Paul Levinson, PhD, is Professor of Communication & Media Studies at Fordham University in NYC. His nonfiction books, including The Soft Edge (1997), Digital McLuhan (1999), Realspace (2003), Cellphone (2004), and New New Media (2009; 2nd edition, 2012), have been translated into ten languages. His science fiction novels include The Silk Code (winner of Locus Award for Best First Science Fiction Novel of 1999, author’s cut ebook 2012), Borrowed Tides (2001), The Consciousness Plague (2002), The Pixel Eye (2003), The Plot To Save Socrates (2006, 2012), and Unburning Alexandria (2013). He appears on CNN, MSNBC, Fox News, and numerous TV and radio programs. His 1972 LP, Twice Upon a Rhyme, was re-issued in 2010. He reviews television in his InfiniteRegress.tv blog, and was listed in The Chronicle of Higher Education’s “Top 10 Academic Twitterers” in 2009.
by Paul Levinson
Time travel is a tricky business. I don’t mean actual time travel, which is worse than tricky, and is probably impossible, since the only way grandparent paradoxes can be surmounted is by invoking a Multiple Worlds Interpretation, in which a new universe is created every nanosecond anyone travels to the past. For example, if in my journey to the past I prevent my grandparents from meeting, how did I come to exist and travel to the past in the first place? The MWI would allow it: in World 1, I travel to the past and prevent my grandparents from meeting, which triggers World 2, in which I was never born. This doesn’t solve every problem – what would happen to me, would I just snap out of existence, or continue as some kind of special being (PL #1) who would continue living in World 2, even though you and everyone else in that world would be #2?
Questions like that are what make me think that time travel is likely impossible. And they also make writing about time travel a tricky business – but lots of fun, if you enjoy giving your synapses a wrapped-into-pretzels workout. The key is taking the paradoxes that lurk around every time traveling corner seriously. Even if we don’t adhere to the MWI, in which a new universe comes into being with every drop of the time traveler’s hat, we need to trace the consequences of every act of the time traveler in the past – and the future, too, in which time travel runs smack dab into free will. If you travel to the future and see me wearing a light blue shirt tomorrow, does that mean I have no choice but to put on that blue shirt tomorrow morning?