"Anderson, Poul - Fire Time" - читать интересную книгу автора (Anderson Poul)

However, by that time travelers who had gone elsewhere were bringing a flood of exotic tales.... Anubelean studies languished until a global association of scientific and humanistic institutions had been founded and funded.... Not only the fascination of Ishtar and Tammuz spoke for establishing a permanent base on the former. A wish did. to help the living natives through the next of those crises which had dogged their entire history, indeed their evolution....

Rhetoric. Dejerine wanted dullness. He skipped to a chapter self-proclaimed as dryly factual.

Per se, the system is nothing extraordinary. Companion stars often have widely differing masses, therefore developmental histories, and eccentric orbits are more a rule than an exception.

The three members of Anubelea seem to be approximately as old as Sol. Hence Bel, the G2 star, can expect four or five billion years of steady shining in the future. Ea, the red dwarf, will endure far longer than that. But Anu, the most massive, has inevitably aged fasterIt is not enormously bigger than Bel, 1.3 times, which is to say the mass is 1.22 Sol. In its heyday it did not shine too fiercely for at least one of its planets to spawn protein-in-water life and oxygen-releasing photosynthesis. But perhaps-we continue pathetically ignorant-the greater irradiation hastened evolution. Whatever the causes, we do know that about a billion years ago, Tammuz (Anu III) had brought forth intelligent beings who had in turn brought forth a technological civilization.

By then, their sun had burned sufficient hydrogen that it could no longer stay on the main sequence. It had begun to swell, to become a red giant. At present its total luminosity equals 280 Sols; and this is slowly, inexorably rising.

To understand the situation on Ishtar, let us imagine its sun, Bel, as stationary, Anu and Ea revolving around it. Needless to say, in actuality the three stars move around a common center of mass. But given their changing configurations, only mathematics can well describe this. (See Appendix A.) A Bel-centered diagram is valid geometrically, to a first approximation, though false dynamically.

In this picture, Anu moves around Bel in a huge ellipse. At its maximum distance, it is some 224 astronomical units off, scarcely more than the chief star in the skies of Ishtar. At closest approach, it comes within 40 astronomical units of Bel, i.e., between about 39 and 41 of Ishtar, depending on the planetary position. The orbital period is 1,041 Terrestrial years. That is, each millennium the red giant sweeps near. . ..

The path of Ea is still more majestic and eccentric. It is always too remote to have a measurable direct effect, although it looms large in every known Ishtarian mythology. And it is interesting in its own right for the single planet it possesses, a superjovian....

In the present epoch-which for all practical purposes covers millions of past and future years-Anu at periastron to Bel adds approximately 20 per cent to the irradiation which Ishtar normally receives. This corresponds to a rise in black body temperature of 11░ C.

Theoretical calculations must be used carefully. A planet, especially if it has atmosphere and hydrosphere, is not a black body. For example, heat will cause the formation of clouds from evaporated water, which will reflect back more radiation than formerly; but meanwhile greenhouse effect will operate the more strongly as more water vapor enters the air. And then there are the differing, though always large, thermal inertias of various regions. . . .

Since periastron passage is necessarily rapid, the time during which Anu is important to Ishtar is arbitrarily estimated at a century. As it approaches, at first there is small result except its increasing apparent size and brightness. Time is needed to heat an entire planet. Storms, droughts, and similar disasters do not become major until about the period when Anu is closest. Thereafter, while the red giant recedes, they grow progressively worse-just as the hottest time of an ordinary year comes after the summer solstice and may last beyond the autumnal equinox.

All in all, it is thus for about one century out of ten that nature on Ishtar is in turmoil. ...

Having no large moon. the planet processes slowly. Through this past geological era, the inclinations of orbits and spin axes have made Ishtar's northern hemisphere bear the brunt. Ifperiastron occurs at midwinter, Arm will be ca. 26░ from the north celestial pole; if at midsummer, ca, 28░. This means that these colatitudes get the maximum exposure. Their temperatures rise well above the "theoretical," with everything that that implies. At their antipodes, a third of the globe never sees Anu during this time, not until it is swiftly moving away. Although the passing star is probably responsible for the lack of ice caps at either pole, the antarctic continent remains bleak. We could wish for a more reasonable energy distribution; but the universe has never shown much interest in being reasonable....

The book fell on Dejerine's lap. He woke merely to enter his bed.



FIVE



ITS TASSU GARRISON would not yield Tarhanna to siege before they had plucked the leaves of their manes and shaved the turf of their pelts to eat-and then not until they had burned what strength that last starvation ration gave them. Belike many would still try to lift ax or pike when the legionaries broke down undefended gates. Knowing this, a regiment of the Zera Victrix moved north with engines trundling among them for the demolition of walls: ballistas, trebuchets, testudo-roofed ram-

Larreka wouldn't have ordered that, Arnanak thought in glee. He's too wise. But Larreka had gone South-OverSea. His vice commandant, Wolua, was less patient, less able to foresee possible countermoves. Amanak had hoped his enemies would seek to regain the town quickly, and laid plans for this. When he was sure, his couriers went out; drums cast word across canyons; and where they would not be seen by outland forelopers, smoke signals puffed by day and beacon fires flashed by night.

Wolua was no fool. It was merely that two or three hundred years in service seemed to have made his thinking run in deep channels, not become free-ranging like Larreka's. As he led his force up the road, he kept a web of scouts far-flung on either side of the Esali. The Tassui had nothing to match that corps-chosen and trained for fleetness, schooled to read maps and use compasses, equipped with telescopes, portable heliographs, bottles of tiny bluesmoke bugs which were not found in Valennen, even magical voicecasters from Humanworld in the hands of a few key officers. The scouts did not simply prevent an adversary from surprising their main body; they found and killed hostile counterparts, to keep foes in the dark about their own side.

Or thus it had been until lately. Amanak had a new response.

Small, swiftly scuttering, his dauri were not likely to be seen; if seen, they would likely be taken for animals; if a legionary who saw one chanced to know a little Tassu folklore, the most he would likely think was: "Holy Sun, those stories may be true! Maybe there are spooks in the Starktands that get down here sometimes ... yes, doesn't the legend say they come in numbers as harbingers of the thousand-yearly destruction-?"

Amanak's grasp of their whistling, trilling speech was not firm. Nor could they move as fast as the legionary outrunners. But they told him what he needed to leamHe knew the size and composition of the force from Port Rua, he knew day by day where it was, and on this basis he could direct his plan of battle.

He stood waiting to call the charge. Beside him was Kusarat, the Overling of Sekrusu. News of the capture of Tarhanna had decided that powerful but hitherto unsure chief, and he had lately arrived at the head of three hundred armed oathgivers. They were very welcome, as much for their example as their strength. Amanak was willing to show their leader every sign of honor, pretend that he and he were equals. The Overling of Ulu understood it would take years to bind all households to him in such wise that they agreed he had in truth become the master of South Valennen.

"What did you do?" Kusarat asked.