March 21, 2010, 5:00 pm — Updated: 5:00 pm --> Think Globally By STEVEN STROGATZ Steven Strogatz on math, from basic to baffling. Tags: differential geometry, geometry, straight lines, the globe The most familiar ideas of geometry were inspired by an ancient vision — a vision of the world as flat. From parallel lines that never meet, to the Pythagorean theorem discussed in last week..