone — an oracle, in effect, telling us a lot about the enemy that we can’t possibly know yet because our own time line hasn’t intersected with them. Yet more cheating. But we’re alive.”

“I don’t understand. Why wouldn’t we be?”

“Because—” She stared at him for a moment. “Do you know what happens to people who use causality violation as a weapon?” she asked. “You’re incredibly close to doing it, which is crazy enough. And you got away with it! Which simply isn’t in the script, unless the rules have changed.”

“Rules? What are you talking about?”

“Rules.” She rolled her eyes. “The rules of physics are, in some cases, suspiciously anthropic. Starting with the Heisenberg Principle, that the presence of an observer influences the subject of observation at a quantum level, and working from there, we can see a lot of startling correlations in the universe. Consider the ratio of the strong nuclear force to the electromagnetic force, for example. Twiddle it one way a little, and neutrons and protons wouldn’t react; fusion couldn’t take place. Twiddle it in a different direction, and the stellar fusion cycle would stop at helium — no heavier nuclei could ever be formed. There are so many correlations like this that cosmologists theorize we live in a universe that exists specifically to give rise to our kind of life, or something descended from it. Like the Eschaton.”

“So?”

“So you people are breaking some of the more arcane cosmological laws. The ones that state that any universe in which true causality violation — time travel — occurs is de facto unstable. But causality violation is only possible when there’s a causal agent — in this case an observer — and the descendants of that observer will seriously object to causality violation. Put it another way: it’s accepted as a law of cosmology because the Eschaton won’t put up with idiots who violate it. That’s why my organization tries to educate people out of doing it. I don’t know if anyone told your Admiralty what happened out in the back of beyond, in what is now the Crab Nebula: but there’s a pulsar there that isn’t natural, let’s put it that way, and an extinct species of would-be galactic conquerors. Someone tried to bend the rules — and the Eschaton nailed them.”

Ilya forced himself to uncurl his fingers from the arms of his chair. “You’re saying that the capsule we’re about to retrieve is a bomb? Surely the Eschaton would have tried to kill us by now, or at least capture us—”

She grinned, humorlessly. “If you don’t believe me, that’s your problem. We’ve seen half a dozen incidents like this before — the UN Defense Intelligence Causal Weapons Analysis Committee, I mean — incidents where one or another secret attempt to assemble a causality-violation device came to grief. Not usually anything as crude as your closed timelike flight path and oracle hack, by the way; these were real CVDs. History editors, minimax censors, grandfather bombs, and a really nasty toy called a spacelike ablator. There’s a whole ontology of causality-violation weapons out there, just like nukes—

atom bombs, fission-boosted fusion bombs, electroweak im-ploders, and so on.

“Each and every one of the sites where we saw CVDs deployed had been trashed, thoroughly and systematically, by unidentified agencies — but agencies attributable to the Eschaton. We’ve never actually seen one in the process of being destroyed, because the big E tends toward overkill in such cases — the smallest demolition tool tends to be something like a five-hundred-kilometer asteroid dropped on the regional capital at two hundred kilometers per second.

“So I guess the big surprise is that we’re still alive.” She glanced around at the vacant chairs, the powered-down workstation on the table. “Oh, and one other thing. The Eschaton always wipes out CVDs just before they go live. We figure it knows where to find them because it runs its own CVD. Sort of like preserving a regional nuclear hegemony by attacking anyone who builds a uranium enrichment plant or a nuclear reactor, yes? Anyway. You haven’t quite begun to break the law yet . The fleet is assembling, you’ve located the time capsule, but you haven’t actually closed the loop or made use of the oracle in a forbidden context. You might even get away with it if you hop backward but don’t try to go any earlier than your own departure point. But I’d be careful about opening that time capsule. At least, do it a sensible distance away from any of your ships. You never know what it might contain.” Ilya nodded reluctantly. “I think the Captain should be aware of this.”

“You could say that.” She looked at the console. “There’s another matter. I think you need all the advantages you can get your hands on right now, and one of them is spending most of his time sitting in his cabin twiddling his thumbs. You might want to have a word with Martin Springfield, the dockyard engineer. He’s an odd man, and you’ll need to make more allowances in his direction than you’d normally be inclined to, but I think he knows more than he’s letting on — much more, when it comes to propulsion systems. MiG wasn’t paying him two thousand crowns a week just because he has a pretty face. When MiG sold your Admiralty this bird, it was also betting on a fifty-year maintenance and upgrade contract — probably worth more revenue than the initial sale, in fact.”

“What are you trying to say?” Ilya looked irritated. “Engineering issues aren’t up to me, you should know that already. And I’ll thank you for not telling me my—”

“ Shut up .” She reached over and grabbed his arm — not hard, but firmly enough to shock him. “You really don’t understand how an arms cartel works, do you? Look. MiG sold your government a ship to perform to certain specifications. Specifications that could fulfill the requirements your Admiralty dreamed up. The specs they designed it to are a different matter — but they certainly intended to charge for upgrades throughout its life. And they’ve probably got more experience of real-world interstellar combat requirements than your Admiralty, which — unless I’m very much mistaken — has never before fought a real interstellar war as opposed to sending a few gunboats to intimidate stone-age savages. Be nice to Springfield, and he may surprise you. After all, his life depends on this ship doing its job successfully.” She let go.