Isaac Asimov: Nightfall (novel)

“Lunch, yes,” said Sheerin once again, even less enthusiastically than before.

The great dome of the Saro University Observatory, rising majestically to dominate the forested slopes of Observatory Mount, glinted brilliantly in the light of late afternoon. The small red orb of Dovim had already slipped beyond the horizon, but Onos was still high in the west, and Trey and Patru, crossing the eastern sky on a sharp diagonal, etched shining trails of brightness along the dome’s immense face.

Beenay 25, a slender, agile young man with a quick, alert way of carrying himself, darted briskly about the small apartment below the Observatory in Saro City that he shared with his contract-mate, Raissta 717, gathering his books and papers together.

Raissta, sprawled comfortably on the worn green upholstery of their little couch, looked up and frowned.

“Going somewhere, Beenay?”

“To the Observatory.”

“It’s so early , though. You usually don’t go there until after Onos sets. And that won’t be for hours yet.”

“I’ve got an appointment today, Raissta.”

She gave him a warm, seductive look. They were both graduate students in their late twenties, each an assistant professor, he in astronomy, she in biology, and they had been contractmates only seven months. Their relationship was still in its first bloom of excitement. But problems had already arisen. He did his work in the late hours, when usually only a few of the lesser suns were in the sky. She was at her freshest and best in the period of high daylight, under the golden glow of bright Onos.

Lately he had spent more and more time at the Observatory, and it was getting so that they were almost never awake at the same time. Beenay knew how trying that was for her. It was trying for him. All the same, the work he was doing on Kalgash’s orbit was demanding stuff, and it was leading him into ever more difficult regions that he found both challenging and frightening. If only Raissta would be patient just another few weeks—a month or two, maybe—

“Can’t you stay here a little while longer this evening?” she asked.

His heart sank. Raissta was giving him her come-here-and-let’s-play look. Not easy to resist, nor did he really want to. But Yimot and Faro would be waiting.

“I told you. I have an—”

“—appointment, yes. Well, so do I. With you.”

“Me?”

“You said yesterday you might have some free time this afternoon. I was counting on that, you know. I cleared a whole swatch of free time of my own—did my lab work in the morning, as a matter of fact, just so—”

Worse and worse, Beenay thought. He did remember saying something about this afternoon, completely overlooking the fact that he had arranged to meet the two younger students.

She was pouting now, and somehow smiling at the same time, a trick that she managed to perfection. Beenay wanted to forget all about Faro and Yimot and go to her right away. But if he did that, he might be an hour late for his appointment with them, which wasn’t fair. Two hours, maybe.

And he had to admit to himself that he was desperately eager to know whether their calculations had confirmed his own.

It was practically an even struggle: the powerful appeal of Raissta on the one hand, and the desire to put his mind at rest concerning a major scientific issue on the other. And though he had an obligation to be on time for his appointment, Beenay realized in some confusion that he had made an appointment of sorts with Raissta too—and that was a matter not only of obligation but of delight.

“Look,” he said, going to the couch and taking her hand in his. “I can’t be in two places at once, okay? And when I told you what I did yesterday, it had slipped my mind that Faro and Yimot would be coming to the Observatory to see me. But I’ll make a deal with you. Let me get up there and take care of the thing with them, and then I’ll skip out and be back here a couple of hours from now. How does that sound?”

“You’re supposed to be photographing those asteroids this evening,” she said, pouting again, and not smiling at all this time.

“Damn! Well, I’ll ask Thilanda to do the camera work for me, or Hikkinan. Or somebody. I’ll be back by Onos-set, that’s a promise.”

“A promise?”

He squeezed her hand and gave her a quick sly grin. “One that I’ll actually keep. You can bet on that. Okay? You aren’t angry?”

“Well—”

“I’ll get Faro and Yimot out of the way as fast as I can.”

“You’d better.” As he began to assemble his papers again she said, “What is this business with Faro and Yimot that’s so terribly important, anyway?”

“Lab work. Gravitational studies.”

“Doesn’t sound all that important to me, I have to say.”

“I hope it turns out not to be important to anybody,” Beenay replied. “But that’s something I need to find out right now.”

“I wish I knew what you were talking about.”

He glanced at his watch and took a deep breath. He could stay here another minute or two, he supposed. “You know I’ve been working lately on the problem of the orbital motion of Kalgash around Onos, don’t you?”

“Of course.”

“All right. A couple of weeks ago I turned up an anomaly. My orbital numbers didn’t fit the Theory of Universal Gravitation. So I checked them, naturally, but they came out the same way the second time. And the third. And the fourth. Always the same anomaly, no matter what method of calculation I used.”

“Oh, Beenay, I’m so very sorry to hear that. You’ve worked so hard on this, I know, and to discover that your conclusions aren’t right—”

“What if they are, though?”

“But you said—”

“I don’t know if my math is right or wrong, at this point. As far as I can tell it is, but it doesn’t seem conceivable that that can be so. I’ve checked and checked and checked, and I get the same result each time, with all sorts of cross-checks built in to tell me that I haven’t made an error in computation. But the result that I’m getting is an impossible one. The only explanation I can come up with is that I’m starting from a cockeyed assumption and doing everything else right from then on, in which case I’m going to come up with the same wrong answer no matter which method of checking my calculations I use. I might just be blind to a fundamental problem at the base of my whole set of postulates. If you start with the wrong figure for planetary mass, for instance, you’ll get the wrong orbit for your planet no matter how accurate the rest of your calculations may be. Are you following me?”

“So far, yes.”

“Therefore I’ve given the problem to Faro and Yimot, without really telling them what it’s all about, and asked them to calculate the whole thing from scratch. They’re bright kids. I can count on them to do decent math. And if they end up with the same conclusion I did, even though they’re coming at it from an angle that completely excludes whatever error I might have built into my own line of reasoning, then I’ll have to admit that my figures are right after all.”

“But they can’t be right, Beenay. Didn’t you say that your findings are contrary to the Universal Law of Gravitation?”

“What if the Universal Law is wrong, Raissta?”

“What? What?”

She stared at him. There was utter bewilderment in her eyes.

“You see the problem?” Beenay asked. “Why I need to know right away what Yimot and Faro have found?”

“No,” she said. “No, I don’t understand at all.”

“We can talk about it later. I promise.”

“Beenay—” Half in despair.

“I’ve got to go. But I’ll be back as fast as I can. It’s a promise, Raissta! A promise!”