This a phenomenon which I notice everyday but never really took an interest in.
Why does a fan (or any other rotary object), when spinning really fast, 'appear' to slow down, upto a certain rpm, then start rotating backwards? If this is some kind of optical illusion why does it reverse at a certain rotary speed?
Can it be due to the asynchronous(fluctuations) velocity which tend to produce after-images in a place other than the one, one would expect the blade to be in at that particular time? But still the question would be about the rotation sense reversal? Could someone pitch in? Thanks in advance!!