As a general rule, I dislike time-travel stories. On the thematic side, many wind up being blunt and bludgeoning “commentaries” about what’s wrong with the world today (similarly to zombie movies), or condescending and superficial cultural missions to the ignorant. On the technical side, science fiction stories can quickly become irritatingly unbelievable given that characters have the superpower ability to disrupt the chain of cause and effect: they can act on hindsight preemptively (to go back in time before problems develop and nip them in the bud), or create hordes of paradoxes (such as the killing-one’s-own-grandfather paradox and others).

I was thus rather bemused to find that (without intending to) I’d read three science fiction stories in May that all dealt with time-travel and liked two of them: To Say Nothing of The Dog by Connie Willis, The Door Into Summer by Robert Heinlein, and The Anubis Gate by Tim Powers.

A Little Light-Hearted Paradox

Austin Powers II is only an OK movie, but it has a great bit of handwaving about the problems with time-travel (image via: this site):

Austin: So, Basil, if I travel back to 1969 and I was frozen in 1967, I could go look at my frozen self. But, if I’m still frozen in 1967, how could I have been unthawed in the 90s and traveled back to the 60s? (crosses eyes) Oh, no, I’ve gone cross-eyed.

Basil Exposition: I suggest you don’t worry about those things and just enjoy yourself.
[turns to camera]
Basil: That goes for you all, too.
Austin: Yes.

Essentially, the movie deals with the paradoxes inherent in time-travel stories by not taking them seriously. Many of my favorite movies about time travel (and most famous time-travel movies) are comedies (Back to the Future, Bill and Ted’s Excellent Adventure). If your goal, like Bill and Ted’s, is to bring actual famous historical figures to southern California for a high-school class presentation, I’m not going to be spending too much time looking for technical inconsistencies.

Restricted Travelers

Back to the Future was was also light-hearted, so one might expect the creators to have been breezy about the rules. But take a look at this list of answers posed to them, you can see they were not. One example:

Q: What happened to old Biff when he staggered out of the DeLorean in 2015?

A: Our intention regarding old Biff was that upon his return to 2015, he would be erased from existence because he had changed his entire destiny by giving his younger self the Sports Almanac. (Probably, Lorraine shot him sometime around 1996!). After old Biff clutches his chest and staggers (the same symptoms that Marty exhibited in Back to the Future when he was beginning to be “erased”), we actually filmed him falling onto the street and vanishing, and we previewed the movie this way (see The Secrets of the Back to the Future trilogy). However, the vast majority of the audience did not understand it, so we decided to cut it out, leaving the answer ambiguous, and subject to various interpretations—besides the above explanation, you can believe that Old Biff had a heart attack from the shock of time travel of from flying the car, or from something that happened to him in 1955. (image via: IMDb)

Even in this lighthearted comedy, the directors obviously felt it was worth their time to understand and account for the potential paradoxes of time travel. A novel writer is going to have a lot more audience time to work with than these directors, and so should be held to a higher standard.

The primary way to make a believable time-travel system is similar to that for creating a believable magical system: limit the ways in which powers can be used. In Back to the Future, they needed a massive amount of electricity, high speed, and bizarrely complex technology. In The Door Into Summer, Heinlein subjected time-travel to a variation of Newton’s third law of motion: in order to send something a certain amount of time into the past, a person must send an equal mass an equal amount of time into the future. Furthermore, one can never be certain which of the two items will go forward and which backwards, and there was a significant chance of miscalculation (whoops, you appeared eight feet underground). Add to that the good old standby of a government coverup, and you have a story world in which you can believe time-travel is nearly unheard of.

Self-Healing and Immutable Timelines

In To Say Nothing of the Dog (as well as The Doomsday Book, which is set in the same world), Willis uses an even more clever control mechanism—one I’d never seen before. She controls time travelers by giving the universe the ability to “heal” inconsistencies. Willis first draws a distinction between significant and insignificant events. While travelers are able to change minor events, the universe itself will prevent them from changing major events by blocking them from entering time portals, sending them to the wrong time or place, or when travelers think of clever ways to set off large chain reactions with small action, the universe will also set off a group of of events that cumulatively nullify the impact of the catalyzing action.

In the (exemplary) short story “The Merchant and the Alchemist’s Gate”, Ted Chiang takes this method even a step further: his narrator and the creator of his time portals are both devout Muslims in a unspecified time probably around the late Middle Ages. In it, the world has a strict timeline: travelers will never be able to change the past, even if they think they can. Unlike the movie Twelve Monkeys, which posits an unchangeable but impersonal timeline, in “The Merchant and the Alchemist’s Gate”, the immutability of the timeline is conceived of as being ensured by God.

Don’t Look at My Time-Travel System, Look at My Characters

Finally, since time-travel systems are often fraught, another way to deal with them is to shift the focus of the story away from being plot driven and towards being more character driven.

The Door Into Summer includes some of Heinlein’s prescient predictions about the future (the story was written in 1957 about a character who travels to 2000), but some extremely off predictions as well (the hero’s inventions are targeted at very 1950s housewives, presumed to still be the majority of women in 2000). Plot-wise it’s a basic, old-fashioned “triumph of the tough guy” story. In order to make it really carry, though, Heinlein needed a main character compelling enough to round out a standard plot with the difficulties of time-travel, and I thought he did.

In contrast, I never warmed to the main character of Tim Power’s The Anubis Gate enough to enjoy the story. With such a convoluted storyline it was always going to be more plot driven than character driven, but for me, the plot so overwhelmed the character that it seemed pushy: I couldn’t get into the story, because I always felt aware of Powers as he moved his characters around.

Though I liked The Door Into Summer, I liked Connie Willis’s To Say Nothing of the Dog much more. The story’s base time (from which the time-traveling characters originally travel from) is 2057, but the majority of the story takes place in Victorian England. Willis’s insight was to give the entire story pacing and style modeled on that of Victorian writers, particularly Jerome K. Jerome (the book takes its title from the subtitle of Jerome’s Three Men In A Boat).

The flowery and anachronistic language, comedy of errors convolutions, and eccentric characters left me cross-eyed but amused. I don’t think the story was free of self-contradiction. (She sets a precedent that time-travelers will see the results of their actions when returning to the future, but at the end of the book Ned seems to see a woman at Coventry whose history he’d changed—who should no longer have been there. If you can explain this, please let me know!) However, her focus was on the characters and her tone was sufficiently lighthearted that I didn’t worry too much about the time travel. When I did, the work she’d done to create her self-healing timeline satisfied me.

Done as well as Willis did, a time travel story can become a marvelously contorted tale.

Everybody loves to think that it’s the size of the fight in the dog, not the dog in the fight, that determines things. I like those underdogs so much, I was in the very small group of people who could suspend their disbelief enough to enjoy the Ewoks in Star Wars, Return of the Jedi. Of course, I was eight at the time, but…

The little two-foot teddy bears of Star Wars are the icons of Plucky Baseline characters: creatures or people that are hopelessly technologically backwards and yet still manage to overcome their hyper-advanced technologically- and sociologically-developed opponents (link is to the Orion’s Arm – a cooperative sci-fi universe project, a decent argument against the character type, though laced with the group’s own jargon).

Pluck in Action Movies and Fantasy Stories

For fiction set in our own world, plucky characters can usually get away with quite amazing upsets. Action heroes, especially, count on great indulgence from us in suspending our disbelief so they can win gunfights against dozens of opponents, jump vehicles over, around, and through bizarre obstacles, and generally act like one-man armies. Perhaps my favorite example of relatively believable pluck is when Sean Connery, playing Indiana Jones’ dad in Indiana Jones and the Last Crusade, manages to defeat a German WWII plane by scaring up a flock of geese to jam the plane’s propeller.

In fantasy stories as well, since the rules of the world are largely author-defined, writers can embed trade-offs in the rules of their universes that provide opportunities for Pluck. Usually the most powerful “technology” in a fantasy story will be magic, and thus the powers of wizards will need to be curtailed strongly in some way.

The default way to give non-wizards a chance is to make magic require extreme mental effort from wizards. I’ll mention I just finished Tim Power’s The Anubis Gate, and wizards in the story are limited both by the need to be close to “sources” of magic to perform greater feats, and the physical toll magic takes on them (pain and weakness, bleeding from the eyes, fatigue…).

Moreover, at the heart of almost all magical stories are human or human-like characters with strengths and weaknesses recognizably similar to our own.

Inhuman Perfection

The major difference in space-age science fiction is that there will be inhumanly advanced characters. We are already able to greatly increase the toughness of human beings, and may soon be able to significantly increase human intelligence, and this is in the 21st century. A casually spacefaring population will have had centuries to improve, advance, strengthen, and increase their longevity.

In such a battle against more recognizably “human” opponents (which would likely be the “good guys”, because nobody enjoys rooting for the overdog), the advanced race would win every time. Not most every time—absolutely every time, regardless of pluck. The battle wouldn’t be conceptually like Drake vs. the Spanish Armada, it would be like A Herd of Sheep vs. Boston, Massachusetts.

If a military dictatorship has access to mass genetic modification and cloning technologies, energy weapons, and super-advanced alloys, it will not lose to Ewoks. The dictatorship would not make the soldiers’ strength or reflexes, armor or equipment, susceptible to the sticks of little savages any more than it would create them with exposed brains.

(images: walker, ewok)

Hitting Above Weight Class

Of course there are lots of tropes in science fiction that stretch believability: that’s part of the fun. But to really draw in readers (less credulous than I was at eight) a science fiction writer will need to put together a force better than Fightin’ Ewoks. Readers are unlikely to believe your featherweight can take on a heavyweight in the ring, but they might believe a middleweight could do it.

Here are a few ideas for putting enough firepower in the hands of your overmatched heroes to make their upsets believable. If you can think of more, please respond with comments—I’m just improvising here.

1. If your advanced opponents are divided, a minority of them may either tip the balance by joining the heroes weakening the primary opponents.
2. In a more sinister twist, a high-level third party may actually be found to have manipulated the heroes, carefully guiding them to victory for its own purposes.
3. Technology at the fringes of an advanced society may be sufficiently up-to-date to pose a reasonable challenge to superior opponent technology at the center (provided the fringes have sufficient communications to stay “in the loop”).
4. Since some technologies are so advanced and as-yet scientifically unproven to be indistinguishable from magic (according to Arthur C. Clarkes old adage), you can use the fantasy tools such as trade-offs and critical weaknesses to give the antagonists vulnerabilities (an example of this would be in Larry Niven’s Ringworld, in which humans defeat more militarily capable opponents by improvising a weapon out of spaceship thrusters).
5. Throttling back the technological advancement of your societies makes it easier for humans like us to compete—if you want less of a gap between us and frontrunners, set the story closer to the present.
6. While it’s a recognizable sci-fi cliche, another way of making normal people important in the future is to have everyone live in the wake of the collapse of a superior civilization. Whatever destroyed that civilization or broke it up conveniently leaves some of the tools behind—allowing access to futuristic technologies without the insurmountable intellectual gulfs that would necessarily accompany them. As I said, though, this is a cliche and that means it would take more work to make a fresh story with this premise.