The Book
This note is very much a scattershot response to yours, intended to touch on a few minor points which caught my mind.
Concerning John-A, I believe that anyone who moves backward in time intrinsically destroys the "original" history (a term I've had to explain in answering a question about my Terminator analysis) which led to his trip; that history had to exist in the sense that it is necessary in order to reach the time from which he left; but I expect that his trip will result in time itself snapping back to the moment to which he returns, and therefore proceeding no further than the moment he left until it repeats the intervening years--and time may continue based on the replaced history.
But I think it may not.
Intrinsic in John-A's ability to travel through time is his ability to destroy time itself; it is possible to create a paradox or anomaly so severe that history cannot continue beyond the point at the future end of the time trip. (I've discussed this in some detail on my site; two movies which are very interesting in this regard are Flight of the Navigator, which seems to understand the notion of the original timeline quite well, and Millennium, which displays some foolish ideas but clearly recognizes the problem of the altered timeline.)
I would be careful about suggesting that "loops" in a timeline are normative. "Anomalies" and "paradoxes" may be normative, but as I understand the meaning of "loop", one would be sufficient to end time as we know it.
To say that the number of possibilities exceeds our imagination is not the same thing as to say that it is infinite. The distance from one end of the universe to another has been roughly estimated by astrophysicists (the edges have been found). It is an incredibly large distance which uses numbers for which we have no names and units beyond our comprehension; but it is still finite. There is a finite amount of matter within a finite space at the baseline; and if we multiply my possible choices by one hundred decillion (and so increase the number of possibilities exponentially), we still have a vast but finite number. The concept of "infinite"--limitless--is theoretical, and has no real existence. There are an infinite number of points between two points in a line, because theoretically we can divide the distance into smaller and smaller pieces; but we have come to believe that there is a minimum distance in real space, a length which cannot be cut in half, a particle which is not composed of smaller particles. We assume time to be infinite, but that is an unfounded assumption.
As C. S. Lewis once said, all of science can be summarized into the phrase, "Humpty Dumpty is falling"--with no certainty of whether he was ever at the top of a wall, or notion of whether there's a bottom. Since science is about what is observed, it is difficult for it to say with certainty how things were when, if ever, they were or will be different. Immanuel Kant posed what may be the ultimate puzzle about time and infinity. If there is a beginning of time, then "before" time began, there was no medium in which change could occur, and thus no possibility that time could begin; but if time has no beginning, then the past is eternal, and if the past is eternal then we have come through an infinite period of time to reach the present--but it is not possible to finish an infinite period of time, so we could not then have reached the present. Whatever the truth about the beginning (or the end) of time, it may be beyond our comprehension; it is certainly beyond our experience.
Concerning the edge of the universe, I am no expert on that. What has been explained to me is that at the origin of the universe there was no space, and all matter had compacted to a singularity (having no dimension at all). Matter exploded, and as it moves outward it "creates space" around it. Thus we have (by some means beyond my knowledge) detected the edge of space itself, and have every reason to believe that beyond that there is no additional centimeter (the "nothing" of "The Neverending Story"?); but as matter thrusts toward the edge, space is created to accommodate it. As this is only the most recent theory I have heard in a field which is not mine, I cannot say much more about it.
I can indeed imagine an alternate reality in which an alternate me "snaps". I can imagine each of us becoming Hitler, the Marquis de Sade, and Jack the Ripper. But as I consider it, I realize that there are unimaginably more morally wrong paths than morally right ones; and if this is one of so vast a number of universes, I begin to wonder why it isn't far more evil than it is. People usually raise the problem of evil in the terms, "If there is a God, how could he allow this evil?" But I would say, "If there are infinite universes, why is such a small percentage of the people in this one truly malevolent and vicious?" If the number of evil possibilities so overwhelms the number of good possibilities, why is it that the number of good choices made overwhelms the number of evil choices? Even apart from my personal feelings that individuality and autonomy are more than an illusion, it seems to me, given the assumption that all possible universes exist, that the reality of this universe is improbable.
Your tongue-in-cheek absurd notion reveals your commitment to the standard unprovable assumptions of the scientific method (philosophy was a major interest of mine in college). Hume insisted that that is exactly the kind of thing you really don't know. The ultimate empiricist, Hume maintained that all of our scientific observations tell us only what is happening right now, and that we have no basis or right to presume that the "rules" we derive existed before we observed them, or that they will continue to exist in the next moment. Thus, you may know that your deck was in the back yard before, but just as you admit that you don't know it's there now, you also don't know that it will be there when you get back to it. But the mistake most people make is in the concept of "proof". We think that for something to be true, it must be proved by scientific evidence to scientific standards. But scientific evidence is not absolute proof; nor is it the only kind of evidence. If I wonder what is at the end of the road, I may go to the end of the road to see it--this would be scientific evidence. Scientific evidence is based on observation and reproducibility, that is, something is deemed so if everyone who performs the same experiment gets the same result. However, such scientific experiments proved "spontaneous generation", the belief that live maggots would spring from dead meat, by a generation of scientists who did not understand what they observed in the field of biology. In science, this is avoided by the process of prediction and experiment--by determining that if a theory is true, then a certain experiment will have a certain outcome.
Eventually, most scientific theories are at least modified if not abandoned, as experiments uncover incorrect predictions--even Newtonian Mechanics is "false", in that it fails to account for the behavior of objects as they approach light speed (among other things). But if I want to know the end of the road, I could also ask several people coming the other direction what was there, and see if they gave similar accounts--this would qualify as legal evidence. In law, we identify different levels of proof. A "preponderance of evidence" means only that something is more likely than not; "clear and convincing" means that other possibilities seem extremely unlikely; and "beyond a reasonable doubt" means that no reasonable person could come to any other conclusion. If your son comes inside and tells you that the lawn needs cutting, is that not evidence that it is still there? And is that evidence significantly worse than if you look out the window and see it yourself? To find out what is at the end of the road, I could seek historical evidence. There may be maps and books in the local library or township records office which tell when and why that road was built, and what was built since then. Historical evidence is sometimes difficult to gather and interpret, but it, too, has rules which create levels of certainty. And at this point it is probably apparent to you that most of what you know--especially most of the scientific information you know--you believe based on evidence which is not scientific. You and I have never performed the experiments which demonstrate the basics of relativity; we have probably not even read the data from those experiments. Rather, we have only the testimony of those who taught us this information, who themselves probably learned it as we did. As legal evidence, this would be hearsay, inadmissible in most English-heritage courts most of the time, because it is something that neither we nor our teachers knew of our own knowledge, but only a recitation of what we have been told by others, and therefore suspect. After all, the jury may evaluate whether we are honest and intelligent; but they cannot evaluate whether those who told us were honest and intelligent, and so cannot reasonably weigh the reliability of the information.
Thank you again for entertaining my thoughts; as Augustine said, "I am one of those who by profiting writes, and by writing profits."
And let me pass on a gem of my own. In another more magical universe (created for Multiverser), Ruthra C. Kralc has postulated, "Any sufficiently advanced magic is indistinguishable from technology."
--M. J. Young
