2006.02.06
What would you do if you had a time machine? Did I hear something about lottery tickets, or maybe importing flying cars from the future? No silly, you would go back in time and kill your younger self. Then you would never be able to use the time machine to go back in time in the first place. So you're safe! But wait! Now that you're safe, you can go back in time and do the deed after all. But wait! And so on.
People always bring up this paradox when they talk about time travel. Science fiction authors have solved the problem long ago using multiple time lines. You can go back and kill your younger self. By changing history you have created a new time line with a dead younger you, and your older self with blood on your hands. Supposedly the original time line is still out there trucking along with your family filing a missing person report, despite the "I'm off to the past, back for dinner" note you left.
The thing to realize though, it is not the murder of your younger self that caused the time line to split. It was your arrival itself that cleaved history. Your very appearance and the air molecules that were pushed out of the way as you popped in have changed history irrevocably. Even if you send one tiny photon back in time, that is enough to shift things ever so slightly into a parallel history.
Movies don't usually handle these issues very well at all. For example Back to the Future makes no sense whatsoever. Doc Brown in the movie seems to explain the situation using the standard multiple timeline paradox avoidance, but the events contradict that when Marty starts to fade away by interfering with his parents' first date. What if Marty failed and he popped out of existence? The paradox still holds that he should now be safe because he never existed to interfere in the first place. If the movie is really using the multiple timeline idea, then Marty shouldn't be fading at all, but by failing he would be stuck in a history where he was never born. That situation would not be a paradox, because Marty came from the parallel timeline.
In the movie Marty doesn't fail and he returns to his present time of 1985. Here we see the changes wrought by the coaching he gave his young father. A new truck! A well adjusted family! And best of all a cowering Biff who seems to have become some kind of servant. What I want to know is, what happened to the Marty that grew up in this new blessed home? Our Marty seems to have no memory of getting this new truck, but his new family seems to know him well. Maybe Marty II also took Doc's time machine and went off to other timelines. That idea would have been cool, but Doc gives no indication that he ever knew a Marty II with a fancy truck and an affluent family.
So finally I am going to say something about the book I mentioned yesterday. It's Stephen Baxter's The Time Ships. I just finished reading it for the second time. Sometimes when I re-read a book it doesn't live up to the golden memory of the first reading. This book however was just as enthralling as it was when I first read it ten years ago. The story picks up right where the original H.G. Wells novel, The Time Machine, left off, and takes the story to its extreme. I only wish H.G. Wells could have read this sequel himself.
Maybe this book isn't fine literature, and I know you literary snobs out there like to pick on science fiction. In fact The Time Ships is a bad example, because it actually does have two three dimensional main characters. Another Baxter book (co-written with Arthur C. Clarke) that is a better example of a pure science fiction book of ideas, and little else, is The Light of Other Days. This book is also about time, but not traveling through it. I can't really say more without ruining it for you. The ideas in it though are so interesting, you don't care that the characters are two dimensional. At least I don't.
I know some people are not satisfied with these kinds of books. They need art and emotion. I enjoy those kinds of books too. Recently, I very much enjoyed Snow Falling on Cedars, which is a book quite different from, for example, Snow Crash. I enjoyed both equally, but in different ways. I guess I can't relate to people who can't enjoy both types of books, whether they are literary snobs or "Sci-Fi" nerds. To me those kinds of people are lacking some dimension of imagination. They themselves are two dimensional characters.
As I was telling my family during our conversation yesterday, the deep reason I like the kinds of science fiction stories that show visions of the future is my disappointment with death. It isn't the fear of death, but my disappointment in not knowing the end to our story, which is the future history of the human race, and whatever life comes after us. Being a skeptic I have my doubts about an afterlife, so if there isn't one, I will be quite annoyed that I won't get to see what happens at the end of the story. Yes, it would be hard to feel anything with no afterlife, but I can be annoyed now!
Today's interesting link: Hyperspace Star Polytope Slicer
--Old blog comments:
February 6th, 2006 at 8:45 pm
jer Says:
I've had many a conversation regarding the way movies munge timetravel over
the years. One of my favorites involves Back to the Future 3; see
during all the antics of trying out different types of fuels in the
DeLorean, there was in fact a dublicate DeLorean sealed up in the cave.
Couldn't they have simply syphoned out the gas for use in the other
DeLorean? Sure, I suppose it's a possibility that Doc would have
drained the tank before putting the car in storage, but he surely
wouldn't have simply thrown the gasoline away?
In any case, being able to write about time travel as you are, I think you'd be interested in a podcast that I discovered the other day called the Sci Phi Show. Phi as in philosophy. This entertaining Aussie basically talks about scifi movies and the philosophies either beind them or insinuated by them. Each episode is about a different movie/philosophical theme, and the time travel one was rather informative. Here's a link to that particular show:
http://www.ourmedia.org/node/97250
Enjoy!
ps, I replied to your comment on my TAM4 post.
-February 6th, 2006 at 9:33 pm
GNBenson Says:
Thanks for reading my post. I was a little shocked about how
long it came out so I didn't think anyone would put in the effort.
(I probably wouldn't have myself!) I will try to keep things trim
next time. I will surely check out that podcast. It sounds interesting.
As I said in my reply in your blog I will send an e-mail later to write a little more about atheism. In fact now that the gears are turning in my head I might use that e-mail as a basis for my next post.