Pelorat said, "Isn't all that typical of the kind of star about which habitable planets are to be found?"
"Typical," said Trevize, nodding in the dimness. "And, therefore, what we'd expect Earth's sun to be like. If that is where life developed, the sun of Earth would have set the original standard."
"So there is a reasonable chance that there would be a habitable planet circling it."
"We don't have to speculate about that," said Trevize, who sounded puzzled indeed over the matter. "The Galactic map lists it as possessing a planet with human life-but with a question mark."
Pelorat's enthusiasm grew. "That's exactly what we would expect, Golan. The life-bearing planet is there, but the attempt to hide the fact obscures data concerning it and leaves the makers of the map the computer uses uncertain."
"No, that's what bothers me," said Trevize. "That's not what we should expect. We should expect far more than that. Considering the efficiency with which data concerning Earth has been wiped out, the makers of the map should not have known that life exists in the system, let alone human life. They should not even have known Earth's sun exists. The Spacer worlds aren't on the map. Why should Earth's sun be?"
"Well, it's there, just the same. What's the use of arguing the fact? What other information about the star is given?"
"A name."
"Ah! What is it?"
"Alpha."
There was a short pause, then Pelorat said eagerly, "That's it, old man. That's the final bit of evidence. Consider the meaning."
"Does it have a meaning?" said Trevize. "It's just a name to me, and an odd one. It doesn't sound Galactic."
"It isn't Galactic. It's in a prehistoric language of Earth, the same one that gave us Gaia as the name of Bliss's planet."
"What does Alpha mean, then?"
"Alpha is the first letter of the alphabet of that ancient language. That is one of the most firmly attested scraps of knowledge we have about it. In ancient times, 'alpha' was sometimes used to mean the first of anything. To call a sun 'Alpha,' implies that it's the first sun. And wouldn't the first sun be the one around which a planet revolved that was the first planet to bear human life-Earth?"
"Are you sure of that?"
"Absolutely," said Pelorat.
"Is there anything in early legends-you're the mythologist, after all-that gives Earth's sun some very unusual attribute?"
"No, how can there be? It has to be standard by definition, and the characteristics the computer has given us ate as standard as possible, I imagine. Aren't they?"
"Earth's sun is a single star, I suppose?"
Pelorat said, "Well, of course! As far as I know, all inhabited worlds orbit single stars."
"So I would have thought myself," said Trevize. "The trouble is that that star in the center of the viewscreen is not a single star, it is a binary. The brighter of the two stars making up the binary is indeed standard and it is that one for which the computer supplied us with data. Circling that star with a period of roughly eighty years, however, is another star with a mass four fifths that of the brighter one. We can't see the two as separate stars with the unaided eye, but if I were to enlarge the view, I'm sure we would."
"Are you certain of that, Golan?" said Pelorat, taken aback.
"It's what the computer is telling me. And if we are looking at a binary star, then it's not Earth's sun. It can't be."
71.
TREVIZE broke contact with the computer, and the lights brightened.
That was the signal, apparently, for Bliss to return, with Fallow tagging after her. "Well, then, what are the results?" she asked.
Trevize said tonelessly, "Somewhat disappointing. Where I expected to find Earth's sun, I found a binary star, instead. Earth's sun is a single star, so the one centered is not it."
Pelorat said, "Now what, Golan?"
Trevize shrugged. "I didn't really expect to see Earth's sun centered. Even the Spacers wouldn't settle worlds in such a way as to set up an exact sphere. Aurora, the oldest of the Spacer worlds, might have sent out settlers of its own and that may have distorted the sphere, too. Then, too, Earth's sun may not have moved at precisely the average velocity of the Spacer worlds."
Pelorat said, "So the Earth can be anywhere. Is that what you're saying?"
"No. Not quite 'anywhere.' All these possible sources of error can't amount to much. Earth's sun must be in the vicinity of the co-ordinates. The star we've spotted almost exactly at the co-ordinates must be a neighbor of Earth's sun. It's startling that there should be a neighbor that so closely resembles Earth's sun-except for being a binary-but that must be the case."
"But we would see Earth's sun on the map, then, wouldn't we? I mean, near Alpha?"
"No, for I'm certain Earth's sun isn't on the map at all. It was that which shook my confidence when we first spied Alpha. Regardless of how much it might resemble Earth's sun, the mere fact that it was on the map made me suspect it was not the real thing."
"Well, then," said Bliss. "Why not concentrate on the same co-ordinates in real space? Then, if there is any bright star close to the center, a star that does not exist in the computer's map, and if it is very much like Alpha in its properties, but is single, might it not be Earth's sun?"
Trevize sighed. "If all that were so, I'd be willing to wager half my fortune, such as it is, that circling that star you speak of would be the planet Earth. Again, I hesitate to try."
"Because you might fail?"