Op about to pop. I've always liked Op Art, and one of the masters of the form, Victor Vasarely, is the creator of Cheyt M, above. Like M.C. Escher, op art played with space and depth without the benefit of fancy computer programs to work out all the math. Thanks to the internet, you can play with an interactive Vasarely Bubble, or go insane looking at some high-octane optical illusions. It's, like, far out, man.