Parallel universes are on the rise, as you can see from that line graph.
In the TV show Lost, the characters detonated a hydrogen bomb in an electromagnetic pocket so as to change the past and create an alternate timeline wherein the first five seasons of Lost never happened. (Obviously, fans of Lost loved this idea.)
In the TV show Fringe, there's a parallel universe where 9/11 never happened and Spock is human. Naturally, this universe has declared war on the normal one, 'cause nobody but nobody messes with Spock's ears.
This guy claims to have actually come into contact with agents from a parallel universe where the Beatles never broke up (and cover bands are killed on sight). Luckily, this agent had a tape of the Beatles' heavily-edited new album which, uh, harks to all their solo work.
If Spock wasn't having a hard enough time already, he fell victim again to the new Star Trek movie's alternate timelines, thanks to those meddlesome black holes of scifi yore. (Who knew that black holes could either destroy planets or spew people into different universes depending on your plot's need?)
Obviously, we need to sit down and listen to Red Hot Chili Peppers' "Parallel Universe" on repeat and consider this trend. Why the crap do we like thinking about parallel universes so much?
You could say it's a very human concern. Our good friend Bobby Frost wrote a whole poem about the irrevocable nature of decisions, the tragedy of only being able to take one path when presented with two.
I also think that we enjoy seeing "What if?" scenarios played out as a way of measuring the worth of our decisions. Whatever difference it was that Bobby was talking about, we want to measure it. It's isolating the variables in our lives so as to solve the equation, to know exactly what values X and Y should be.
I posit that life isn't an equation to be solved, an experiment to carry out or any kind of surgical process. The reason that our choices and decisions are so important to us is because they can't be isolated, and that we can only make every decision exactly once. There's no rewind on reality.
The idea that blowing up a hydrogen bomb or vaulting through a black hole can change a whole lifetime of decisions is the stuff of scifi, and I love it. But I wonder if maybe we focus too much on big decisions that spin lives and universes one way or the other, and not enough on small decisions that build up over time to make us who we are: stuff like what we watch, comments we make, who we talk to. Maybe we focus too much on decisions we already made a long time ago.
A parallel universe based on whether or not I say "hey" to a guy may not be that interesting, but that's the kind of decision we all make every day that builds our characters. Just food for thought.