User talk:Pebblepond

Gnomonic projection
Hi @Pebblepond, and welcome to Wikipedia. I reverted your change to Gnomonic projection in special:diff/1211655063. The gnomonic projection, a perspective projection through the center of the sphere, maps every great circle on the sphere to a straight line in the plane, and every straight line on the plane is mapped to from some great circle on the plane. That is, it produces a 1:1 correspondence between great circles on the sphere and lines in the plane (with the exception of the "equator", a great circle parallel to the projection plane, which maps to a "line at infinity"). You might have been thinking of the stereographic projection, for which great circles passing through the point where the projection is centered are mapped to straight lines through the origin in the plane, while other great circles map to circles in the plane (and other lines in the plane come from circles passing through the projection point). Cheers, –jacobolus (t) 19:46, 3 March 2024 (UTC)