MC Escher (there was even a tailored version of this MC Escher photo, revised to make a joke about how the Bush administration used the same excuses for going into Iraq as they now use for why we can't leave)
- The Mobius Strip
- and (as foreshadowed above) . . . limits.
(Did you know that if you rotate a two-dimensional curve such as the one represented by the function f(x)=1/x around the x-axis you create a three-dimensional figure with a definite volume but an infinite area? Mind = blown. Is that right? Jerry? Joe? Help me out here.)