When I was 14, I made a painted globe of Mars based on a flat Mercator Mars map by the astronomer E. M. Antoniadi. I and my colleagues Dave Goldberg and Bob Vanderbei (who invented the “Purple America” map for showing election results) have produced what we believe to be the most accurate flat map of the Earth ever made. Depicting the curved surface of the Earth on a flat map has been the cartographers’ problem for centuries. No flat map of the Earth can be perfect. But flat maps are easy to store and manufacture and are therefore desirable.