The rotation and precession of relativistic reference frames

The Clifford algebra of three- and four-vectors is reviewed and used to examine the nature of the rotation and precession of accelerating reference frames in Minkowskian space-time, and freely falling reference frames in general relativity. It is shown that the usual interpretation of Thomas precession must be modified because in space-time three-vectors in one frame of reference cannot be related to three-vectors in another.