XXIX
THE SOLUTION OF THE PROBLEM OF GRAVITATION ON THE BASIS OF THE GENERAL PRINCIPLE OF RELATIVITY
F the reader has followed all our previous I considerations, he will have no further diffculty in understanding the methods leading to the solution of the problem of gravitation.
We start off from a consideration of a Galileian domain, i.e. a domain in which there is no gravitational field relative to the Galileian reference-body . The behaviour of measuring-rods and clocks with reference to is known from the special theory of relativity, likewise the behaviour of “isolated” material points; the latter move uniformly and in straight lines.
Now let us refer this domain to a random Gauss co-ordinate system or to a ‘‘mollusk” as reference-body . Then with respect to there is a gravitational field (of a particular kind). We learn the behaviour of measuring-rods and clocks and also of freely-moving material points with reference to simply by mathematical transformation. We interpret this behaviour as the
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