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"Hot Tub Time Machine" hits fast forward on time travel movies

With the release of Hot Tub Time Machine, we have entered a new era of science fiction. But unless you were paying close attention, you may have missed the paradigm shift.

In past decades, movies about time travel seemed to focus primarily on the butterfly effect (how a small change in the past can make a huge difference in the present) and paradoxical questions (What if you traveled back in time and prevented your own birth?).

Those sorts of premises are the basis for movies like The Butterfly Effect (surprise surprise), Back to the Future (I, II, and III), The Terminator series, Bill and Ted's Excellent Adventure, and on and on. It wasn't always that way. In fact, I would call the sort of time travel those movies depict as the second coming of time travel fiction. It's a very empowering take on things, which is just what you might expect from the me generation of the time, because it emphasizes how important even the least significant being or event can be in the long run.

In older interpretations of time travel, people and their actions are essentially meaningless in the grand scheme of things. The classic book (and later movie) The Time Machine by H. G. Wells, for example, follows a brilliant scientist's adventures as he travels across hundreds of centuries. At the end of the book, after battling the evil Morlocks and falling in love with a beautiful and fragile Eloi, he ends up right back where he started, just in time for dinner. He fails to convince his dinner guests that he went anywhere (anywhen?) at all, primarily because he might as well never have left, for all the difference it made.

In Wells' interpretation, it's as if past, present and future are somehow permanently set, inscribed on the four dimensional universe like a panorama chiseled on the Great Wall of China; we can only see a little at any moment, but no matter how far forward or back we move, we can't change the pictures.

You may not have realized it, if you happened to see Hot Tub Time Machine, but we have now moved on to yet another interpretation of time travel: the multiverse.

Considering the fact that Hot Tub's Adam (John Cusack), Lou (Rob Corddry) and Nick (Craig Robinson) were weened on movies like Back to the Future, it's not surprising that they believe the old school time travel rules they remember from their youth. That's why they struggle to do exactly the same things they did on their epic ski trip in the 1980's, for fear that even the slightest change in the past will jeopardize the present existence of Adam's nephew Jacob (Clark Duke).

In the end (I'll try to be vague enough not to spoil it for anyone) they return to a radically different present than the one they left. However, it's not because of the butterfly effect or the grandfather paradox. The shift in premise is a bit subtle, but there are no time travel paradoxes in Hot Tub because their actions in the past don't actually change the present, instead the movie just follows the group along a path to a different, but equally valid, present.

Imagine the multiverse to be like a tree with many branches. Going back down the tree to murder your grandfather creates a new branch that leads to a time where your father and you don't exist. The branch you came from (where your grandfather did not die) is still there, as are many branches where different versions of you exist, and many where you don't exist at all.

The slightly different approach to time travel in Hot Tub leads to all sorts of mayhem and humor similar to, but not exactly like, the sort of stuff we've seen in the movies for ages. Nevertheless, I highly recommend Hot Tub, both because I love the sort of comedy that Cusack, Corddry and Robinson bring to their roles and because the film marks a major shift in science fiction. Mark my words, one day Hot Tub Time Machine will be required watching in film history classes everywhere, at least in this branch of the multiverse.


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