Why should the luminiferous ether, or any primordial medium in which it may have been generated, be regarded as in any way "spiritual"?
It would be hard to say why the luminiferous ether should be relegated to the "unseen world" any more than the material atom.
We treat the luminiferous ether on mechanical principles, and, from the composition and resolution of its vibrations we deduce all the phenomena displayed by crystals in polarized light.
The luminiferous ether is a substance which fills all space, and surrounds the atoms and molecules of bodies.
Nothing could more forcibly illustrate the isolation, if I may use the term, of the luminiferous ether from the air.
For the waves of sound we have the air of our atmosphere; but the stretch of imagination which filled all space with a luminiferous ether trembling with the waves of light was so bold as to shock cautious minds.
So also, if light is only a mode of motion, luminiferous æther has no greater power when undulating in the open air than when at rest in a dark room.
Radiant light consists in undulations of the luminiferous aether.
A luminiferous aether pervades the universe, rare and elastic in a high degree.
Light, per se, can be transmitted only through the luminiferous ether, as we have seen in the chapter on light in Volume II.
Heat is a motion of the ultimate particles or atoms of matter, and Light is a motion of the luminiferous ether transmitted in waves that are transverse.
One thing we are sure of, and that is the reality and substantiality of the luminiferous ether.
Nothing, for example, could be really more profound than the difference between waves of compression and rarefaction transmitted through the luminiferous ether and the translation of their impact into light.
Sir Oliver Lodge is inclined to discover in theluminiferous ether an environment in which discarnate personality could function.
Again, these coats and humors depend upon light, and light depends for its transmission, probably, upon that exceedingly elastic medium called the luminiferous ether.
Why should it not be transmitted by means of the luminiferous ether to the limits of the universe?
Now, I am not going to assert that the spiritual body will be composed of this luminiferous ether.
It is the luminiferous ether, that attenuated medium by which light, and heat, and electricity are transmitted from one part of the universe to another, by undulations of inconceivable velocity.
But if the luminiferous ether is not matter, and fluid matter, too, what is the meaning of its undulations?
The prevailing hypothesis of a luminiferous ether, in other respects not without analogy to that of Descartes, is not in its own nature entirely cut off from the possibility of direct evidence in its favor.
The luminiferous ether surrounds and is influenced by the ultimate particles of matter.
One substance only in the universe has been hitherto proved competent to transmit power at this velocity; the luminiferous ether.
Although apparently dark, a room is penetrated by imperceptible rays of external light from lamps or other luminiferous bodies.
But, inasmuch as the term 'ether' is also applied to a familiar organic compound, we may distinguish the ultra-material luminiferous medium by calling it the Ether of Space.
Hence the luminiferous medium must be a special kind of substance; and it is called the ether.
The luminiferous medium is therefore, during the passage of light through it, a receptacle of energy.
We have to show that the properties of the electro-magnetic medium are identical with those of the luminiferous medium.
We have now to show that the properties of the electro-magnetic medium are identical with those of the luminiferous medium.
In order to account for this wave motion, he supposed all space to be filled with a luminiferous Aether, which would be to his light waves what air is to sound waves.
Young in his first Hypothesis on the Aether medium states that, "A Luminiferous Aether pervades the Universe rare and elastic in a high degree" (Phil.
Thus the physicists were bound to arrive at the theory of the "quasi-rigid" luminiferous ether, the parts of which can carry out no movements relatively to one another except the small movements of deformation which correspond to light-waves.
But if the luminiferous ether is not matter, and fluid matter too, what is the meaning of its undulations?
The prevailing hypothesis of a luminiferous ether, in other respects not without analogy to that of Descartes, is not in its own nature entirely cut off from the possibility of direct evidence in its favour.
In the present scientific age every one knows that light is transmitted across space through the medium of the luminiferous ether.
This great fact once ascertained, it became clear that the notion that electric phenomena are affections of the luminiferous ether was no longer a mere speculation but a scientific theory capable of verification.
For many years the luminiferous medium was identified with the isotropic solid of the theory of elasticity.
If light and electricity be understood as particular forms of motion, then we must inevitably recognise the existence of a peculiar luminiferous (universal) ether as a material, transmitting this form of motion.
The majority of physicists regard the luminiferous ether as consisting of "discrete particles"--"elementary molecules of inconceivable minuteness and tenuity.
Such increased knowledge has radically changed our conceptions of the luminiferous aether, converting its vibrations from longitudinal into transverse.
With all our belief of it, it will be well to keep the theory of a luminiferous aether plastic and capable of change.
As far as our knowledge of space extends, we are to conceive it as the holder of the luminiferous aether, through which are interspersed, at enormous distances apart, the ponderous nuclei of the stars.
Now the substitution of transverse for longitudinal vibrations in the case of light involved a radical change of conception as to the mechanical properties of the luminiferous medium.
This result gives us a clear view of the relationship of the two substances to the luminiferous aether.
The theory of theluminiferous ether as the medium of the transmission of light is one of these pretentious bridges of words.
Modern science, while it rejects the notion of the luminiferousparticles of the old philosophy, has cogent proofs of the existence of a luminiferous ether with definite mechanical properties.
This, however, does not concern us; as far as our knowledge of space extends, we are to conceive of it as the holder of this luminiferous ether, through which the fixed stars are interspersed at enormous distances apart.
