Return to Physics of the Ether
143. The Interchange of Motion at the Discharge of a Gun. — The physical process involved at the discharge of a gun presents some points worthy of notice, which we will here allude to. Considering the state of the case previous to the discharge, it is well, first, to have a clear conception of the fact of the ether pervading with the utmost facility the body of the cannon, the ether occupying the molecular interstices and surrounding the molecules of the metal, so that, therefore, the slightest difference of the ether pressure (due to any disturbing cause) would immediately readjust itself across the body of the gun. It may perhaps facilitate the conception of this, if the known fact be kept in view that even the gross molecules of matter (such as the molecules of hydrogen gas) will permeate and pass through iron at a moderate temperature; and the dense metal, gold, is permeable by water under pressure. So that in addition to the molecular interstices which the ether pervades freely, the metal must also be porous.
We observe, therefore, before the discharge, the ether enclosing its intense store of motion pervading the body of the cannon, and inserting itself between every molecule of gunpowder, ready to part with a portion of its motion at any instant. The molecules of gunpowder are also in an intense state of vibration, due to the high absolute temperature existing (normal temperature). We note, therefore, an ingeniously disposed and delicately poised train of matter, at present in a state of dynamic equilibrium, the whole pervaded by a physical agent of exhaustless energy, from which it is only necessary to divert a small portion in order to cause the
Propulsion of the shot. The blow struck upon the percussion cap, y urging a few of the vibrating molecules into proper proximity, is sufficient to upset this equilibrium of motion, and brings the ether into action, the motion passing from the ether through the train of matter to the shot, and thence to the ether (in the waves emitted by the incandescent gases, the work of the shot, &c), in a cyclical process. As regards the mode in which the process effects itself, the same considerations apply as in the case already considered of the explosion of the mixed gases, oxygen and hydrogen.
During the time of the explosion the ether particles in the bore of the gun lose a certain fraction of their normal velocity by transference to the molecules of gunpowder, which loss of motion, if it continued without renewal, would conduce to a reduction of the ether pressure in the interior of the gun; so that the inference is necessary that on the instant of the disturbance of the equilibrium of the ether pressure by the motion transferred to the first few molecules of gunpowder, a readjustment of pressure com-
mences to take place across the body of the gun in the form of a wave, the free communication existing with the external ether rendering it impossible for any appreciable difference of pressure to accumulate; and, therefore, during the whole time of the explosion a continuous wave, representing a succession of small decrements of velocity sustained by the ether particles (the decrements being very small compared with the normal velocity of the particles), must pass through the gun, the energy of the ether within the gun being in this way sustained continuously during the explosion; and on account of the high speed of the particles the loss of motion is, during the comparatively slow process of the explosion, spread over a vast radial volume of the ether, whereby local disturbance of the equilibrium of the ether is prevented. The spherical wave expands as it recedes, distributing the loss of motion at last over so vast a number of particles, that the loss of motion, although existing as a whole, soon practically ceases to exist as far as each particle taken by itself is concerned. It forms a point of mechanical interest to note the process by which this motion is renewed, and the lost motion got rid of, transmitted to a distance, and dissipated by subdivision; also to note the neat way in which the two mechanical conditions fit into each other, viz. the high speed of the particles of the agent being the only condition on which the agent can effect an intense development of work, and at the same time this is the very condition on which alone the renewal of transferred motion can take place with adequate speed.
144. The interchange of motion in such a case as this, and, indeed, in the general phenomena of the interchange of motion between the ether and the molecules of matter, might properly be regarded as constituting a " focus of energy." When, for example, in the present case, the process of the explosion has attained its maximum, we have a focus of energy, represented by the projected shot and products of combustion, or we have motion withdrawn from all sides radially and concentrated at a focus, the loss of motion by the ether diminishing as the square of the distance from the focal point Conversely, when the projected products of combustion at first vibrating up to incandescence, suddenly lose their motion by retransference to the ether, we have a loss of motion by matter at a focal point, and an equivalent gain of motion by the ether, the gain diminishing radially from the focal point; the collective sum of motion having remained constant at every instant, before, during, and after the explosion. The gain of motion at the focus being concentrated at a point of space, is extremely intense; and since this motion is that of visible masses, and of palpable clouds of expanding vapour, this gain of motion naturally appeals directly to the senses. The equivalent loss of motion by the ether being subdivided or distributed over a vast radial volume of the ether, and this loss representing but a very
small part of the normal velocity of the particles, this loss of motion naturally cannot appeal directly to the senses; indeed, if the loss of motion could make itself directly palpable to the senses, then the agent would be incompetent to perform its work properly, , 145. If the effect of the explosion of gunpowder be considered, then it may be said that, as a mechanical means to an end, the action of the ether is the only conceivable process by which the result could be attained, for the object is to impart suddenly to small masses of matter (the molecules of gunpowder) a rapid motion, for the production of a forcible mechanical effect Now, to impart this rapid motion there must exist a still more rapid motion at disposal, or, in other words, the component particles of the motive agent must have a higher velocity than that intended to be developed, for in order for the particles of the agent to sustain their action against the small masses (molecules), these particles must at least have such a velocity as to enable them to follow up with facility the movements of the small masses. Thus, for instance, in a precisely analogous way, the motion of the molecules of gunpowder must be more rapid than the motion of the shot, or these molecules would be wholly incapable of sustaining their action against the rapidly advancing shot. So in the same way the motion of the ether particles must be more rapid than that of the molecules of gunpowder, or these particles would be wholly unable to sustain their action against the molecules. The molecules of gunpowder merely serve as the convenient mechanism to transmit the motion of the ether to the shot, for the gunpowder, like the shot, has no motion of its own, and, therefore, must have the motion imparted to it. The ether, on the other hand, does not require to have motion imparted to it, since it already has motion. The ether is, therefore, the only competent source of motion; or the ether transfers motion which it already has through the gunpowder to the shot, the sum of motion thereby remaining constant.
146. We have now to consider a few points as regards the mode of action of the process. Here again the influence of vibrating energy upon the positions of equilibrium of molecules, as illustrated by the expansion and eventual dissociation of matter by heat, has an important part to play. The explosion of gunpowder being simply a case of rapid combustion, precisely the same considerations apply here with reference to the gradual approach of the components of the compound molecules after combination, subject to the utilization of the heat, as was treated of in the case of combustion; and with the additional important practical point here, viz. that the pressure against the shot is thereby greatly equalized and the initial strain moderated, or the advance of the shot along the bore of the gun brings the ether into fresh action.
In order to follow the steps of the process we must consider certain points. The first act of the ether is to generate the
translatory motion of approach of the molecules in. the process of combination. Those molecules which approach each other in the process of combination to form compound molecules, we shall term " components." Secondly, this translatory motion of approach of the components is resolved into a vibratory motion of the components, due to these components in their mutual approach being driven against the intercepted oscillating ether column in synchronous vibration. The compound molecules immediately after combination are therefore vibrating powerfully. This sudden development of vibrating energy has, by the stationary vibrations suddenly set up in the intervening ether, the effect of driving apart in all directions the compound molecules which, after combination, happen to be in the vicinity of others, a general translatory motion of compound molecules (the motion of gaseous matter) being thus set up, by which the molecules are driven in all directions with great force against the shot.
147. When two molecules are forcibly urged towards each other, whereby the molecules are driven against the intercepted oscillating ether column, the accession of vibrating energy thus produced acts as a resistance tending to check the approach of the molecules, or this accession of vibrating energy tends to urge the molecules farther apart; so therefore, conversely, an accession of vibrating energy artificially produced (as by heat) will urge the molecules farther apart. Thus the vibrating energy (heat) produced at the approach of molecules in the act of combination tends to urge the molecules farther apart, and the effect, therefore, is that the molecules do not approach into such close proximity as they would do if this accession of vibrating energy were not developed; and as this vibrating energy (heat; is subsequently expended, the molecules gradually approach into closer proximity. Since, therefore, an accession of vibrating energy urges molecules apart, i.e. produces a translatory motion of the molecules from each other, vibratory motion is thereby convertible into trans- latory motion; and since, conversely, a translatory motion of two molecules towards each other is followed by an accession of their vibratory motion, translatory motion is thereby convertible into vibratory motion.
148, The mutual convertibility of these two fundamental forms of motion admits of further illustration if we take the case of a metallic bar; when by producing a motion of translation of the molecules of the bar towards each other (by compressing the bar), this translatory motion is converted into vibratory motion (heat); and, conversely, when the vibratory motion of the molecules of the bar is artificially increased (as by heating the bar), this vibratory motion is converted into translatory motion, or the molecules are caused to recede (as observed in the expansion of the bar).
So in the case of the action of the gunpowder under consideration, the sudden development of vibratory motion in the compound molecules after combination, causes these molecules to recede or
rebound from each other in all directions, vibratory motion being thereby converted into translatory motion; or the vibrating energy of the ether column intercepted between each pair of receding molecules is reduced by an amount representing the translatory motion imparted to the molecules, and thus the molecules are chilled at their recession.
149. Translatory motion and vibratory motion are therefore mutually convertible, or the one will produce the other. These constitute the two fundamental and interconvertible forms of motion, by the permutations of which all the varied molecular effects are produced. The mutual convertibility and dependence of these two fundamental forms of motion constitute, therefore, an important practical principle in connection with the working of physical phenomena.
150. Thus, in the physical process involved in the case of gunpowder, translatory motion is first converted into vibratory motion, as illustrated by the development of vibratory motion (heat), due to the translatory motion of approach of the components of the molecules under the action of the ether; and then this vibratory motion is reconverted into translatory motion, as illustrated by the sudden rebound of the intensely vibrating compound molecules after combination. The principle involved in the process of the explosion is therefore simply that translatory motion is converted into vibratory motion, and then reconverted into translatory motion. These form the necessary mechanical steps of the simplest conceivable character, by which the translatory motion of approach of the components of the molecules under the action of the ether is finally resolved into a form of motion capable of acting against the shot.
151. As regards the order of the steps of the physical process, the mode of action in the case of gunpowder may serve as a type of explosives, and of all cases of combustion and of chemical reactions generally; or in all cases translatory motion is converted into vibratory motion, and then reconverted into translatory motion; or to particularize more exactly, the translatory motion of approach of the components to form compound molecules is converted into a vibratory motion of these components, and this vibratory motion of the components is finally converted into a translatory motion of compound molecules.
In some cases of extremely feeble reactions the vibratory motion (heat) developed may not be sufficient to cause an actual rebound of compound molecules in the form of vapour, but the compound molecules may simply recede from each other a short distance in translatory motion without actually separating. The amalgamation of zinc may serve as an illustration of such a feeble chemical process. Here, after translatory motion has been converted into vibratory motion (heat) at the approach of the component molecules of mercury and zinc to form compound molecules, these compound molecules merely recede a short
distance from each other by the conversion of vibratory motion into translatory motion (as illustrated by the slight expansion of the zinc from the heat developed); but the vibratory motion is here not intense enough to cause a rebound of the compound molecules in the form of vapour. In the case of the approach of the molecules of oxygen by the combustion of a piece of magnesium wire, on the other hand, the vibratory motion developed is such that by its conversion into translatory motion the compound molecules of the solid magnesia are driven from each other in the vaporous form,
152. Translatory motion and vibratory motion, therefore, being interconvertible, these two forms of motion have necessarily an intimate dependence upon each other, the slightest increase or diminution of the one being followed by a corresponding increase or diminution of the other. Thus, for example, in the illustrative case of the gunpowder, as the translatory motion of the compound molecules is being expended by transference to the shot, vibratory motion (heat) is being continually converted into fresh translatory motion, or the translatory motion of the compound molecules is sustained at the expense of their vibratory motion; and this vibratory motion is itself again sustained at the expense of the translatory motion of approach of the components of the com- pound molecules under the action of the ether, these components being slowly and forcibly urged into closer proximity by the ether as the shot advances, thereby developing fresh vibratory motion, and, by its conversion into translatory motion, giving a fresh impulse to the shot. The advance of the shot along the bore of the gun, therefore, brings the ether into fresh action, or the demand for energy causes a fresh supply.
153. As an analogous example of the interconvertibility and mutual dependence of translatory motion and vibratory motion, we may take the known fact that, in the case of gases, temperature and pressure are mutually dependent. The temperature (heat of the gas), however, consists in the vibratory motion of the molecules which give rise to the observed rapid and periodic ether waves of heat, the pressure of the gas being produced by the translatory motion of the molecules; and any disturbance or variation of one of these forms of motion is attended by a variation of the other, or the equilibrium of motion readjusts itself by conversion of the one form of motion into the other. Thus, if an impulse be given to the translatory motion of the rebounding molecules of a gas by suddenly compressing it, then the equilibrium of motion readjusts itself by the conversion of the excess of translatory motion into vibratory motion (heat), as indicated by the rise of temperature; and, conversely, if the vibratory motion is artificially increased (as by exposing the gas to a source of heat waves), then the excess of vibratory motion is converted into translatory motion, as indicated by the rise of pressure. The increase in the velocity of translatory motion attendant on the increase of the
vibratory motion in heating a gas is also illustrated by the increased velocity with which the molecules of a heated gas in their mutual interchange of motion transmit any impulse (such as a wave of sound).
The interchange of motion between two gaseous molecules forms an illustration of the permutations of translatory motion and vibratory motion. Thus, at the approach of the two molecules, each comes to the end of its path previous to rebounding, by converting its translatory motion into vibratory motion (heat), and, conversely, the rebound takes place by the conversion of vibratory motion into translatory motion. The interchange of motion be- tween a group of molecules forms a perfectly analogous case. Thus, at the interchange of motion between two billiard-balls, for example, each ball comes to rest for an instant (previous to rebounding} by converting its translatory motion into vibratory motion (heat); and at the rebound vibratory motion is, conversely, converted into translatory motion.
154. The general phenomena of evaporation constitute another example of the interconvertibility of these two fundamental forms of motion. Thus, to take the important practical case of the generation of steam, for instance. Here, by the transmission of vibratory motion from the molecules of fuel to the molecules of water, the rebound of these water molecules in free translatory motion (in the form of steam), takes place by the conversion of their vibratory motion (heat) into translatory motion.
An endless variety of examples might be referred to, as illustrative of the important part these two fundamental forms of motion have to play in the working of physical phenomena; indeed, from the very fact that all molecules on the earth's surface possess an extreme intensity of vibratory motion, and since translatory motion constitutes the one conceivable permutation of which vibratory motion admits, and since also all physical processes in their fundamental working depend on translatory movements of approach and recession, in which these two forms of motion are directly concerned, there is, therefore, perhaps scarcely a move- ment of matter in which the interconvertibility of these two fundamental forms of motion has not a part to play.