As I’ve said in the past, I love speculative fiction in all forms, especially stories in the fantasy genre. I also love to discuss them with fellow fans. Lately, I’ve been wondering why many fans (including me) can accept certain unrealistic elements in speculative fiction, but not others. I also wonder why those boundaries seem to be different for everyone—and if writers should worry about this balance when they’re writing, and if so, how.

But first, a clip from The Big Bang Theory that illustrates exactly what I mean…

So why does Sheldon accept that Superman can fly, yet go on to complain about the fact that when he saves Lois Lane from a fall, his success doesn’t conform to the laws of physics? The logic of the story dictates that Superman must rescue Lois, or the ending won’t be as satisfying to the audience. (Unless the audience wants a dark or genre-defying Superman story, which is another discussion entirely!) Since Sheldon didn’t mind one violation of physics (a man flying), why does he care so much about the second violation?

You could argue that this is due to Sheldon’s career as a physicist. But then how he can accept Superman’s impossible abilities in the first place? Besides, this kind of conversation happens constantly, not just among fans who are physicists. I’ve overheard plenty of heated debates exactly like this one, while standing in line at comic conventions. So, why? Why do some fans dislike certain scientific inaccuracies in their speculative fiction, while letting other inaccuracies slide?

Honestly, I don’t know the answer. But it may have something to do with what I like to call the Personal Logic Threshold (PLT).

Basically, the Personal Logic Threshold refers to the point at which an individual can no longer suspend their disbelief while experiencing a story. Many times, the occurrence is distracting enough that the person can no longer pay attention to the story at all. Instead, they fixate entirely on the moment that bothered them. Usually, it happens because the story broke the laws of physics in some way, or because some kind of logical fallacy or plot hole occurred. The trouble is, this threshold differs for everybody. I’ll give an example.

(Spoiler warning for The Hobbit: Battle of the Five Armies up ahead!)

The final movie in Peter Jackson’s version of The Hobbit features a lengthy battle. At one point, Legolas is fighting some orcs atop a mountain, around the crumbling ruins of a fortress. He starts to fight inside one of the towers, which falls over and wedges between two cliffs. Unbelievably, he continues to fight, as though the tower has simply become a bridge. In the end, the tower begins to break apart. Legolas then proceeds to jump across the falling rubble like it’s a staircase, in order to reach solid ground and avoid a deadly fall.

After we saw the movie, several of my friends pointed out that this moment defies the laws of physics. Which it does. In the real world, Legolas wouldn’t be able to push up from those falling bricks in order to step across them like that. It’s physically impossible. My friends disliked this moment; some of them were even angry it happened. As for me? I didn’t love it, but at the same time, I felt it wasn’t completely out of place in a Tolkien story. Here’s why:

Legolas is an Elf, part of a magical race. One thing Elves can do—which Legolas demonstrates in both the book and movie versions of The Fellowship of the Ring—is walk on top of the snow without snowshoes, when no one else can. (Not even hobbits, who are smaller and move quietly.) This implies that the way an Elf walks doesn’t conform to our laws of physics. Tolkien never wrote anything about Elves being able to float across falling rubble. But Legolas, like Superman, already defies physics in that respect. So from my point of view, I didn’t think that him jumping across falling rubble was entirely inconsistent with the setting. I thought it was cheesy, but not so implausible that it truly bothered me (especially when compared to other problems I had with the film).

My friends, on the other hand, acknowledged that they could accept a Legolas who walked on snow, but they could not accept a Legolas who floats over falling rubble. For them, it broke their Personal Logic Threshold. The idea bugged them too much for them to accept it as a part of the narrative. Clearly, this is a subjective phenomenon, and varies from fan to fan.*

So should writers worry about this? If nothing else, I think it’s useful to acknowledge that it happens, and try to understand why.

From what I can tell, this break happens in one of two ways. Sometimes, individuals in the audience are concerned with accuracy in a specific area of a story. This usually happens because they have expertise in that area, so they tend to fixate on it. (Like Sheldon with physics, for example.) However, this can also happen when a story goes too far for the audience’s tastes, breaking the rules in a way that doesn’t fit with their idea of what the story was supposed to be like. In the case of Legolas, my friends felt the falling rubble episode was a cheesy “action” moment, which undermined the serious tone of Tolkien’s setting.

(Also worth noting: the Legolas example comes from an adaptation of a beloved author’s work, not from the author himself. This is another factor that can affect a fan’s ability to accept such a moment as a valid part of the narrative.)

So what can those of us who are interested in stories and writing learn from the Personal Logic Threshold? I’ll deal with that in my next post.

(Note: for this reason, Teatime Tuesday will be Teatime Thursday this week!)

*The question of whether stories that conform to the laws of physics are “better” in some way is another subject entirely.