Tuesday, June 21, 2011

Time Travel Science Behind Dormant

Part two of my series on the science behind Dormant is about time travel.

Everyone time travels. We age and the planets move around the sun, but that’s not the stuff of science fiction. Despite our measurements of time on the face of a clock, it does not flow at a constant rate. Time is relative. In addition to the spatial dimensions of length, width, and depth, the most crucial fourth dimension is time. I’m sure that other Trekkies out there have heard of the space-time continuum. Time can’t exist without space and space can’t exist without time.

Time travel to the future has been proved. Gravitational time dilation occurs because time passes faster in orbit. Global positioning satellites accrue an extra third-of-a-billionth of a second daily. Personally, that kind of miniscule time difference is hard to grasp, but it does exist. Gravity is a curve in space-time, according to Einstein’s theory of general relativity; gravity pulls not only on space but also on time.

Speed is also a factor in time. The closer you get to the speed of light, the more slowly time passes. The illustration postulates a “twin paradox.” One twin goes off on a voyage close to the speed of light and the other one stays home. When the space-traveling twin returns home, he has aged only a little, while the twin at home has aged at a regular pace.

Time travel to the past is under debate. A variety of methods have been proposed for how this might happen (e.g., cosmic strings). I like the wormholes in Star Trek. When a wormhole pops up, you know the crew is off on an adventure. Wormholes are a hypothetical tunnel connecting two regions of space-time. A wormhole can bridge two parts of one universe or two completely different universes. “Wormholes are the future, wormholes are the past,” said physacist Michio Kaku, author of Hyperspace and Parallel Worlds. The challenge comes in punching a hole in the fabric of space-time. The energy required would be enormous, equal to the energy of an entire star.

Physicists who doubt the possibility of time travel to the past cite string theory, which views matter in a mind-boggling 10 dimensions. I can’t wrap my brain around that many dimensions, so I have to take their word for this. However, the theory says that if you are very optimistic and fiddle with the wormhole openings, you can change the shortcut to go not only from one point to another in space, but also from one moment in time to another. The problem is that despite time travel to the past being theoretically possible, it is practically impossible. We just don’t have the technology.

So what about the grandfather paradox of science fiction fame? If you could travel to the past and murder your own grandfather, do you cease to exist? The causality chain that made you doesn’t exist, so you don’t exist. Perhaps the answer is that you can’t murder your own grandfather because your gun jams, or he bends over to tie his shoelace.

My attempts to wrap my brain around the topic of time travel included reading books like Black Holes, Wormholes, and Time Machines, by Jim Al-Khalili. Many of the physics concepts are beyond me, because my brain just does not work that way, but I learned enough to flesh out the time travel experiments of my physicist character, Dr. Preston Scott. His research creates a unique kind of trouble for Jackie Davenport.

The Science Behind Dormant


  1. Enjoyed the Time Travel 101 lesson. Thanks.

  2. Time travel is one of those things I can't really get my head around. I guess that goes for most of physics actually. :)

  3. I recently needed to help my partner out on a scifi script involving wormholes and time travel. The only wormhole physics book that I could find with enough detail to allow me to extract useful jargon was The Physics of Stargates by Enrico Rodrigo. You can find a Wormhole FAQ excerpt from his book here.

  4. Robert: Glad it made some kind of sense! :)

    Coral: Ditto, but I'm completely fascinated with the ramifications of time travel.

    Rick: Thank you for the reading references! Your book looks more recent than the one I read. I just wish it was available as an ebook. I'm headed over to check out the Wormhole FAQ now.