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.