The Illusionist

I was reading the AARP magazine the other day.
I'm not really in favour of AARP, but I joined for the discounts and then never even used my card.
But this issue has some interesting articles, one of which contained this picture: the Checker Shadow Illusion.
Look carefully at the two labelled squares.
Are they the same shade of grey?

Believe it or not, they are. You can check it by blocking off the surrounding squares.
This optical illusion tricks the brain into seeing colours as it thinks they should be, rather than as they are.
I was blown away and had to do a little Google.
You know I did!
Edward H. Adelson is a professor of Vision Science in the Department of Brain and Cognitive Sciences at MIT. The Adelson Lab studies problems in visual perception.

This design, the Munker-White Illusion, has a similar effect on the brain's power of perception.
The colours within in each rectangle are exactly the same shade.

If you want to see some very short videos of more Adelson illusions and the scientific explanations of the phenomena, go here.

The world is full of mysteries.

And here I go, trying to think new thoughts every day, staving off the Big A.