Foundation's Edge - Isaac Asimov [160]
Pelorat rose at once. "I thought you had left us."
"Not at all. I had reports to make out, work to do. May I join you now, Dom?"
Dom had also risen (though Trevize remained seated). "You are entirely welcome and you ravish these aged eyes."
"It is for your ravishment that I put on this blouse. Pel is above such things and Trev dislikes them."
Pelorat said, "If you think I am above such things, Bliss, I may surprise you someday."
"What a delightful surprise that would be," Bliss said, and sat down. The two men did as well. "Please don't let me interrupt you."
Dom said, "I was about to tell our guests the story of Eternity. --To understand it, you must first understand that there are many different Universes that can exist--virtually an infinite number. Every single event that takes place can take place or not take place, or can take place in this fashion or in that fashion, and each of an enormous number of alternatives will result in a future course of events that are distinct to at least some degree.
"Bliss might not have come in just now; or she might have been with us a little earlier; or much earlier; or having come in now, she might have worn a different blouse; or even in this blouse, she might not have smiled roguishly at elderly men as is their kindhearted custom. In each of these alternatives--or in each of a very large number of other alternatives of this one event--the Universe would have taken a different track thereafter, and so on for every other variation of every other event, however minor."
Trevize stirred restlessly. "I believe this is a common speculation in quantum mechanics--a very ancient one, in fact."
"Ah, you've heard of it. But let us go on. Imagine it is possible for human beings to freeze all the infinite number of Universes, to step from one to another at will, and to choose which one should be made 'real' --whatever that word means in this connection."
Trevize said, "I hear your words and can even imagine the concept you describe, but I cannot make myself believe that anything like this could ever happen."
"Nor I, on the whole," said Dom, "which is why I say that it would all seem to be a fable. Nevertheless, the fable states that there were those who could step out of time and examine the endless strands of potential reality. These people were called the Eternals and when they were out of time they were said to be in Eternity.
"It was their task to choose a Reality that would be most suitable to humanity. They modified endlessly--and the story goes into great detail, for I must tell you that it has been written in the form of an epic of inordinate length. Eventually they found (or it is said) a Universe in which Earth was the only planet in the entire Galaxy on which could be found a complex ecological system, together with the development of an intelligent species capable of working out a high technology.
"That, they decided, was the situation in which humanity could be most secure. They froze that strand of events as Reality and then ceased operations. Now we live in a Galaxy that has been settled by human beings only, and, to a large extent, by the plants, animals, and microscopic life that they carry with them--voluntarily or inadvertently--from planet to planet and which usually overwhelm the indigenous life.
"Somewhere in the dim mists of probability there are other Realities in which the Galaxy is host to many intelligences, but they are unreachable. We in our Reality are alone. From every action and every event in our Reality, there are new branches that set off, with only one in each separate case being a continuation of Reality, so that there are vast numbers of potential Universes--perhaps an infinite number--stemming from ours, but all of them are presumably alike in containing the one-intelligence Galaxy in which we live. --Or perhaps I should say that all but a vanishingly small percentage are alike in this way, for it is dangerous to rule out anything where the possibilities approach the infinite."
He stopped, shrugged slightly, and added, "At least, that's the