Watching spinning wheels

In 125 A.D. Apuleius experimented with a flickering light stimulus produced by the rotation of a potter's wheel, and found it could be used to induce a type of epilepsy.

Around 200 A.D. Ptolemy noted that when he placed a spinning spoked wheel between an observer and the sun, the flickering of the sunlight through the spokes of the spinning wheel could cause patterns and colours to appear before the eyes of the observer and could produce a feeling of euphoria.

These days people try to reproduce these same effects by using revolving wheel films – examples of which can be found on the Internet. For example

Revolving wheel films - Youtube film (opens in new window).

Other alternatives might include the stripe of a rotating drum with alternating black and white, the gaze retreats to fixate on a new stripe as the drum moves.  This is first a rotation with the same angular velocity, then returns in a saccade in the opposite direction. The process proceeds indefinitely.  We are actually inducing a form of voluntary nystagmus.

This is what prayer wheels were intended to do, you are actually meant to stare at them not walk on by……………..

In olden days, the spinning wheel had a similar effect and of course we have this built into the legends of sleeping beauty, here the witch shows Sleeping Beauty the spinning wheel.

But the options are numerous………

Observations

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• Apuleius and Isis