Fast Money

Rub two coins together and see three!


How to Fool Yourself

This is not a get-rich-quick scheme. Like most such plans, this too is an illusion. Get two identical coins. Hold them together. Rub the coins against each other rapidly up and down. An image of a third coin drops down between the two real ones.


Why You're Fooled

The phantom coin is caused by a slight afterimage left by the real coins, which has not had time to fade. The receptors on your retina will keep sending messages to your brain for a brief period after a stimulus is removed. By continually moving the coins you keep the afterimage going. Here's a mystery waiting to be solved: no one knows why the image always appears below the real coins, not above.

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