Antipodal Map
The map which takes points on the surface of a sphere S^2 to their antipodal points.
See also
Antipodal PointsExplore with Wolfram|Alpha
WolframAlpha
Cite this as:
Weisstein, Eric W. "Antipodal Map." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/AntipodalMap.html