3.2.8  Experimental Verification

Special Relativity is also criticized for various other philosophical reasons and its rejection of mathematical physics per se, but the overwhelming majority of scientists agree that it has been verified in many different ways and there are no inconsistencies within the theory. Additionally, since Special Relativity reduces to the Newtonian mechanics when the speed become very small compared to the speed of light, this means that it satisfies the “correspondence principle”, which requires that a more general theory must reduce in some limit to more restrictive theories.

After the original aether dragging experiments by Michelson-Morley, many similar and more accurate experiments were conducted in the 1920s, all confirming the original result. Another type of interferometer experiment was the Kennedy-Thorndike experiment in 1932, by which the independence of the speed of light from the velocity of the apparatus was confirmed. Also time dilation was directly measured in the Ives-Stilwell experiment in 1938 and by measuring the decay rates of moving particles in 1940. All of those experiments have been repeated several times with increased precision.

Nevertheless, in 1962, J. G. Fox pointed out that all previous experimental tests of the constancy of the speed of light were conducted using light which had passed through stationary material: glass, air, or the incomplete vacuum of deep space. As a result, all were thus subject to the effects of the extinction theorem. This implied that the light being measured would have had a velocity different from that of the original source. He concluded that there was likely as yet no acceptable proof of the second postulate of Special Relativity. However, this surprising gap in the experimental record was quickly closed in the ensuing years, by experiments by Fox, and by Alvager et al., which used gamma rays sourced from high energy mesons. The high energy levels of the measured photons, along with very careful accounting for extinction effects, eliminated any significant doubt from their results.

Many other tests of Special Relativity have been conducted, testing possible violations of Lorentz invariance in certain variations of Quantum Gravity. However, no sign of anisotropy of the speed of light has been found even at the level, and some experiments even ruled out any violations.

Moreover, the General Theory of Relativity, that will be reviewed in section 3, extended the theory into non-inertial frames and explained gravity in terms of space-time structure by using non-Euclidean geometry invented by Riemann. In this way, gravitation is shown to be a result of the curvature of space-time in the vicinity of mass, which was verified by measuring the amount of the deflection of light in the eclipses of 1919 and 1921.

However, although the null results of Michelson-Morley experiments were considered a strong evidence against the existence of stationary aether, but there is yet no other theoretical account that could explain this constancy and invariance of the speed of light in all frames, which forms Einstein’s critical postulate. The Duality of Time, however, will bring back the same classical concept of aether in a novel manner that explains the constancy and invariance of the speed of light, and leads to all the three principles of Special and General Relativity together, because the perpetual creation in the inner levels of time implies genuine complex-time geometry. The Duality of Time also satisfies the correspondence principle because its dynamic and self-contained Euclidean space-time, that is intrinsically granular, reduces to the non-Euclidean space-time continuum of General Relativity when we consider the coexistence of all the dimensions of space in, and with, time, as it has been introduced in chapter I and will be explained further in chapter V.