In Newton's Model Physics found a rigorous representation of Gravity, which ruled unchallenged for centuries and even currently continues to be the most pertinent approximation for low speeds and weak Field areas. Optics, on the contrary, lacked a consistent theory and accumulated without cease new problems and difficulties. As we said above, physicists abandonned the corpuscular theory of light and replaced it with wave theory, without , unfortunately, renouncing the mechanistic view of Universe. And following the habit of mechanistic thinking, they glued these hardly compatible concepts with a crutch of all crutches, with a hypothetical corpuscular "substance" called Aether.

It has been conceived by analogy with well known wave phenomena such as sound whose propagation is supported by discrete media, by oscillating particles of corpuscular fluids - gases or liquids. Light manifesting however, essentially different behaviour than sound, like propagating through vacuum, the theory started with severe problems whose apparent solutions created other, still more complex ones, reaching the apogee after the discovery of the electro-magnetic field by Maxwell. The complexity of mathematics trying obstinately to save the purely abstract mechanistic crutch, surpassed that of most known theories. Aether was probably the largest waste of effort and ingenuity in the history of Science which shows how dangerous it is to found scientific theories in aprioristic metaphysical beliefs such as the mechanistic determinism.

This seems to be a crucial lesson for us living in an epoch ruled increasingly by irrational beliefs, torn by religious, chauvinistic wars and genocides, where dogmatism is gaining all social domains including established science and education, where exorcists graduating from the Pontifical Regina Apostolorum University of Vatican, together with other Creationists and Intelligent Designers infiltrate "scientific education" and start talking about resurrecting geocentric cosmology founded in sacrosanct verbatim interpretation of Genesis. Amidst this deluge of aggressive irrationality, the souvenir of Aether mishaps may help to save at least the rationality of Science. As the Aether theory has been irremediably scrapped, we shall briefly mention some of its principal problems without entering into details of involved complex mathematics. Light propagates through vacuum, thus what appears as vacuum, the whole cosmic space must be full of Aether from apparent vacuum to "material substances" such as glass or air, through which light propagates as well. Mechanistic view suggests that Aether should present resistance to movements of stellar bodies. but no such effect has been observed and they keep on moving undisturbed through interstellar space.

So, Aether had to be retackled so that it interacts with light but not with "matter". Mathematic difficulties apart, how could such a "substance" be reconciled with the mechanistic view, is more than we can say. Apparently, the Olympus of a priori allows to stretch any point to make it fit any preconceived commonplace. Anyway, all these efforts were in vain: going through glas or water light changes speed, so Aether has to interact with "matter". New mathematical crutches reached hardly ever equaled complexity having to take care of an additional difficulty, namely polarisation requiring transverse light waves. Those require in turn the propagating medium to behave as a solid. So one had to deal with a "substance" which behaves like a solid with respect to light, like no-interaction vacuum with respect to "matter" of stellar bodies, while interacting with "matter" which it permeates like glass or water in a way to modify the speed of light waves in function of their length. Mathematical problems apart, the pile of contradictions involved by such "substance" should have indicated its aberration, but what would one not do to save an irrational belief; so mathematical arobacies described a "substance" solid-like at ultramicroscopic sizes, vacuum-like at macroscopic sizes, sometimes interacting with "matter" and sometimes not.

One would expect that Maxwell's definition of light being a particular case of electro-magnetic FIELD propagating at the speed C, would sound the knell of Aether phantasm. Especially, considering that Galilean Relativity banning absolute speed and privileged Referentials, required this C to be the same in all IR's. But the mechanistic dogma was too strong and rather than call it in question, one sacrificed on its altar the very base of contemporary Physics, the Galilean Relativity. One declared that Aether is a universal ABSOLUTE, absolutely immobile Referential, in which light moves at C. Strangely enough nobody noticed, or at least nobody mentioned that Mechanics being at the time defined and covariant exclusively in IR's, it was illegal to apply mechanistic principles to the absolute Aether, nor that all other IR's which became absolute by virtue of their relations to Aether, thus making Physics universally unfounded and undefined. Be it as it may, light was supposed to move in other Referentials, for instance at Earth, at speed Ce = C + Ve, where: Ce is speed of light with respect to Earth, Ve is speed of Earth with respect to Aether. This assumption called for empiric verification: Ce measured as different from C would 1. confirm the existence of Aether, 2. determine the ABSOLUTE spead of Earth with respect to ABSOLUTELY immobile Aether. However, the Michelson-Morley experiment proved that light moved with respect to Earth at Maxwell's speed C, thus refuting the hypothesis of universal, absolute and absolutely immobile Aether.

With unbelievable obstinacy some physicists made last superhuman efforts to save mechanistic dogma by restructuring Aether so that it would be "dragged" by stellar bodies thus moving in their vicinity at their speed. However, this hypothesis would involve C depending of the speed of light source which was experimentally refuted and Aether finally died taking with it into the grave the dogmatic, metaphysical mechanistic "determinism". This critique of the Aether Model may look rather severe, but it may by no means be interpreted as looking down on Planck, Maxwell, Lorentz and other great physicists who argued for it with ingenuity surpassing most other scientific endeavors. It is meant to emphasize the dangers of founding dogmatically Models of Phenomena in aprioristic metaphysical beliefs, dangers actually more serious for Global than for Physical Models. For physical theories such dangers are, after all, of abstract and intellectual nature. For Global Phenomena encompassing demography, ecology, religious and ethnic fundamentalism, globalised economy, politics and warfare, they are factual, casting doubt upon the very survival of the mankind.