THE THEORY OF MATTER

Without going into great detail, or attempting to trace the history of the various discoveries which led up to it, it may now be stated definitely that matter is built-up of electricity. For the proof of this, the scientific world has to thank Sir J. J. Thomson, who first popularized this view in his book “Electricity and Matter.” He was closely seconded by Sir Oliver Lodge, Sir William Crookes, and many other eminent scientists. On this view, matter totally disappears, as such; it becomes super-sensible; it is resolved into energy. Electricity and the ether somehow are responsible for matter, but just how was not at the time understood.

It took many years of patient research to arrive at definite conclusions; in fact, it may be said that definite conclusions have not even yet been reached,—though more or less unanimity of opinion exists as to the structure of atoms. The new theory of matter is that each atom is built up of negative “electrons,” and positive “protons”—the former revolving round the latter in orbits analogous to those of our solar system. The protons, positively charged, remain in the center of the atom; the electrons, negatively charged, circle about them, just as our planets circle about the sun. The number of these protons and electrons varies according to the nature of the element. Hydrogen representing unity, has but one electron revolving around a single proton; helium comes next, with two; and so on, up the scale, until we reach uranium, which has ninety-two. The positive and the negative charges balance one another in all stable atoms; and when this is not the case, the atom tends to go to pieces or disintegrate; electrons are shot off, which join some other atom, and radio-activity results. The nature of the element itself is accordingly changed, and may even be so fundamentally changed by this process that it turns into something else; i. e., the transmutation of one element into another has taken place, as dreamed of by the alchemists! Hence we often hear of the “new alchemy.” This, in rough outline, is the modern conception of the atom, and of the constitution of matter generally.

WITHIN THE ATOM

Let us now endeavor to analyze the atom more closely, in the light of these newer researches. We have seen that the electrons revolve round the central protons. These protons are probably composed of electrons and hydrogen nuclei. The total central “sun”—to use the astronomical analogy—is known as the nucleus. The relative sizes of these bodies may be appreciated when it is stated that they have been compared to the sizes of the planets, relative to the distances separating them from the sun. Vast spaces exist, therefore, within the atom, in which the electrons revolve. Yet the atoms themselves are inconceivably small! The following quotation from Bertrand Russell’s “A. B. C. of Atoms” will perhaps make this clear. He says:

“It will help us to picture the world of atoms if we have, to begin with, some idea of the size of these units. Let us begin with a gramme of hydrogen (1/453 of a pound), which is not a very large quantity. How many atoms will it contain? If the atoms were made up into bundles of a million-million, and then into a million-million of these bundles, we should have about a gramme and a half of hydrogen. That is to say, the weight of one atom of hydrogen is about a million-millionth of a million-millionth of a gramme and a half. Other atoms weigh more than the atom of hydrogen, but not enormously more; an atom of oxygen weighs sixteen times as much, an atom of lead rather more than 200 times as much. Per contra, an electron weighs very much less than a hydrogen atom; it takes about 1,850 electrons to weigh as much as one hydrogen atom.”

ELECTRONS

The inner rings of electrons give rise to X-rays when they are disturbed, and it is chiefly by means of X-rays that their constitution is studied. The nucleus itself is the source of radio-activity.... The most complex atom known is that of uranium, which has, in its normal state, 92 electrons revolving round the nucleus, while the nucleus itself probably consists of 238 hydrogen nuclei and 146 electrons....

Under normal conditions, when the hydrogen atom is unelectrified, the electron simply continues to go round and round the nucleus, just as the earth continues to go round and round the sun. The electron may move in any one of a certain set of orbits, some larger, some smaller, some circular, some elliptical. But when the atom is undisturbed, it has a preference for the smallest of the circular orbits, in which the distance between the nucleus and the electron is about half a hundred-millionth of a centimetre. It goes round in this tiny orbit with very great rapidity; in fact its velocity is about a hundred-and-thirty-fourth of the velocity of light, which is 186,000 miles a second. Thus the electron manages to cover about 1,400 miles in every second. To do this, it has to go round its tiny orbit about seven thousand million times in a millionth of a second; that is to say, in a millionth of a second it has to live through about seven thousand million of its “years”!

Such figures, such facts, stagger the imagination. The mind of man cannot really conceive them. And yet we know that they are not fanciful; calculations and indirect measurements have been made with the utmost exactitude. And, after all, the infinitely little is no more staggering than the infinitely great. For in astronomy we know that stars billions of miles distant from us in space have been seen, measured, photographed and analyzed. Tens of thousands of “light-years” separate us from them (i. e., space which would be travelled by light, speeding at 186,000 miles a second). And yet the structure of the atom closely resembles the planetary system! Is the whole Universe, great and small, built according to the same plan, according to the same model? It would appear so!