2007-03-26 08:56:51 · 8 answers · asked by jennytheowl 1 in Cars & Transportation ➔ Safety
Because video of action is actually many still shots per second. The film captures the wheels at one position, and when it captures the next position, the tire has rotated almost one full rotation so that the wheel appears to be slightly behind where it was when it was shot the first time. (does this make sense?)
2007-03-26 09:00:51 · answer #1 · answered by Nasubi 7 · 4⤊ 0⤋
Actually, there is no such thing as a " motion picture ". It's a series of pictures ( about 24 per second ) each advanced a tiny bit from the last. Because we are able to retain a split second of vision after the picture disappears ( called persistance of vision ) the series appear to be a continous motion.
When wheels are turning at the speed that brings the spoke not quite to the right position, the wheel will appear to be standing still, or turning in the wrong direction.
You can duplicate this by settling back in a reclining chair under a ceiling fan, the chair doesn't have to be directly under. Now adjust the fan at medium or slow speed. While looking directly at the hub of the fan, blink your eyes very rapidly. You can make the fan appear to stop or reverse.
2007-03-26 16:25:17 · answer #2 · answered by Anonymous · 0⤊ 0⤋
The speed of the rotation of the wheels, allows you to see certain parts of the wheel at certain times. Therefore, if they appear to be moving backwards, it is because the progression of the wheels, the parts you can see are positioned a bit backwards every time you can see it. It is more difficult to do in person, because there is no camera following a car. You only get to see cars at a glance in real life. But if someday you are a passenger in a car on the highway, look to see if you can see the same effect on the cars around you, especially if the traffic moves and then stops and moves again.
2007-03-26 16:04:14 · answer #3 · answered by Joseph L 4 · 0⤊ 1⤋
the camera has so many frames per second,. when the wheel speed catches up with the speed of the camera, the wheel appears to stand still. when it exceeds the speed of the camera, the wheel appears to turn backwards. its called xyncronization. an optical illusion.
2007-03-26 16:13:12 · answer #4 · answered by oldtimer 5 · 1⤊ 0⤋
this is caused by the frame rate and the ability of the human brain to percieve things that the eye sees.
2007-03-26 16:00:51 · answer #5 · answered by daryleddy 2 · 0⤊ 0⤋
Watch a car go down the street in real life.
They do it there too
2007-03-26 16:00:54 · answer #6 · answered by jenimiper 3 · 1⤊ 1⤋
Magic.
2007-03-26 16:01:46 · answer #7 · answered by Anonymous · 0⤊ 3⤋
since they are going so fast it appears that way.
2007-03-26 16:00:56 · answer #8 · answered by fourcheeks4 5 · 0⤊ 3⤋