The Science Behind Discworld's Flat Earth on the Back of a Turtle

The world is flat, and resting on the backs of four elephants who, in turn, stand upon the back of a giant, space-faring turtle. Welcome to Terry Pratchett's Discworld. How does it all work? Pratchett, along with Professors Ian Stewart and Jack Cohen, explain it all in The Science of Discworld IV. »7/16/13 1:45pm7/16/13 1:45pm