Singularity Sky (26 page)

Time travel destabilises history.

History is a child of contingency; so many events depend on critical misunderstandings or transient encounters that even the apocryphal butterfly’s wing is apt to stir up a storm in short order. A single misunderstood telegram in June of 1917 permitted the Bolshevik revolution to become a possibility; a single spy in 1958 extended the Cold War by a decade. And without both such events, could a being like the Eschaton ever have come to exist?

Of course, in a universe which permits time travel, history itself becomes unstable—and the equilibrium can only be restored when the diabolical mechanism edits itself out of the picture. But that’s scant comfort for the trillions of entities who silently cease to exist in the wake of a full-blown time storm.

It’s hardly surprising that, whenever intelligent beings arise in such a universe, they will seek to use closed timelike curves to prevent their own extinction. Faster-than-light travel being possible, general relativity tells us that it is indistinguishable from time travel; and this similarity makes the technologies of total annihilation dreadfully accessible. In the small, stupid little organizations like the New Republic seek to gain advantage over their contemporaries and rivals. In the large, vast, cool intellects seek to stabilize their universe in the form most suitable to them. Their tampering may be as simple as preventing rivals from editing them out of the stable historical record—or it may be as sophisticated as meddling with the early epochs of the big bang, back before the Higgs field decayed into the separate fundamental forces that bind the universe together to ensure just the right ratio of physical constants to support life.

This is not the only universe; far from it. It isn’t even the only universe in which life exists. Like living organisms, universes exist balanced on the edge of chaos, little bubbles of twisted ur-space that pinch off and bloat outward, expanding and cooling, presently giving birth to further bubbles of condensed space-time; a hyperdimensional crystal garden full of strange trees bearing stranger fruit.

But the other universes are not much use to us. There are too many variables in the mix. As the initial burst of energy that signals the birth of a universe cools, the surging force field that drives its initial expansion becomes tenuous, then breaks down into a complex mess of other forces.

The constants that determine their relative strengths are set casually, randomly. There are universes with only two forces; others, with thousands.

(Ours has five.) There are universes where the electron is massive: nuclear fusion is so easy there that the era of star formation ends less than a million of our years after the big bang. Chemistry is difficult there, and long before life can evolve, such universes contain nothing but cooling pulsars and black holes, the debris of creation brought to a premature end.

There are universes where photons have mass—others where there is too little mass in the universe for it to achieve closure and collapse in a big crunch at the end of time. There are, in fact, an infinity of universes out there, and they are all uninhabitable. There is a smaller infinitude of possibly habitable ones, and in some of them, intelligent life evolves; but more than that we may never know. Travel between universes is nearly impossible; materials that exist in one may be unstable in another. So, trapped in our little fishbowl of space we drift through the crystal garden of universes—and our own neighborly intelligences, beings like the Eschaton, do their best to prevent the less-clever inmates from smashing the glass from within.

The man in gray had explained all this to Martin at length, eighteen years ago. “The Eschaton has a strong interest in maintaining the integrity of the world line,” he had said. “It’s in your interest, too. Once people begin meddling with the more obscure causal paradoxes, all sorts of lethal side-effects can happen. The Eschaton is as vulnerable to this as any other being in the universe—it didn’t create this place, you know, it just gets to live in it with the rest of us. It may be a massively superhuman intelligence or cluster of intelligences, it may have resources we can barely comprehend, but it could probably be snuffed out quite easily; just a few nuclear weapons in the right place before it bootstrapped into consciousness, out of the pre-Singularity networks of the twenty-first century. Without the Eschaton, the human species would probably be extinct by now.”

“Epistemology pays no bills,” Martin remarked drily. “If you’re expecting me to do something risky …”

“We appreciate that.” The gray man nodded. “We need errands run, and not all of them are entirely safe. Most of the time it will amount to little more than making note of certain things and telling us about them—but occasionally, if there is a serious threat, you may be asked to act. Usually in subtle, undetectable ways, but always at your peril. But there are compensations.”

“Describe them.” Martin put his unfinished drink down at that point.

“My sponsor is prepared to pay you very well indeed. And part of the pay—we can smooth the path if you apply for prolongation and continued residency.” Life-extension technology, allowing effectively unlimited life expectancy beyond 160 years, was eminently practical, and available on most developed worlds. It was also as tightly controlled as any medical procedure could be. The controls and licensing were a relic of the Overshoot, the brief period in the twenty-first century when Earth’s population blipped over the ten-billion mark (before the Singularity, when the Eschaton bootstrapped its way past merely human intelligence and promptly rewrote the rule book). The after-effects of overpopulation still scarred the planet, and the response was an ironclad rule—if you want to live beyond your natural span, you must either demonstrate some particular merit, some reason why you should be allowed to stay around, or you could take the treatment and emigrate. There were few rules that all of Earth’s fractured tribes and cultures and companies obeyed, but out of common interest, this was one of them. To be offered exemption by the covert intervention of the Eschaton—

“How long do I have to think about it?” asked Martin.

“Until tomorrow.” The gray man consulted his notepad. ‘Ten-thousand-a-year retainer. Ten thousand or more as a bonus if you are asked to do anything. And an essential status exemption from the population committee.

On top of which, you will be helping to protect humanity as a whole from the actions of some of its more intemperate—not to say stupid— members.

Would you care for another drink?“

“It’s alright,” said Martin. They’re willing to pay me? To do something I’d volunteer for? He stood up. “I don’t need another day to think about it.

Count me in.”

The gray man smiled humorlessly. “I was told you’d say that.”

The gold team was on full alert. Not a head moved when the door opened, and Captain Mirsky walked in, followed by Commodore Bauer and his staff.

“Commander Murametz, please report.”

“Yes, sir. Time to jump transition, three-zero-zero seconds. Location plot confirmed, signals operational. All systems running at an acceptable level of readiness for engagement plan C. We’re ready to go to battle stations whenever you say, sir.”

Mirsky nodded. “Gentlemen, carry on as ordered.” The Commodore nodded and quietly instructed his adjutant to take notes. Elsewhere on the ship, sirens blatted: the clatter of spacers running to their stations didn’t penetrate the bulkheads, but the atmosphere nevertheless felt tense. Low-key conversations started at the various workstations around the room as officers talked over the tactical circuits.

“Ready for jump in two-zero-zero seconds,” called Relativistics.

Rachel Mansour—wearing her disarmament inspector’s uniform—sat uncomfortably close to one of the walls, studying a packed instrument console over the shoulder of a petty officer. Brass handles and baroque red LEDs glowed at her; a pewter dog’s head barked silently from an isolation switch. Someone had spent half a lifetime polishing the engravings until they gleamed as softly as butter. It seemed a bitter irony, to observe such art in a place of war; the situation was, she thought, more than somewhat repulsive, and finding anything even remotely beautiful in it only made things worse.

The Festival: of all the stupid things the New Republic might attack, the Festival was about the worst. She’d spoken to Martin about it, piecing together his information with her own. Together they’d pieced together a terrifying hypothesis. “Herman was unusually vague about it,” Martin admitted. “Normally he has a lot of background detail. Every word means something. But it’s as if he doesn’t want to say too much about the Festival.

They’re—he called them, uh, glider-gun factories. I don’t know if you know about Life—”

“Cellular automata, the game?”

“That’s the one. Glider guns are mobile cellular automata. There are some complex life structures that replicate themselves, or simpler cellular structures; a glider-gun factory is a weird one. It periodically packs itself into a very dense mobile system that migrates across the grid for a couple of hundred squares, then it unpacks itself into two copies that then pack down and fly off in opposite directions. Herman said that they’re a realspace analogue: he called them a Boyce-Tipler robot. Self-replicating, slower-than-light interstellar probes that are sent out to gather information about the universe and feed it back to a center. Only the Festival isn’t just a dumb robot fleet. It carries upload processors, thousands of uploaded minds running faster than real time when there are resources to support them, downloaded into long-term storage during the long trips.”

Rachel had shuddered slightly at that, and he hugged her, misapprehending the cause of her distress. She let him, not wanting him to realize he had upset her. She’d dealt with uploads before. The first-generation ones, fresh from the meat puppet universe, weren’t a problem: it was the kids that got her. Born—if you could call it that—in a virtual environment, they rapidly diverged from any norm of humanity that she could see. More seriously, their grasp of the real world was poor. Which was fine as long as they didn’t have to deal with it, but when they did, they used advanced nanosystems for limbs and they sometimes accidentally broke things—planets, for instance.

It wasn’t intentional malice; they’d simply matured in an environment where information didn’t go away unless someone wanted it to, where death and destruction were reversible, where magic wands worked and hallucinations were dangerous. The real universe played by different rules, rules that their horrified ancestors had fled as soon as the process of migrating minds into distributed computing networks had been developed.

The Festival sounded like a real headache. On the one hand, an upload civilization, used to omnipotence within its own pocket universe, had decided for no obvious reason to go forth and play the galactic tourist. On the other hand, physical machinery of vast subtlety and power was bound to do their bidding at each port of call. Bush robots, for example: take a branching tree of fronds. Each bough split into two half-scale branches at either end, with flexible joints connecting them. Repeated down to the molecular level, each terminal branch was closed off with a nanomanipulator. The result was a silvery haze with a dumbbell-shaped core, glittering with coherent light, able to change shape, dismantle and reassemble physical objects at will—able to rebuild just about anything into any desired physical form, from the atomic scale up. Bush robots made the ultimate infantry; shoot at them, and they’d eat the bullets, splice them into more branches, and thank you for the gift of metals.

“I’m worried about what will happen when we arrive,” Martin admitted. He’d wrung his hands while he spoke, unconsciously emphasizing his points. “I don’t think the New Republicans can actually comprehend what’s going on.

They see an attack, and I can understand why—the Festival has destroyed the political and social economy on one of their colonies as thoroughly as if it had nuked the place from orbit—but what I can’t see is any possible avenue to a settlement. There’s not going to be any common ground there.

What does the Festival want? What could make them go away and leave the Republic alone?”

“I thought you didn’t like the New Republic,” Rachel challenged.

He grimaced. “And I suppose you do? I don’t like their system, and they know it. That’s why I’m sitting in this cell instead of in my cabin, or on the engineering deck. But—” He shrugged. “Their social system is one thing, but people are people everywhere you go, just trying to get along in this crazy universe. I don’t like them as individuals, but that’s not the same as wanting them dead. They’re not monsters, and they don’t deserve what’s coming to them, and life isn’t fair, is it?”

“You did your bit to make it that way.”

“Yes.” He dropped his gaze to the floor, focusing intently on something invisible to her. “I wish there was an alternative. But Herman can’t just let them get away with it. Either causality is a solid law, or—things break. Far better for their maneuver simply to fail, so the whole voyage looks like a cack-handed mess, than for it to succeed, and encourage future adventurers to try for a timelike approach on their enemies.”

“And if you’re lashed to the mast as the ship heads for the maelstrom?”

“I never said I was omniscient. Herman said he’d try to get me out of here if I succeeded; I wish I knew what he had in mind. What are your options like?”

Her lips quirked. “Maybe he nobbled my boss—he taught me never to travel at sea without a lifeboat.”

Martin snorted, obviously misunderstanding: “Well, they say a captain always goes down with his ship—shame they never mention the black gang drowning in the engine room!”

An announcement from the helm brought Rachel back to the present:

“Jump in one-zero-zero seconds.”

“Status, please,” said Commander Murametz. Each post called out in order; everything was running smoothly. ‘Time to transition?“

“Four-zero seconds. Kernel spin-down in progress; negative mass dump proceeding.” Far beneath their feet, the massive singularity at the core of the drive system was spooling down, releasing angular momentum into the energetic vacuum underlying space-time. There was no vibration, no sense of motion: nor could there be. Spin, in the context of a space drive, was a property of warped patches of space, nothing to do with matter as most people understood it.