Douglas R. Hofstadter is College of Arts and Sciences Distinguished Professor at Indiana University, Bloomington. His books include the Pulitzer Prize–winning Gödel, Escher, Bach: An Eternal Golden Braid; The Mind’s I; Fluid Concepts and Creative Analogies; I Am a Strange Loop; and Surfaces and Essences: Analogy as the Fuel and Fire of Thinking. Scott Kim is a puzzle creator and graphic designer who has been making ambigrams since the 1970s.