This article presents the historic development of the aether theory from a scientific (rather than a philosophical) perspective. In step-by-step table format, one may follow the chronology of the exploration of various theories of the medium of the universe —the medium, sometimes equated with absolute space. One may follow the twists, turns and detours —the unexpected experimental results, the new theoretical insights, the unfortunate misinterpretations— of one of the most compelling concepts in modern physics. ...
The highlight of the theory development came in the pivotal year of 2002 with the introduction of two testable models based on luminiferous AND gravitational aether: One of these employs a dynamic aether as the first luminiferous-and-gravitational aether in the context of the expanding universe model. The other employs the dynamic aether as the first luminiferous-and-gravitational aether in the context of the non-expanding cellular-universe model. In both theories, it is the presence of aether that causes actual relativistic effects.
For a printable copy follow: The History of the Aether Theory (includes detailed references).
Aether is the basic substratum of all space; aether is the raw essence of the Universe. Aether permeates the innermost recesses of all matter. Without it the universe is contrary to nature, contrary to reason and common sense. Without it the universe is utterly absurd.
And what is worrying is that the scholars who have meticulously assembled our complex picture of the universe know it is absurd.
Consider this: The cosmology that is studied in universities the world over, and practiced in the relevant research departments, is a cosmology devoid of the concept of aether. Assumed to be a dispensable relic of 19th century voodoo science, the aether was discarded a long time ago. And the resulting universe model, missing a vital ingredient, has not worked properly since. In fact, as a depiction of reality the class of expanding universe models —of which the various big bang (BB) models are a subset— has been an utter and complete failure.
Sean M. Carroll, a physicist at the California Institute of Technology, sums up one of his extensively researched and densely-referenced papers on The Cosmological Constant  with the conclusion (which he bases on the no-aether interpretation of the evidence allegedly showing that the cosmological constant, Λ, dominates the universe, that the expansion of the universe is accelerating, and that the majority of the matter content in the universe must be in an unknown non-baryonic form): “Nobody would have guessed that we live in such a universe. ... This scenario staggers under the burden of its unnaturalness, ...”
|Professor Sean Carroll is a proponent of the General-Relativity expanding-universe —even though he finds it to be staggeringly unnatural. |
Image source: www.thegreatcourses.com.
As I understand it, a universe that is “preposterous” is (and my Webster Dictionary will back me up) a universe that is "contrary to nature, reason, or common sense; utterly foolish; absurd." Undoubtedly this is the meaning that the professor intended.
One must realize that Sean Carroll  is not some rebellious radical trying to overthrow the expanding universe paradigm, or trying to reinstate the aether. Not at all. As a practicing physicist/cosmologist and a recognized authority on the expanding universe, he is steadfastly committed to resolving the absurdity without venturing outside the BB box, so to speak. In Carroll’s view, "... a major challenge to cosmologists and physicists in the years to come will be to understand whether these apparently distasteful aspects of our universe are simply surprising coincidences, ...[whose] underlying structure we do not as yet comprehend."
Unfortunately he is like many others who, for whatever the reason, are unwilling or unable to examine plausible solutions outside of BB cosmology.
What one must realize is that BB cosmology as a plausible theory has two towering handicaps. First, it embraces the unscientific concept of the expansion-of-the-whole-universe. This is blatantly unscientific because it involves an unnecessary extrapolation of a perfectly valid regional phenomenon called space expansion (regardless of how space is defined). Second, it is based on an incomplete theory of gravity, Einstein’s general relativity, which implicitly denies the existence of aether-space.
Aether is the ingredient without which these two handicaps cannot be overcome while maintaining the all-important connection with physical reality. Aether is the ingredient without which the picture of our Universe is quite unnatural and simply preposterous.
The history of conventional cosmology, as the science striving to model the real world, is a revelation of failure; and, after more than a century of Ptolemaic tinkering Academic Cosmology has managed to construct “the preposterous universe.” The cosmology practiced by modern Academia may be said to have originated in 1905 with Einstein’s theory of relativity. In that year, by one of the giants of physics, the foundation was laid; and the fateful error-of-omission was rooted. Einstein’s highly influential theory of motion, space and energy was the first 20th-century theory to embrace the popular misinterpretation of the Michelson and Morley experiment of 1887. In 1905 Einstein incorporated an implied rejection of luminiferous aether. Although there is nothing in the theory explicitly denying its existence, the authoritative message was that aether is superfluous and unnecessary.
When it came time to construct the first scientific model of the Universe, the task naturally involved Einstein, who by 1916 had formulated general relativity, a new theory of gravity. As one would expect, general relativity, being a purely geometric model of space and time, also denied the existence of aether (thereby maintaining consistency with special relativity). Hence, Einstein’s general-relativity universe-model of 1917 and all his subsequent cosmology models contained the implicit aether denial. Furthermore, since almost all 20th century universe models are based on general-relativity, they compliantly deny aether as well.
The vast majority of journal publishers participate in the denial. Any theory or model that dares to incorporate the aether concept will simply not be accepted for mainstream publication.
There are some serious problems associated with aether denial. The problems are several and multi-layered. I will deal with these later and shed further light on how 20th century scientific cosmology got it so terribly wrong. But first I will detail the historic development of the aether theory.
Aether was needed for several reasons: (1) Philosophically it has always been difficult to define absolute and total nothingness. Aristotle rejected the notion; in his worldview there was no void or vacuum. Descartes considered “it contrary to reason to say that there is a vacuum or space in which there is absolutely nothing.”  (2) During the Scientific age there arose the demand for a suitable medium for the propagation of light. In this capacity it was called the luminiferous aether. Isaac Newton, Christian Huygens, and Thomas Young were the early developers of this idea. (3) With Faraday’s discovery of lines of electrical and magnetic force, the need for some conducting medium was glaringly obvious. (Remember those lines of force magically revealed by a sprinkling of iron filings?) Faraday’s abstract field concept could be more meaningful if there was some appropriate medium to fill it. (4) Then, with Clerk Maxwell’s electric and magnetic wave theory there again was a need for a propagating medium. A more inclusive luminiferous aether was called for. Aether was enlisted to serve for the propagation needs of all electromagnetic waves.
And there were further reasons.
(5) Aether provided the perfect explanation for the phenomenon called stellar aberration which had been discovered by the English astronomer James Bradley early in the 18th century. The aberration of starlight is the apparent angular displacement of a star in the direction of motion of the observer. Because of the motion of the Earth around the Sun at a speed of about 30 km/second, an observer will see a star not in its true position but in an apparent position. An explanation of the effect is consistent with the motion of Earth through ‘stationary’ aether.
(6) There was (and still is) a need to establish a frame of reference for the measurement of what is termed absolute motion. Referencing relative motion, of course, was not a problem; the details (at least for classical speeds) had been worked out by Galileo. With his equations, one could relate the velocity of an object to any arbitrarily chosen frame of reference (stationary or moving). However, what if one wanted to determine the motion of something, not with respect to another object or frame, but rather with respect to space itself? In other words, take away the “relative” aspect and try to define some sort of fundamental meaning of motion. If space is truly and totally empty, then there is a problem. Then there would be no way to reference absolute motion —no way to answer the question, absolute motion with respect to what? Clearly, something more than “space” was needed. And for 19th-century physicists like Augustin Fresnel, Albert Michelson and Edward Morley, and others, aether was just the thing. Aether could give motion its deeper meaning. The frame “attached” to a proposed aether, and motionless with respect to it, could serve as a preferred frame of reference. Absolute speed then acquires meaning —absolute speed with respect to aether-space (not with respect to the observer).
The motivation for such a reference was extremely important and should not be underestimated. “Without such a reference ... the very idea of motion becomes vague, and all of the nineteenth century development of physics becomes shaky.”  By mid-nineteenth century it became clear that no material object in the universe represented a state of absolute rest and that absolute motion could not therefore be measured relative to any material object.  It was not merely a hypothetical issue. The need for some kind of absolute reference was real; after all, physicists were incorporating into their theories and equations a kind of motion that was inexplicably invariant. The speed of light —the speed of photon particles or EM waves— is absolute. It is undeniably so. Its absolute value is about 300,000 km/second; but absolute (or invariant) with respect to what? The observer is irrelevant; with or without the observer, the speed has a fixed value. Why?
The contemporary way of expressing the historic question goes like this. If all motion is relative, as Einstein’s special relativity theory claims, then how is it possible to enforce Nature’s absolute speed-limit. Her strict speed-of-light barrier is imposed on all entities (entities of all scales). In a rational world, an absolute limit needs absolute motion to which it can be applied. Clearly, the motivation for invoking aether-space resides not only in the historic past.
(7) Both Newton’s “spooky” action at a distance and Einstein’s curvature magic were unacceptable as causal explanations of gravity. Aether was needed to (somehow) convey the gravitational force or effect. René Descartes and Christian Huygens invoked a swirling aether-fluid to convey gravitation. Newton himself suggested that there may be variations of some sort in an all-pervading aether. Then jumping to the 21st century: Reginald Cahill explains gravity as a self-dissipating (contractile) process of aether-space; and DSSU theory (the theory of the Dynamic Steady State Universe) explains unified gravity (Lambda and normal gravity) as a dual-dynamic process of aether.
(8) Undoubtedly, the most powerful motivator was the experimental results that demanded the existence of aether. The repeated detection of absolute motion —of Earth’s absolute motion through space— provided the vital evidence of a preferred frame-of-reference, which is simply the frame in which the aether is at rest. Beginning with the famous experiment of 1887 and then in at least six other documented experiments, the evidence was found. As we saw earlier, the concept of absolute motion is inseparable from the concept of aether. Thus, if you find evidence of the former then your theory must include the latter.
The notion of a universal medium permeating all space has undergone many vicissitudes and spawned even more variants.
The posited substance called aether has changed considerably over the time period covered by the Table. Sometimes the change was radical. It is a pattern that the history of science has witnessed before. For instance, the electron posited by J. J. Thompson differs radically from the electron defined by Schrödinger’s wave equation, which in turn differs just as radically from the electron defined by Dirac’s relativistic theory of the electron. In the same spirit, the static aether of Huygens and Maxwell differs radically from the mono-dynamic aether of Augustin Cauchy which in turn differs radically from the dual-dynamic aether of DSSU theory. Electron or aether, when posited under a more advanced theory was able to explain more phenomena.