[31]Hertz onElectric Waves.
[31]Hertz onElectric 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, fromArt. 75we 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.
This law was proved by Coulomb by means of an instrument known as Coulomb's Torsion Balance, and I must refer the reader to any work on electricity for a full establishment of this law. Suffice to say, that it has been experimentally demonstrated that the law holds good in relation to the phenomena of electricity; and, wherever we get the two kinds of electricity present in any medium or conductor, owing to the polarization of its particles, there we have this law operating in relation to the intensity of the repulsions of the two bodies directly concerned.
We have already learned that the sun is an electrified body, and from that hypothesis we have arrived at the conclusion that the earth and all the other planets are electrified bodies. This being so, it naturally follows that the intensity of the centrifugal force between any two of these bodies, as the sun and the earth for example, or the sun and Jupiter, is subject to the law of inverse squares; and that the repulsion of the sun and the earth for each other is always regulatedby their distance, being inversely as the squares of the distance between them.
Thus, if the distance between the sun and any planet is reduced to one-half, which is an exaggerated view, the intensity of the centrifugal force is increased four times; if the distance be doubled the force is reduced to four times its former intensity, and so on.
Whatever the distance may be between the sun and any of the planets, if that distance be increased or decreased, then the intensity of the centrifugal force due to electric waves is increased or decreased in accordance with the law of inverse squares. This agrees with the centripetal law of Gravitation, as the Attraction of Gravitation is also subject to the same law of inverse squares, and, as we have seen (Art. 83), its path coincides with the path of centrifugal force, as it pursues the path represented by the straight lines joining the two bodies.
So that, whenever, and wherever, at any point in space in relation to the central body, the sun, the intensity of the attractive force is increased according to the law of inverse squares by the distance from the central body being diminished, at exactly the same time and in exactly the same manner, the repulsive force due to aetherial electric waves is also increased. If the attractive force is doubled, then the repulsive force is doubled. If the attractive force is halved, the repulsive force is halved. If the attractive force is lessened gradually, then the repulsive force is lessened gradually; and if quickly, by the quicker motion of the planet through space, then the repulsive motion is also increased with a quicker motion.
Further, like the repulsive power of light and heat, the repulsive power of electricity takes exactly the same path as the attractive power of Gravitation.
Thus we learn that the sun is the centre of two forces: first, a centrifugal force due to the pressure of the aetherial medium which is ever directed away from the sun, and which may either be produced by electric or thermal or light waves; and second, it is the centre of a centripetal force known as the Law of Gravity, whatever that may be due to. Further, the centrifugal force is also subject to the same law of intensity as the centripetal force, and moreover takes exactly the same path which the centripetal force takes.
So that we have only to prove that they both agree in another particular, viz. that their power is regulated by the product of their masses, and then we shall have discovered a real physical force, which is the exact complement and counterpart of the centripetal force due to gravity.
Art. 85.Second Law of Electricity. (Product of Masses.)--We have nowto prove that the centrifugal force exerted by any electrified body operates upon another electrified body in the same proportion and with exactly the same force which governs the centripetal force. FromArt. 21we learn that the centripetal force which is exerted by one body upon another is equal to the product of their masses. In order, therefore, for any centrifugal force to be the exact counterpart of that force, it too must be subject to the same law of proportion, that is, the repulsive force between any two bodies must be equal to the product of their masses.
We have shown that there is a repulsive force exerted by the Aether from the phenomena of heat, light, and electricity, and that that repulsive force or energy fulfils every condition required by a centrifugal force or motion, with the exception of the part referring to the fact that such a force must be proportionate to the product of their masses. What we were unable to accomplish, however, from the phenomena of heat or light we are now able to accomplish from the phenomena of electricity
For in the phenomena of electricity we find a law which runs thus: “The force of repulsion” (which is the part of electricity we are now dealing with) “between two electrified bodies is equal to the quantities of electricity with which the body is charged.” This law was established and proved by Coulomb by means of a delicate instrument known as the Torsion Balance, with which he also established the law of inverse squares.
It will be seen at a glance that there is a slight difference between stating the law of proportion with reference to the centripetal force, and the centrifugal force or motion. In the former we state the proportion is equal to the product of the masses, while in the latter we say that the proportion is equal to the product of the quantities of electricity.
In the one case we deal with the mass of the body, whether it be atom, molecule, planet or star; in the other case we deal with quantities of electricity. At first sight it may seem that there is little, if any, connection between the two laws, but a careful reflection of the hypotheses laid down with regard to the aetherial medium will show that there is not only a close connection between these two laws of proportion, but also that the law governing the repulsive power of the aetherial electric waves is the direct outcome of the law of proportion governing the centripetal force. Let us restate our case in regard to the aetherial medium.
We have learned that the Aether is gravitative, and that it also has an electro-magnetic basis is proved from Maxwell's electro-magnetic theory of light. Let me ask the reader this question therefore. If the Aetherbe gravitative, what must be the rule governing the extent and density of the aetherial atmosphere surrounding any planet or sun or other body? If the Law of Gravity teaches us anything at all, it distinctly teaches us that the gravitating power of any body is regulated by the mass of the body, as the law states that the attraction is proportionate to the product of the masses. It states nothing about volume or condition of a body.
The exact size or state of a body has no direct result bearing on gravitation attraction; the underlying principle being that the attractive force is dependent on the mass, and only on the mass of a body. So that if the volume of any body, whether atom, planet, satellite or sun, be doubled, its attractive power remains the same, simply because the mass of the whole body remains the same. Mass, we are told by mathematicians, is equal to the volume multiplied by the density, and whenever we increase the volume of a body we decrease the density, the total mass of the body remaining the same.
If the volume be doubled, then the density of the body would be halved, andvice versâ, but through all the changes of volume and density that may arise from the addition of heat or diminution of heat, the total mass of a body always remains the same. Looked at from the atomic standpoint, taking hydrogen as unity, an atom of oxygen would always weigh sixteen times an atom of hydrogen, and this principle applies throughout the whole realm of the atomic world. Further, the same principle or law, that the mass is equal to the volume multiplied by the density, is true of the planetary or even the stellar world. Thus the great regulating principle of the attractive force of gravity is mass, and not volume, or density, or any other condition.
Now as Aether is subject to the attractive force of gravity, the extent of the aetherial field, and the density of the Aether near the surface of any body, must be subject to the same law regarding mass. That is, the aetherial atmosphere of any atom, or molecule, or satellite, or planet, or star is dependent upon the mass of the atom, the molecule, or the planet, or the star as the case may be.
Thus an atom of oxygen would have a larger or denser aetherial atmosphere than an atom of hydrogen, exactly proportionate to their respective masses. A planet whose mass was represented by 1,000,000 tons would have twice the quantity of Aether around it, compared to a planet weighing only 500,000 tons, and so on, the aetherial atmosphere always being proportionate to the mass of the planet, or the satellite, or the sun, or the star. The fact which we learn from these considerations isthat the quantity of Aether, which is attracted by any body, is always proportionate to the mass of the body attracting it.
But we have learned fromArt. 78that Aether has an electro-magnetic basis, and that the density of the Aether is co-equal with electric density, so that the quantity of Aether which is attracted and held bound by any body is really equal to the quantity of electricity that such a body is covered with, or is charged with. If the quantity of Aether around any body is doubled because its mass is doubled, then the quantity of electricity is also doubled, but as long as the mass remains unaltered, the quantity of electricity held bound by that mass remains unaltered also. The area of the mass may be doubled, and in that case the density of the electricity would be halved, but as long as the mass remained the same, the quantity of electricity would remain the same also. So that we learn from this reasoning that the mass of a body, and quantities of electricity on that mass, are always proportionate to each other, because of the fact that Aether is gravitative, and also has an electro-magnetic basis.
If we wanted further evidence of the hypothesis that has just been advanced, such evidence is to be found in the hypothesis suggested by Faraday as to the electro-chemical equivalents of all elements. According to this hypothesis every element has its exact electro-chemical equivalent, or definite quantities of electricity are to be found in association with each and every particular atom of each element. Writing on the subject in hisExp. Res., par. 852, he says: “The theory of definite electro-chemical action appears to me to touch upon the absolute quantity of electricity or electrical power belonging to different bodies. Although we know nothing of what an atom is, yet we cannot resist forming some idea of a small particle which represents it to our mind, and though we cannot say what electricity is, so as to be able to say whether it is a particular matter or matters, or mere motion of ordinary matter, yet there is immensity of facts which justify us in believing that the atoms of matter are in some way endowed or associated with electrical powers to which they owe their most striking qualities, and amongst them their chemical affinity.” Further, in Art. 857, he states: “I can have no doubt that, assuming hydrogen as 1, and dismissing small fractions for the simplicity of expression, the equivalent number or atomic weight of oxygen is 8, of chlorine 36, of bromine 78.4, and of lead 103.5, etc., notwithstanding that a high authority doubles several of these numbers.”
Then, writing upon the definite relationship of these equivalents in compounds, he states (Art. 835): “Electro-chemical equivalents arealways consistent, that is, the same number which represents the equivalent of a substanceAwhen it is separating from a substanceBwill also representAwhen separating from a third substanceC. Thus 8 is the electro-chemical equivalent of oxygen, whether separating from hydrogen, tin, or lead; and 103.5 is the electro-chemical equivalent of lead, whether separating from oxygen, or chlorine, or iodine.”
Here, then, from the pen of one of the greatest thinkers and experimentalists of modern times we have confirmatory evidence that the mass of any body is practically synonymous with the quantity of electricity associated with that body. For if the principle is true in its application to atoms, it is true in its application to molecules; and if it is true in relation to molecules, it is equally true in relation to small bodies composed of molecules. And if it holds good in relation to small bodies, the principle is equally true in its application to larger bodies, as the earth, and therefore is of universal application and proves the statement already made, that the masses of bodies and quantities of electricity in association with that mass are always proportionate to each other.
We are now in a position to compare the proportion of the centripetal and centrifugal forces. The attractive power of the former, between two bodies, is equal to the product of their masses; the repulsive power of the latter is equal to the product of the quantities of electricity bound to them, and that, as we have seen, is regulated by the respective mass of each body. Let us apply this fact to the solar system and see how it works.
Taking the mass of the earth as unity, we find that the mass of the sun is 324,000 greater, so that the attractive power of the two bodies would be represented by the product of the two numbers; but because the sun is that number of times greater, its aetherial and, therefore, its electric field would be so many times greater, with the result that the proportion of the repulsive forces between the two bodies would be exactly the same as the attractive forces between the two bodies, that is, if the mean distance remains the same.
In the same way, it can be shown that the attractive forces between the earth and Jupiter exactly equal the repulsive forces between the two planets at their mean distance, or the attractive forces between any two planets or satellites are exactly counterbalanced by the repulsive power of the centrifugal force at their mean distances.
Thus the centrifugal force of every body is the exact opposite of its centripetal force at their mean distance, because the laws governing the centrifugal force are the exact counterpart of the laws governing the centripetal force. A comparison of the two will prove this. FromArts. 20,21, andArt. 22we have seen that the centripetal force is exerted alongthe straight lines joining the attracting bodies, that the intensity of the attracting body is inversely as the square of the distance, while the total force is proportionate to the product of their masses.
From the phenomena of light, heat, and electricity, we learn that the centrifugal force due to aetherial pressure is exerted along straight lines, that the intensity is inversely as the square of the distance, while the total force between two bodies is equal to the product of the quantities of electricity, which are regulated by the product of their masses.
Thus, if every planet and satellite could be conceived to be motionless in space, and these two forces could be set in operation without producing rotation or translation in space, which is impossible, then every planet and satellite would occupy, by the joint exercise of these two forces, the same position in relation to the sun represented by their mean distances, as long as the solar system existed as a separate system in the realm of aetherial space. We have therefore discovered by strict philosophical reasoning, based on Newton's Rules of Philosophy, a real tangible centrifugal force existing throughout the universe; because it is entirely due to the pressure of an universal Aether, whose operation is ever directed from a central body, which force was indicated by Herschel, and its existence to his mind was demonstrated by the repulsion exhibited in connection with the tails of comets.
We have now to go a step further, and show that the same pressure also includes the magnetic phenomena, as indicated by Clerk Maxwell, and that magnetic phenomena are also due to the aetherial medium, and then we shall have linked together in one common medium the majority of the forms of energy, as light, heat, electricity and magnetism, with which we are familiar.
If it be demonstrated that these two forces, the centrifugal force and the centripetal force, can conjointly account for all the motions of the celestial bodies, then we shall have conclusive evidence that one of the forces is physical and due to the pressure of a physical medium. After that it will be comparatively easy to show that the centripetal force is also due to the same aetherial medium, and then we shall have accomplished that which we set out to accomplish, viz. the establishment of a physical cause for universal Gravitation, which physical cause is alone to be found in the pressures, tensions and motions of an universal Aether.
Art. 86.Electro-magnetism.--We have now to look at the relation of magnetism to electricity, or, in other words, to prove the identity that exists between magnetism and electricity. InArt. 78we have proved the identity between electricity and light, so that if we can now prove the identity between electricity and magnetism, then, wherever we get aetherial light waves, we must also get aetherial electro-magnetic waves.
As the light waves due to the vibrations of the Aether are practically universal in extent, then it must follow, if the identity of the light waves with electro-magnetic waves is established, that the universality of electro-magnetic waves is established also, with the natural result, that, wherever we get these electro-magnetic waves, there we shall have the conditions by which all electro-magnetic phenomena are produced.
Now it can be demonstrated by actual experiment that wherever we get a circular current of electricity, there we have magnetic phenomena manifested. The two are inseparably connected, and it is impossible to obtain the one without the other. For example, suppose we have a wire conveying a current of electricity and make it into a coil as in Figure 15, what is the result? The result is, that the coil of wire has actually been converted into a magnet.
It will attract iron filings that are brought near it, and also magnetize an iron bar placed in the centre of the coils, and convert that into a magnet. Indeed, there is nothing which can be done by an ordinary bar magnet which cannot be done by a coiled wire conveying an electric current.
From this and similar experiments it can be demonstrated that wherever we get a circular current of electricity, there, associated with that current, are all the phenomena incidental to and associated with the ordinary bar magnet. This leads us to the truth discovered by Ampère, that magnetism is nothing more or less than electricity in rotation, or that it is due to a whirl of electricity circulating round the molecule of any body. From certain experiments which he made in relation to the mutual action of two circuits on each other, with currents flowingthrough them, he came to the conclusion that the magnetism of the molecule of each magnet is due to electric currents circulating round it.
The question arises as to what effect our new theory of the Aether has upon Ampère's theory: does it confirm it, or does it destroy it? We have learned that every atom has its aetherial atmosphere, so to speak, which is bound to the atom by the Law of Gravitation (Art. 45). We have also learned that Aether has an electrical basis, as proved by Maxwell and Hertz, so that we learn that every atom has really an aetherial electric atmosphere in association with it. We have only to conceive of this atmosphere being set in rotation either by the rotation of the atom or molecule itself, or by outside agencies, and we have at once a physical interpretation of Ampère's theory of magnetism in the rotation of electric currents around the atom, such currents being due to the circulating or rotating motion of the Aether which surrounds the atom or molecule.
Fig: 15.
Thus we learn from experiment, and from Ampère's theory also, that magnetism is directly associated with circulating currents of electricity, and that wherever we get currents of electricity circulating round any atom or body, there we get all the phenomena associated with magnetism. That is to say, we shall have such phenomena as magnetic fields, magnetic lines of force, magnetic induction, and the production of permanent magnets by electricity.
Further, with reference to the identity of electricity and magnetism, Faraday has conclusively proved their relation to each other; and I would strongly advise any reader who desires further light on the subject to carefully read paragraphs 3265-3269 in hisExperimentalResearches, where he will find experiments which place the identity of electricity and magnetism beyond the possibility of doubt. In paragraph 3265 he writes: “The well-known relation of the electric and magnetic forces may be thus stated. Let two rings in planes at right angles to each other represent them. If a current of electricity be sent round the ringEin the direction marked, then lines of magnetic force will be produced. As these rings represent the lines of electro-dynamic force and of magnetic force respectively, they will serve for a standard of comparison.”
“I have elsewhere called the electric current or the line of electro-dynamic force an axis of power having contrary forces exactly equal in amount in contrary directions (517). The line of magnetic force may be described in precisely the same terms, and these two axes of power considered as right lines are perpendicular to each other,” etc.
Fig: 16.
Again in 3267 he adds: “Like electric currents or lines of force, or axes of power when placed side by side attract each other. This is well known and well illustrated when wires carrying such currents are placed parallel to each other. But like magnetic axes of power or lines of force repel each other. The parallel case to that of electric currents is given by placing two magnetic needles side by side with like poles in the same direction.”
Then in 3268 he shows that these effects are not merely contrasts, but they are contrasts which coincide when the two axes of power at right angles to each other are considered. Then in 3269 he adds: “The mutual relation of the magnetic lines of force and the electric axis of power has been known since the time of Oersted and Ampère,” and further states he is of the opinion that “the magnetic lines have a physical existencethe same as the electric lines,” and having that opinion, asks whether “the lines have a dynamic condition analogous to the electric axis to which they are so closely and inevitably associated, or whether they consist in a state of tension of the Aether round the electric axis, and may therefore be considered as static in their nature.” Thus Faraday proved the intimate and close relationship that existed between the electric current and the circles which represent the magnetic force in association with that current; and, what is more noticeable, he asks whether such magnetic results are due to a state of tension in the Aether around the axis of the electric current, evidently being of the opinion that the Aether played an important part in the phenomena of magnetism, as well as in electricity, as other parts of his writings abundantly show.
If, therefore, there is this close identity between electricity and magnetism, then in view of the fact that all electricity is due to the motions of the universal Aether, it must follow that all magnetism is also due to motions of the same aetherial medium, which is as universal as it is invisible.
What these motions are has already been indicated by previous statements in this article, being comprised of circular or rotatory motions of the aetherial electric medium about any body, whether that body be an atom, planet, or sun or star. Such a conclusion as this is perfectly in harmony with Maxwell's electro-magnetic theory of light, as the conclusion that he arrived at in that theory was, that the light waves were identical in nature and character with electro-magnetic waves produced by an electro-magnetic source.
Up to the present we have only dealt with the electric character of those waves, and have therefore now to deal with the magnetic character of the same. So that throughout the whole realm of space, and indeed wherever there is Aether, there we have the conditions which give rise to magnetic phenomena, such as those already indicated.
It matters not whether it be in the atomic systems whose combinations comprise all material forms of life with which we are familiar, or whether it is in the systems of planets that revolve around their central sun, or whether it be in the constellations that fill the universe, wherever we find the Aether, there we find the conditions in that Aether which will produce all the results ordinarily produced by magnetism, or with which magnetism is associated, and it is to the application of these phenomena to our solar system that we will now turn our attention.
Art. 87.The Earth a Magnet.--If there is any fact in relation to a planet that holds good, it is that the earth, with which planet we aremore intimately associated than any other, is a magnet.
This truth was clearly explained by Dr. Gilbert about the year 1600 in his work on “De Magnete.” Not only has the earth geographical North and South poles, but it has also magnetic North and South poles, and indeed has all the phenomena incidental to a magnet, such as magnetic dip and magnetic lines of force, as we shall see later on.
We know, however, that the earth is simply one of a system of planets, which revolves with all the others of that system round its central body the sun; and the question arises, whether the earth is the only one out of all the planets that is actually a magnet. Suppose it is affirmed that the earth is the only planet which is a magnet. On what basis would such a statement be made? The only ground for making such a statement that I can see is, that we have never lived on Mars or Jupiter or Saturn, or any of the other planets, and therefore been unable to experiment on them, which reason is totally insufficient and inadequate for such a conclusion.
If philosophy simply dealt with the results attained by such limited reasoning, then the progress of science would be retarded, and would be limited and confined to actual experience obtained on our own planet and in relation only to that planet. But philosophy is not satisfied with such a narrow and limited outlook, but drawing its conclusions from actual experience on our own planet, in accordance with the rules of philosophy, it seeks to apply such experience gained to the explanation of phenomena of other planets which also revolve round the sun.
By such reasoning we learn that all the other planets have North and South geographical poles like our earth, although we have never actually trodden on those planets, or discovered the poles. We also learn that Mars possesses climatic conditions probably similar to our own earth, as there are certain changes on the surface around the poles, which by analogy we assume to be caused by increase and decrease of snow during the Arctic winter and summer of Mars respectively.
The analogy between our earth and the other planets is very full and complete, as the following results show. Our earth has an atmosphere, so have all the rest of the planets. The earth revolves on its axis from West to East, so do all the rest. The earth possesses two geographical poles, so do all the other planets. The earth revolves round the sun in an orbit of elliptic form, so do the other planets. The earth fulfils all the laws of motion as given by Newton, and all the other planets do the same. The earth fulfils all Kepler's laws, and this is also true of all the others. Indeed, the only difference apparently that exists atpresent between the earth and all the other planets is, that our earth is a magnet, while at present it is not conceded that all the others are magnets.
Now such a conclusion I venture to say is altogether opposed to every rule of philosophy. For if experience be any guide in philosophy, then according to experience and observations made in respect to the only planet that we can actually experiment on, it most conclusively follows, that not only the earth, but every planet, and indeed every satellite that revolves round its primary planet, is a magnet; otherwise the rule of philosophy which permits us to formulate hypotheses based on experience is entirely violated, and ceases at once to be an universal rule.
So that either the earth is not a magnet, or else, being a magnet by our second Rule of Philosophy, all the other planets are magnets also. This conclusion has already been arrived at by Lord Kelvin, who in writing in hisPopular Lectures[32]on the subject says: “If it is true that terrestrial magnetism is a necessary consequence of the magnetism and the rotation of the earth, other bodies comparable in these qualities with the earth, and comparable also with the earth in respect to materials and temperature, such as Venus and Mars, must be magnets, comparable in strength with the earth; and they must have poles similar to the earth, North and South poles on the North and South sides of the equator. It seems probable also that the sun, because of its great mass and its rotation in the same direction as the earth's rotation, is a magnet, with polarities on the North and South sides of the equator, similar to terrestrial North and South magnetic poles.” Further, such a conclusion is entirely in harmony with the view of the solar system revealed inArt. 81, where we saw that each planet was an electrified body having its own electric field, with its lines of force, being capable of giving rise to all the phenomena associated with electricity. So that if we combine that view of the subject with the view that we are now coming to, we arrive at the conclusion that each planet and satellite, and indeed all bodies that move or revolve in space, are electro-magnets giving rise to magnetic waves in the Aether, which assumption is fully consistent with the electro-magnetic theory of light.
We must now go one step further and apply a similar line of reasoning to the sun, when we shall arrive at exactly the same result that Lord Kelvin arrived at, according to the previous extract. All planets possess an atmosphere, the sun also possesses an atmosphere. All planets revolve on their axes from West to East, so does the sun. All planets possess a North and South pole the same as the sun.
The equatorial diameter of every planet is greater than its polar diameter, and the same truth applies to the sun. It is hotter at the equatorial regions of every planet, and this truth also applies to the sun. Now, if the sun agrees with all the planets in these respects, then we may philosophically conclude that it agrees with them in another respect, viz. that the sun is also a magnet possessing its own magnetic field, which is co-equal and co-extensive with its aetherial electrical field. We have already seen that the sun is an electrified body, possessing its electric field, with its electric lines of force. Therefore the sun is also a magnet, or, to speak more correctly, it is an electro-magnet, and as such gives rise to electro-magnetic waves.
The conclusion to which we have come, that the sun is an electro-magnet, can be arrived at from an altogether different method of reasoning, and as that different method of reasoning will tend to confirm the statement made, I will just indicate it, and then leave it for fuller development in another article.
It is a matter of common knowledge to all students, that the magnetism of the earth varies in several important particulars from time to time. The magnetic poles of the earth do not always occupy the same place in relation to the geographical poles, so that the magnetic force varies as regards intensity or magnitude. The reasons of the variations have never been satisfactorily accounted for, though various hypotheses have been suggested as a solution from time to time.
There is, I believe, only one satisfactory solution to the problem, and that is, that the sun is an electro-magnet, and this conclusion may be arrived at by strictly adhering to Newton's rules of Philosophy. For we have learned that any hypothesis put forward to account for any phenomena, must be simple in character, must agree with experience and observation, and, lastly, must satisfactorily account for the phenomena sought to be explained.
Here then are the variations in time of the magnetic force of the earth, the variations in intensity, and in the inclination of the magnetic axis, together with other variations. What solution shall we offer to such a problem? The only philosophical solution that can be suggested lies in the statement that the sun is an electro-magnet. Such statement is simple in conception, does not violate our experience or observation, as we find a similar revolving body, the earth, which is a magnet; and further, such a statement I premise will satisfactorily account for the whole of the variations and changes in relation to the magnetic forces of the earth. We shall see that this is so when we consider more fully the sun as an electro-magnet. Therefore, apart altogether from any previous analogies, we can philosophically arrive at the conclusionthat the sun is an electro-magnet, as well as all the planets.
That being so, it will possess its magnetic field, its magnetic lines of force, and be capable of bringing into operation in the solar system all the phenomena or effects associated with any ordinary magnet that we may experiment with on the earth.
[32]Popular Lectures, Vol. II.
[32]Popular Lectures, Vol. II.
Art. 88.The Sun an Electro-magnet.--If the sun is an electro-magnet, as stated in the previous article, then it is necessary for us to apply the phenomena of magnetism to it in order to ascertain what effect such application will have on the solar system as a whole.
Fig: 17.
The first thing that we will look at is the magnetic field which is always associated with every magnet. The magnetic field may be defined as that region or space around every magnet in which the magnetic force acts or is in operation. An illustration of a magnetic field may easily be obtained by taking a bar magnet and bringing near to it a magnetized needle, when it will be found that the needle will set itself in various positions relative to the magnet, on account of the lines of force which exist in the field. Thus letA B(Fig. 17) be a bar magnet with its North pole at pointAand South pole at pointB. If a number of freely suspendedneedles be hung above it, as shown in the figure, they assume the positions indicated there. It will be seen that at the North and South poles the needles hang vertical, while midway between the two poles there is no dip of the needle, as it is parallel to the bar magnet; while between the place of no dip and the place of vertical dip, which is directly over each pole, the dip gradually changes, becoming more and more vertical as it gets nearer to the pole. If the bar magnet be a strong one, then its magnetic field will be manifested at a great distance; and any magnetized needle brought into the field will be, affected by the same, and will tend to set itself along the lines of force.
As already stated inArt. 80, it was Faraday who originated the term “Lines of Force,” and gave to the world some idea of the motions of the aetherial medium, which plays so important a part in electro-magnetic phenomena. A visible manifestation of these lines of force which gather round every magnet may be made by strewing iron filings over a piece of glass, underneath which are several bar magnets, when it will be found that the iron filings will set themselves in well-defined lines or curves, which Faraday termed “Lines of Force.”
Fig: 18.
As the bar magnets are placed in different positions, North pole to North pole, or North to South, and so on, the iron filings will change the figures assumed, indicating in, each case the effect of the lines of force of each magnet upon one another. The iron filings strewed over the magnet are magnetized by induction, with the result that the North pole of one filing attracts the South pole of the next one to it, and this is continued along the whole of one line of force, as revealed by the united iron filings. Faraday believed in the real physical existence of these lines of force, and that belief has been perfected by Clerk Maxwell in two papers which he wrote on “Physical Lines of Force,” which will be considered in another article. We will simply deal with them at present as indications of the existence of the magnetic forces in the medium surrounding any magnet.
Let us apply these facts to the solar system and see what the application yields. We have the sun revolving in the Aether medium represented by the circleSin Fig. 19. Then we have the lines of force extending in curved linesE. andW., but in almost straight lines North and South. We will suppose the axis of the sun to be vertical for the sake of simplicity. It may be asked, how far will these lines of force stretch out into space? The reply is that they stretch and extend throughout the whole solar system, and far away into the depths of space, though with ever-decreasing intensity according to the law of inverse squares. Wherever the aetherial light waves are manifested, there the electro-magnetic waves, with all that they imply,are manifested also. We know that the light waves are existent at least as far as Neptune, a distance of 2800 millions of miles, therefore at least to that extent the electro-magnetic waves are manifested; and wherever the electro-magnetic waves to which the sun has given birth are manifested, there we have the existence of the electro-magnetic field, which is co-existent and co-extensive with the electric field of the sun. Further, wherever we get the magnetic field, there we get the lines of force which are as real as air or ocean currents, and are caused, as Maxwell indicated (Art. 44), by the motions of the atomic Aether. Wherever these lines of force are closest together, there the intensity of the magnetic force is at its greatest.