Geek moment: Does Connie Willis' Time Travel Require a God?

Wandered in on my partners Sarah and Charles, who were discussing time travel in Connie Willis novels (Connie Willis, for those who have missed out, is the best science fiction novelist currently writing). In Doomsday Book, her best novel, Willis presents a world in which time travel is possible, but the universe – through some unknown mechanism – refuses to allow time travel that would cause paradoxes. And although people can travel from the present to the past and return, they can’t take anything from the past into the future.

In To Say Nothing of the Dog (the very funny sequel to grim-as-an-Idaho-bagel Doomsday Book), Willis develops her time-travel rules further: it turns out that objects can be brought forward in time, just as long as they were about to be lost to history forever, anyway. Kittens who were about to drown; priceless works of art moments away from being destroyed by fire; that sort of thing.

So it turns out that history can be altered; we can subtract, for example, a cat with no problem. But only so long as no one is in a position to ever notice the cat’s absence.

Sarah argued that Willis’ view of time travel was at the least deistic, and probably theistic. The universe isn’t random or arbitrary in what objects it allows to jump forward in time; it will allow such jumps only if it doesn’t cause a problem in human perceptions. This suggests a human-biased watchmaker, doesn’t it? The system decides what time travel is legitimate based on what humans would notice. (That other creatures – for instance, fish that might have found nourishment in an unfortunate cat’s corpse – not to mention the cat itself – have their life-paths altered doesn’t bother whatever’s in charge of time-travel).

Charles came up with an interesting counter-argument, pointing out that Sarah’s case was a bit like arguing that the laws of physics prove that the universe was designed for human life; because if any of those physical laws were even slightly different, human life as we know it could not exist. The problem with that argument is that if the laws of physics worked some other way, then whatever existed under those laws might say the exact same thing.

Looked at this way, Willis’ time travel isn’t necessarily deistic It isn’t that time travel adjusts itself around human perceptions of what is or isn’t an important alteration in the universe’s timeline. Rather, our perceptions of what is and isn’t a significant change are created by the time-travel changes the universe permits. If time-travel made it possible to change who our grandmother was or who won World War Two, then we wouldn’t perceive those things as significant changes; it would seem perfectly normal for the identity of our ancestors to change from moment to moment, just as it’s normal for the sun’s light to increase and then grow dim throughout the day..