In a previous post, I claimed to have spent Worldcon discussing such subjects as the “seven types of elasticity in time travel” and “four types of alternate technological history.” Ted Chiang was kind enough to take time off from his furious writing schedule and inquire if I could elaborate. (Bluff-calling bastard.)
Certainly, I can elaborate. I wouldn’t just throw those numbers around like they were nothing, would I?
Tonight, I’ll start with the major forms of time-travel elasticity. Seven of them. Um, yes.
But let us start by defining our terms. For those of you who may not know, elasticity in time travel stories is a tendency for historical events to wind up the way they’re “supposed to,” a narrative device to make things palatable to those of us living in a fixed history. Elasticity is the timeline “snapping back” to its “proper” shape, more or less. Generally, TV and Hollywood time travel tales are more conservative, employing firmer elastics than literary sf, which doesn’t mind messing up the timeline a little, or destroying it altogether.
So here are the seven flavors of time travel in all their glory. Well, okay, the first three:
Type 1: The Full Elastic Jacket
Doug and Tony go back in time, and find themselves on the Titanic. So they head up to the bridge and tell the captain that the ship will soon hit an iceberg and sink. Full of Victorian hubris (okay, Edwardian hubris, and maybe some gout) the Captain proclaims, “This ship is unsinkable!”
Doug and Tony try various other avenues, but nothing they do will change history. The Titanic sinks on schedule, but not before they are whisked back into the present, having learned a valuable lesson about pride going before a sink. And that you can’t to jack with a time tunnel.
This is an actual Time Tunnel episode. It’s also the plot of a kid’s book I read once. But you know what? There are 1,005 books on Amazon with the word “Titanic” in the title, so I ain’t looking it up.
Doug and Tony weigh the ethics of saving some male Guggenheims and a few hundred lower-class types.
Type 2: Achy Breaky Time
In this schema, travelers can go back in time and change history, but they better not mess it up too much! Basically, the timeline is like your parents’ liquor cabinet. You don’t have to leave it exactly like you found it, but be careful. One drop too many and there’s going to be a freakout of major proportions.
John Varley’s Millenium is about Achy Breaky Time. Travelers from the future jump back to the present to steal people who are seconds away from dying in plane crashes. They use these lucky/unlucky souls to repopulate their own barren era.
Generally, the plane crash destroys all evidence of the travelers’ appearance in our time, preserving the timeline from paradox. But one day, a weapon from the future is accidentally left behind, survives the crash, and is discovered by a present-day crash investigator. This anachronistic artifact begins a chain of changes in the timetime, history slowly stretching out of shape. The changes build up slowly but surely, until “timequakes” start to rumble. Unless the anomaly is fixed, the timeline itself may be destroyed, which pretty much means everyone, everywhere and everywhen, is doomed. Time is elastic like a rubber band; you can change its form, but it will eventually snap.
High stakes. Except, of course, that if the heroes fail all the people they were trying to save never existed in the first place. No harm, no foul.
Also, when exactly are the timequakes happening? And when the heroes say that time is running out, which time is running out?
Type 3: Heisenberged Time
In Kage Baker’s “Company” novels, you can change history, but not recorded history. Thus the agents of the Company can go back and grab extinct species, lost artworks, and other vanished ephemera. But these agents are limited in their actions by time’s elastic, which is inscribed in the history books in their future employers’ libraries.
Exactly how this works scientifically, and what constitutes “recorded history,” is best not thought about too much. But it does eliminate paradoxes, because we all know that all the important history is written down.
Baker’s other ingenious move is to make time travel possible back to any point, as long as it’s before time travel was invented. All eras after that moment are inaccessible, which is a totally cool and Heisenburgian idea: The invention of time travel has changed the nature of time itself, changing it from elastic to totally locked up and inaccessible.
Okay, that’s three. I’m going to sleep now, and I’ll do the other four . . . soon. (Help me out here, guys.)
And then the four types of alternate technology. Oh, yeah, looking forward to those.