Sometimes I get bitten by the science bug. It usually starts with an article or a documentary on Discovery Channel - some topic sparks my interest and I spend a few days reading articles on the internet and checking books out of the library. By the time I'm done, I have a pretty fair idea about how this thing works.

One of my longstanding favorite topics is the idea of "multiple universes." The concept I like is the "diverging paths" theory. For the uninitiated, the theory (really a hypothesis, but why split hairs?) is that for every choice we make there exists a reality in which the opposite choice was made. For example, if I chose to turn left at the stop sign there's a reality in which I turned right. Consequently, there are realities in which I went straight, backed up or never even made it to the stop sign at all. For every possible choice, there is a reality in which that choice was made.

Multiple realities. Multiple universes.

Let's get heavy.

Ok, so recently I watched a program on the SciFi channel called "The Triangle." The basic premise is that a billionaire shipping tycoon hires four "experts" to tell him why his ships keep disappearing in the Bermuda Triangle. I won't spoil the show for you. If you're a scifi fan you should give it a watch, though. But suffice to say the story line involved theories of alternate realities and time distortions. In short, it was right up my alley.

But it got me to thinking. How does time relate to multiple realities? If each reality represents a path generated by an alternative choice made at any given time, you would think that time would be a constant. But then there's the notion of time travel.

Let me stop for a moment here and say that there is actually ample research to support both of these scifi concepts. First, noted scientists such as Stephen Hawking have hypothesized that time travel is possible, especially if one could approach the event horizon of a black hole. The idea is that as you get closer to the event horizon, time is dilated. It slows down enough that if you could move around the rim of the black hole at the speed of light then suddenly cut across the middle you could actually meet yourself before you left!

By necessity, if you could do such a thing then it stands to reason you could prevent yourself from making the trip in the first place. At which point theories tend to go crazy. What would happen to the "first" you? Would you simply cease to exist? And if so, you wouldn't be there to warn yourself not to go around the black hole, and therefore you'd make the trip, arrive before you left, stop yourself from making the trip...

This is sometimes called a "grandfather paradox." The idea is that if you could travel through time and kill your own grandfather before you were born, you'd never be born and you could never travel through time and therefore your grandfather would be safe. Of course, then you're born after all and you continue on this vicious cycle. A paradox.

But there are theorists who believe a paradox is actually impossible, and that if time travel does exist then there is a mechanism in place to prevent it from mucking up existence with some sort of mobius loop. The mechanism is what we discussed earlier - multiple realities. Instead of causing a never-ending loop and/or destroying the universe, a new reality would be created. In the case of the black hole, there would be a reality in which you had stopped your "alternate" self from going around the black hole in the first place, and thus now there is a universe in which you and your doppleganger exist side by side. By necessity, you would have crossed out of your original universe and therefore would no longer exist there. Time would go on without you.

In the grandfather example, a new universe would be created in which you were never born, and now you would exist as a being with no origin, no beginning. You would have no parents - in fact for all intents and purposes you would have sprung into existence only at the moment you arrived in the past. Creepy, huh?

So here's where my current musings started. If time travel is a possibility, and if multiple realities do exist, is "time" really a constant?

Think about this - You breach whatever barrier presents us from moving between one reality and another. While in this alternate reality you meet yourself, you help build a house, you play poker, you do a thousand little things. You and your alternate shelve are good pals. You have no problem sharing the same ice cream cone. But let's say that somehow someone alters time in your universe. They do something sinister, like keep you from being born.

In theory, they're creating an alternative time-line - one in which you were never born and never entered into another universe. But (and here's where it gets really tricky) that would mean that not only would there be a universe in which you never existed there would by necessity have to be a universe in which you never arrived to become buddy-buddy with your alternate self.

Ok now I need to step back again, because frankly this is confusing stuff we're dealing with! Let's call your original universe "Universe A." The alternate reality you visit is "Universe B." When Mister X goes back in time and wipes you out before you're born, he creates "Universe C." Now I know what you're thinking, that would make the Alternate Universe, in which you would now never arrive, "Universe D."

But would it?

If every alternate universe exists as a result of an alternative choice being made, would a new universe be spawned if the choice was PREVENTED? Can the ominous execution of your grandfather actually spawn TWO universes at the same time?

It comes down to a question of targets.

See, this (for me) is where the Alternate Reality and Paradox theories start to get really, really messy. Let's say that Universe A and Universe C were literally identical in every way. Every choice the same, every outcome identical. If not for the intervention of our notorious grandpa killer, they would have remained one universe - Universe A. Universe C would not have existed. And in universes A, whatever choices or actions you took landed you in a specific reality, Universe B. But because of Mr. X killing off gramps, you never went to Universe B, and therefore never had any contact with your alternate.

Because the outcome of Universe B doesn't hinge on your crossing over, it's entirely possible that for the first time in all of this we've actually managed to CHANGE a timeline without creating an alternative to it! At this point, time is no longer "constant." It has been somehow twisted - a pocket exists somewhere in which you were there, but you aren't.

So is that our missing "Universe D?" A pocket dimension that no one would even remember? Is it truly possible for something to NEVER have existed? Or rather, for it to be so thoroughly wiped out of existence that there could be no access to it and no memory of it? Or is it possible that regardless of the fact that you would never have actually been there, a reality still exists in which you were? Every possible outcome does, after all, mean every possible outcome. So in theory there is a reality which did no exist until you arrived.

Actually, there is a quantum theory that would support this. The idea is that we create reality by observing it. We change the world around us by our expectations of it. And if this is true, then it turns a lot of "alternate reality" theories on their ears. Because it implies that we actually have to ablity to create an entire universe just by expecting it to be there.

Mull that one over while you eat your Frosted Flakes.