While looking for optical illusions to motivate my discussion of
probability illusions I came across this illusion on Wikipedia (by Adrian
based on the original created by Edward H.
In the picture below compare the squares A and B. As hard as it is to
believe, both squares are exactly the same shade of grey.
Don't believe it? Then scroll down.
The wikepedia page explains how to prove the squares are the
same, but the the link to a video did not work, so I decided to create
to run just right click and save)
Other great optical illusions: