Greg Egan
PERMUTATION CITY
STREET SCENE
There were cyclists and pedestrians on the street—all recorded. They were solid rather than ghostly, but it was an eerie kind of solidity; unstoppable, unswayable, they were like infinitely strong, infinitely disinterested robots.
When Paul reached the corner, the visual illusion of the city continued off into the distance; but when he tried to step forward, the concrete pavement under his feet started sliding backward, like a treadmill.
He was on the edge of his universe.
PROLOGUE
(Rip, tie, cut toy man)
JUNE 2045
Paul Durham opened his eyes, blinking at the room’s unexpected brightness, then lazily reached out to place one hand in a patch of sunlight at the edge of the bed. Dust motes drifted across the shaft of light which slanted down from a gap between the curtains, each speck appearing for all the world to be conjured into, and out of, existence—evoking a childhood memory of the last time he’d found this illusion so compelling, so hypnotic:
Paul felt utterly refreshed—and utterly disinclined to give up his present state of comfort. He couldn’t think why he’d slept so late, but he didn’t much care. He spread his fingers on the sun-warmed sheet, and thought about drifting back to sleep.
He closed his eyes and let his mind grow blank—and then caught himself, suddenly uneasy, without knowing why.
He leaped out of bed and crouched down on the carpet, fists to his eyes, face against his knees, lips moving soundlessly. The shock of realization was a palpable thing: a red lesion behind his eyes, pulsing with blood… like the aftermath of a hammer blow to the thumb—and tinged with the very same mixture of surprise, anger, humiliation and idiot bewilderment. Another childhood memory:
He rocked back and forth, on the verge of laughter, trying to keep his mind blank, waiting for the panic to subside. And eventually, it did—to be replaced by one simple, perfectly coherent thought:
What he’d done to himself was insane—and it had to be undone, as swiftly and painlessly as possible.
Then he began to remember the details of his preparations. He’d anticipated feeling this way. He’d planned for it. However bad he felt, it was all part of the expected progression of responses. Panic. Regret. Analysis. Acceptance.
Two out of four; so far, so good.
Paul uncovered his eyes, and looked around the room. Away from a few dazzling patches of direct sunshine, everything glowed softly in the diffuse light: the matte white brick walls, the imitation (imitation) mahogany furniture; even the posters—Bosch, Dali, Ernst, and Giger—looked harmless, domesticated. Wherever he turned his gaze (if nowhere else), the simulation was utterly convincing; the spotlight of his attention made it so. Hypothetical light rays were being traced backward from individual rod and cone cells on his simulated retinas, and projected out into the virtual environment to determine exactly what needed to be computed: a lot of detail near the center of his vision, much less toward the periphery. Objects out of sight didn’t ‘vanish’ entirely, if they influenced the ambient light, but Paul knew that the calculations would rarely be pursued beyond the crudest first-order approximations: Bosch’s
He had been aware of the technique for decades. It was something else to experience it. He resisted the urge to wheel around suddenly, in a futile attempt to catch the process out—but for a moment it was almost unbearable, just