A sphere is a possible finite Life universe in the form of a sphere. The simplest way to do this is to use an m × n rectangle with the top edge joined to the left edge and the bottom edge joined to the right edge. It is similar to a torus except that it has adjacent pairs of sides joined instead of opposite pairs. With this configuration, the top-left and bottom-right corner cells become the "poles" of the sphere which have themselves as three of their neighbors. The other two corner cells have only one of themselves as a neighbor.
- Sphere at Wikipedia