Via Cliff Pickover’s entertaining and educational Twitter timeline, we discovered this beautiful essay by Evelyn Lamb, a promising postdoc at the University of Utah. Dr Lamb describes the fascinating and paradoxical topology of a strange surface–the Möbius strip–a surface with only one side and only one boundary. Among many other things we did not know is this: “You may have heard of the four-color theorem: any map can be colored using four distinct colors so that no bordering countries share a color. This theorem is not quite true as stated. We need to specify that the map is on a sphere or plane. Different surfaces have different ___-color map theorems, and for the Möbius strip, it’s the six-color map theorem.” Bravo!

Credit: Evelyn Lamb