Whenever you read a book, something rides shotgun on your shoulder, an internal filter, if you like. Its purpose is to check for things that don’t work – be it because you know that’s not true or you don’t believe that could happen. I’m sure you can think of examples – the idiot who insists on checking that creak on the stair, alone, in the dark, when two of her friends have already died a gruesome death. Or the hero miraculously appears from somewhere, just in time. Or the way all the planets out there seem to have the same gravity as Earth with breathable atmosphere.
It’s up to the author to ensure that filter in people’s brains is never activated. Or if it is, it doesn’t override the impulse to read the book. This is particularly true in genre fiction like science fiction and fantasy because of the world building aspects. You don’t ever want somebody reading your work to sit back and say ‘I don’t believe that’.
And yet.
A reader/watcher can become so engrossed in the story that the filter doesn’t work at all. Let me give you an example. I fell in love with Star Wars went I went to see The Empire Strikes Back. Sure, I have a history degree, but astronomy and cosmology have fascinated me for years. I read about stars, I was familiar with the Hertzsprung-Russell Diagram, I had my own astronomical telescope. I giggled in Star Wars episode 4 (A New Hope) when Han Solo purported to have done ‘the Kessel run in under 12 parsecs*’. And yet, even after watching TESB a dozen times, I had to read in an article somewhere, the story’s biggest flaw. Want to guess? Or do you already know? The Millenium Falcon’s hyperdrive failed. And yet the ship made it to Bespin (pretty far) without either Han or Leia collecting a grey hair. Let’s put that into perspective. The nearest star to us (apart from Sol) is over four light years away. Even travelling at light speed that’s a four year trip. So my in-built belief-suspender was glued to the seat, watching the movie.
On the other hand, when I watched the movie ‘The Rock’ (Sean Connery – they had to break INTO Alcatraz) there’s this scene where the guys have to get underneath a thing rather like a piston. Sean had done it many years ago, when he was the only person to escape the famous prison. So we’re watching this sequence. I sat back, turned to the OH and said, ‘OK, he had to do that to get out. But why don’t they just use that door over there?’
FAIL
That was the end of that movie for me.
What about you? Care to share some examples?
*parsec is a measure of distance, not time. Definition here
gretavanderrol.wordpress.com 
I have tonnes (we all do), but one I was thinking about recently was the second Bourne film. The whole premise was that the CIA thought Bourne had give rouge and blown up a building to assassinate someone.
They apparently thought this because one of the bombs accidentally didn’t go off and his fingerprints or something were left behind. But they knew Bourne was one of those elite super-assassins, so how could they believe he would be that sloppy?
I mean, they said in the first one that the point of people life Bourne was that they killed people in a way that made it look like that hadn’t been assassinated. It just didn’t make sense. Any idiot world have guessed it was a frame job, which it’s of course what it was.
Yes, a bit ordinary. And doesn’t it turn you off?
The challenge that I always see in SF is the creation of sufficient diversity and complexity in a world. Take Earth: not just the 70/30 sea/land split – not just the polar caps/tropical rain forest split – but the fact that when people first walked on the Moon, other people in New Guinea were still living in the *Stone Age* and had never seen metal tools.
I find believability challenged if the world is too small, simple and uniform. There needs to be a background sense that if you went a little distance, eco-geologic and socioeconomic structures would be confusingly different.
LOL, great subject, and example, Greta!
This is what I refer to as the “Ha-ha test,” and yet, I feel it is applied by different readers dependent on their own filter.
When I watched the Star Wars movies, I had already suspended disbelief long before the “parsecs” line because, to me, it was already established as a parody of its own sort. It didn’t matter to me (the ignorant viewer) what a parsec was or whether the passage of time was consistent with the law of the time-space continuum (if that even makes any sense). Before I’d gotten to that point, I’d already cast aside the “oh, come on” response, and was happy to be the idiot viewer.
There’s a big diff between fiction and film, though. With fiction, we don’t have the conceit of visual special effects to build the world that makes readers believe. We have only words on the page.
In my genre (crime/mystery), I have a simpler task, because I am not building a new world, only working inside a construct we are already familiar with, even accounting for the differences in legal systems. Sure, there’s a criminal defense lawyer out there who might point out the unlikelihood of a US Attorney subverting justice the way he did. What is he?
A doubter. They’re all over the place. We’re not writing for doubters. Our duty is not to them.
Yes, I think you’re right about books rather than film. As you say, just watching Star Wars you simply HAVE to put that belief filter in a box and shut the lid. Personally, I find it easier to believe some of the crime/thriller plots maybe because I know less about that part of the world. But also because I read an awful lot about organisations like the German SD under the Nazis. People can do terrible things.
But yes, you’re right. There are always doubters.
If there’s enough emotional engagement with the story, we are more willing to take the ride.