[math-fun] A distant branch of my family is named Bellows.

Including one who, honest to God, was christened Sniffin Kelly Bellows. But they were not mathematicians--the Bellows Theorem is actually about bellows. It states that some nonconvex polyhedra (e.g. http://gregegan.customer.netspace.net.au/SCIENCE/Steffen/Steffen.html) can actually flex, but not breathe. Thus, PolyhedronData["Steffen"] could produce a tetradecahedron GraphicsComplex with a symbolic parameter which would wash out under the "Volume" operation. Corollary: A geometrically (and musically) ideal accordion would be silent. --rwg