i have a really dumb question!

I think I saw the explanation of that on Mr. Wizard a long time ago....it's a scientific reason....I just don't know it...

I got this from a Science Web Site:

The illusion happens because tv cameras shoot 60 pictures per second. If the spokes of the wheel are spinning at, say, 59 turns per second, there will be a mismatch, and the wheel may seem to spin slowly backwards. To make it clearer, try imagining a giant stop watch on a stage. Let's say it has a fast-moving hand that sweeps once around the dial in one second. If you turned out all the lights and turned on a strobe light that flashed exactly once per second, the hand would look frozen, because you would only see it when it was straight up at 12 o'clock. Now, imagine you set your strobe to flash a little more quickly, so it would light up the clock before the hand reached noon. So it would flash once when the hand was at noon, then again when the hand had only reached eleven, and then when it reached just ten, and so forth. To the audience it would look like the hand was slowly moving backwards. When a wheel is spinning at just a touch less than the speed at which a television camera records it, the same thing happens.

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Posted by dengal

I got this from a Science Web Site:

The illusion happens because tv cameras shoot 60 pictures per second. If the spokes of the wheel are spinning at, say, 59 turns per second, there will be a mismatch, and the wheel may seem to spin slowly backwards. To make it clearer, try imagining a giant stop watch on a stage. Let's say it has a fast-moving hand that sweeps once around the dial in one second. If you turned out all the lights and turned on a strobe light that flashed exactly once per second, the hand would look frozen, because you would only see it when it was straight up at 12 o'clock. Now, imagine you set your strobe to flash a little more quickly, so it would light up the clock before the hand reached noon. So it would flash once when the hand was at noon, then again when the hand had only reached eleven, and then when it reached just ten, and so forth. To the audience it would look like the hand was slowly moving backwards. When a wheel is spinning at just a touch less than the speed at which a television camera records it, the same thing happens.

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very interesting. thank you for that!