Schild’s Ladder

light-years wide. If there were preexisting laws behind the border, we might hope to discover them that way, but that’s not what we’re dealing with. On our side of the border, there’s a tight correlation stretching across all of space-time: the dynamics being followed at different times and places has become a tangle of mutual interdependence. What lies behind the border isn’t correlated from place to place, or from moment to moment. What we’re sampling with our probe graphs might as well be random noise at every level.”

Rasmah stood, just ahead of a dozen other people. The others resumed their seats, and Tarek begrudgingly followed.

She said, “This is wonderful speculation, Sophus, but how do you plan to test it? Do you have any solid predictions?”

Sophus gestured at the space behind him, and a set of graphs appeared.

“As you see, I can match the borderlight spectrum. That’s not claiming much. I can match the half-c velocity of the border, which is slightly harder. And I can match the pooled results of all the experiments performed here so far: namely, their complete failure to identify anything resembling a dynamic law.

“So much for retrodiction. I’m making the following prediction: when we repeat the old experiments, re- scribe the old probe graphs, and monitor the results with your new spectrometer…we’ll find exactly the same thing, all over again. No patterns will emerge, no symmetries, no invariants, no laws.

“We’ve already discovered that there’s nothing to be discovered. All I can predict is that however hard we look, that absence will be confirmed.”

Chapter 8

Yann rolled off the bed and landed on the floor, laughing.

Tchicaya peered over the edge. “Are you all right?”

Yann nodded, covering his mouth with a hand but unable to silence himself.

Tchicaya didn’t know whether to be annoyed or concerned. Acorporeals taking on bodies often mapped them in unusual ways. Perhaps laughter was Yann’s only available response to some terrible psychic affront that Tchicaya had unwittingly inflicted.

“You’re sure I haven’t hurt you?”

Yann shook his head, still laughing helplessly.

Tchicaya sat on the edge of the bed, struggling to regain his own sense of humor. “This is not a reaction I’m accustomed to. Rejection and hilarity are perfectly acceptable responses, but they’re supposed to occur much earlier in proceedings.”

Yann managed to regain some composure. “I’m sorry. I didn’t mean to offend you.”

“I take it you’re not interested in finishing what you started?”

“Umm.” Yann grimaced. “I could try, if it’s important to you. But I think it would be very difficult to take seriously.”

Tchicaya planted a foot on his chest. “Next time you want an authentic embodied experience…just simulate it.” He still felt a pang of lust at the touch of skin on skin, but it was fading into a kind of exasperated affection.

He crouched down and kissed Yann on the mouth, meaning it as a gesture of finality. Yann smiled, puzzled. “That was nice.”

“Forget it.” Tchicaya stood and started dressing.

Yann lay on the floor, watching him. “I think I’m getting all the signals you talked about,” he mused. “But they’re so crude, even now. And before, it was just a single message, repeating itself endlessly: Be happy, be happy, be happy! Do you think there’s something wrong with this body?”

“I doubt it.” Tchicaya sat cross-legged on the floor beside him.

“You expected more?”

“I was already happy, so it was a bit redundant.”

“How happy?”

“As happy as it’s possible to be, for no particular reason.”

“I have no idea how to interpret that. What gets to count as a particular reason?”

Yann shrugged. “Something more than being told by my body: Be happy. Be happy…why?”

“Because you’re with someone you like. And you’re making them happy, too.”

“Yes, but only if they accept the same reasoning. That’s circular.”

Tchicaya groaned. “Now you’re being disingenuous. It’s a tradition, passed down from reproductive biology. Every tradition’s arbitrary. That doesn’t mean it’s empty.”

“I know. But I still expected something more subtle.”

“That takes time.”

“What, hours?”

“Centuries.”

Yann narrowed his eyes with suspicion.

Tchicaya laughed, but made a face protesting his honesty. “On Turaev, it takes six months of attraction before anything’s physically possible.” Like most generic bodies, the Rindler's were promiscuous: any two of them could develop compatible sexual organs, more or less at will. You could wire in your own chosen restraints while you inhabited them, but since leaving home, Tchicaya had never felt the need to delegate the task. “The waiting was nice, in its own way,” he admitted. “You might think it was risking an awful anticlimax, but I think the buildup improved the sex itself almost as much as it raised expectations. Acting on the spur of the moment is more likely to be disappointing.”

Yann protested, “I’ve been contemplating this for almost six months.”

“Since I arrived? I’m flattered. But then, who else would you dare to ask?”

Yann smiled abashedly. “How could I not be curious? It’s what flesh is famous for. However undeservedly.” He watched Tchicaya carefully, serious for a moment. “Have I hurt you?”

Tchicaya shook his head. “That usually takes longer, too.” He hesitated. “So what do acorporeals do, instead? When I was a child, I used to imagine that you’d all have simulated bodies. Sex would be just like embodied sex, but there’d be lots of colored lights, and cosmic bliss.”

Yann guffawed. “Maybe twenty thousand years ago there were people that vacuous, but they must have all decayed into thermal noise before I was born.” He added hastily, “I’m not saying you’re wrong to continue the tradition. You’ve mapped some stable mammalian neurobiology, and it’s not too pathological in its original form. I suppose it still serves some useful social functions, as well as being a mild existential placebo. But when you have a malleable mental structure, intensifying pleasure for its own sake is a very uninteresting cul-de- sac. We worked that out a long time ago.”

“Fair enough. But what do you do instead?”

Yann sat up and leaned against the side of the bed. “All the other things the embodied do. Give gifts. Show affection. Be attentive. Sometimes we raise children together.”

“What kind of gifts?”

“Art. Music. Theorems.”

“Original theorems?”

“If you’re serious.”

Tchicaya was impressed. Mathematics was a vast territory, far more challenging and intricate than physical space. Reaching a theorem no one had proved before was a remarkable feat. “That’s positively…chivalric,” he said. “Like a knight riding off to the edge of the world, to bring back a dragon’s egg. And you’ve done that, yourself?”

“Yes.”

“How often?”

“Nine times.” Yann laughed at Tchicaya’s expression of astonishment, and added, “It’s not always that serious. If it was, it really would be as daunting as winning the hand of medieval royalty, and no one would