The Enigma Of The Universe : 4. General Theory Of Relativity

In 1916, eleven years after the formulation of the special theory of relativity, Einstein extended it to interpret more general cases of non-uniform motion, i.e., where one frame of reference moves with an accelerated velocity relative to the other. This is known as 'the general theory of relativity'. Its chief achievement is the explanation of the law of gravitation on a more refined and accurate basis than that given by Newton. Einstein has explained here the effect of the mass of the physical substances on the four dimensional continuum of space and time.