Talk:Midpoint

Conjugate of infinity
I am not happy with this section added by. Reasonings about inversions (which really assume spherical geometry and orthographic projection) lead virtually to the fact that midpoint between two poles is not uniquely defined. But this may be explained shorter. Even worse, in projective geometry arbitrary three point on one line may be mapped to other arbitrary three point on (the same or another) line ⇒ midpoints are not defined at all. Does anybody object against removal? Incnis Mrsi (talk) 08:11, 22 February 2012 (UTC)
 * I decided not to wait for a feedback, but to rewrite it itself as Midpoint, eliminating misleading hints that the midpoint is defined in projective geometry and totally deleting off-topical inversion stuff. Incnis Mrsi (talk) 09:40, 22 February 2012 (UTC)