I have a confession to make, namely that the supposed "rotating" snakes and "crawling" worms and various other actually static illusions that have been constructed in endless variations by Akiyoshi Kitaoka all leave me cold, cold, cold. The only way for me to see any illusion of movement is to use the "right hand bar" that allows you to move browser windows up and down to jog the image slightly vertically, and then and only then is there a very brief and unconvincing sense of slight movement. On the other hand, I do get a strong and very immediate illusion of motion from the artwork here.

For such reasons, I think this recent (Spring, 2006) illusion from Kitaoka is one of his best. The animated gif changes the background color at regular intervals, and the change in color provides a very strong illusion that the circles of "peaches" are rotating significantly at each color change. Another version of the illusion is seen here.

Here, from the “Archimedes Lab” website (click on the image to be taken to the site) is a variant, an expanding and shrinking cube.

Want a preview of week's illusion? Click here