Optical Illusions

by Karel Thönissen

Today, I experienced a great case of serendipity. My brother mailed me a link to a collection optical illusions from which above image was taken. It contains many of the illusions that became popular through the works of M.C. Escher, Bruno Ernst and Penrose. The list is part of MathWorld, an encyclopedia compiled by Eric Weisstein with the help of mathematicians and the Internet community. Also visit the section on recreational mathematics.

When searching for the background of the author and his site, I stumbled across the encyclopedia that MathWorld really is. A great resource for those who use math for their work or study! Other useful math and science resources can be found elsewhere on the Wolfram-site, the host of MathWorld.