Permalink Submitted by Marianne on October 26, 2015

You are correct. No point on the plane projects to the North pole itself. But as a sequence of points move out towards infinity on the plane, their projections move towards the North pole on the sphere. So you now declare that infinity is a point, though not a point on the plane. It's an additional point. Its projection is the North pole of the sphere.

## You are correct. No point on

You are correct. No point on the plane projects to the North pole itself. But as a sequence of points move out towards infinity on the plane, their projections move towards the North pole on the sphere. So you now declare that infinity is a point, though not a point on the plane. It's an additional point. Its projection is the North pole of the sphere.