Introduction to General Relativity

Abstract

We shall assume familiarity with the special theory of relativity (SR). Two inertial observers, i.e., two observers who move uniformly in a straight line relative to each other, describe nature in identical terms. Certainly, aesthetics demands that if nature would not show preference for one or the other of two observers in uniform rectilinear motion relative to each other, then it should also not show any preference between two observers with any type of relative motion. This implies that we must search for a more general principle of relativity demanding invariance, not merely under Lorentz transformations, but under more general transformations arising out of nonuniform relative motion of two observers. This was one motivation for going over from SR to the general theory of relativity (GR).