**einstein**

In *A Review of Einstein's Relativity*, Dr. Lawrence Stephenson shows that the equations of special and general reletivity can be derived without two unnecessary assumptions made by Einstein, the first explicit, the second implicit:

- "Light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body."
- The transit time from emitter to receiver is exactly half the total round trip time back to emitter.

Instead Stephenson notices that "the observed velocity of light has always been found to have a definite value relative to the detector which is used for measurement." The understanding of relativity presented in this book is actually more consistent with Mach's principle, Einstein's inspiration, than Einstein's conception, yet without the distortion of time and space seemingly demanded by Einstein's work.

The reader gains three useful results:

- A readily understood visual picture of both the special and general relativity theories.
- An original way of understanding the "anomalies" of relativity.
- A model of gravity consistent with Mach's principle.

Short and to the point, this book addresses the questions of motion and optics at a fundamental level, understandable to the novice, yet challenging to the expert. Highly recommended.