Elytron

“ Jimmy looked relieved.
“Now,” continued the doctor, “the theory is that all matter is composed of an infinite number of electrons. An electron is the smallest thing that can be conceived, smaller even than the atom which used to be thought of as the unit. There may be millions, billions, quadrillions of them in a thing as big as a hickory nut. And when these electrons get busy you can look out for things to happen.
“Every hot object sends out electrons. That’s the reason that the filament in the electric light tube sends them out.” ”

“ The act of ionization by ether waves, i.e., by X-rays or light, seems to consist in the hurling out with an energy which may be very large, but which depends upon the frequency of the incident ether wave, of one single electron from an occasional molecule over which this wave passes.
3. The act of ionization by rapidly moving -particles consists generally in the shaking loose of one single electron from the atom through which it passes, though in the case of helium, two electrons are certainly sometimes removed at once. ”

“ Any charged particle, irrespective of its energy, moving in any medium—air, water, soil, or living tissue—creates ion pairs at the rate of about one per 32 electron-volts. A one-million-electron-volt particle produces about 30,000 ion pairs before losing all of its energy. (When it does lose its energy, if it is a positively charged particle, it will pick up enough electrons to become neutral. An alpha particle, for example, will become an ordinary helium atom; a proton will become an atom of hydrogen.) ”

“ It is possible to impart to a single electron a known amount of energy by making it travel along an electric field with a measured drop of potential. If this projectile hits an atom it may cause one of the electrons circulating in the atom to jump to an upper orbit, but, of course, only if its energy is sufficient to supply that required for the jump; if the electron has too little energy it can do nothing and must pass on with its energy intact. ”

“ In its normal state, the atom, whose nucleus and electrons are in electrical balance, exhibits no electrical effects; but within a thermionic tube, the impact upon the gas atoms of the electrons, passing from cathode to anode at velocities induced by ionization voltages, forces off negative electrons from the atoms. The atoms from which the electrons have thus been detached are then electrically positive and are known as ions. Ionization, which begins at the ionization voltage, is increased with increasing voltages as the tube approaches saturation, when extreme ionization takes place ”

“ As your current starts up from zero, the electron gun squirts a bouquet of electrons into a chamber built like a pair of pie plates set rim to rim. The magnet's field begins to build up at the same time, and the resulting increase in field strength accelerates the electrons and at the same time, its increasing field keeps the little devils running in the same orbit. Shoot it with two-hundred-cycle current, and in the half cycle your electrons are made to run around the center a few million times. That builds up a terrific velocity—measured in six figures, believe it or not. ”

“ At the high temperature inside a star the battering of the particles by one another, and more especially the collision of the ether waves (X-rays) with atoms, cause electrons to be broken off and set free. These free electrons form the third population to which I have referred. For each individual the freedom is only temporary, because it will presently be captured by some other mutilated atom; but meanwhile another electron will have been broken off somewhere else to take its place in the free population. ”

“ But the coating accepted the terrific charge and prevented the normal urge of electrons to leave by secondary emission—"
"What is secondary emission?"
"When an electron hits at any velocity, it drives from one to as high as fifty electrons from the substance it hits. The quantity depends upon the velocity of the original electron, the charges on cathode and anode, the material from which the target is made, and so on. We soaked 'em in like a sponge and took it bad. But the next time, we'll coat the ship with the opposite stuff. We'll take a bit of Venus Equilateral for ourselves." ”

“ There is more than one way in which an atom can obstruct ether-waves, but there seems to be no doubt that for X-rays both in the stars and in the laboratory the main part of the opacity depends on the process of ionization. The ether-wave falls on an atom and its energy is sucked up by one of the planet electrons which uses it to escape from the atom and travel away at high speed. ”

“ I need hardly say that it makes no difference to us whether we are asked to drive a tramway car, a railway train, or a host of machines in a factory or workshop. All that we electrons in the motor require is to have sufficient energy passed along to us from our fellows in the distant dynamo. Again I admit frankly that the atoms of matter play a very important part in these our heaviest duties, but you will see that without our active assistance they could not transmit the necessary energy to a distant car or train. ”

“ That the electron is a fundamental constituent of all matter is attested by the fact that charge and mass are the same regardless of the source or manner of production. Whether emitted by a heated metal, under the action of ultra-violet light, from a radioactive substance, by a body exposed to X-rays, as a result of friction, it is the same negatively charged particle that constitutes the cathode ray of the discharge tube. ”

“ Some people may find it difficult to believe that our rate of march is so very slow. Their front door is a good many yards away from their electric bell, but it does not take us an hour, or any appreciable part of a minute, to summon the maid. The secret is that there is a whole regiment of us along the wire, and before one of us moves on to a neighbouring atom, another electron must move off that atom and on to its neighbour, and so on. ”

“ When we maintain the field constant and vary the charge on the drop, the granular structure of electricity is proved by the discontinuous changes in the velocity, but when we maintain the charge constant and vary the field the lack of discontinuous change in the velocity disproves the contention of a fibrous structure in the field, unless the assumption be made that there are an enormous number of ether strings ending in one electron. Such an assumption takes most of the virtue out of an ether-string theory. ”

“ Taking as a basis the estimate of Lord Kelvin on the speed of projected 'particles in a Crookes' bulb, we arrive easily by the employment of very high potentials to speeds of as much as a hundred kilometres a second. Now, again, the old question arises: Are the particles from the electrode, or from the charged surface generally, including the case of an external electrode, projected through the glass or aluminum walls, or do they merely hit the inner surface and cause particles from the outside of the wall to fly off, acting in a purely mechanical way, as when a row of ivory balls is struck? ”

“ Here is the electron, the atom of electricity demanded by the theory of Lorentz.
But what of the positive electron? Search for this has often been made, but the mass of the positively charged particles has always proved to be comparable with that of an atom. There are some indications that positive electrons may be identical with positively charged atoms of hydrogen or of the gas helium whose atomic mass is four times that of hydrogen; but for the present we can say only that positive electricity is never found dissociated from matter of atomic dimensions. ”

“ If, for example, it is desired to place a positive electron upon a given drop the latter is held with the aid of the field fairly close to the negative plate, say the upper plate; then an ionizing agent—X-rays or radium—is arranged to produce uniform ionization in the gas between the plates. Since now all the positive ions move up while the negatives move down, the drop is in a shower of positive ions, and if the ionization is intense enough the drop is sure to be hit. In this way a positive charge of almost any desired strength may be placed upon the drop. ”

“ The term electron was suggested, a good many years ago, by Dr Johnstone Stoney, for the unit charge of electricity which is carried by an atom of hydrogen when hydrogen atoms move in a liquid or gas under the directing influence of the electric current. Some chemists speak of the electrons, which are the β-rays from radium, and the kathode rays produced in almost vacuous tubes, as non-material particles of electricity. Non-material means devoid of mass. ”

“ Thus we have in the interior of a star something familiar and extensively studied in the laboratory.
Besides the atoms and ether waves there is a third population to join in the dance. There are multitudes of free electrons. The electron is the lightest thing known, weighing no more than 1⁄1840 of the lightest atom. It is simply a charge of negative electricity wandering about alone. An atom consists of a heavy nucleus which is usually surrounded by a girdle of electrons. It is often compared to a miniature solar system, and the comparison gives a proper idea of the emptiness of an atom. ”

“ The Beta rays were later christened Electrons. They are particles of disembodied electricity, here spontaneously liberated from the atoms of matter: only when the electron was isolated from the atom was it recognised for the first time as a separate entity. Electrons, therefore, are a constituent of the atoms of matter, and we have discovered that they can be released from the atom by a variety of agencies. Electrons are to be found everywhere, forming part of every atom. ”

“ To make the electron's story as realistic as possible, it has been necessary to give the imaginary electron perfect freedom of knowledge concerning itself and its surroundings. In our schooldays we had to write the autobiographies of steel pens, and such-like, but these inanimate things had to be endowed with powers of thought, feeling, and desire. It is very important, however, to remember that an electron is a particle of negative electricity—a real existing thing. ”

“ Ionization can be effected in many ways. To expel an electron against the attractive force of the remainder of the molecule, work is required, and the necessary energy may be furnished by X rays or rays, or by collision with other electrons.... At high temperatures, when the conditions of maximum entropy demands an appreciable amount of ionic dissociation, the requisite energy is drawn from the environment.... The work required to ionize a single molecule, when expressed as the number of volts through which an electron must fall to acquire this energy, is the ionization potential ”

“ For instance, if an electron is acting as a satellite to one particular kind of atom, its rate of revolution around that atom may be very different from that of an electron similarly attached to another kind of atom. We electrons are all identical, but the speed of revolution is determined by the kind of atom. The reason is very simple; electrons revolve around some atoms at a much greater distance than they would around other atoms. Those making only the smaller orbits not only get around their atoms in less time, but they are also travelling at a greater pace. ”

“ What one usually knows instead, is the roentgen dosage to a piece of tissue, which consists of many cells. If the charged particles inducing the ionization are electrons (as they are when the primary radiation is a beta ray or a gamma ray) , the ionization will be distributed more or less uniformly among the cells in the affected neighborhood. If the charged particle is heavy—a proton or an alpha ray—the density of ionization which it produces is much greater, so that some cells receive a good many more ion pairs, while others nearby may receive none. ”

“ The energy of the escaping electron must come, then, in some way or other, from the incident light, or from other light of its frequency, since it is characteristic of that frequency alone.
When, however, we attempt to compute on the basis of a spreading-wave theory how much energy an electron can receive from a given source of light, we find it difficult to find anything more than a very minute fraction of the amount which it actually acquires. ”

“ If you think of the giant size of an electric tramway car or a railway train, and try to compare one of these with an electron, such as your humble servant, it will seem quite ridiculous that I should suggest that it is we electrons who move those huge vehicles. ”

“ If other electrons follow the first within a wire, their passage along the wire will be what is called an electric current.
When the electron is subjected to an acceleration, a transverse wave is produced, and an electromagnetic radiation is generated, of which the character may naturally change with the manner in which the speed varies. If the electron has a sufficiently rapid periodical movement, this wave is a light wave; while if the electron stops suddenly, a kind of pulsation is transmitted through the ether, and thus we obtain Röntgen rays. ”

“ The main parts of a cyclotron are represented in Fig. 2. Charged particles (ions) are accelerated inside an evacuated tank. This is to prevent the beam from colliding with [Pg 4] air molecules and being scattered. The vacuum tank is placed between the poles of an electromagnet, whose field bends the ion beam into a circular orbit.
The operation begins when the ions are introduced into the region between two accelerating electrodes, or "dees." [2] Because the ions carry a positive electric charge, they are attracted toward that dee which is electrically negative at the moment. ”