why is it that when u look at the wheels of a moving car (forwards) they look like they r going backwards???

Answer 1

Because your eyes take snapshots, rather than a continuous feed of stimuli. So if something is repeated faster than the framerate of the snapshots, the result can be interpreted wrong and create the illusion of moving backwards.

Answer 2

that doesn't always happen, but it does at certain rotation speeds of the wheels. why? because human eyes don't see the world smoothly, they see in in frames. I think the human eye sees at about 20hz (as in 20 frames per second).

Now think about how that affects you seeing a rotating object: if the object rotates exactly once, twice, three times, etc. every time your eye sees it, you won't be able to tell it's spinning at all. If it is spinning at just over one, two, three times a frame, you will see it moving forwards slowly (because you see it moving a little bit every frame

Now if it is moving slightly less than one, two, three times a second you will see it going backwards slowly for the same reason.

If you watch a cars wheels closely while the car is accelerating, it will appear as though the wheels start to spin faster, then start slowing down, then start spinning faster, then start slowing down again, etc. This is because of the way your eye interprets the frames.

Answer 3

I think it nearly gives ur answer!


It's an optical illusion. Your eye tries to follow the spokes but can't quite follow along so it stutters along as best as it can making it seem like it is going in reverse.Think of the wheel spokes as the frames on a film reel clicking by at 24 frames a second. The film seems to be moving along seamlessly but is actually stopping 24 times a second. If the film slowed enough you would see the individual frames. When the wheel slows enough you can see the details of the wheel, until then your vision stutters along trying it's best to make sense of it all.

by the courtesy of "iamacarguyru"

Answer 4

It does not happen in normal light.
It only happens with fluorescent or otherwise strobing light (and then only at certain speeds).
It is due to "persistance of vision"; the same phenomenon that causes a sequence of discrete (still) frames in a video movie to appear as a continuum.

Answer 5

Because of motion and speed we cannot se which side is moving