Wednesday, October 24, 2012

Time Travel: Many Worlds vs Causality

Time travel, as far as I can tell, will pretty much remain fiction.  But that's not to say it's not fun to conduct thought experiments into the "what-if" scenarios.  Rules of time travel in fiction have varied, but recently I had the fortune to read two great novels back to back that described things in their own clever way.

Neal Stephenson has an interesting talk about his book "Anathem" on youtube.  The talk surrounds his involvement with the Long Now clock. The Long Now clock is designed to have a period of ten thousand years.  His book Anathem builds a story around a similar clock in a fictional universe that is used to limit interactions of scholars for long periods of time with the outside world and each other.  I ended up buying and reading the book.  I'll avoid spoilers and just recommend it as a great read.  In it he ends up describing a Many Worlds interpretation of time travel.

At some point during the few weeks it took me to read it, I was drinking beer with a friend and ended up talking about how great Anathem was.  During our conversation he recommended an Orson Scott Card book: "Pathfinder".  A few days later he brought me his copy of the book and it sat on my shelf until I finished Anathem.  When I did finally get around to it, I was excited as the plot developed into a causal interpretation of time travel.  What an awesome transition of thought.  All the rules in Anathem were different in Pathfinder.

Reading these two books back to back ended up being interesting and useful.  It was neat to see two of my favorite authors try their hand at the notoriously difficult thematic concept of time travel.  If you have the chance to pick either one of these books up, I'd recommend the experience of reading the other one immediately afterward.