The book introduces two dominant concepts: the existence of the *aether* (the medium for the transmission of light) and *gravitational reduction of rest mass*.

Regarding the first, a proof of aether's existence is given, enabling a logical explanation of the seeming paradoxes of special relativity.

The reduction of rest mass in a gravitational field may be proved by consideration of the annihilation of an electron-positron system deep in a gravitational field. All of the energy of the resultant gamma rays derives from the rest mass of the pair, but the gamma rays will be measured to be red-shifted (reduced in energy) by distant observers. In a time-independent gravitational field, energy must be conserved, so the reduced energy of the gamma rays implies the reduced rest mass of the electron-positron pair.

Rest mass reduction may be said to be the embodiment of gravitational potential energy: it explains the gravitational red shift, and also implies a heretofore unexpected phenomenon - *gravitational length dilation*. This latter phenomenon implies that the presently accepted geometry is incorrect, indicating that the structure of a black hole has been badly misunderstood. Correcting for this effect yields the correct geometry and explains several otherwise puzzling phenomena, including the astounding reversal of centrifugal force near a black hole (the Abramowicz effect).