Questioning Einstein: Is Relativity Necessary? by Tom Bethell is a serious scholarly work that is very well written, absorbing the reader in a tale of long-neglected experimental results that plays out to a deep satisfaction in finally answering the question, \"Why can\'t I understand relativity?\" This is a fresh, unique review of both special and general relativity. It takes for granted that Einstein s mathematics is properly done. It does not quarrel with the numerous experimental results that support Einstein\'s general relativity theory.

Then what is the quarrel with Einstein? Bethell argues that special relativity theory is wrong and general relativity theory is not necessary. For example, Einstein himself derived E = mc2 without relativity theory, and he also argued in a lecture in 1920 at Leiden that space without ether is unthinkable, only 15 years after having said that the ether was superfluous.

Bethell\'s book is not mathematical; after all, he does not quarrel with Einstein s mathematics. Importantly, it is strongly based on experimental foundations. Time dilation, for example, is supported by but not proved by moving muons and clocks carried around the globe.

In particular, Bethell promotes Petr Beckmann s case that the medium of propagation of light is the dominant gravitational field. That idea is actually part and parcel of Einstein s general theory of relativity, save that the latter hides the simplicity behind tensors in curved space-time.