Page:Benton 1959 The Clock Problem (Clock Paradox) in Relativity.djvu/34



The satellite may check Einstein's theory by using two so-called atomic clocks, one of which would remain on earth while the other goes aloft.

A discussion of space-time relationships, including slowing down of clocks.

The experiment was devised to test directly whether time satisfies the requirements of relativity.

It is shown that a correct application of Huygen's principle in the theory of the experiment leads to the same expression for the expected result as derived in the simple classical theory. The effect due to path difference is shown to be the same as the effect derivable from the relative rotation of the interfering beams. Critics of the classical theory have mistakenly regarded the latter as a compensating factor almost exactly offsetting the first.

According to the leading cosmological theories, intergalactic space is spherical, the radius of curvature varying with time. According to Eddington, there are only two ways to account for the large speeds of recession of the spiral nebulae, they are produced either by a scattering force, (called cosmical repulsion), predicted by the general theory of relativity, or the receding velocities now observed have existed from the beginning. For completeness, he advances as a third possibility an oscillating model of the universe. Today the question which of these two ways must be taken is still unsettled. As Eddington remarked, our first hope for further progress is some quantitative test. In this paper an extensive program for astronomical observation is indicated in order to test the alternate cosmological theories.