The principles of general relativity

Abstract

Abstract Chapter 9 examines the principles that guided Einstein in his quest for a relativistic theory of gravitation, paying particular attention to the principle of equivalence. One school of thought considers this an unnecessary process, but rather argues that it is sufficient to state the theory and investigate its consequences. There seems little doubt, however, that consideration of these physical principles helps give insight into the theory and promotes understanding. After a discussion of the various roles that mass plays in Newtonian theory, namely, inertial mass, passive gravitational mass, and active gravitational mass, the principle of equivalence is introduced and various formulations of this are presented. There then follows a discussion of the other principles that explicitly or implicitly played in important role in the development of a relativistic theory of gravitation, namely Mach’s principle, the principle of general covariance, the principle of minimal gravitational coupling, and the correspondence principle.