30

In Epic, here's leaf man mocking human moves in a slow manner:

enter image description here

Why do human movements look very slow from a tiny creature's point of view?

  • For some resources and ideas from a physics-perspective, check out this Reddit thread. – Bobson Dugnutt Mar 14 '17 at 16:56
  • 7
    (note that the image is not a gif, don't wait for it to animate) – A.L Mar 15 '17 at 16:01
47

Flies and other insects do indeed process visual information much more quickly than we do. Something about higher metabolism and a shorter optic nerve allowing information to be transmitted faster by orders of magnitude.

This is why, when you're trying to swat a fly, it always manages to escape at the last possible second. From its perspective, we do appear to be moving in slow-motion.

The movie is riffing off this detail, using the existence of an intelligent character who is also tiny to highlight the way tiny creatures would (and do) perceive us.

  • 19
    I suggest that a fly's ability to avoid a swat is that it instinctively and/or reflexively takes off backwards when it detects something rapidly approaching. My ratio of flies killed to flies escaped is HEAVILY weighted to the flies killed portion. Simply shift your target to slightly behind the fly and your accuracy will increase. Also, swat faster. Once the swat is started, you don't need to visually track it. Simply swat where you believe the fly will be. – Michael Richardson Mar 14 '17 at 16:03
  • 4
    @MichaelRichardson I think the location of the flies matters too. I swatted flies easily by hand in Colorado, but I have a much harder time in Idaho. – Erik Mar 14 '17 at 16:21
  • 6
    Actually, just blow on the fly gently, it will hang on to the wall tighter, then smash it with your hand. This works every time (assuming you're close enough to be able to blow on it). Also, another thing flies have is shorter life spans (which links back to the fast metabolism). I've seen several cartoons make fun of that fact. – Stephan Branczyk Mar 14 '17 at 17:06
  • 5
    Neatest way to kill the flies is to just slowly smush them. If you move slowly enough, this becomes nearly imperceptible to the fly. Like watching mountains move. It will just think the object has always been there, right above it, this whole time. If you go slow enough, you can catch and release or smash them, but you gotta go reeeeal slow. – coblr Mar 14 '17 at 19:49
  • 16
    This is why I love stack exchange - this answer has devolved into the best ways to kill flies. – n_b Mar 15 '17 at 16:14
36

Slower movements can be used to exaggerate the size of objects. This comes from one of the 12 principles of animation, specifically timing. When done correctly, the amount of time things take can help convey different aspects of the item being animated. This video does an excellent job explaining animation in the game Shadow of the Colossus. The link starts around 2:56, which states:

You can use timing to communicate all kinds of stuff, like, for example, size.

  • Nice reference. You deserve an extra credit – xDaizu Mar 15 '17 at 8:57
  • 1
    @xDaizu ba-dum-tss, but seriously, Extra Credits is great and their videos on the principles of animation are really good. – David Starkey Mar 15 '17 at 13:28
  • This principle is at least grounded in intuition - a large object moving at the same speed as a small object would appear to be moving slower, because the same distance is smaller relative to the size of the object. (There's also the matter of a larger object having way more inertia and therefore being slower to change velocity as well.) – fluffy Mar 15 '17 at 19:59
8

Humans look slow partly because they are moving slowly relative to their body size. So, even if humans are actually much faster than a tiny creature in absolute terms, their movements will look slow.

In general, small creatures are able to cover a greater relative distance in small time. California mite covers 322 body lengths per second, which is equivalent to a person running roughly 580 m/s (ScienceDaily on this record)

Houseflies appear to be extremely quick when they fly at 2 m/s (8 km/h). Large ships don't look as fast at their top speed (> 50 km/h). Passenger airplanes move slowly across the sky at 500 knots (> 800 km/h).

  • This reaffirms the suspicion of the OP that large things seem slower, but does not really explain why. – AnoE Mar 16 '17 at 10:43
  • @Anoe Thanks for the feedback. I tried to explain that if two bodies move with the same absolute speed, then speed relative to body size will be greater for a smaller body. Wording leaves a lot to be desired, though, I'll try to improve it. – default locale Mar 16 '17 at 11:04
  • 1
    Yeah, @defaultlocale. A diagram (2 "sight lines" meeting at the "eye") that shows how perceived size scales with real distance would be helpful, I think. – AnoE Mar 16 '17 at 11:37
0

Small creatures have much greater tolerance of acceleration, which is the rate of change of speed. This arises from Newton's law, force = mass times acceleration. The force to tear sinews or squash organs is much the same for a human and for a flea. But the mass of a flea is far smaller, and so the acceleration to which it can subject itself is far higher. This is also the reason that a squirrel can fall out of a tree and run away when it hits the ground, unharmed (or maybe a bit bruised). The same drop would likely kill you.

Small creatures may have faster perception. We can't know subjectively what it is like to be a sparrow, but we can prove that it must have control over its wings faster than a human is capable of, because otherwise it could not fly. Hummingbirds react and accelerate so quickly that the human eye can rarely follow them between a foot away from your hand and somewhere else.

You must log in to answer this question.