At each corner of the figure depicted, two rectangular prisms join at a 90 degree angle. If any of the triangle's three corners is obscured, the resulting image is consistent, but if all three are left visible, the image is geometrically impossible. The illusion relies on the inevitable loss of information that results from projecting a three-dimensional figure onto a two-dimensional plane. (Image by MIT OCW.)
In this class we will study a cluster of puzzles, paradoxes and intellectual wonders - from Zeno's Paradox to Godel's Theorem - and discuss their philosophical implications.