The picture above is not an animated GIF. There is nothing spinning, it's all an optical illusion which happens in your mind. If you don't believe this, print it in colour on paper and convince yourself!! Whenever you look at some point directly, you'll realize that it doesn't move but everything you're not looking at directly seems to rotate. The red markers are there to guide your eye and proove that the wheels at this point are static. Send me your theories about what's going on here!!! (It's a so-called peripheral drift illusion.)

Are you prepared for some more of these pictures?

Prof. Dr. Michael Bach (University of Freiburg) explains optical illusions like the picture above on his webpage -- have a look!

Prof. Akiyoshi Kitaoka (Ritsumeikan University, Kyoto, Japan) created several variants of his "Rotating Snake Illusion".

-- Markus Ehrenfried