The various forms of elasticity constitute a middle ground, where you can have a little of both. I think they’re popular because nowadays we’re attracted to both notions: we like the idea that some things are meant to be, but we also like the idea that our choices matter. (In the past, people were more accepting of the idea of fate than they are now, I think.)

From a physics standpoint, I think you can argue for either immutable time or radically changeable time (or a multiverse), but I don’t know of any basis for an elastic model. Immutable time is a consequence of various physical theories, including special relativity. But if you posit that you can change anything, the mathematics of chaotic systems implies that shifting even a single molecule will eventually result in global changes.

Oddly, this reminds me of a recent article I read on the resurgence of the “Great Man” theory of history. The idea that, at any given time, there are about 12 people who are creating the world had falled out of academic favor for some decades, replaced with the notion that economic, social, political etc forces were shaping events more than individuals, who were simply stepping in to fill roles dictated for them by larger forces. I.e., if you did assassinate Hitler, someone else would have stepped into the power vacuum in Germany and mobilized tensions there to similar effect. However, ironically, George W. has renewed interest in the “Great Man” theory. While the artile wasn’t suggesting W was in any way “great,” it pointed out that in almost-single handedly forcing a war that a) wasn’t necessary and b) wasn’t popular with congress, the people, or the world at large, he has demonstrated how much (catastrophic) effect one individual really can have.

The other thing this discussion brings to mind is the way that science filters through into pop culture and effects our fictions. The original Star Trek very much adhered to the notion of “one timeline”, which, when broken, was always repaired – the break and it’s correction (as Spock points out in “City on the Edge of Forever”) always part of the design. This holds sway through the TNG episode, “Yesterday’s Enterprise,” in which Guinan senses the wrongness of a universe in with the Federation and Klingon Empire are at war, and impresses Picard on the necessity of repairing the damage. (Picard raises the question, “How do we know this timeline isn’t any more right than any other?” and Guinan stares him down.)

But this notion of a single timeline begins to break down with the latter episode “Parallels”, which sees Worf permeating through a variety of alternative timelines until everything culminates in a clusterfuck of thousands of Enterprises from a myriad different universes.

By Deep Space Nine, the notion of one time-line has radically broken down, as withness an episode whose title escapes me, in which Chief O’Brien is constantly teleporting back and forth to a future in which the station is destroyed. Despite the fact that each trip exposes him to radiation poisoning, he makes one final attempt to avert the encroaching disaster, meets himself of just minutes later on, dies, and sends his minutes-into-the-future self back in his stead. Upon his return, he wonders if he really has the right to call Kieko his wife, given that “her” O’Brien died in a timeline that was then prevented from occuring, and is reassured by his best friend that he’s still the Chief, even if his memories are out of whack by a few minutes. Since “most of him” is the same, that’s good enough.

Finally, when we get to Voyager’s first few seasons (where my knowledge of Trek ends, as my viewing of Trek did too), time has become elastic, fractal, alterable, permeable, and generally good for twisting into any shape the writers need. The two-part episode “Future’s End” sees multiple versions of characters encountered with no attempt to match cause to effect. Here, a crashlanding in the past has resulted in a boom in 1990s computer technology (seemingly the boom we ourselves experienced – thus the alteration IS the correct time), but the 29th Century timecop that is sent to prevent it is re-encountered twice, once as a sane individual aware of the outcome of the episode’s action, and once as a homeless man wandering deranged from the initial crash. Both versions co-exist in the same (final) timeline, and alterations and corrections made in the episode do not erase or negate the mad homeless version’s existance. I quite watching soon afterwards, but kept enough tabs on the show to know that they continued to play with multiple versions of their characters, and multiple co-existing and interacting timelines.

I haven’t quite put my finger on it yet, but I think that the move from an absolute time to fluid/fractal timelines somehow coincides with blurring questions of individuality and identity unconsciously coopted from the zeitgeist. It used to give me fits when Jeri Taylor would tell me “absolutely the holographic doctor is a person” and Brannon Braga would turn around and tell me “absolutely he is not.” They didn’t know themselves, but unconsciously, a lot of that series was about ascribing “personhood” to inanimate, but sentient-seeming, objects, which, to me, was perfectly appropriate for and indicative of an age where a woman ran over a biker because her tamaguchi needed food. As tragic as that sounds, one day our robot masters will site it as a watershed in human/machine empathy.

Though you might be able to get around that by waving your hands and saying “quantum” a lot.

I think I can accept a variety of explanations as long as the logic works within the context of each story and they don’t go changing rules on me halfway through. For instance, I was fine with The Terminator, but disturbed how the theory was perverted in T2, and despite the fact that I hated almost everything about the third one, I was pleased that they made a few steps towards going back to the original interpretation of how time worked.

Looking forward to the other three!

In the romance genre, you’re lucky if the time travel plotline is used for anything more than a device to get the heroine into poufy long skirts and on a horse. Lots of being hit on the head with a magic rock in modern Cleveland and waking up in 15th century Scotland and the like. I don’t read TT romance for that reason. I have read Willis and even Stephen Baxter, though I don’t know if it’s possible to understand exactly what he’s getting at without a PhD in String Theory.

I’d been trying to study the way time travel works in fiction (you should see my Netflix queue) and had THOUGHT I’d boiled it down to: 1) this was the way it was supposed to be (a’la THE TERMINATOR); 2) you can’t change anything, even if you try; 3) parallel worlds; 4) actually changing the future from the past.

This is obviously much more complicated. Perhaps I need to start hanging with the SF folks more often.