system
Given the following post, respond as if you're commenting on Reddit:
human
Why do car wheels look like they're turning in reverse when they're driving forward?
gpt
Our eyes take in sight at a limited speed. When you look at a wheel that is turning, you don't see it at *every* position from 0 to 360 degrees. Instead, you see it's position at certain intervals of time, for example, every twentieth of a second.

But what if the wheel is rotating 20 times a second? Then, every time your eye looks, it sees the wheel in the same place as it was before, and it looks like the wheel isn't turning at all!

If the wheel turns just a little less than 20 times a second, then each time your eye sees the wheel, it will have turned, say 355 degrees around. But because your eye didn't see it at any point during those 355 degrees, it will look like the wheel turned very slowly 5 degrees the other way.