Eli5: Why do wheels look like they’re spinning the wrong way when going fast?

Question

Eli5: Why do wheels look like they’re spinning the wrong way when going fast?

In: Physics

Answer 1

It only looks like that in videos and its because the cammera takes like 24 pictures a second, and if the rotor or whatever is spinning in a frequency thazs close to that 1/24th of a second or a multiple of that, you will have each frame of the video show a still image of the wheel or rotor but shifted a bit in one direction. Show these frames at some speed again, aka play the video and you will see the illusion of movement.

You can get a similar effect with stroboscope lights without a cammera.