Artist and MIT professor Erik Demaine makes flat geometric diagrams spring into elegant, three-dimensional origami sculptures. By Marina Koren, SMITHSONIAN.COM, JANUARY 23, 2013 The shape of a Pringle, mathematically speaking, is called a hyperbolic paraboloid. Artists have been folding paper into this shape for years. The twist? Hyperbolic paraboloids shouldn’t exist in origami—it’s impossible to make such…