Do you remember the first time you had a crush? Well, how about an author-crush? That’s what I call it when I find an author whose work I enjoy so much that I feel compelled to read his or her entire collected works. In recent years, this has included Arthur Conan Doyle and Jules Verne, but it all started with Kurt Vonnegut. I vividly remember the experience of reading Slaughterhouse 5 in high school, and within a year I had read every one of his 14 novels. Not only was Slaughterhouse 5 a gateway to science fiction in general and Vonnegut specifically, but it was my first exposure to time travel in literature.
In Vonnegut’s story, the main character, Billy Pilgrim, is “unstuck in time.” He does not travel to the far flung past nor the distant future. Instead, he is able to travel along his own timeline, from birth to death, and is doomed to do so forever. For the reader, the story takes one through different events in his life, but not in a linear fashion, and he always returns to the same experience. He and his platoon were trapped in a slaughterhouse during the bombing of Dresden in WWII (like Vonnegut himself), and he finds himself reliving this trauma over and over again. Pilgrim makes these journeys within his own body, he is not watching the events of his life unfold from outside himself. Rather, he re-visits scenes from his life but is powerless to change them.
When a person mentions time travel, this is not what usually comes to mind. Generally, we think of a person climbing into a contraption such as the one in H. G. Wells‘ classic The Time Machine and riding their way through time, their own body unchanged. This may happen purely out of curiosity, but as often as not the goal is to avert a disaster. In some earlier installments of this series I discussed alternate histories and making your story futuristic, so it might seem like there isn’t anything left to say about time. I may have discussed the past and the future, but that still leaves us with the mechanics of time travel.
For my birthday in 2013, I received an incredible collection of short stories called The Time Traveler’s Almanac. This tome, numbering a whopping 948 pages, was edited by Ann and Jeff Vandermeer (of The Steampunk Bible fame), and contains the best of the best when it comes to time travel fiction. In addition to tales written by notables such as Ursula K. Le Guin, William Gibson, Ray Bradbury, and Isaac Asimov, there are very interesting essays that divide the sections. The information in this article is largely adapted from “Time Travel in Theory and Practice” by Stan Love.
We are all traveling through time, it is simply in one direction at a uniform speed of 3600 seconds per hour. This doesn’t sound nearly as fun as it is to imagine a quick jaunt to the Jurassic or popping over to 2300 for a cup of hydroponic super coffee. This is the stuff the imagination, of science fiction. But, hard science does offer some interesting tidbits about what we could expect from time travel with the knowledge we already have.
Albert Einstein offers us two theories concerning traveling forward through time, a General one and a Special one. General Relativity has to do with the interaction between extremely massive objects and smaller ones that are trying to escape their gravitational pull. Now, assuming that your ship can move at just barely slower than the speed of light, and you are trying to get away from say, a black hole or a neutron star, time acts really funny. Inside the ship, time will slow down, at least as it appears to an outside observer. If you get too close, the tidal forces of the black hole will tear you apart. The side of the ship facing the gravitational force would experience a stronger pull than the other side, and stretch away from the other side of the ship, causing the whole thing to elongate. This phenomenon has the delightful name of “spagettification” or “the noodle effect.” The side closer to the gravitation force will also experience time slightly differently (due to gravitational time dilation) than the side that is farther away, and both of these are different than what the outside observer experiences.
When I learned about Special Relativity, I was in a delightful class with the nickname of “Physics for Poets” (the more lyrical counterpart to “Rocks for Jocks”). My professor was a long-since tenured, adorable old man who wrote and illustrated his own text book, which meant stick figures and rudimentary rockets. He explained the classic Twin Paradox of special relativity using stick figures named Moe and Joe (and later their sister Roe, but we only need the first two for this theory). This thought experiment has been part of the discussion of physics since the early 1900s, and will remain a thought experiment until we are able to travel at near light-speed.
Alright, so there are twins named Moe and Joe. Moe gets into a rocket ship, and Joe stays behind on Earth. As Moe’s rocket approaches near light-speed, Joe checks in with a telescope. Moe will appear to be moving in slow motion from Joe’s outside vantage point. Moe’s clock will tick at a slower rate than Joe’s, and the wavelengths of the light source in her rocket will shift toward the red end of the spectrum (because they are being made longer through the noodle effect). When Moe returns to Earth, she will have experienced a fraction of the Earth-time that Joe did, and so Joe will be older. There is a lot of math and experimentation with super small objects to back this up, and you are welcome to explore that further on your own if you are really into facts and figures, but the stick figures and kindly old professor was good enough for me.
So, in theory it is totally possible to move quickly into the future, but so far we haven’t come even close to reaching the speed required to try it out with a human being. A person would have to get up to about 300,000 km/second in order to do this, and so far we have not discovered an energy source capable of generating this much energy. And frankly, if we did, I doubt we would use it to hurtle someone into the future. Because, like I said, we are already moving into the future all the time.
Later this week, we will take a look at the scientific implications of moving backwards through time, so stay tuned for part 10.2 of the How to Punk Your Steam series.