Tom explained. The older woman frowned. “I don’t like this, dear,” she said. “Yasmin’s been breaking down, closer and closer to hysteria, ever since we left those peasants. She’s not prepared for a guerrilla existence. She’s used up her last resources.”
“You reckon she’s quantum-jumpin’ already?”
“I don’t know. But I do think we should force her to take a drink, to put her to sleep.”
“Hm.” Tom glanced at the dark head, bent over some arithmetical calculations. “Could be. But no. Let her do what she chooses. She hasn’t bubbled her lips yet, has she? And—we are the free people.”
He went on with Dagny in a rather hopeless discussion of possibilities open to them. Once they were interrupted, when Yasmin asked if he had a trigonometric slide rule. No, he didn’t. “I suppose I can approximate the function with a series,” she said, and returned to her labors.
Has she really gone gollywobble? Tom wondered. Or is she just soothin’ herself with a hobby?
Half an hour later, Yasmin spoke again. “I have the solution.”
“To what?” Tom asked, a little muzzily after numerous gulps from the bottle. They distilled potent stuff in Hanno. “Our problem?”
“Oh, no, my lord. I couldn’t—I mean, I am nobody. But I did study science, you remember, and… and I assumed that if you and Lady Dagny said this was a young system, you must be right, you have traveled’ so widely. But it isn’t.”
“No? What’re you aimed at?”
“It doesn’t matter, really. I’m being an awful picky little nuisance. But this can’t be a young system. It has to be old.”
Tom put the bottle down with a thud that overrode the storm-yammer outside. Dagny opened her mouth to ask what .was happening. He shushed her. Out of the shadows across his scarred face, the single eye blazed blue. “Go on,” he said, most quietly.
Yasmin faltered. She hadn’t expected any such reaction. But, encouraged by him, she said with a, waxing confidence:
“From the known average distance of the sun, and the length of the planet’s year, anyone can calculate the sun’s mass. It turns out to be almost precisely one Sol. That is, it has the mass of a G2 star. But it has twice the luminosity, and more than half again the radius, and the reddish color of a late G or early K type. You thought those paradoxes were due to a strange composition. I don’t really see how that could be. I mean, any star is something like 98 per cent hydrogen and helium. Variations in other elements can affect its development some, but surely not this much. Well, we know from Nikean biology that this system must be at least a few billion years old. So the star’s instability cannot be due to extreme youth. Any solar mass must settle down on the main sequence far quicker than that. Otherwise we would have many, many more variables in the universe than we do.
“And besides, we can explain all the paradoxes so simply if we assume this system is old. Incredibly old, maybe almost as old as the galaxy itself.”
“Belay!” Tom exclaimed, though not loudly. “How could this planet have this much atmosphere after so long a time? If any? Don’t sunlight kick gases into space? And Nike hasn’t got the gravity to nail molecules down for good. Half a standard Gee; and the potential is even poorer, the field strength dropping off as fast as it does.”
“But my lord,” Yasmin said, “an atmosphere comes from within a planet. At least, it does for the smaller planets, that can’t keep their original hydrogen like the Jupiter types. On the smaller worlds, gas gets forced out of mineral compounds. Vulcanism and tectonism provide the heat for that, as well as radioactivity. But the major planetological forces originate in the core. And the core originates because the heavier elements, like iron, tend to migrate toward the center. We know Nike has some endowment of those. Perhaps more, even, than the average planet of its age.
“Earth-sized planets have strong gravity. The migration is quick. The core forms in their youth. But Mars- sized worlds… the process has to be slow, don’t you think? So much iron combines first in surface rocks that they are red. Nike. shows traces of this still today. The midget planets can’t outgas more than a wisp until their old age, when a core finally has taken shape.”
Tom shook his head in a stunned fashion. “I didn’t know. I took for granted—I mean, well, every Mars-type globe I ever saw or heard of had very little air—I reckoned they’d lost most o’ their gas long ago.”
“There are no extremely ancient systems in the range that your travels have covered,” Yasmin deduced. “Perhaps not in the whole Imperial territory. They aren’t common in the spiral arms of the galaxy, after all. So people never had much occasion to think about what they must be like.”
“Uh, what you been sayin’, this theory… you learned it in school?”
“No. I didn’t major in astronomy, just took some required basic courses. It simply appeared to me that some such idea is the only way to explain this system we’re in.” Yasmin spread her hands. “Maybe the pro-lessors at my university haven’t heard of the idea either. The truth must have been known in Imperial times, but it could have been lost since, not having immediate practical value.” Her smile was sad. “Who cares about pure science any more? What can you buy with it?
“Even the original colonists on Nike—Well, to them the fact must have been interesting, but not terribly important. They knew the planet was so old that it had lately gained an atmosphere and oxygen-liberating life.
So old that its sun is on the verge of becoming a red giant. Already the hydrogen is exhausted at the core, the nuclear reactions are moving outward in a shell, the photosphere is expanding and cooling while the total energy output rises. But the sun won’t be so huge that Nike is scorched for—oh, several million years. I suppose the colonists appreciated the irony here. But on the human time-scale, what difference did it make? No wonder their descendants have forgotten and think, like you, this has to be a young system.”
Tom caught her hands between his own. “And… that’s the reason… the real reason the sun’s so rambunctious?” he asked hoarsely.
“Why, yes. Red giants are usually variable. This star is in a transition stage, I guess, and hasn’t ‘found’ its period yet.” Yasmin’s smile turned warm. “If I have taken your mind off your troubles, I am glad. But why do you care about the aspect of this planet ten mega-years from now? I think best I do try to sleep, that I may help you a little tomorrow.”
Tom gulped. “Kid,” he said, “you don’t know your own:strength.”
“What’s she been talking about?” Dagny demanded. Tom told her. They spent the rest of the night laying plans.
Now and then a mid-morning sunbeam struck copper through the fog. But otherwise a wet, dripping, smoking mystery enclosed the barge. Despite its chill, Tom was glad. He didn’t care to be interrupted by a strafing attack.
To be sure, the air force might triangulate on the radio emission of his ruined plane and drop a bomb. However—
He sat in the cockpit, looked squarely into the screen, and said, “This is a parley. Agreed?”
“For the moment.” Karol Weyer gave him a smoldering return stare. “I talked with Fish Aran.”
“And he made it clear to you, didn’t her about the lingo scramble? How often your Anglic and mine use the same word different? Well, let’s not keep on with the farce. If anybody thinks t’other’s said somethin’ bad, let’s call a halt and thresh out what was intended. Aye?”
Weyer tugged his beard. His countenance lost none of its sternness. “You have yet to prove your good faith,” he said. “After what harm you worked—”
“I’m ready to make that up to you. To your whole planet.”
Weyer cocked a brow and waited.
“S’pose you give us what we need to fix our ship,” Tom said. “Some of it might be kind of expensive—copper and silver and such, and handicrafted because you haven’t got the dies and jigs—but we can make some gold payment. Then let us go. I, or a trusty captain o’ mine, will be back in a few months… uh, a few thirty-day periods.”
“With a host of friends to do business?”
“No. With camarados to ‘change. Nike lived on trade under the Terran Empire. It can once more.”
“How do I know you speak truth?”
