“That must be how you got the perceptron to Earth,” Hunt said.
“Almost to Earth,” Eesyan told him. “A black hole large enough to take a sizable object creates a significant gravitational disturbance over a large distance. Therefore we don’t project things like that into the middle of planetary systems; it would disrupt clocks and calendars and so on. We exited the perceptron outside the solar system, and it had to make the last lap in a more conventional way.”
“So a round trip needs four conventional stages,” Lyn commented. “Two one way, and two the other.”
“Correct.”
“Which explains why it took something like a day to make it from Thurien to Earth,” Hunt said.
“Yes. Instant planet-to-planet hopping is out. But communications is another matter entirely. We can send messages by beaming a gamma frequency microlaser into a microscopic black-hole toroid that can be generated in equipment capable of operating on planetary surfaces without undesirable side effects. So instant planet-to-planet data-links are practicable. What’s more, generating the microscopic black holes needed for them doesn’t require the enormous amount of energy that holes big enough to send ships through do. So we don’t do a lot of instantaneous people-moving unless we have to; we prefer moving information instead.”
It fitted in with what Hunt already knew: he and Lyn were really at McClusky, and all the information they were perceiving was being transmitted there through vJsA.1~. “That explains how
the information gets sent,” he said. “But what’s the input to the system? How is it originated in the first place?”
“Thurien is a fully ‘wired’ planet,” Eesyan explained. “So are most of the other planets in the portions of the Galaxy where we have spread. VISAR exists all over those worlds, and in other places between, as a dense network of sensors located inside the structures of buildings and cities, distributed invisibly across mountains, forests, and plains, and in orbit above planetary surfaces. By combining and interpolating between its data inputs, it is able to compute and synthesize the complete sensory input that would be experienced by a person located at any particular place.
“vIsAR bypasses the normal input channels to the brain and stimulates symbolic neural patterns directly with focused arrays of high-resolution spatial stress-waves. Thus it can inject straight into the mind all the information that would be received by somebody physically present at whatever place is specified. Also it monitors the neural activity of the voluntary motor system and reproduces faithfully all the feedback sensations that would accompany muscular movements and so forth. The net result is to create an fflusion of actually being at a remote location which is indistinguishable from the real thing. Physically transporting the body would add nothing.”
“Star travel the easy way,” Lyn murmured. She gazed around as they came to the end of the arcade and turned off to begin walking across a curved, sweeping surface that had looked like a wall a minute ago, but now seemed to be pivoting slowly as they moved onto it and lifting the whole of the arcade and the structures connected to it up at an increasing angle behind them. “This is all real and twenty light-years away?” she said, still sounding disbelieving. “I really haven’t come here?”
“Can you tell the difference?” Eesyan asked her.
“How about you, Porthik?” Hunt asked as a new thought struck him. “Are you actually here. . . there. . . whatever, in Vranix, or what?”
“I’m on an artificial world twenty mifflon miles from Thurien,” Eesyan replied. “Calazar is on Thurien, but six thousand miles from Vranix at a place called Thurios-the principal city of Thurien. Vranix is an old city that we keep preserved for sentimental and traditional reasons. Frenua Showm, whom you were also expecting to meet and will very shortly, is on a planet called
Crayses, which is in a star system about nine light-years from Gistar.”
Lyn was looking puzzled. “I’m not quite sure I get this,” she said. “How do we all manage to get consistent impressions when we’re in different places? How do I see you there, Vic next to you, and all this around us when it’s scattered all over the Galaxy?” Hunt was still too boggled by what Eesyan had said a moment earlier to be able to ask anything.