Relativity: The Special and the General Theory, The Masterpiece Science Edition,

Relativity: The Special and the General Theory, The Masterpiece Science Edition, by Einstein, Albert. hardcover edition. ISBN: 7801318626165.

Robert Geroch builds on Einsteins work with commentary that addresses the ideas at the heart of the theory, bringing a modern understanding of relativity to the text. He elucidates how special relativity is a reconciliation of the contradictions between the nature of light and the principle of relativity; he expands on Einsteins treatment of the geometry of space-time and the fundamental notion of an "event"; he explains in detail, but without technical language, the equivalence of inertial and gravitational mass, a cornerstone of general relativity.