Keywords: Earth (46), GPS (40), longitude (38), latitude (38), sphere (36)

The brain is wider than the sky, For put them side by side;

The one the other will include, With ease, and You beside.

Emily Dickinson

A logical starting point for investigating the surface of the Earth is to examine its general shape-an approximate sphere. The sphere looks like a simple object, having no holes, no twists, and a generally smooth and uniform appearance. The geometry of the Earth as a sphere is anything but simple.