---
title: "Criticism of the theory of relativity"
chunk: 4/9
source: "https://en.wikipedia.org/wiki/Criticism_of_the_theory_of_relativity"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:36:32.666932+00:00"
instance: "kb-cron"
---

=== Aether and absolute space ===
Many physicists (like Hendrik Lorentz, Oliver Lodge, Albert Abraham Michelson, Edmund Taylor Whittaker, Harry Bateman, Ebenezer Cunningham, Charles Émile Picard, Paul Painlevé) were uncomfortable with the rejection of the aether, and preferred to interpret the Lorentz transformation based on the existence of a preferred frame of reference, as in the aether-based theories of Lorentz, Larmor, and Poincaré. However, the idea of an aether hidden from any observation was not supported by the mainstream scientific community, therefore the aether theory of Lorentz and Poincaré was superseded by Einstein's special relativity which was subsequently formulated in the framework of four-dimensional spacetime by Minkowski.
Others such as Herbert E. Ives argued that it might be possible to experimentally determine the motion of such an aether, but it was never found despite numerous experimental tests of Lorentz invariance (see tests of special relativity).
Also attempts to introduce some sort of relativistic aether (consistent with relativity) into modern physics such as by Einstein on the basis of general relativity (1920), or by Paul Dirac in relation to quantum mechanics (1951), were not supported by the scientific community (see Luminiferous aether#End of aether?).
In his Nobel lecture, George F. Smoot (2006) described his own experiments on the Cosmic microwave background radiation anisotropy as "New Aether drift experiments". Smoot explained that "one problem to overcome was the strong prejudice of good scientists who learned the lesson of the Michelson and Morley experiment and Special Relativity that there were no preferred frames of reference." He continued that "there was an education job to convince them that this did not violate Special Relativity but did find a frame in which the expansion of the universe looked particularly simple."

=== Alternative theories ===
The theory of complete aether drag, as proposed by George Gabriel Stokes (1844), was used by some critics as Ludwig Silberstein (1920) or Philipp Lenard (1920) as a counter-model of relativity. In this theory, the aether was completely dragged within and in the vicinity of matter, and it was believed that various phenomena, such as the absence of aether drift, could be explained in an "illustrative" way by this model. However, such theories are subject to great difficulties. Especially the aberration of light contradicted the theory, and all auxiliary hypotheses, which were invented to rescue it, are self-contradictory, extremely implausible, or in contradiction to other experiments like the Michelson–Gale–Pearson experiment. In summary, a sound mathematical and physical model of complete aether drag was never invented, consequently this theory was no serious alternative to relativity.
Another alternative was the so-called emission theory of light. As in special relativity the aether concept is discarded, yet the main difference from relativity lies in the fact that the velocity of the light source is added to that of light in accordance with the Galilean transformation. As the hypothesis of complete aether drag, it can explain the negative outcome of all aether drift experiments. Yet, there are various experiments that contradict this theory. For example, the Sagnac effect is based on the independence of light speed from the source velocity, and the image of Double stars should be scrambled according to this model—which was not observed. Also in modern experiments in particle accelerators no such velocity dependence could be observed. These results are further confirmed by the De Sitter double star experiment (1913), conclusively repeated in the X-ray spectrum by K. Brecher in 1977;
and the terrestrial experiment by Alväger, et al. (1963);, which all show that the speed of light is independent of the motion of the source within the limits of experimental accuracy.

=== Principle of the constancy of the speed of light ===
Some consider the principle of the constancy of the velocity of light insufficiently substantiated. However, as already shown by Robert Daniel Carmichael (1910) and others, the constancy of the speed of light can be interpreted as a natural consequence of two experimentally demonstrated facts:

The velocity of light is independent of the velocity of the source, as demonstrated by De Sitter double star experiment, Sagnac effect, and many others (see emission theory).
The velocity of light is independent of the direction of velocity of the observer, as demonstrated by Michelson–Morley experiment, Kennedy–Thorndike experiment, and many others (see luminiferous aether).
Note that measurements regarding the speed of light are actually measurements of the two-way speed of light, since the one-way speed of light depends on which convention is chosen to synchronize the clocks.

== General relativity ==