Aether and Gravitation Part 19

If _M_ represents Mercury, _V_ represents Venus, and _E_ represents the Earth (Fig. 10), then it can readily be seen that all these would be negatively electrified on the side facing the sun; and, as they rotate on their axes, each part of the planet would be positively and negatively electrified once each day.

We are a.s.suming that the medium is at rest, but according to our conception in Art. 44, all the aetherial atoms are in rotation on their axes, in the same way that the earth rotates on its axis, so that each of these aetherial atoms would present different parts of its surface to the sun as it rotates on its axis; but, as that does not affect the principle of induction, such a fact need not now be fully considered.

Let us now ask, What is the result of all the planets becoming electrified bodies in the same way that the sun is an electrified body?

Arguing from experience, we come to the conclusion that each planet must also possess its electric field, which also must have its lines of force, its different potentials at different distances, and its equipotential surfaces. So that Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Ura.n.u.s, and Neptune all have their electric fields, with their own lines of force, and with their equipotential surfaces.

If we carry the a.n.a.logy further still, then it can also be proved that the Earth, and those planets which have moons or satellites, also act inductively on their satellites, with the result that they too become electrified bodies, with their own smaller electric fields and lines of force. This may seem at first sight a little confusing, but the confusion will gradually disappear if we will look at it carefully for a moment or two. Let us endeavour to picture the solar system from this new standpoint, and map out the equipotential surfaces, which this idea suggests. Let _S_ represent the sun (Fig. 14), the initials of all the planets and satellites representing the various planets; then we get the following plan of the solar system with the various equipotential surfaces shown by the circular lines.

We are now supposed to be looking down on all the solar system from above it, so to speak, so that we should be looking at what we call the North Poles of the sun and planets.

[Ill.u.s.tration: Fig: 14.]

Thus we see that the equipotential surfaces around the sun are huge circles which stretch out as far as Neptune or even beyond, but within those circles we find each of the planets revolving round the sun, each with its own equipotential spheres, which are circles also, while around the various planets are the satellites, from the moon of our Earth, to the two satellites of Mars, five of Jupiter, eight of Saturn, each with its own lines of force and electric fields.

Of course we must not forget that all these revolve round the sun, and the question may suggest itself to the reader's mind, if such a result is possible. I shall prove later on, that according to Maxwell such an event is possible, but at present we will consider them stationary.

Now let us see how such a conception compares with our hypothesis of a gravitative Aether. If Aether be gravitative, then the sun must have an attraction for the Aether, and its aetherial field would stretch out into s.p.a.ce as far as Neptune at least.

So that it can readily be seen that the aetherial field of the sun's attractive power coincides with the electric field which the sun possesses as an electrified body. Again, if Aether be gravitative, then all the planets must also have an aetherial field, which will be co-extensive with their electric field also. The same principle applies to each of the satellites, with the result that they too will possess an aetherial field which will be equal in extent and limit to their electric field.

As the satellites revolve around their primary planet taking their electric fields with them, so the planets with their a.s.sociated satellites revolve around the sun taking their electric and aetherial fields with them. Thus we get a glimpse, though at this point very shadowy and indistinct, of those motions of the universal Aether, which help to const.i.tute the harmony, beauty, and order of the universe. We have seen, therefore, that as the sun is an electrified body, so all the planets and satellites are electrified bodies also, each possessing its own field, with all that such a field implies.

We shall find that such a conception is borne out by experience and observation, when we come to deal with the Earth as a magnet; because we shall afterwards learn that the Earth is an electro-magnet, possessing its magnetic field, which is co-existent and equipollent with its electric field.

[Footnote 28: _Exp. Res._, 1297, 1298.]

[Footnote 29: Par. 1298.]

ART. 82. _Energy of the Field._--We have seen in Art. 79 that every electrified body has an electric field. We have further learned, in carrying the electro-magnetic theory of light to its logical conclusion, that all the planets and satellites together with the sun must be electrified bodies, each possessing its electric field.

We have now to determine the effect of such a truth from its dynamical aspect upon the bodies within the field, that is to say, we have to consider the energy of such electric fields, and endeavour to find out the effect of such energy upon other bodies within that field.

Maxwell,[30] in his introduction to a paper on "The Dynamical Theory of the Electro-magnet Field," writes on the matter thus: "It appears therefore that certain phenomena in electricity and magnetism lead to the same conclusion as those of optics, namely, that there is an aetherial medium pervading all bodies and modified only in degree by their presence; that the parts of this medium are capable of being set in motion by electric currents and magnets; that this motion is communicated from one part of the medium to another by forces arising from the connection of these parts; that under the action of these forces, there is a certain yielding depending upon the elasticity of these connections; and that therefore energy in two different forms may exist in the medium, the one form being the actual energy of motion of its parts, and the other being the potential energy stored up in the connections in virtue of their elasticity."

The two forms of energy he gives us in his work on _Magnetism and Electricity_, where, in the quotation already given in Art. 79, he states them to be electro-static and electro-kinetic energy, while in paragraph 792 of the same work he adds: "The intrinsic energy of the medium is half electro-static and half electro-kinetic, that is, half is due to electricity and half is due to magnetism."

We are, however, only dealing at this point with the electro-static energy in the electric field, as we shall deal with the electro-kinetic energy in the following chapter.

We have, therefore, to conceive of an electrified body generating electric or electro-magnetic waves, which speed away from the generating source on every side with the velocity of light. Now we have already seen that the aetherial waves which give rise to heat and light possess a repulsive power, that is, they exert a pressure on the body with which they come into contact.

If, therefore, in the electric field there is this energy manifested as proved by Maxwell, and that energy takes partly the form of a pressure as stated by Maxwell, then we have in the electro-static energy of the electric field, another indication of that centrifugal force for which we are looking, and whose existence was so satisfactorily demonstrated to Herschel by the phenomena of comets' tails.

That there is this pressure in an electric field was conclusively proved by Maxwell, and experimentally demonstrated by Professor Lebedew (Art.

77). Maxwell distinctly states on this point, "that the combined effect of the electro-static and electro-kinetic stresses is a pressure equal to 2 P. in the direction of the propagation of the waves," that is, away from the electrified or charged body.

He continues: "Thus, if in strong sunlight the energy of light which falls on one square foot is 83.4 foot-pounds per second, the mean energy in one cubic foot of sunlight is about .0,000,000,882 of a foot-pound, and the mean pressure on a square foot is .0,000,000,882 of a pound weight. A flat body exposed to sunlight would experience this pressure on its illuminated side only, and would therefore be _repelled_ from the side on which the light falls."[31]

This pressure only gives the result due to the pressure of one cubic foot of sunlight. What must be the pressure, therefore, due to the whole of the sunlight received by the flat body from the sun? The total pressure, whatever it may be, would be equal to 2 P. according to Maxwell, and half of that is due to electricity, and half due to magnetism. Now such a result is entirely in harmony with the conception of the Aether as given in this work. For, if Aether possess an electric basis as suggested by Maxwell, and it is also gravitative as suggested in Art. 45, then it must follow, as pointed out in a previous Art., that throughout the field there is a varying difference in the potential of the field; the potential being regulated by the electric density, that density being equivalent to the aetherial density. Further, as the elasticity of the medium which regulates the pressure is proportional to the density, so the pressure must decrease, as the elasticity decreases--that is, as the electric potential decreases, or the electric density is diminished. Therefore, if the sun be an electrified body, ever generating electro-magnetic waves which speed away from it on every side, then, whenever any of these waves come into contact with a planet or comet, that planet or comet would be repelled from the sun by the pressure of these electro-magnetic waves to which the sun gives rise in its electric or electro-magnetic field.

Thus we again come to the conclusion that the sun is not only the centre of a centripetal force due to Gravitation, and subject to certain laws, whose physical cause is unknown, but it is equally the centre and source of a centrifugal force, in that it is an electrified body, and gives rise to electric waves which produce a pressure on any body upon which they fall, in the sun's electric or aetherial field. It has only to be demonstrated, therefore, that this centrifugal force satisfactorily fulfils all the laws required as laid down in Art. 24, that is, that its course is along the same path as the Centripetal Force of Gravitation, that it is subject to the same law of intensity, which is inversely as the square of the distance; and further (what is the most important at this stage), that the combined effect of the pressure of two bodies is equal to the product of their ma.s.ses, then we shall have discovered that which we set out to discover, viz. a complementary force to the attractive force of Gravitation.

Unlike the centripetal force, however, the centrifugal force will be purely a physical one, due to a purely physical medium, the Aether, whose properties and motions can be accounted for on a physical, and not on a hypothetical basis.

Further, as the planets are also electrified bodies (Art. 81), they too will possess an electric field, and will generate electric waves, which will also exert a centrifugal force upon all bodies upon which the waves fall. So that, like the sun, the planets are not only the centre of a centripetal force, which ever acts towards their centre; but they are also the centre of a centrifugal force, due to the aetherial electric waves to which they give rise in the Aether.

The application of the same principle may be extended to every satellite that exists in the solar system, and indeed to every particle and atom of matter that exist throughout the universe, for wherever we find the Aether, there we find this centrifugal force, which is due to the electric aetherial waves generated by the atom or particle of matter, or by any combination of atoms, as a meteor, satellite, planet, sun or star.

[Footnote 30: _Collected Papers_, by Niven.]

[Footnote 31: _Magnetism and Electricity_, Arts. 791 and 793.]

ART. 83. _Electric Radiation._--We learn, therefore, that the sun, together with every planet and satellite in the solar system, is the centre of a centrifugal force, which is due to the radiation of electric waves by an electrified body. We have now to prove that this force fulfils all the laws required, in order for it to become the complementary law to the Centripetal Force of Gravitation. We will first show that this centrifugal force which proceeds from the electrified body is radiated out into s.p.a.ce in straight lines with the velocity of light and radiant heat.

As we have already seen, it was due to the genius of Hertz to show the ident.i.ty between electric radiation and radiant light and heat. In his paper on Electric Radiation he says:[32] "I have succeeded in producing distinct rays of electric force, and in carrying out with them the elementary experiments which are commonly performed with light and radiant heat." We have seen in Arts. 65 and 76 that radiant heat and light are propagated in straight lines, so that, according to Maxwell's electro-magnetic theory, a ray of electric radiation should also be propagated in straight lines.

This Hertz proved, and gave his results in his paper "On the Action of a Rectilinear Oscillation upon a Neighbouring Circuit," in which he fully demonstrated that when electric action takes place between two charged bodies, the electric force is radiated out into s.p.a.ce in straight lines in the same way that light and radiant heat are radiated. In his paper on "The Finite Velocity of Electro-magnetic Actions," he showed that the velocity of the electro-magnetic waves was the same as that of light. In the summary of this paper (paragraph 3) he states: "There are many reasons for believing that the transverse waves of light are electro-magnetic waves; a firm foundation for this hypothesis is furnished by showing the actual existence in free s.p.a.ce of electro-magnetic transverse waves which are propagated with a velocity akin to light."

Again, in his paper on "Electric Radiation," he not only showed how the radiation was propagated in straight lines, like light, but also proved that while it was reflected by metals, the electric beam was able to pa.s.s through doors and stone walls, and adds, "that it was with astonishment that one saw the electric beam appear inside a closed room after its pa.s.sage through the door."

Thus Hertz has shown that both electric and magnetic effects are propagated through the Aether with finite velocity, and that that velocity is exactly the same as the velocity of light. He further proved that this propagation takes place in straight lines, in the same way that radiant heat and light are propagated. This being so, it is necessary for us to apply these truths to the solar system, with a view to find out what such a result teaches us.

We have seen in a preceding article, that the sun is an electrified body; therefore it, too, must generate these electro-magnetic waves, and radiate them into s.p.a.ce on every side with the velocity of light. Let us try to picture the scene. Let _S_ represent the sun, and the circle round it represent the equipotential spheres which exist round the sun.

(See Figs. 10 and 11.) As the intensity of the electric force is greater nearer the sun than further away, these equipotential surfaces will be closer nearer the sun than further away.

Then let the straight lines which radiate out from the sun represent the path of an electric ray. It can be easily seen that these electric rays cut the equipotential surfaces at right angles, as they pa.s.s from the centre of the sun outwards into s.p.a.ce. Now these lines not only represent the path which the electric ray takes in its journey through s.p.a.ce, but exactly coincide with the electric lines of force as conceived by Faraday. This great thinker and experimentalist not only conceived lines of magnetic forces existing in the dielectric or medium between two electrified bodies, which in this case is the Aether, but also conceived lines of electric force which started at a conductor, or an electrified body, and radiated out into s.p.a.ce.

Thus a line of electric force has a definite direction, and always starts from an electrified body. If it were possible to move a planet along one of these lines of force, its path would be that of a straight line. If on the other hand a planet moved at right angles to one of these lines of force, that is, along the surface of an equipotential sphere, then no work would be done against the electric force, as on such a sphere the electric force would be of the same intensity.

So that from Hertz' experiments it can be demonstrated, that if there be any electric force existent in the Aether, due to the action of the sun upon the Aether, then such a force is directed along the path of a straight line into s.p.a.ce with the velocity of light, which, as already pointed out, is the path taken by a ray of radiant heat and light, and coincides with the path taken by the centripetal force.

It has been demonstrated that such electric force is accompanied by a repulsive force, or more correctly a pressure, so that here we have further evidence of the existence of a centrifugal force which finds its generating source in the sun, which is also the centre of the attractive force of Gravitation in the solar system.

The application of Hertz' experiments may be made not only to the sun, but also to every planet and satellite that exists in s.p.a.ce with the same result; and, further, may be extended to every particle and atom that exists throughout the universe. For, according to Art. 43, we have learned that Aether is universal, and we have seen that it is gravitative, and have learned from the electro-magnetic theory of light that it has an electro-magnetic basis. Therefore, to be thoroughly consistent, we must not stop in the application of this principle at any point in the whole universe.

Either the whole principle is of universal application, or it ceases to be a universal law. Therefore, if there is this centrifugal force operating along a straight line from the centre of an electrified body, such centrifugal force must be in its application universal, in order to be complete, and in order to satisfactorily form the counterpart of the centripetal force which is also universal, and operates along the straight line joining the centres of gravity of any two bodies.

[Footnote 32: Hertz on _Electric Waves_.]

ART. 84. _Law of Inverse Squares._--We have learned therefore from the preceding Arts., that the solar system may be looked upon as an electric field, with the sun as the electrified body occupying the centre. We have also seen that there is a centrifugal force in all electric fields, which is due partly to electric waves, and partly to the magnetic waves of the Aether.

It will be interesting to find out, what law governs the intensity of this force in any part of the field, or at a given distance from the central body. We have seen (Art. 66) that the law governing the intensity of heat at any distance from the sun, is the law of inverse squares. Further, from Art. 75 we have also learned that light is subject to the same law of inverse squares, as indeed it should be, if it be due to one and the same medium, the Aether.

If, therefore, electricity is also due to certain motions of the aetherial medium originated by the action of an electrified body as the sun, in the same way that light and heat waves are originated, then it ought to follow that the repulsive power of electricity is also subject to the same law of inverse squares. As a matter of fact, that is exactly the state of affairs, so that we find the intensity of the repulsive power in the Aether from any central body, due to the electric waves, or the pressure due to the wave motions of the electric Aether, in relation to that body, is governed and controlled by the same law that governs light and heat.

It may be suggested that such a coincidence is not a very strong argument, as all forces emanating from a central body are subject to the same law of inverse squares. In reply to that, I should like to point out, that even that objection only strengthens the conception of the Aether that we are endeavouring to complete. Our contention is, that all physical forces, whether they be light, heat, electricity, magnetism or Gravitation, are all due to the motions of the aetherial medium; which motions may be generated by a heated or luminous or electrified body, and are radiated from such a body in waves of concentric spherical form, and are all subject to the laws of inverse squares.

So that the fact of the intensity of the centrifugal force due to the repulsive power of electricity falling into line with the law governing light and heat is, to my mind at any rate, only a clearer proof of the one common origin of all the physical forces. The law of inverse squares in relation to electricity may be thus stated. The Centrifugal or Repulsive Force between two charged electrified bodies acts inversely as the square of the distance between them.