Aether and Gravitation Part 22

From the foregoing extracts taken from Maxwell's writings, we learn that the const.i.tution of the Aether, as given in Art. 44, exactly coincides with, and satisfactorily fulfils the conditions that he lays down with reference to his physical conception of the lines of force around a magnet or electrified body.

So that the theory of Maxwell is not merely hypothetical, as is suggested by scientists, but exactly describes the conditions and state of the atomic Aether medium which surrounds all magnets. We have, however, seen that the sun is a magnet, and therefore it possesses around it on every side, the same as any other magnet, these aetherial lines of force composed of infinitesimal vortices, or mere whirling points which correspond to an aetherial atom.

These aetherial lines of force stretch out into s.p.a.ce on every side of the sun, and in fact form concentric magnetic sh.e.l.ls around the sun; which magnetic sh.e.l.ls coincide with the equipotential surfaces of the Aether viewed merely from the point of elasticity and density of the medium. We learn by experiment, that these lines are closest together nearest to the magnet, which fact agrees with the statement that Aether is gravitative, and therefore the Aether would be densest nearest the sun. That is, the atoms would be pressed closer together, so that the lines of force of which these atoms are composed ought also to be closer together at the surface of the magnet, which we find by experiment is the case. As the sun is an electro-magnet, therefore, it possesses these magnetic lines of force on all sides, forming a series of magnetic sh.e.l.ls. We have now arrived by the aid of Maxwell's theory to a physical conception of the Aether from a magnetic standpoint, which fully agrees with our physical conception of the Aether which was arrived at by purely philosophical reasoning, based on Newton's Rules of Philosophy.

Thus we are able to combine into one whole by our conception that Aether is matter, and therefore atomic and gravitative, not only Faraday's Lines of Force, but also Maxwell's physical conception of the same, apart from the solutions given to the other problems of science by the self-same conception, which solutions will be dealt with in their proper order.

As further evidence of Maxwell's belief in the physical existence of Faraday's Lines of Force, let me again quote from his paper on "Action at a Distance,"[36] already referred to in Art. 43. He writes: "Its minute parts may have rotatory as well as vibratory motions, and the axes of rotation form those lines of Magnetic Force which extend in unbroken continuity into regions which no eye has seen.... These lines must _not be regarded as mere mathematical abstractions_. They are the directions in which the medium is exerting tension like that of a rope, or rather like that of our own muscles."

[Footnote 34: _Exp. Res._]

[Footnote 35: _Magnetism and Electricity._]

[Footnote 36: _Collected Works_, by Niven.]

ART. 90. _Terrestrial Magnetism._--We have already seen that the earth is a magnet, and like any other magnet will therefore possess its magnetic field with its magnetic lines of force. The earth's magnetic field is co-existent and co-equal with its electric field (Art. 80), and that is co-existent with the earth's aetherial atmosphere which is held bound to the planet by the force of gravity.

How far the earth's magnetic field reaches, is impossible to say, but we know that it extends at least as far as 260,000 miles, the distance of the moon; as we find that this satellite of the earth is affected very considerably by the electro-magnetic attractive power of the earth. Any body which is placed in the earth's magnetic field is affected by the lines of force which exist in the magnetic field; for wherever the field exists, there the lines of force exist also.

These lines of force, which are a.s.sociated with the earth, extend therefore into s.p.a.ce, and any body such as the moon would become a magnet, if not already one by the process known as magnetic induction, which physical process is well ill.u.s.trated in the action of a magnet upon iron filings strewed over it as in the ill.u.s.tration (Art. 88).

An experiment which well ill.u.s.trates the inductive power of the earth's magnetism, may be made by placing a poker in one of these lines of force, whose direction can be found at any part of the earth's surface by means of proper instruments. When the poker is so placed, it will be seen that it has actually become magnetized by the magnetism of the earth, and it is itself able to attract iron filings or small needles.

These lines of force of the earth are closer together nearest to the earth's surface than further away in s.p.a.ce, and congregate around the North and South magnetic poles, where they are greatest in number in a given area, and there the magnetic intensity is the greatest.

Faraday, writing on the terrestrial lines of force, says: "The lines of force issue from the earth in the northern and southern parts with different but corresponding degrees of inclination, and incline to, and coalesce with each other over the equatorial parts. There seems reason to believe that the lines of magnetic force which proceed from the earth return to it, but in their circuitous course they may extend through s.p.a.ce to a distance of many diameters of the earth, to tens of thousands of miles."[37]

From this extract it will be seen that Faraday was of the opinion that the lines of force extended beyond the atmosphere of the earth into the Aether, which statement is confirmed by other parts of his writings; though he was not able to give any physical explanation of how these lines extended beyond the atmosphere on account of the doubtful const.i.tution and character of the Aether, although in another part of his work he definitively refers to the magnetic character of s.p.a.ce.

In writing on the magnetic character of s.p.a.ce he says:[38] "From such experiments, and also from general observations and knowledge, it seems manifest that the lines of magnetic force can traverse pure s.p.a.ce, just as gravitating force does, and as static electric forces do (1616), and therefore s.p.a.ce has a magnetic character of its own, and one that we shall probably find hereafter to be of the utmost importance in natural phenomena." With the view of the Aether presented in this work, viz. that Aether is matter, though in an infinitely more rarefied and elastic form, we can now see the physical cause of the lines of force with which by his imagination he filled all s.p.a.ce.

Again, from the conception of the Aether presented to the reader in Art.

45, we learn that around any body in s.p.a.ce there are existing aetherial concentric spheres or sh.e.l.ls which are equipotential surfaces, or surfaces of equal pressure, and that these surfaces coincide with the electric equipotential surfaces, as shown in Art. 80.

Not only so, but they coincide with the magnetic sh.e.l.ls which the lines of force actually form around a circular and globular magnet, as the earth. For it must not be forgotten that these lines of force exist equally on all sides of the earth, and therefore really form a spherical sh.e.l.l, or to speak more correctly an aetherial electro-magnetic sh.e.l.l, which is an oblate spheroid in shape, partaking of the shape of the earth or other planet which the lines of force surround.

If these sh.e.l.ls were divided into two equal halves, the line so dividing them would be called the magnetic equator, and on that line any magnet would set itself in a horizontal position, so that all round the earth on the magnetic equator would correspond to a line of no dip. At the magnetic poles, a magnet would set itself vertically, or at an angle of 90, and between these two parts, the place of no dip, and that of 90, the dip gradually changes as ill.u.s.trated in the figure. Again, in relation to the magnetism of the earth we find that there are certain variations in the magnetic force, which not only influence the dip at any place, but also the intensity at that place. The variations in Magnetic Force are chiefly three--

1st. Diurnal Variations.

2nd. Annual Variations.

3rd. Secular Variations.

Let us look at these three variations from the standpoint of the magnetic lines of force which exist around the earth, and around every planet. In relation to the variations of the magnetic forces upon the surface of the earth, Faraday points out that these variations are caused by the action of the sun's rays upon the terrestrial lines of force. He uses the following figure to ill.u.s.trate his meaning. Let _H_ be the sun, _E_ the earth--

[Ill.u.s.tration: Fig: 21.]

He writes as follows: "If the magnetic and astronomical poles of our earth be supposed to be coincident, then North and South poles will also represent the North and South magnetic poles, and the different curves cutting the earth will sufficiently represent a course of magnetic lines as they occur at, or about, the surface of the earth. _H_ represents the sun, and _a_ the place immediately underneath it, which is also coincident with the magnetic equator. Point _a_ will be a line of no dip, while at point _b_ there will be dip. This dip will be increased by the action of the sun's rays, because the atmosphere under the influence of the sun's rays has expanded the air, and has thus acquired a power to affect the lines of magnetic force."

"All the lines pa.s.sing through the heated and expanded air will, because of its being a worse magnetic conductor, tend to open out, and the ma.s.s of heated air will as a whole a.s.sume the condition of diamagnetic polarity (2923). The case may be more simply stated for the facility of recollection by saying, that the effect of the sun is to raise the magnetic circles over the equatorial and neighbouring parts from their normal position, in doing which the North and South dip are simultaneously affected and increased."

Thus it can readily be seen that every day as the earth turns round on its axis, and presents each side of the globe successively to the rays of the sun, there should be a gradual change in the intensity of the terrestrial magnetism. In Art. 2925, Faraday points out that the maximum of dip would be when the sun was at its zenith or directly overhead.

With reference to the Annual Variation, Faraday points out (2882) that if the axis of the earth were perpendicular to the plane of its...o...b..t, the intensity and direction of the magnetic forces might be considered constant, but (2883) as the axis of the earth's rotation is inclined 23 to the plane of the ecliptic, the two hemispheres will become alternately warmer and colder than each other, and then a variation in the magnetic condition may arise. The consideration of this annual variation is further considered by Faraday in the subsequent paragraphs to those already quoted, and I must refer the reader to them for fuller details; I wish simply to indicate the possible explanation of the terrestrial magnetism, in so far as that explanation is in conformity with the aspect of the Aether submitted in Chapter IV.

With regard to secular variations Faraday points out (2880) that the temperature of the air at the equatorial parts of the earth is greater than in lat.i.tudes north and south, and as an elevation of temperature diminishes the conducting power of magnetism, so the proportion of force pa.s.sing through those parts ought to be less, and that pa.s.sing through the cooler parts, greater, than if the temperature were at the same degree over the whole surface of the globe.

Now with our definite conception of the aetherial lines of force traversing s.p.a.ce, and existing on all sides of the earth, these suggestions of Faraday's obtain an increased value in relation to the varying intensity of terrestrial magnetism, and will account for the variations in a satisfactory manner from the aetherial standpoint, if taken in conjunction with the electro-magnetic character of the Aether.

Of course, what applies to the earth equally applies to all the other planets, as they also are magnets according to Art. 87, so that they will also possess their magnetic fields, with their own lines of force, and their variations in intensity and magnetic dip.

Hitherto we have only considered the problem of the earth and all the other planets, as magnets, from the stationary standpoint, and the problem faces us as to what effect the movement of the earth and all other planets through the Aether will have upon their magnetic fields, and their lines of force. Now from Clerk Maxwell's mathematical calculations, we learn that the movement of any magnetic body through s.p.a.ce will practically have no effect upon the relation of the field, and the lines of force to the moving magnet; that is to say, the magnetic field and the lines of force move with the earth and the planets through s.p.a.ce, as they journey round the sun with their varying velocity. Maxwell has conclusively proved that the mathematical equations for moving bodies in relation to their magnetic lines of force, and induction, are exactly the same as the equations for stationary bodies, and if this be true, then it follows that the physical conditions for both stationary and moving bodies are the same.

On this point Maxwell writes: "By its motions this (moving) matter carries with it its lines of force, and electricity and magnetism may be regarded as free ends of these lines. Hence when both causes act together there can be no relative motion of true magnetism with reference to surrounding matter," etc.

"Under these circ.u.mstances electricity and magnetism move with the matter in which they are present as if they were indestructible and adhered firmly to the parts thereof." So that from Maxwell's equations and statements we learn that the magnetic lines of force around every planet, and every satellite in s.p.a.ce, move with the planets in their orbits round the sun. But as these magnetic lines of force are composed of aetherial atoms, as already indicated, it follows that the Aether which is a.s.sociated with each planet and held bound to it by the so-called force of gravity moves with the planet also.

This result is entirely consistent with our experience and observation, as we shall see later on. We find that the atmosphere, which is also gravitative, moves with the earth, and therefore from experience we are compelled to arrive at the conclusion that the Aether which is also gravitative moves with each planet, and this result is confirmed by mathematical calculations given by Clerk Maxwell, and is in perfect harmony with the same.

Here then is the key to one of the problems that has been the subject of investigation and research for many years past, and one which is at the present time occupying the attention of some of our most advanced scientists, viz. the relation of the Aether to moving matter.

That problem was solved by Maxwell from an electric and magnetic standpoint, and his result was that the Aether, which we now know to be the source of all electricity and magnetism, moves with the moving matter. What is more, this result has been confirmed by actual experiment made by Michelson and Morley in America, which experiment conclusively proves that Maxwell's result is physically correct, and that the Aether does move through s.p.a.ce with its a.s.sociated planet, and therefore its magnetic field and its lines of force move with it because of the electro-magnetic character of the Aether.

[Footnote 37: Art. 2850, _Exp. Res._]

[Footnote 38: Art. 2757, _Exp. Res._]

ART. 91. _Solar Magnets._--We have now to attack the problem as to the cause of all the satellites and planets, together with the sun, being electro-magnets. What is the continuing and ever-acting cause which makes all planetary bodies, including the sun, their centre, to be permanent magnets? According to the Rules of Philosophy there are two causes which would be simple in conception, which are suggested by experiment and observation, and both causes would satisfactorily account for all the planets being magnets.

The first cause suggested to our minds is, that in view of the fact that the sun is an electro-magnet, and therefore possesses a magnetic field with its aetherial line of force, all the planets may become magnets by the process of magnetic induction, which process has already been ill.u.s.trated by the action of the iron filings placed over the magnet.

Such a hypothesis would fulfil all the Rules of Philosophy, as it would be simple in conception, would not violate experience, and would satisfactorily account for the fact sought to be explained.

But such a hypothesis would be based upon the a.s.sumption that the sun was an electro-magnet, and then we should have to find out the cause of that fact also. Hence the hypothesis that the planets are magnets, because they are situated in the magnetic field of the sun, is not a satisfactory solution of the whole problem, as it fails to account for the fact that the sun is also an electro-magnet. We must therefore seek for another solution of the problem, which, while fulfilling all the Rules of Philosophy as laid down in Art. 3, will also account for the sun being an electro-magnet, as well as every planet, satellite, meteor, or any other body that exists in s.p.a.ce. If we can ascertain such a cause by philosophical reasoning, then we may say we have satisfactorily solved the problem as to the cause of all planetary and stellar bodies being electro-magnets.

If, at the same time, we can solve other outstanding problems by the solution thus offered, then such solution is more likely to be correct than if it simply solved the problem of solar magnetism. The only other solution that can possibly present itself to our minds, as to the cause of all magnetism in any planet, sun, or star, is the explanation which has already been given in Art. 86 on electro-magnetism.

In that article we learned that magnetism was really due to the circular motion of an electric current; and that, whenever and wherever we had an electric current moving or revolving with a circular motion, there we should always have those conditions which would give rise to an electro-magnet. As long as the current continued to flow in its circular course, so long would there be those conditions which would give rise to permanent magnetism.

Now in the solar system we find that there are these magnets, which have been in existence for millions of years. We also learn from the electro-magnetic theory of light that Aether has an electro-magnetic basis, which gives rise to electro-magnetic waves when disturbed, or set in motion by any heated or luminous body. It can readily be seen, therefore, that we have only to set this electro-magnetic Aether in circular motion around any planet or sun, and we have at once a circular current of electricity flowing round that planet or sun, which would give rise to those conditions by which any body within its influence may be formed into a magnet.

Our hypothesis, therefore, to explain the reason why all the planets and the sun are magnets, is that the electro-magnetic Aether moves round the sun or planet or satellite as the case may be, thus giving rise to currents of electricity around the planet or sun, and so forming those conditions in the Aether by which the permanency of any planetary or stellar magnetism may be maintained and perpetuated.

In other words, to put it plainly and tersely, each aetherial atmosphere revolves round the planet, subject to certain limitations, in the same way that the aerial atmosphere turns round with the earth, as that planet revolves on its axis. At first sight, such an a.s.sumption may seem impossible, but a little careful consideration will show not only the possibility of such a cause, but will establish it, as the only reasonable and philosophical explanation for the phenomena we are seeking to explain, viz. the electro-magnetism of all celestial bodies.

There is nothing extravagant in this a.s.sumption, as we already have a similar ill.u.s.tration in the case of the atmosphere which goes round with the earth as it revolves on its axis. We have only to extend the same principle a little further, viz. to the aetherial atmosphere, and we at once get the true physical conception of the hypothesis suggested to explain the magnetism of all celestial bodies. We have already learned that Maxwell has proved that the equations for moving magnetic bodies are the same as those for stationary bodies, from which we came to the conclusion that the electric and magnetic field of any planet goes with that planet as it revolves on its axis in its journey round the sun.

I would like to ask the reader to try to conceive of any electric or magnetic field traversing s.p.a.ce in a.s.sociation with any planet or sun which is revolving on its axis, while that electric or magnetic field does not revolve either partially or wholly with the revolving body. The field can only be stationary relatively to the planet or sun, as it revolves with the planet or sun on its axis.

There may be, as there doubtless are, conditions governing that revolution, as is the case with the atmosphere moving and revolving with the planet, but it is an absolute impossibility for Maxwell's equations relating to moving magnetic bodies to be carried to their logical conclusion, without affirming some such hypothesis as we have affirmed in relation to the cause of all solar magnetism.