Nightfall by Isaac Asimov, Robert Silverberg Page B

owlish smiles. What a strange pair they are, he thought, not for the first time. They both came from some backwater farming province—Sithin, maybe, or Gatamber. Faro 24 was short and roly-poly, with a languid, almost indolent way of moving. His general style was easygoing and casual. His friend Yimot 70 was incredibly tall and thin, something like a hinged ladder with arms, legs, and a face, and you practically needed a telescope to see his head, looming up there in the stratosphere above you. Yimot was as tense and twitchy as his friend was relaxed. Yet they were inseparable, always had been. Of all the young graduate students, one notch down the Observatory’s table of organization from Beenay’s level, they were by far the most brilliant.
    “We haven’t been waiting long,” Yimot said at once.
    “Only a minute or two, Dr. Beenay,” Faro added.
    “Not quite ‘doctor’ yet, thanks,” Beenay said. “I’ve still got the final inquisition to go through. How did you manage with those computations?”
    Yimot said, twitching and jerking his impossibly long legs around, “This is gravitational stuff, isn’t it, sir?”
    Faro nudged him so vigorously in the ribs with his elbow that Beenay expected to hear the sound of crunching bone.
    “That’s all right,” Beenay said. “Yimot’s correct, as a matter of fact.” He gave the tall young man a pale smile. “I wanted this to be a purely abstract mathematical exercise for you. Butit doesn’t surprise me that you were able to figure out the context. You figured it out
after
you had your result, didn’t you?”
    “Yes, sir,” said Yimot and Faro at the same time. “We ran all the calculations first,” Faro said. “Then we took a second look, and the context became apparent,” said Yimot.
    “Ah. Yes,” Beenay said. These kids were sometimes a little unnerving. They were so young—only six or seven years younger than he, as a matter of fact, but he was an assistant professor and they were students, and to him and them both that was a vast barrier. Young as they were, though, they had such extraordinary minds! He wasn’t altogether pleased that they had guessed at the conceptual matrix within which these calculations were located. In fact, he wasn’t pleased at all. In another few years they’d be right up here on the faculty with him, perhaps competing for the same professorship he hoped to get, and that might not be fun. But he tried not to think about that.
    He reached for their printout.
    “May I see?” he asked.
    Hands fluttering wildly, Yimot handed it over. Beenay scanned the rows of figures, calmly at first, then with rising agitation.
    He had been pondering, all year long, certain implications of the Theory of Universal Gravitation, which his mentor Athor had brought to such a summit of perfection. It had been Athor’s great triumph, the making of his lofty reputation, to work out the orbital motions of Kalgash and all six of its suns according to rational principles of attractive forces.
    Beenay, using modern computational equipment, had been calculating some aspects of Kalgash’s orbit around Onos, its primary sun, when to his horror he observed that his figures didn’t check out properly in terms of the Theory of Universal Gravitation. The theory said that at the beginning of the present year Kalgash should have been
here
in relation to Onos, when in undeniable fact Kalgash was
there.
    The deviation was trivial—a matter of a few decimal places—but that wasn’t trivial at all, in the larger sense of things. The Theory of Universal Gravitation was so precise that most people preferred to refer to it as the
Law
of Universal Gravitation. Its mathematical underpinning was considered impeccable.But a theory that purports to explain the movements of the world through space has no room for even small discrepancies. Either it is complete or it is not complete: no middle way was permissible. And a difference of a few decimal places in a