When the car is fast, why does the wheel look like a turn
I have this feeling, it is illusion. Simply said: people observe the object with a visual pause. Probably 1/24 S. If the wheels do not turn in 1 / 24S, the wheels look backwards, but if you turn more than one turn in 1 / 24S, it looks like a slow forward. Details: This illusion is so strange, no matter who, when the first time to see will be inexplicable. The reason is this. When you walk down the fence and slide through the fence on the fence, you must not see the spokes continuously, but wait for a certain time to see them once. Because the wood on the fence at a certain time to cut off your line of sight once. The film shows the image of your wheel is not continuous, but across a certain time (24 frames per second). There may be three cases here, let us study one by one. The first possible situation is that in the time when the line of sight is cut off, the wheel has time to turn the number of integers - the number of integers is 2 or 20 does not matter, as long as the integer on the line. At this time the wheels of those spokes on the screen position with their previous picture on the location of exactly the same. At the next time interval, the wheel turns the number of turns (because the length of the time interval and the speed of the car are constant), so the position of the spoke is the same as before. We see the spokes from beginning to end in the same position, so it will come to this wheel is not turning the conclusion.
The wheels in every time interval, not only have time to turn the number of rounds of the integer, and also turned a little small half turn. When we see this changing picture, we do not think there is an integer number of turns here, but only the wheels are slowly turning (only a small fraction of each week). The results we feel that although the car go very fast, the wheel has turned very slow
Simply said is the visual error. When the frequency of rotation of the blade = your visual interval, you seem to have a slow sense of rotation in the opposite direction. For example: you are looking at a person running around the playground, you first saw him when he was in position A, and then you closed your eyes, and then opened when he found him behind A, you Thought he was back, in fact he had almost finished a circle.
