“The Great Circle Mapper displays maps and computes distances along a geodesic path. It includes an extensive, searchable database of airports and other locations.”

Seth Dixon‘s insight:

The shortest distance between two points is not a straight line…well, that depends on your map projection.  A flat map always distorts something when representing our three-dimensional Earth—whether it is distance, direction, shape or area—something gets distorted on our maps.  A great circle is the shortest distance between two points on the surface of a sphere, so that’s going to be the quickest travel route between points (which is why so many airline route seem to arc).  This website Great Circle Mapper generates great circles that show the shortest distance between two points on many map projects will be an arc.  Why does this particular route arc ‘bend’ north for a while and then south?  Get out a globe for added perspective.   

See on www.gcmap.com