Saturday, June 20, 2009

Wormholes, Worldlines and Whatnot

In the first blog in this series, I talked about the many reasons that I felt time travel stories don’t work. I specifically mentioned the main physical, metaphysical, logical and aesthetic objections. In the second blog, I bravely took up the other side, and discussed how the Many Worlds Theory effectively rebuts the metaphysical objections, and to some extent, the logical ones. However, the physical, aesthetic, and to some extent, the logical objections remain. What’s a time travel advocate to bring up in his defense now? Answer: Wormholes.


A wormhole functions according the idea that spacetime is curved, and there can essentially be a situation where a bridge is created cutting right through that curve, a sort of tunnel between an earlier and later time. In other words, if time were a straight line ----, it would take you a certain amount of time to get from point A to point B. But if time were more of a “C” shape, you could get from one end of the C to the other much faster by cutting through it rather than going around the curve.

This indeed solves a lot of problems. It counters the physical objection, because you can have a wormhole where objects are not moving at the speed of light inside the tunnel, although they might appear to be to outside observers (a wormhole is not simply two black holes with a bridge between them, but rather a black hole and a white hole linked by negative energy).
The show Sliders made heavy use of wormholes and the Einstein-Rosen bridges between them. Wormholes also take care of my main logical objection, the Tourist Trap, which was that if time travel is possible at one point, it becomes possible simultaneously throughout the time stream. Scientists have postulated that time travel through a wormhole would require the “stationary end” to appear first. In other words, a wormhole couldn’t open up allowing you to travel back to someplace where there wasn’t a wormhole before. The point of this being that we may not have experienced time travel yet because the first “stop,” or the first wormhole, hasn’t been created/found yet.


There has been another use of time travel in fiction that I haven’t mentioned yet, but that I have found to be very effective. This is the idea of the worldline. Worldlines are essentially lines that travel through space and time at once, as opposed to a timeline that simply marks the passage of time. In other words, a person’s life, drawn on a graph, would be a worldline, as it plots their movement through space and time. Some time travel stories intimate that it is possible to travel back and forth on your own worldline, since it is simply a line that exists in the universe, not something that is being created or destroyed. Under the right circumstances you should able to walk back and forth along it like the path to your tomato garden.

This still does not address my aesthetic objection, which you’ll remember was that time travel stories are simply messy: Specifically, it 1. disrupts continuity and makes it difficult to invest in the characters, and 2. creates the slippery slope: You go back and change something, I go back and fix it, you go back and unfix it, ad infinitum. To close out this extended rant, I’d like to take a look at how some time travel stories handle all this and how effective I think it has been.

Star Trek

I frankly think that time travel has made Star Trek a pretty big mess. You can argue with the last movie that the Romulan time trip created a new, alternate timeline, and that the initial timeline is moving forth as it always had (albeit without a Spock). That’s okay, I guess, but I suspect we will never see our “real” timeline again, and even that timeline has been removed by so many jumps it hardly matters (for example in Star Trek, First Contact, the Borg go back in time and take over Earth, radically changing its history. The Enterprise crew goes back and fixes it. However according to the Many Worlds theory, the initial timeline was unchanged by the Borg, and the Borg’s new timeline was unchanged by the Enterprise; we simply have three different universes in effect. Yes I have a headache now too).

Quantum Leap, Watchmen, Slaughterhouse Five

I lump these together because they all make what I think is effective use of the “Worldline” theory of time travel. Dr. Sam Beckett can only travel back and forth through time within his own lifetime, while Dr. Manhattan experiences different times in his life simultaneously. Billy Pilgrim has come “unstuck” in time, and experiences his life randomly through time, jumping from one point to the next without rhyme or reason (or at least without rhyme). In each case, the universe is not offended by their time travel.
Back to the Future

Back to the Future alludes to the Many Worlds theory, but not quite effectively. Dr. Brown does explain how moving through time creates an alternate timeline. However, he creates a sticky situation when he does a test run by sending his dog three minutes into the future. The dog has clearly reappeared in the same timeline, which forces us to confront the possibility that somehow moving ahead in time does not create new timelines while moving backwards does. Marty also finds that changing the past is affecting his original present (the picture with his siblings disappearing as they are “uncreated”), which gives rise to the “grandfather paradox” anew.


Sliders handles the wormhole idea pretty well, but its protagonists are jumping through dimensions, not moving through time and space. There are no paradoxes because they never encounter the same timeline twice, although Quinn Mallory’s quest to return to his home dimension may prove impossible.

Comic Books

Members of the Legion of Superheroes travel freely back and forth through time with little concern about the consequences. The mainstream DC universe has not created a very sophisticated look at time travel although they used to have an interesting conceit where if you went back to a time where you already existed, you would appear as a wraith, since the same person cannot “be in two places at once.”

The Terminator

Terminator time travel isn’t too unwieldy for a number of reasons. The first is that only a handful of people go back before the time travel device is destroyed, and they can’t travel the other way. There are still some paradox issues, but since time travel is used so sparingly, it doesn’t interfere with the story too much.

Okay. I’m finally done with the time travel stuff. Next week I’ll go back to ranting about traffic patterns in L.A. or bad poker beats or why some Right to Lifers are psychotic or whatever.

No comments: