Accelerando

technology has given rise to a whole new family of species – fast-moving

corporate carnivores in the Net. The planet Mercury has been broken up

by a consortium of energy brokers, and Venus is an expanding debris

cloud, energized to a violent glare by the trapped and channeled solar

output. A million billion fist-sized computing caltrops, backsides glowing

dull red with the efflux from their thinking, orbit the sun at various

inclinations no farther out than Mercury used to be.

Billions of fleshbody humans refuse to have anything to do with the

blasphemous new realities. Many of their leaders denounce the uploads

and AIs as soulless machines. Many more are timid, harboring self-

preservation memes that amplify a previously healthy aversion to having

one's brain peeled like an onion by mind-mapping robots into an all-

pervading neurosis. Sales of electrified tinfoil-lined hats are at an all-time

high. Still, hundreds of millions have already traded their meat puppets for

mind machines, and they breed fast. In another few years, the fleshbody

populace will be an absolute minority of the posthuman clade. Sometime

later, there will probably be a war. The dwellers in the thoughtcloud are

hungry for dumb matter to convert, and the fleshbodies make notoriously

poor use of the collection of silicon and rare elements that pool at the

bottom of the gravity well that is Earth.

Energy and thought are driving a phase-change in the condensed matter

substance of the solar system. The MIPS per kilogram metric is on the

steep upward leg of a sigmoid curve – dumb matter is coming to life as

the mind children restructure everything with voracious nanomechanical

servants. The thoughtcloud forming in orbit around the sun will ultimately

be the graveyard of a biological ecology, another marker in space visible

to the telescopes of any new iron-age species with the insight to

understand what they're seeing: the death throes of dumb matter, the

birth of a habitable reality vaster than a galaxy and far speedier. Death

throes that, within a few centuries, will mean the extinction of biological

life within a light-year or so of that star – for the majestic Matrioshka

brains, though they are the pinnacles of sentient civilization, are

intrinsically hostile environments for fleshy life.

* * *

Pierre, Donna-the-all-seeing-eye, and Su Ang fill Amber in on what they've discovered about the bazaar -

as they call the space the ghost referred to as the demilitarized zone – over ice-cold margaritas and a very good simulation of a sociable joint. Some of them have been on the loose in here for subjective years. There's a lot of information to absorb.

'The physical layer is half a light-hour in diameter, four hundred times as massive as Earth,' Pierre explains.

'Not solid, of course – the largest component is about the size my fist used to be.' Amber squints, trying to remember how big that was – scale factors are hard to remember accurately. 'I met this old chatbot that said it's outlived its original star, but I'm not sure it's running with a full deck. Anyway, if it's telling the truth, we're a third of a light year out from a closely coupled binary system – they use orbital lasers the size of Jupiter to power it without getting too close to all those icky gravity wells.'

Amber is intimidated, despite her better judgment, because this bizarre bazaar is several hundred billion times as big as the totality of human presingularity civilization. She tries not to show it in front of the others, but she's worried that getting home may be impossible – requiring enterprise beyond the economic event horizon, as realistic a proposition as a dime debuting as a dollar bill. Still, she's got to at least try. Just knowing about the existence of the bazaar will change so many things…

'How much money can we lay our hands on?' She asks. 'What is money hereabouts, anyway? Assuming they've got a scarcity-mediated economy. Bandwidth, maybe?'

'Ah, well.' Pierre looks at her oddly. 'That's the problem. Didn't the ghost tell you?'

'Tell me?' Amber raises an eyebrow. 'Yeah, but it hasn't exactly proven to be a reliable guide to anything, has it?'

'Tell her,' Su Ang says quietly. She looks away, embarrassed by something.

'They've got a scarcity economy all right,' says Pierre. 'Bandwidth is the limited resource, that and matter.

This whole civilization is tied together locally because if you move too far away, well, it takes ages to catch up on the gossip. Matrioshka brain intelligences are much more likely to stay at home than anybody realized, even though they chat on the phone a lot. And they use things that come from other cognitive universes as, well, currency. We came in through the coin slot, is it any wonder we ended up in the bank?'

'That's so deeply wrong that I don't know where to begin,' Amber grumbles. 'How did they get into this mess?'

'Don't ask me.' Pierre shrugs. 'I have the distinct feeling that anyone or anything we meet in this place won't have any more of a clue than we do – whoever or whatever built this brain, there ain't nobody home anymore except the self-propelled corporations and hitchhikers like the Wunch. We're in the dark, just like they were.'

'Huh. You mean they built something like this, then they went extinct? That sounds so dumb…'

Su Ang sighs. 'They got too big and complex to go traveling once they built themselves a bigger house to live in. Extinction tends to be what happens to overspecialized organisms that are stuck in one environmental niche for too long. If you posit a singularity, then maximization of local computing resources – like this – as the usual end state for tool users, is it any wonder none of them ever came calling on us?'

Amber focuses on the table in front of her, rests the heel of her palm on the cool metal, and tries to remember how to fork a second copy of her state vector. A moment later, her ghost obligingly fucks with the physics model of the table. Iron gives way like rubber beneath her fingertips, a pleasant elasticity. 'Okay, we have some control over the universe, at least that's something to work with. Have any of you tried any self- modification?'

'That's dangerous,' Pierre says emphatically. 'The more of us the better before we start doing that stuff.

And we need some firewalling of our own.'

'How deep does reality go, here?' asks Sadeq. It's almost the first question he's asked of his own volition, and Amber takes it as a positive sign that he's finally coming out of his shell.

'Oh, the Planck length is about a hundredth of a millimeter in this world. Too small to see, comfortably large for the simulation engines to handle. Not like real space-time.'

'Well, then.' Sadeq pauses. 'They can zoom their reality if they need to?'

'Yeah, fractals work in here.' Pierre nods. 'I didn't -'

'This place is a trap,' Su Ang says emphatically.

'No it isn't,' Pierre replies, nettled.

'What do you mean, a trap?' asks Amber.

'We've been here a while,' says Ang. She glances at Aineko, who sprawls on the flagstones, snoozing or whatever it is that weakly superhuman AIs do when they're emulating a sleeping cat. 'After your cat broke us out of bondage, we had a look around. There are things out there that -' She shivers. 'Humans can't survive in most of the simulation spaces here. Universes with physics models that don't support our kind of neural computing. You could migrate there, but you'd need to be ported to a whole new type of logic – by the time you did that, would you still be you? Still, there are enough entities roughly as complex as we are to prove that the builders aren't here anymore. Just lesser sapients, rooting through the wreckage. Worms and parasites squirming through the body