“Nothing in the world is easier than traveling in time. Just wait five minutes, and you will have moved that far into the future.”
–Sean Carroll’s review of J. Richard Gott III’s Time Travel in Einstein’s Universe: The Physical Possibilities of Travel Through Time, published in 2002 in Physics Today, link
But what about time travel the way you and I usually think of it–what about accelerating forward or backward in time? This is the sort of question you ask yourself if you’re either a nerd or a writer working on a time travel novel. I happen to be both.
I’ve found out some pretty cool things about time travel in the past couple weeks, the most exciting being that I am a time traveler in the super-cool sense–I have accelerated through time! So have you if you’ve ever flown from London to New York or an equivalent distance. You see, according to Einstein’s theory of relativity, time is elastic, not constant, and depends upon the speed at which we move. But it’s more than theoretical. Atomic clocks have been used to confirm that if you fly from London to New York, you will have accelerated a few billionths of a second in time. (Paul Davies, “Time Loops: A Talk With Paul Davies” on 3rd Culture, link.)
Accelerating forward in time is possible. Accelerating forward enough to be exciting, well, it’s technically possible, but we can’t move that fast yet. We’d at least need to reach the speed of light to be able to really do anything cool.
Although I still think it’s cool that I can call myself a time traveler. I’m going to call myself a time traveler, anyway!
So what about backwards time travel? As a historical fantasy writer, this is the stuff I’m most interested in, and it’s anybody’s guess as to whether or not it’s possible. There are lots of theories as to why it’s not possible, and there are lots of theories about how it might in fact be done. (See Wikipedia for a basic overview.) I, of course, am going to pretend that it’s totally possible!
Oddly (or at least, I thought so), the concept of backwards time travel is a pretty modern idea. (Again, see the Wikipedia article.) It first appeared in the 1700s. But forward time travel in myth has been around since ancient days. I wonder what this says about the nature of man. Have we in the past been looking ever forward to the wonders of the future, and now that the wonders of the future have begun to appear, we look for the wonder in our past?
Of course, it’s also possible that Wikipedia has missed some examples of backwards time travel myths. I’ll have to look at other sources…
There is far more I could say about time travel, but I’ll leave that to the physicists. Check out this site if you’re interested. It lists oodles of articles on all things time travel.
I have time traveled ten minutes into the future since I began writing this post.