the DragonBard said:
The human eye works at roughly 24 frames a second.? That's 86400 frames an hour.
That statement is extremely mistaken.
First, anyone who has played video games in the last decade knows there's a ton of difference between <30 fps and >= 60 fps. Movies get away with less because their frames already have motion blur, thus tricking the brain, whereas neither real life nor most video game engines do.
Second, the question of fps required for apparent
smooth motion is totally different from the fps required for being unnoticeable.
Third, even so rephrased, the question doesn't have any simply numeric answer for because eyes/brains do not have any frame rate at all. Visual information is read effectively continuously, barring ultimate physical limits that aren't relevant. What causes apparent smoothness at high frame rates is that neurons don't switch off instantaneously, so visual information is partially retained between frames.
the DragonBard said:
That means you'd have to move those 6 meters in less than 1/24th of a second. ... That's a bit under 323mile per hour, bare minimum speed.
No. No it doesn't. Heck, even if your premises were true in the eye working like a camera, it still wouldn't imply this, because cameras don't work that way either: a fast object generally doesn't get cut out of the frame, but rather gets you an indistinct, blurred frame. And sometimes not even that, depending on range and speed.
It should be obvious that any calculation that does not account for the field of view is going to be utterly meaningless. And that's dependent on distance and relative orientation of velocity, as well as the size of the object. On the other hand, from experience in TV/monitor refresh rates, most objects that enter and leave the human field of view in 10ms or less is going to be effectively invisible, even if they take up a significant chunk of the field of view. Unless they're very bright relative to the background or vice versa, etc.