6: Electricity and its Action Across Space

6: Electricity and its Action across Space
What an electric charge is like.

The whole mass of any body is just the mass of ether surrounding the body which is carried along by the Faraday tubes associated with the atoms of the body. In fact, all mass is mass of the ether; all momentum, momentum of the ether; and all kinetic energy, kinetic energy of the ether. This view, it should be said, requires the density of the ether to be immensely greater than that of any known substance.---SIR J. J. THOMSON.

When a jar is full of gold or of lead, it does not contain more substance than when we think it empty.---DESCARTES.

THE functions of the Ether we have so far dealt with are:---

(1 ) those which depend on its continuity, especially cohesion and gravitation, uniting the particles of matter, and

(2) those which depend on its vibration and wave propagation, including all the phenomena of light and radiation.

We have found that this last enables us to arrive at certain properties of the Ether, properties which in an ordinary medium we should call elasticity and density: and we have further said that these have to be accounted for, not in terms of mechanics, but in terms of electricity and magnetism. To proceed further we must know something about electricity, and about what an electric charge is like.

Electrons and Protons
Discoveries of the present century have shown (what had already been dimly suspected by Faraday and Maxwell in the last century) that electric charges are discontinuous, like matter, that they exist as separate particles, although their field or region of influence extends throughout space.

Electric particles or corpuscles are of two kinds, the positive kind and the negative kind (so-called). They came by these names historically, and whether they are appropriate or not remains to be seen: no importance need be attached to the idea of positive and negative, except that they are opposite in sign, and can therefore neutralise each other. Whether they ever do really neutralise each other we do not know; discharge through vacuum is very difficult, perhaps impossible. To ordinary views it is marvellous that things which differ in potential by a million volts can approach within ultramicroscopic distance and retain their charges without loss: yet as a rule they do.

However this may be under exceptional circumstances, the oppositely charged particles certainly attract each other, and when they come very close together they practically blot out each other's field at a distance, so as to form a sort of neutral combination. Particles need not fall together because they attract each other: the Sun attracts the planets, but they do not fall into it, they revolve round it, and their revolution keeps them sufficiently apart; if their revolution was stopped, they would fall in. So it is also with the positive and negative particles: the negative revolve round the positive, and thus constitute a neutral group which we are familiar with as an atom of matter. That is what an atom of matter is, and that is what is meant by saying that matter is electrically constituted, or that its properties have to be explained electrically in the last resort.

But we are not yet entering on the subject of matter: we are dealing with the electrical particles, and until we know the constitution of those particles we cannot proceed very far. It is fairly evident that they are not foreign bodies in the Ether: they are probably composed of Ether in a certain special condition. For instance they are subject to gravity, whereas the rest of the Ether is not. Certainly the proton has weight, and probably the electron too, though that is not so certain. They are freely capable of locomotion and are very tractable: the rest of the Ether is not. Electrons have been likened to knots on a piece of string. A knot is not a foreign body on the string, like a bead; it is composed of string in a particular configuration, and yet it is not like the rest of the string; it has a structure and identity of its own. If it is loosely tied, it might be moved about along the string. The analogy is an exceedingly rough one, but it may help. The knots can be localised and can be moved about; but unless you can get hold of one end of the string they cannot be untied: they seem permanent. If they were untied, they would be resolved into ordinary string, and the knot, qua knot, would have gone out of existence, though plainly nothing substantial would have been destroyed. Nothing substantial is ever destroyed; a real thing merely changes its form: it may lose the special properties which depend on a particular form, but the substance remains. Real Substance, like Energy, is indestructible.

So it may be presumed that if an electron could be untied or dissolved, it would lose its properties of electric charge and be resolved into ordinary Ether. No one knows how to do such a thing, no one knows if it is possible; but the fact that electric charges or corpuscles are of two opposite kinds, like plus and minus, suggests that they might, by running together, obliterate each other; not destroying their substance, but losing the peculiarities which they possess by reason of their structure, and ceasing to be electric charges. If such real collision ever happens their energy would be emitted into the ether as a flash of radiation. Some great astronomers think that this may be happening in the giant stars; perhaps even in the sun (see Chapter Four).

Moreover we may presume that if it ever becomes possible to produce these charges, they would always be produced in pairs, never a negative alone or a positive alone, but always both. All electric phenomena may be attributed to the attraction which exists between the two opposite charges and their tendency to rush together. They are always united by what are called lines of force, the lines along which the attraction acts: they travel about with these lines of force attached to them; the lines start from a charge of one sign and end on a charge of the opposite sign. And the electrical phenomena that we observe can be expressed in terms of these lines of force,---as Faraday was the first to show, and as J. J. Thomson has further elaborated. The lines of force are called an electric field, and they represent something going on in the Ether: while their end points, the charges themselves, represent structures or singular points in the Ether of at present unknown character.

To proceed further we must make hypotheses. Hypotheses are things to be held lightly and tested: they constitute working clues, they may have more or less truth in them, but until they are confirmed they do not constitute a theory: hypotheses are useful as far as they go.

The forces and the laws according to which they act are not a hypothesis but a fact: and electrical phenomena can be worked out, as Newton worked out the phenomena of Gravitation, without understanding what the thing dealt with really is. Yet the human mind inevitably seeks what everything really is, and during the search makes hypotheses.

We can now summarise briefly what we know. The two oppositely charged particles, the negative and the positive, are called respectively an electron and a proton. They are both exceedingly minute: and there is a sense in which their size has been measured. They are far smaller than atoms, incomparably smaller, the smallest things known: even if there were a hundred or a thousand of them in the atom, they would not be in the least crowded, there would be plenty of empty space. Different atoms are now known to be composed of a different number of electrons, and by their different number and grouping they constitute the different chemical elements. The atoms of all the chemical elements are built of electrons and protons and of nothing else.

I do not want to deal with matter now, only with the Ether; but it is necessary to realise that if the ordinary masses of matter are composed of electrons, and if the electrons are so small that most of the matter is mere emptiness, while yet we know that matter may be as dense as lead or gold or platinum, it is evidence that the particles themselves must be of enormous density, and that that density must belong to the Ether of which they are made. We could not have told what the density of the Ether was but for these structures in it; but by aid of these structures and their behaviour, an estimate has been made of Ether density; and on the view which I advocate it is enormously denser than any form of matter, just about a million-million times that of water.

It used to be thought that the Ether of Space was exceedingly rare, much rarer than air, rarer even than the residual air in a vacuum tube. But if matter is made of Ether, that is to say if matter is built up of electric particles, and those particles are composed of Ether, the view that Ether is rare is untenable. It is the densest thing known: there can be nothing more massive than Ether: for, being a continuum, it is incompressible. No part of it can be denser than the rest. The knots on a bit of string are no denser than the rest of the string; and by weighing a knot and determining its size, we could estimate the density of the string. In the parable or rough analogy, we must suppose that the unknotted parts of the string are inaccessible to us and escape observation: we are only aware of the knots, we have to infer the rest of the string. We infer that it is just as massive as any modified portion of it can be. The modification into matter does not increase the fundamental density. This, if true, will be as Descartes surmised (see quotation at beginning of chapter). In other words, the apprehensible modification of Ether that we call matter need not be any denser or contain more real substance than the rest.

If Space is completely full of substance, and if that substance is of great density, a difficulty has sometimes been felt as to the possibility of locomotion, whether indeed motion was possible in a plenum. The difficulty is not a real one. Resistance to motion is due to viscosity, not to density; and the ether certainly has no viscosity: it is not at all like treacle, it is perfectly limpid. Density is no cause of friction, but it is a cause of inertia, and inertia is just what moving bodies exhibit. While as to motion through a substance of which Space is already full, one need only point out that a fish can move freely in the depths of ocean. This difficulty is imaginary; or, in so far as it is genuine, it can be countered in other ways.

Suffice it to say then that arguments too elaborate to be reproduced here, but which I have published elsewhere, give the density of Ether compared with water, as 1 followed by twelve 0's,---of that order of magnitude. Let us grant this as a working hypothesis, without further argument: on that basis we can proceed.

The rate of propagation of ether-waves depends on the ratio of elasticity to density. It is that which determines the velocity of light; but the velocity of light is known: so if the density is granted, the elasticity is known too. It must be expressed as 1 followed by thirty-three 0's. It is excessively great!

But what kind of elasticity is it ? When we were treating of waves we saw that there were several kinds of elasticity: a gas had one kind, a solid had another. What kind is the elasticity of Ether? We do not know; probably it is a new kind. Attempts have been made to explain it by the vortex motion of a perfect fluid: Lord Kelvin made such attempts: the calculations were very difficult: the result is not wholly satisfactory. We have to admit that we do not positively know the kind of elasticity it is. The simplest plan is to assume the simplest case, that it corresponds in some way to the incompressibility: in other words that it represents or involves or has the same value as the pressure. I shall make this further hypothesis, that everywhere the Ether is under a pressure represented by 10 to the power 33.

Granting that pressure, we can go forward again; and the existence of an electron can be understood: we can reckon that it is this pressure which holds the charge together against the mutual repulsion of its parts. It can do so only if the electron is of a certain size: the size can be calculated, and it comes out just the same as the size determined by experiment. The charge of the electron is in equilibrium, on a sphere of known size, under this enormous etheric pressure.

On this view the existence of an electron can be fairly understood. Can the existence of a proton be understood too? No: there we are in a difficulty. The proton is more massive than can easily be accounted for: and why it is more massive we can only guess: indeed at present we can hardly guess, or at least the guesses are not very satisfactory. That remains at present an outstanding puzzle: the question is one that has hardly yet been faced. One guess is that the electron is hollow, like a bubble, that it has an electric field which by itself would cause the bubble to expand, but that it is kept in equilibrium and of a certain size by the etheric pressure. On this view there is no substance in its interior; in itself such an electron is not massive at all, its apparent mass is due to its electric field and to nothing else. Whereas the interior of a proton, instead of being hollow, may be full---filled with extra ether; all that which was removed from the electron being crammed into the proton, so as to account for its great massiveness or what we may call its weight. A proton is more than a thousand times as heavy as an electron, about 1840 times by direct measurements; and what is called "the atomic weight," or the weight of an atom, depends almost entirely on the weight of the protons it contains. The hydrogen atom contains only one, the helium atom contains four, the lithium atom seven, the oxygen atom sixteen, and so on---in accordance with the list of atomic weights long empirically known in Chemistry, the heaviest being uranium, which contains 238. The atomic weights are certain enough; the number of protons in a specified atom is fairly certain also. What is not known is why the proton has such a weight, and why the weight of an electron is so much less. In every other respect the two charges seem equal and opposite: electrically they are equal and opposite: materially (whatever that may mean) they are not.

A charged body has additional mass. The whole mass of an electron is accounted for by its electric field. Not so with a proton. That has mass over and above its electric charge,---mass presumably belonging to its ether content. It seems extra full, while an electron seems empty. Electrically they are equal and opposite. Materially they are as 1840 to 1. A queer number this 1840. It is only known roughly, it is not known to be an exact number; but it probably is, and if so it must have a deep meaning---a meaning not yet begun to be deciphered.

We are safe in saying that the weight of matter depends on the protons, that is the positive units, which go to form the nucleus of the atom, while the chemical properties of the atom depend on the electrons which circulate round the nucleus. These planetary electrons are active and energetic and produce conspicuous results: they characterise the atom by its spectrum; they confer on it its chemical properties; but they add to its weight hardly at all. It is a curious state of things, but the evidence for it, so far, is good.

For the rest we can only say that an electron behaves as if it were hollow, with no mass other than its electric field ; while a proton behaves as if it were crammed with matter. We might guess that its nucleus contained the substance removed from the nucleus of an electron; thus constituting an individualised portion of the main ether, endowed with locomotive powers, and inseparable from its electric field. This is an idea that must be elaborated elsewhere; we are now near or perhaps beyond the confines of knowledge.

Reverting to our parable at the end of Chapter Three about explorers plunging through an obscure wood, we can realise that the work of our Elders was all preparation: our scientific ancestors tried every other road, and failed, and by their failure pointed us out a new way. They dimly perceived two obscure regions ahead, which we have begun to enter---the region labelled "relativity" and the region labelled "quanta"; their labour was by no means lost, it is all part of the great scheme. They cleared the ground to an amazing extent, their achievements will all fit in to the work of present and future generations, but it may be necessary to lose sight of some of their work for a time. They have erected gorgeous dynamic structures, massive buildings, firm and solid. We, immersed in the thicket, cannot hope to build as yet: the time for building will come, the time for exploring is on us: we are bound to follow the gleam.