Schild’s Ladder

Sophus laughed. "I wish all Yielders were so easily discouraged."

Tchicaya caught the change in Mariama’s demeanor as he was finally labeled for her. She did not appear surprised, or cooler toward him, but a look of resignation crossed her face, as if she was letting other possibilities slip away.

He replied, "I didn’t say I believed you. Now I know you’re just spreading misinformation."

Sophus said, "The data’s all public; you should judge for yourself. But I’m giving a presentation later today that might interest you."

"On why we should all give up and go home? Yielders first, of course."

"No. On why we shouldn’t, even if I’m right."

Tchicaya was intrigued. "Dishing out despair with one hand, taking it away with the other. You’re never going to drive us away like that."

"I’m really not interested in driving anyone away," Sophus protested. "The more people there are working on this, the sooner we’ll understand it. I’m happy to share my ideas with everyone — and if some Yielder beats me to the punch line because of it, and fails to show reciprocal generosity, what have I lost?"

"You’re not afraid we’ll get through the border first? And shore up what you hope to annihilate?"

Sophus smiled amiably. "There might come a point when that’s a real threat. If I’m ever convinced that we’ve reached it, I suppose I might change my strategy. For now, though, it’s like a game of Quantum Pass-the-Parcel: all the players work simultaneously to tear off the wrapping, and all the players share the benefits. Why convert to the classical version? This is faster, and much more enjoyable."

Tchicaya let the argument rest. It would have been impolite to state the obvious: when Sophus finally decided that sharing his insights had become too risky, it would not be to his advantage to announce the fact. At that point, the most logical strategy would be to continue displaying the same generosity as he’d shown in the past, but to replace the genuine, hard-won conjectures he’d revealed to his opponents in the past with equally well-crafted red herrings.

When they reached Mariama’s cabin, Sophus left them. Tchicaya hung back in the corridor, unsure whether she wanted him to stay or go.

She said, "Would you come in, if you’re coming in?"

He sat cross-legged on the bed while she moved around the cabin. She’d included some physical ornaments in her transmission — a handful of carved rocks and blown-glass objects that the Rindler's reception unit had obligingly re-created for her from spare materials — and now she couldn’t decide where to put them.

"I traveled light, myself," Tchicaya said teasingly. "It didn’t seem fair to ask them to cannibalize the ship to provide me with knickknacks."

Mariama narrowed her eyes. "Aren’t you the puritan? Not to the point of amnesia, I hope."

He laughed. "Not these days." In the past, he’d left some rarely used memories behind in the Qusps of his body trail. With fullsensory recall, the amount of data mounted up rapidly, and there’d come a point when knowing precisely what it had been like to shake water out of his ears in a river on Gupta or roll over and fart while camping in a desert on Peldan didn’t really strike him as a crucial part of his identity.

Yet he’d gathered up all the trivia again, before any of the Qusps were erased. And now that there was nowhere he could store his memories in the expectation that they’d remain secure — even if he archived them with a fleeing acorporeal community, their safety would come at the price of accessibility — they all seemed worth dragging around with him indefinitely.

Mariama finally settled on the shelf by the bed as the place for an elaborately braided variant of Klein’s bottle. "Holding on to your memories is one thing," she said. "It doesn’t stop you going over the horizon."

Tchicaya snorted. "Over the horizon? I’m four thousand and nine years old! Take out Slowdowns and travel insentience, and I’ve barely experienced half of that." Information theory put bounds on the kind of correlations anyone could sustain between their mental states at different times; the details depended on the structure of your mind, the nature of its hardware, and, ultimately, on the recently rather plasticized laws of physics. If there were unavoidable limits, though, they were eons away. "I think I can still lay claim to doing a far better job of resembling myself — at any prior age — than a randomly chosen stranger."

Mariama folded her arms, smiling slightly. "In the strict sense, obviously. But don’t you think people can cross another kind of horizon? The strict definition counts everything: every aspect of temperament, every minor taste, every trivial opinion. There are so many markers, it’s no wonder it takes an eternity for all of them to drift far enough to change someone beyond recognition. But they’re not the things that define us. They’re not the things that would make our younger selves accept us as their rightful successors, or recoil in horror."