A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Ed Popko
Date: 2020 Jan 26, 04:36 -0800
Frank's great circle analogy with a tunnel between two points on earth and projecting its midpoint and other tunnel points to the surface of the earth (from the center of the earth) is really a nice visualization.
It's somewhat surprising that if the tunnel points are all equally spaced and prjected, the arc distances between great circle points near mid-tunnel points are much larger than arc distances near the tunnel's endpoints.