Foundation and Earth - Isaac Asimov [68]
His hands flickered over the softly glowing keys of the computer, feeding it the necessary information. He then placed his hands on the handmarks on the desk. He waited while the computer worked out the conventions of the known co-ordinates, paused a moment, then interpreted the co-ordinates of the nearest Forbidden World by the same conventions, and finally located those co-ordinates on the Galactic map in its memory.
A starfield appeared on the screen and moved rapidly as it adjusted itself. When it reached stasis, it expanded with stars bleeding off the edges in all directions until they were almost all gone. At no point could the eye follow the rapid change; it was all a speckled blur. Until finally, a space one tenth of a parsec on each side (according to the index figures below the screen) was all that remained. There was no further change, and only half a dozen dim sparks relieved the darkness of the screen.
“Which one is the Forbidden World?” asked Pelorat softly.
“None of them,” said Trevize. “Four of them are red dwarfs, one a near-red dwarf, and the last a white dwarf. None of them can possibly have a habitable world in orbit about them.”
“How do you know they’re red dwarfs just by looking at them?”
Trevize said, “We’re not looking at real stars; we’re looking at a section of the Galactic map stored in the computer’s memory. Each one is labeled. You can’t see it and ordinarily I couldn’t see it either, but as long as my hands are making contact, as they are, I am aware of a considerable amount of data on any star on which my eyes concentrate.”
Pelorat said in a woebegone tone, “Then the co-ordinates are useless.”
Trevize looked up at him, “No, Janov. I’m not finished. There’s still the matter of time. The co-ordinates for the Forbidden World are those of twenty thousand years ago. In that time, both it and Comporellon have been revolving about the Galactic Center, and they may well be revolving at different speeds and in orbits of different inclinations and eccentricities. With time, therefore, the two worlds may be drifting closer together or farther apart and, in twenty thousand years, the Forbidden World may have drifted anywhere from one-half to five parsecs off the mark. It certainly wouldn’t be included in that tenth-parsec square.”
“What do we do, then?”
“We have the computer move the Galaxy twenty thousand years back in time relative to Comporellon.”
“Can it do that?” asked Bliss, sounding rather awe-struck.
“Well, it can’t move the Galaxy itself back in time, but it can move the map in its memory banks back in time.”
Bliss said, “Will we see anything happen?”
“Watch,” said Trevize.
Very slowly, the half-dozen stars crawled over the face of the screen. A new star, not hitherto on the screen, drifted in from the left hand edge, and Pelorat pointed in excitement. “There! There!”
Trevize said, “Sorry. Another red dwarf. They’re very common. At least three fourths of all the stars in the Galaxy are red dwarfs.”
The screen settled down and stopped moving.
“Well?” said Bliss.
Trevize said, “That’s it. That’s the view of that portion of the Galaxy as it would have been twenty thousand years ago. At the very center of the screen is a point where the Forbidden World ought to be if it had been drifting at some average velocity.”
“Ought to be, but isn’t,” said Bliss sharply.
“It isn’t,” agreed Trevize, with remarkably little emotion.
Pelorat released his breath in a long sigh. “Oh, too bad, Golan.”
Trevize said, “Wait, don’t despair. I wasn’t expecting to see the star there.”
“You weren’t?” said Pelorat, astonished.
“No. I told you that this isn’t the Galaxy itself, but the computer’s map of the Galaxy. If a real star is not included in the map, we don’t see it. If the planet is called ‘Forbidden’ and has been called so for twenty thousand years, the chances are it wouldn’t be included in the map. And it isn’t, for we don’t see it.”
Bliss said, “We might not see it because it doesn’t exist. The Comporellian legends may be false, or the co-ordinates may be wrong.”