M. C. Escher (Dutch 1898-1972) made relatively realistic art--landscapes, portraits--until his early middle age. Then, increasingly fascinated by the tension between two-dimensional representation and the mind's tenacious three-dimensional perception, he began to create prints and drawings in which realism collides with impossibility. Working alone, with no mathematics background, he produced "symmetry drawings" that graphically represented the phenomena of crystallography and foretold the concept of a fractal universe. He challenged the hegemony of so-called natural laws with renderings of co