Schild’s Ladder

If the vacuum at the heart of the Quietener changed, her other self would wake, watch the whole event unfold in slow motion, bifurcate a million times, then vanish, before Cass had even noticed the good news. Neither the price nor the payoff were part of her own future, now.

Yet they would all be one person: awake, asleep. The dream she would not remember would be her own.

Here and now, though?

She would have to make do with whatever glimpses she could steal.

She turned to Yann. "Freeze me. One last time."

Chapter 3

Cass looked around the simulated chamber. The display on the wall was densely inscribed with new data, but nothing else appeared to have changed. The Mimosans were the usual icons drawn by her Mediator; she still had no hope of perceiving them as they perceived themselves. The structures in her mind where sensory data was represented hadn’t changed; they simply weren’t coupled to genuine sense organs anymore. It was only the touch of Rainzi’s nonexistent skin against her own — a translation interacting with a simulation — that proved she’d stepped from her world into his.

Or rather, they’d both stepped together into a new world, from which neither of them could hope to emerge.

Cass felt no anxiety, just a bittersweet sense of everything her newfound freedom did and didn’t mean. If she’d abandoned embodiment a year or two earlier, she might have had some prospect of going further: finding a path of gradual change that led to new abilities, such as the power to interpret the Mimosans' language firsthand. As it was, she didn’t even have time for the smallest act of self-indulgence: a simulated swim, a solid meal, a glass of cool water. After five years, all the pleasures she’d been pining for had become attainable at the very moment when they would be nothing but unwelcome distractions.

She slipped her hand free of Rainzi’s and turned to examine the display. A faint spray of particles was radiating out from the center of the Quietener, the sign of an unstable boundary between old vacuum and new.

The data had only been coming in for a few hundredths of a picosecond, so the statistics were still ambiguous. As she watched, rows of figures were updated, the sprinkling of points on half a dozen charts grew denser, curves shifted slightly. Cass knew where every number and every curve was heading; it was like watching the face of a long-awaited friend materialize out of the darkness, having pictured the reunion a thousand times. And if the face might yet turn out to be a stranger’s, that had nothing to do with the way she felt. There was pleasure enough in anticipation; she didn’t need to conjure up traces of doubt just to savor the added suspense.

"What we’re doing isn’t all that unusual," Darsono mused. "I think everyone lives in at least two time scales: one of them fast and immediate, and too detailed to retain in anything but outline; the other slow enough to be absorbed completely. We think our memory has no gaps, we think we carry our entire past inside us, because we’re accustomed to looking back and seeing only sketches and highlights. But we all experience more than we remember."

"That’s not true of everyone," Bakim countered. "There are people who record every thought they have."

"Yes, but unless every part of that record has the potential to be triggered automatically by subsequent thoughts and perceptions — which no one ever allows, because the barrage of associations would drive them mad — it’s not true memory. It’s just a list of all the things they’ve forgotten."

Bakim chortled. "True memory? And I suppose if I perceive something with so much spatial resolution that I can’t give immediate, conscious attention to every last detail simultaneously, it’s not a true perception — it’s just a cruel taunt to drive home all the things I’ve failed to perceive?"

Cass smiled, but stayed out of the argument. With certainty? Probably not. But it was pointless dwelling on every potential branching; if and when she experienced something unpleasant, firsthand, or did something foolish herself, she could regret it. Anything else was both futile and a kind of masochistic doublecounting. (And she would not start wondering if that resolution was universal — a constant across histories, an act of inevitable good sense — or just the luck of one branch.)

Livia said, "I don’t understand what’s happening with the energy spectrum." In the feigned weightlessness of the chamber, she appeared upside down, her face at the upper edge of Cass’s vision. "Does that make sense to anyone?"