The first thing I would say is that the terms 'alternate universe', 'multiverse' and their ilk are misnomers.
The term universe is defined in the American Heritage Dictionary as 'All matter and energy, including the earth, the galaxies, and the contents of intergalactic space, regarded as a whole.'
The term is derived from the latin uni, or one, and versus, or turned. A literal translation is 'All turned to one,' or as stated, a single term that defines everything.
By definition, anything that one would refer to as an 'alternate universe' is already accounted for and contained within the term 'universe.'
That said, my complaint is purely semantic. 'Alternate universe' is a term basically used to give a name to a concept that is difficult to put simply.
As far as living in more than one universe at the same time, if you believe in the 'many worlds' theory, we all already are. The 'many worlds' theory, at its heart, dictates that anything that could possibly happen does happen. To explain more thoroughly- at any point in time where a choice is made, or anything left up to chance happens, the 'worldline' (kind of an amalgamation of timeline and world) splits in as many different directions as there are choices. The implication here is that there are a nearly infinite number of possible universes that exist simultaneously.
This is an absolutely HORRIBLE theory to believe in, not because it is wrong, but because of what it can do to a believer when they come to a serious realization of how huge an effect a seemingly innocuous decision can be. One of the more sinister aspects of the 'many worlds' theory is also known as the butterfly effect. This refers to the fact that our planet is essentially one big continuous system. A butterfly flaps its wings on one side of the planet, which causes a miniscule drop in pressure on one side of the wing and a miniscule increase on the other side. This causes a larger shift as air moves to 'fill the gap' and air expands from the increased pressure point. The changes are always small, but they essentially 'radiate' from there, and ultimately, in one example, cause the path of a major storm to shift less than a single degree. But because of the distance this storm travels, that tiny change in direction causes the storm to make landfall MILES from where it otherwise would.
Does that sound silly? Don't laugh so fast. Watch the weather report sometime. How accurate is it? They can get close sometimes. Other times, storms will form completely unexpectedly or dissipate when disaster is expected. Everything in our world effects everything else in some way. It's physics really- energy and matter are neither created nor destroyed.
This butterfly effect, when viewed in terms of the many worlds theory, has the staggering effect of making simple choices have potentially enormous consequences.
Real life example: You have a choice between a red top or a black top when you go out one day. You choose the red top. That red top stands out a lot more than the black top does, and you catch the eye of a nice guy and hit it off with him. You end up getting married to him, having kids, and all that great stuff. Thats just the result of one simple choice.
In the many worlds theory, however, there is a you who chose the black top instead. You blend with the crowd more without that bright color to distinguish you, and the guy never even notices you. You're out the love of your life.
Easy choice, right? Wrong. In another world, the guy who you would have met chose to stay home and watch tv instead. That red top, instead of attracting the love of your life, got you the attention of a smooth-talking pimp who first gets you drunk, then gets you hooked on heroin, and forces you to work the streets.
What if not attracting attention to yourself means you finish up your degree, or at least finish it quicker, and the work you do, even just as a student in a research lab, leads to a cure for some terrible disease?
You can apply this to any kind of choice, which is why I adamantly refuse to believe in the many worlds theory. Not because I believe it is wrong or right, but because I don't want to live my life in that mindset, second guessing every choice I make, and hoping that the choices others make don't ruin it for me. While the butterfly effect doesn't require the many worlds theory to 'work,' the only thing that would bug me more than obsessing over every little decision would be the thought that, when something goes wrong, theres some smug-ass 'other' me whos coasting through because the decision he made, without even seeing the long term effects, gave him a ride down easy street.
1905
