““The fact that the force of gravity can be made to disappear for a brief time over a small region around any point in a gravitational field by adopting a suitable freely fallinf frame of reference is just like the property of curved surfaces, that we can make a map that despite the curvature of the surface correctly indicates distances and directions in the immediate neighborhood of any point we like. If the surface is curved, no one map will correctly indicate distances and directions everywhere; any map of a large region is a compromise, distorting distances and directions in one way or another.””
