"It was a hard decision to make," answered Chang, "but leaving the morals of it aside, it was the only practicable way. Suppose it were generally known that this one place, in all the known universe, has no age. Imagine all who would want to come here! The planet couldn't hold a fraction of them. Even as it is, we have to space births very carefully lest in a few centuries we crowd ourselves off the world. Furthermore, the unstable social environment produced by such an influx of colonists, most of whom couldn't stand the place anyway, would delay, perhaps ruin, the research by which we hope to find out why life does not grow old here. When we have that answer, and can apply it outside this region of space, all the Galaxy will have immortality. But until then, we must wait." He shrugged, a dim movement in the shining night. "And immortals know how to wait."
"So instead, we simply accept colonists who agree to stay here for life—and then once they get here they're told how long that life will be."
"Yes. Actually, the miracle is that the first colonists stayed at all, after most had fled or gone insane. After all, it was ten or twenty years before we even suspected the truth. A world as alien as this was settled only because planets habitable to man and without aborigines are hard to find. Since then, many more such worlds—normal ones—have been discovered, and few people care to risk madness by coming here. Tanith is an obscure dominion of the Galactic Union, having a certain scientific interest because of its unique natural laws—but not too great even there, when science has so many other things to investigate just now. And we're quite content to remain in the shadow."
"Of course." Langdon looked up to the swarming stars. A sheet of blue auroral flame covered them for a moment.
He asked presently: "How much further have our scientists gotten in explaining the phenomenon?"
"We've come quite a ways, but progress has been mostly in highly technical fields of mathematical physics. You'll have to take a decade or two off soon, Joseph, and learn that subject. Briefly, we do know that this is a region of warped space, similar to those in the neighborhood of massive bodies but of a different character. As you know, natural constants are different in such regions from free space, phenomena such as gravitation and the bending of light appear. This is another sort of geometric distortion, but basically the same. It produces differences in—well, in optics, in thermodynamics, in psi functions, in almost everything. The very laws of probabilities are different here. As a result, the curious phenomena we know appear. Many of them, of course, are simply illusions produced by complex refractions of light and sound waves: others are very real. The time axis itself is subject to certain transformations which produce the temporal mirages. And so it goes."
"Yes, yes, I know all that. But what causes the warp itself?"
"We're not sure yet, but we think it's an effect of our being near the Galactic center of mass, together with—no, it would take me a week to write out the equations, let alone explain them."
There was a comfort in impersonal discourse, but it was a retreat from more immediate problems. Langdon fairly rapped out the question: "How close are you to understanding why we are immortal?"