The World at the End of Time

CHAPTER 23

Reminiscing is a recreation for the elderly. It is what people do when they have outlived all their other occupations—people like Wan-To.

Elderly human beings at least have bodily functions to use up some hours. They have to eat, use the toilet, maybe even hoist themselves into their wheelchairs and complain to those around them. Wan-To didn't have even those ways of passing the time. Wan-To didn't just have very little else to do, he had nothing else to do. In the exhausted, depleted, moribund universe that Wan-To lived in he not only didn't need to do anything to keep on living, he had nothing much in the way of limbs, powers, or effectors to do anything with. His mind still worked—quite clearly, in fact, though at a depressingly slow speed. But everything stayed within his mind. He didn't have any useful appendages anymore to convert any of his mind's impulses into action.

All that being so, Wan-To was lucky he had so much to reminisce about.

He certainly did have a lot of memories. If there had been a contest to see which single being, among all the universe's inhabitants in all the endless eons of its existence, had the most in the way of stored-up memories to take out and chew over, Wan-To would have been the incontestable winner. If your mind remains clear, and Wan-To's had, you can remember a lot out of a lifetime of ten-to-the-fortieth years.

Ten to the fortieth power years … and maybe much more still to come. That was one of the things Wan-To had to think about, for there still was at least one decision he sooner or later would have to make.

That was going to be a very hard decision. Because it was so very hard he preferred not to think about it. (There was, after all, positively no hurry at all.) What Wan-To liked to think about—the only thing that could be described as a pleasure that he still had left—was the days when he had had all the power any being could ever have desired.

Ah, those long-gone days! Days when he carelessly deployed the energies of stars on the whim of a moment—without a care for the future, without penalty for his spendthrift ways! When he cruised at will from star to star, from galaxy to galaxy (wistfully he remembered how wonderful it was to enter a virgin galaxy, bright with billions upon billions of unoccupied stars, and all his!) When he lived off copies of himself for companionship and battled joyfully against them for survival when they turned against him! (Even the frights and worries of those days were tenderly recalled now.) Wan-To remembered lolling on the surface of a star, taking his ease in the cool luxury of its six or seven thousand degrees (and he'd thought that cool!) … and swimming through the star's unimaginably dense core … and frolicking in the corona, temperature now up to a couple million degrees, soaked with X rays, dashing out as far as ten million miles from the star's surface to the corona's fringe and then happily plunging back.

He remembered the fun (and challenges—oh, he relished remembering the challenges!) when he had created those little copies of himself, Haigh-tik and Mromm and poor, silly Wan-Wan-Wan—and Kind and Happy and all the others he had made; he even remembered, though not very well, the terribly stupid matter-copies he had made, like Five. (He didn't actually remember Five as an individual, to be sure. Five had not been important to him—just then.)

What he remembered was living. And though it gave him a sort of melancholy joy to remember, the knowledge that he would never have such times again made him almost despair.

It was only when he was close to despair that he could force himself to think about that other thing, the one about which he would sooner or later have to make a decision. It concerned the only things in the universe that had ever really frightened Wan-To—because there was so much about them that even he had never been able to understand:

Black holes.

There lay the choice that ultimately Wan-To would have to make. Not right away, to be sure—nothing ever had to be "right away" in this dreary eternity—but sooner or later, for the sake of survival.

A black hole might very well give him his best chance for really long-term survival.

Wan-To wasn't sure he quite wanted to survive on those terms. He did not care for black holes. The locked-in singularities where a star once had been—and then collapsed upon itself and pulled space in around it—were about the only sorts of objects in the universe Wan-To had never investigated in person. He hoped he would never have to. They were scary.

The frightening thing about black holes was that inside them the laws of the universe—the laws that Wan-To understood so well—did not apply, because black holes were no longer really parts of the universe. They had seceded from it.

It was easy enough to get inside a black hole—in fact, the problem sometimes was to avoid falling into one. Once or twice Wan-To had to exert himself to steer away from one's neighborhood. But getting in was a purely one-way trip. Once inside, you couldn't get out again. Even light was stuck there.

That wasn't because the immense gravitational field of the black hole pulled light back down to its surface, as, say, the gravity of a planet like the Earth pulls a thrown ball back down. Wan-To knew better than that. Wan-To was quite aware that light can't slow down; that's why c is invariant. The reason even light couldn't escape was simply because the gravity of the black hole wrapped space around it—bent it—so that the light orbited around it eternally, within the Schwarzschild radius of the black hole, as planets orbit around a sun.

But the exact mechanism that caught and held anything that wandered by in those cosmic traps wasn't really what mattered to Wan-To. What mattered was that once you were inside, you couldn't get out again ever—not light, not matter. Not even Wan-To himself.

The things were terrifying.

Nevertheless, they had their virtues, Wan-To told himself. One of those virtues was that a good-sized black hole, say even one of as little as three or four solar masses, would continue its existence for a long time.

That was not just a very long time, like Wan-To's present age of ten-to-the-fortieth years. It was a long long time: ten-to-the-sixty-sixth years, anyway.

Those are numbers that few human beings can ever grasp. Even Wan-To had trouble working with them. Ordinary arithmetic isn't meant for such numbers. But what they mean was that if Wan-To were to take the plunge so that he could live as long as one of those fair-sized black holes—

Which is to say, for 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 years—

And if you subtracted from that his present lifetime (which was to say, the present age of the universe, because by now they were pretty much the same number)—

Which amounted to 10,000,000,000,000,000,000,000,000,000,000,000,000,000 years—

If, then, he succeeded in living as long as that black hole continued to radiate energy, he had still to look forward to—

Another 999,999,999,999,999,999,999,999,990,000,000,000,000,000,000,000,000,000,000,000,000,000 years of existence. If such numbers meant anything at all, even to Wan-To.

And if, of course, you could call that "existence."

Because that radiated "energy" from the black hole wasn't really very energetic at all. Such a black hole didn't begin to radiate in the first place until the mean temperature of the universe—what was called the "background radiation" when human beings first discovered it in their silly little microwave dishes, back in the twentieth century—had dropped to the very low value of one ten-millionth of one degree above absolute zero. It was only at that temperature that the black hole would begin to radiate.

That was very feeble warmth indeed.

Wan-To knew dismally that he could manage to survive, more or less, even with that sort of input—but he did not like the idea at all.

The only thing was that he didn't see any better alternative …

Until he became aware that the tiny tick his few remaining sensors had registered some time earlier was, strangely enough, a sudden and wholly unidentified flux of tachyons.