The human brain has evolved an extraordinary set of software for grappling with its environment. Working with data from multiple sensory inputs, it constructs a highly detailed virtual simulation of our universe.
And it has the ability - perhaps unique in the animal kingdom - to simulate that which is not but might be: imagination.
Using both the experience of past inputs and a toolset of built-in intuitions, the brain makes thousands of little imaginative predictions all the time; to judge distance, calculate consequences of actions, or even "converse" with itself as a second entity. (Most of us have had imagined conversations with persons absent.)
The brain's software for imagining the physical universe (how objects will interact, etc) has been called "folk physics". You can think of these folk physics as a sort of video game physics engine: a recreation of real-world physics, informed by real-world data and accurate to a degree, but still imperfect.
Folk physics aren't quite perfect because the brain has evolved to cope with everyday situations. Our ancestors (and for the most part, modern humans) would usually cope with moderate distances, speeds, sizes, and timespans. When it comes to extreme and unfamiliar situations, the brain's intuitions cease to be useful. For example, at the atomic or astronomic scales, common sense is useless; without tools like science and mathematics, we'd have little hope of ever having a meaningful understanding of realms beyond the mundane.
In other words, the brain can't just grasp this stuff on its own - it needs a lot of help. For instance, great spans of time can be rendered on a graph as visual information. Only then, with the data in a format that the brain understands, can patterns be recognised and useful work be done.
But it's not just the ultimate extremes of our universe that cause the brain to trip up. Oftentimes things much closer to home, only a step or two away from the deeply familiar, can fool our imaginations.
Which brings me to the actual point of this post. Creators of stories have long made their tales exciting by having them take place right on the edges of our experience. In the early days, that meant unexplored caves and mystic forests, peopled by ogres, fairies, gods, and mythical beasts. Today, it means a plethora of science fiction "what ifs". "What if you could read thoughts?" "What if we met aliens?" "What if you could travel back in time?" "What if you could shrink down to the size of an ant?"
These concepts are always fun to explore. They are the best of the human imagination, still hungry to explore that which is not but might be.
Exceedingly often, though, there are catastrophic failures of imaginary perspective. Folk physics fails the storyteller (moviemaker, etc) miserably when they try to picture an unfamiliar perspective.
We've all seen movies where spaceships make noise as they fly by; cartoons where characters can breathe and talk in space without spacesuits; or even movies where the most fundamental of all physical laws - the speed of light - is waived (either for the needs of the story or out of sheer ignorance, it's hard to be certain). This latter faux pas was commited by a Star Trek movie ("Generations"), of all things:
Point: In what is probably the worst production/science gaffe they could possibly make, Soran launches his missile from the planet towards the sun (to blow it up, remember) just as the Nexus is nearing. Immediately the sun darkens and explodes. Do you see what's wrong with this picture?
The sun should not have appeared to change for at least 8 full minutes. Not even counting the time it would take for the missile to reach the sun — let's suppose it has warp capabilities, to get around that issue — the light (and gravity) from the sun can only travel at the speed of light. And since they were on an Earth-looking planet, which is 8 light-minutes away from the sun, then that means there's no possible way the sun would appear to darken immediately—and the gravitational effect on the Nexus would be similarly delayed.
Huge, huge blunder. Somebody (preferably the writers) should have been fired for that one.
So much for Star Trek's reputation of scientific accuracy!
I've also noticed that there are glaring oversights just about any time a character is depicted as shrinking. In "Honey I Shrunk The Kids" (I find it embarrassing to admit I've ever seen this movie), the shrunken kids tame and befriend an ant, which behaves like a large dog. To the diminutive human characters, the ant is the size of a large animal, and so the screenwriters have it behave as one - growling, whimpering, munching food out of the children's hands. Later, it even shows loyalty, sacrificing itself to protect its newfound friends! The writers seem to forget that the ant is not actually a large animal, it just appears large to the newly shrunken humans.
Of course, "Honey I Shrunk The Kids" is a comedy, and can be excused. However, there's another big problem with just about every "shrunken" sequence I've ever seen - and it's a little harder to notice at first.
When you watch the wind blow through the trees, or stalks of a tall grain crop, they sway smoothly and slowly. But if you watch grass, even in a light breeze, it snaps back and forth super-quickly. This is because, of course, the distances involved are so much smaller.
If you were a shrunken, centimeter-high character on a lawn on a breezy day, you wouldn't see large majestic stalks of green grass waving lazily above your head. You'd see them bending double and flashing back and forth almost faster than your eyes can follow. It would be like the worst hurricane footage you've ever seen. It would probably be too overwhelming to cope with. It's understandable why this has never (to my knowledge) been depicted on film.
Also, you wouldn't see the breeze ripple its way through the blades, either. With every gust, all the grass would react in almost perfect unison. (A 10mph breeze can play through almost 15 feet of grass per second.)
So, next time you watch a movie with an unusual view-point, watch for failures of imaginary perspective. You might be surprised.