Physics

Impact and friction. Mechanics regards the effect of impact as taking place in a pure form. But in reality things are different. On every impact part of the mechanical motion is transformed into heat, and friction is nothing more than a form of impact that continually converts mechanical motion into heat (fire by friction known from primeval times).

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The consumption of kinetic energy as such in the field of dynamics is always of a twofold nature and has a twofold result: (1) the kinetic work done, production of a corresponding quantity of potential energy, which, however, is always less than the applied kinetic energy; (2) overcoming – besides gravity – frictional and other resistances that convert the remainder of the used-up kinetic energy into heat. – Likewise on reconversion: according to the way this takes place, a part of the loss through friction, etc., is dissipated as heat – and that is all very ancient!

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The first, naïve outlook is as a rule more correct than the later, metaphysical one. Thus already Bacon (and after him Boyle, Newton, and almost all the Englishmen) said heat is motion[228] (Boyle even said molecular motion). It was only in the eighteenth century that the caloric theory arose in France and became more or less accepted on the Continent.

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Conservation of energy. The quantitative constancy of motion was already enunciated by Descartes, and indeed almost in the same words as now by? (Clausius, Robert Mayer?) On the other hand, the transformation of the form of motion was only discovered in 1842 and this, not the law of quantitative constancy, is what is new.

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Force and conservation of force. The passages of J. R. Mayer in his two first papers to be cited against Helmholtz.

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Force. – Hegel (Geschichte der Philosophie, 1, S. 208) says.

“It is better to say that a magnet has a soul” (as Thales expresses it) “than that it has an attracting force; force is a kind of property that, separable from matter, is put forward as a predicate – while soul, on the other hand, is this movement itself, identical with the nature of matter.”

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Hegel’s conception of force and its manifestation, of cause and effect as identical, is proved in the change of form of matter, where the equivalence is proved mathematically. This had ‘already been recognised in measurement: force is measured by its manifestation, cause by effect.

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Force. If any kind of motion is transferred from one body to another, then one can regard the motion, in so far as it transfers itself, i.e., is active, as the cause of motion, in so far as the latter becomes transferred, i.e., is passive, and then this cause, the active motion, appears as force and the passive as its manifestation. From the law of the indestructibility of motion, it follows automatically that the force is exactly as great as its manifestation, since indeed it is the same motion in both cases. Motion that transfers itself, however, is more or less quantitatively determinable, because it appears in two bodies, of which one can serve as a unit of measurement in order to measure the motion in the other. The measurability of motion gives the category force its value, otherwise it has none. Hence the more this is the case, the more are the categories of force and its manifestation usable in research. Hence this is so especially in mechanics, where one resolves the forces still further, regarding them as compound, and thereby often arriving at new results, although one should not forget that this is merely a mental operation; by applying the analogy of forces that are really compound, as expressed in the parallelogram of forces, to forces that are really simple, the latter still do not thereby really become compound. Similarly in statics. Then, again, in the transformation of other forms of motion into mechanical motion (heat, electricity, magnetism in the attraction of iron), where the original motion can be measured by the mechanical effect produced. But here, where various forms of motion are considered simultaneously, the limitation of the category or abbreviation, force, already stands revealed. No regular physicist any longer terms electricity, magnetism, or heat mere forces, any more than substances or imponderabilia. When we know into how much mechanical motion a definite quantity of heat motion is converted, we still do not know anything of the nature of heat, however much the examination of these transformations may be necessary for investigating this nature of heat. To conceive heat as a form of motion is the latest advance of physics, and by so doing the category of force is sublated in it: in certain connections – those of transition – they can appear as forces and so be measured. Thus heat is measured by the expansion of a body on warming. If heat did not pass here from one body to the other – the measuring rod – i.e., if the heat of the body acting as a measuring rod did not alter, there could be no talk of measurement, of a change of magnitude. One says simply: heat expands a body, whereas to say: heat has the force to expand a body, would be a mere tautology, and to say: heat is the force which expands bodies, would not be correct, since 1. expansion, e.g., in gases, is produced also by other means, and 2. heat is not exhaustively characterised in this way.

Some chemists speak also of chemical force, as the force that makes and maintains compounds. Here, however, there is no real transference, but a combination of the motion of various bodies into a single whole, and so “force” here reaches its limit. It is, however, still measurable by the heat production, but so far without much result. Here it becomes a phrase, as everywhere where, instead of investigating the uninvestigated forms of motion, one invents a so-called force for their explanation (as, for instance, explaining the floating of wood in water by a buoyancy force – the refraction of light by a refractive force, etc.), in which case as many forces are obtained as there are unexplained phenomena, the external phenomenon being indeed merely translated into an internal phrase.[229] (Attraction and repulsion are easier to excuse; here a number of phenomena inexplicable to the physicist are embraced under a common name, which gives an inkling of an inner connection.)

Finally in organic nature the category of force is completely inadequate and yet continually applied. True, it is possible to characterise the action of the muscles, in accordance with its mechanical effect, as muscular force, and also to measure it. One can even conceive of other measurable functions as forces, e.g., the digestive capacity of various stomachs, but one quickly arrives ad absurdum (e.g., nervous force), and in any case one can speak here of forces only in a very restricted and figurative sense (the ordinary phrase: to regain one’s forces). This misuse, however, has led to speaking of a vital force. If by this is meant that the form of motion in the organic body is different from the mechanical, physical, or chemical form, and contains them all sublated in itself, then it is a very lax manner of expression, and especially so because the force – presupposing transference of motion – appears here as something pumped into the organism from outside. not as inherent in it and inseparable from it, and therefore this vital force has been the last refuge of all supernaturalists.

The defect: (1) Force usually treated as having independent existence. (Hegel, Naturphilosophie, S. 79.)[230]

(2) Latent, dormant force – this to be explained from the relation of motion and rest (inertia, equilibrium), where also arousing of forces to be dealt with.

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Force (see above). The transference of motion takes place, of course, only in the presence of all the various conditions, which are often multiple and complex, especially in machines (the steam-engine, the shotgun with lock, trigger, percussion cap, and gunpowder). If one of them is missing, then the transference does not take place until this condition is supplied. In that case one can imagine this as if the force must first be aroused by the introduction of this last condition, as if it lay latent in a body, the so-called carrier of force (gunpowder, charcoal), whereas in reality not only this body but all the other conditions must be present in order to evoke precisely this special transference. –

The notion of force comes to us quite automatically in that we possess in our own body means for transferring motion, which within certain limits can be brought into action by our will; especially the muscles of the arms through which we produce mechanical change of place and motion of other bodies, lifting, carrying, throwing, hitting, etc., resulting in definite useful effects. The motion is here apparently produced, not transferred, and this gives rise to the notion of force in general producing motion. That muscular force is also merely transference has only now been proved physiologically.

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Force. The negative side also has to be analysed: the resistance which is opposed to the transference of motion.

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Radiation of heat into universal space. All the hypotheses cited by Lavrov of the renewal of extinct heavenly bodies (p. 109)[231] involve loss of motion. The heat once radiated, i.e., the infinitely greater part of the original motion, is and remains lost. Helmholtz says, up to now, 453/454. Hence one finally arrives after all at the exhaustion and cessation of motion. The question is only finally solved when it has been shown how the heat radiated into space becomes utilisable again. The theory of the transformation of motion puts this question categorically, and it cannot be got over by postponing the answer or by evasion. That, however, with the posing of the question the conditions for its solution are simultaneously given – c’est autre chose. The transformation of motion and its indestructibility were first discovered hardly thirty years ago, and it is only quite recently that the consequences have been further-elaborated and worked out. The question as to what becomes of the apparently lost heat has, as it were, only been nettement posée since 1867 (Clausius).[232] No wonder that it has not yet been solved; it may still be a long time before we will arrive at a solution with our small means. But it will be solved just as surely as it is certain that there are no miracles in nature and that the original heat of the nebular ball is not communicated to it miraculously from outside the universe. The general assertion that a the total amount (die Masse) of motion is infinite, and hence inexhaustible, is of equally little assistance in overcoming the difficulties of each individual case; it too does not suffice for the revival of extinct universes, except in the cases provided for in the above hypotheses, which are always bound up with loss of force and are therefore only temporary cases. The cycle has not been traced and will not be until the possibility of the re-utilisation of the radiated heat is discovered.

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Clausius – if correct – proves that the universe has been created, ergo that matter is creatable, ergo that it is destructible, ergo that also force, or motion, is creatable and destructible, ergo that the whole theory of the “conservation of force” is nonsense, ergo that all his conclusions from it are also nonsense.

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Clausius’ second law, etc., however it may be formulated, shows energy as lost, qualitatively if not quantitatively. Entropy cannot be destroyed by natural means but it can certainly be created. The world clock has to be wound up, then it goes on running until it arrives at a state of equilibrium from which only a miracle can set it going again. The energy expended in winding has disappeared, at least qualitatively, and can only be restored by an impulse from outside. Hence, an impulse from outside was necessary at the beginning also, hence, the quantity of motion, or energy, existing in the universe was not always the same, hence, energy must have been created, i.e., it must be creatable, and therefore destructible. Ad absurdum!

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Conclusion for Thomson, Clausius, Loschmidt: The reversion consists in repulsion repelling itself and thereby returning out of the medium into extinct heavenly bodies. But just therein lies also the proof that repulsion is the really active aspect of motion, and attraction the passive aspect.

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In the motion of gases – in the process of evaporation – the motion of masses passes directly into molecular motion. Here, therefore, the transition has to be made.

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States of aggregation – nodal points where quantitative change is transformed into qualitative.

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Cohesion – already negative in gases – transformation of attraction into repulsion, the latter only real in gas and ether (?).

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At absolute 0° no gas is possible, all motion of the molecules ceases; the slightest pressure, and hence their own attraction, forces them together. Consequently, a permanent gas is an impossibility. 

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mv2 has been proved also for gas molecules by the kinetic theory of gases. Hence there is the same law for molecular motion as for the motion of masses: the difference between the two is here abolished.

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The kinetic theory has to show how molecules that strive upwards can at the same time exert a downward pressure and – assuming the atmosphere as more or less permanent in relation to universal space – how in spite of gravity they can move to a distance from the centre of the earth, but nevertheless, at a certain distance, although the force of gravity has decreased according to the square of the distance, are yet compelled by this force to come to a stop or to return.

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The kinetic theory of gases:

“In a perfect gas … the molecules are already so far distant from one another that their mutual interaction can be neglected.” (Clausius, p. 6.)[233]

What fills up the spaces between them? Ditto ether.[234] Hence here the postulate of a matter that is not articulated into molecular or atomic cells.

The character of mutual opposites belonging to theoretical development; from the horror vacui[235] the transition was made at once to absolutely empty universal space, only afterwards the ether.

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Ether. If the ether offers resistance at all, it must also offer resistance to light, and so at a certain distance be impenetrable to light. That however ether propagates light, being its medium, necessarily involves that it should also offer resistance to light, otherwise light could not set it in vibration. – This the solution of the controversial questions raised by Mädler and mentioned by Lavrov [Lavrov].[236]

Light and darkness are certainly the most conspicuous and definite opposites in nature; they have always served as a rhetorical phrase for religion and philosophy from the time of the fourth Gospel[237] to the lumières of the eighteenth century.

Fick,[238] p. 9: “the law long ago rigidly demonstrated in physics … that the form of motion called radiant heat is identical in all essential respects with the form of motion that we call light.”” Clerk Maxwell,[239] p. 14: “These rays (of radiant heat) have all the physical properties of rays of light and are capable of reflection, etc…. Some of the heat-rays are identical with the rays of light, while other kinds of heat-rays make no impression upon our eyes.”

Hence there exist dark light-rays, and the famous opposition between light and darkness disappears from natural science as an absolute opposition. Incidentally, the deepest darkness and the brightest, most glaring light have the same effect of dazzling our eyes, and in this way are for us identical.

The fact is, the sun’s rays have different effects according to the length of the vibration: those with the greatest wave-length communicate heat, those with medium wave length, light, and those with the shortest wave-length, chemical action (Secchi, p. 632 et seq.), the maxima of the three actions being closely approximated, the inner minima of the outer groups of rays, as regards their action, coming within the light-ray group.[240] What is light and what is non-light depends on the structure of the eye. Night animals may be able to see even a part, not of the heat-rays, but of the chemical rays, since their eyes are adapted for shorter wave-lengths than ours. The difficulty disappears if one assumes, instead of three kinds, only a single kind of ray (and scientifically we know only one and everything else is a premature conclusion), which has different, but within narrow limits compatible, effects according to the wave-length.

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Hegel constructs the theory of light and colour out of pure thought, and in so doing falls into the grossest empiricism of home-bred philistine experience (although with a certain justification, since this point had not been cleared up at that time), e.g., where he adduces against Newton the mixtures of colours used by painters (p. 314, below).[241]

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Electricity. In regard to Thomson’s cock-and-bull stories, c.f. Hegel, pp. 346-47, where there is exactly the same thing. – On the other hand, Hegel already conceives frictional electricity quite clearly as tension, in contrast to the fluid theory and the electrical matter theory (p. 347).

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When Coulomb says that “particles of electricity repel each other inversely as the square of their distance,” Thomson calmly takes this as proved (p. 358).[242] Ditto (p. 366) the hypothesis that electricity consists of two fluids, positive and negative, whose particles repel each other. It is said (p. 360) that electricity in a charged body is retained merely by the pressure of the atmosphere. Faraday put the seat of electricity in the opposed poles of the atoms (or molecules, there is still confusion about it), and thus for the first time expressed the idea that electricity is not a fluid but a form of motion, a “force” (p. 378). What old Thomson cannot get into his head at all is that it is precisely the spark that is of a material nature!

Already in 1822, Faraday had discovered that the momentary induced current – the first as well as the second, reversed current – “participates more of the current produced by the discharge of the Leyden jar than that produced by the voltaic battery” – herein lay the whole secret (p. 385).

The spark has been the subject of all sorts of cock-and-bull stories, which are now known to be special cases or illusions: the spark from a positive body is said to be a “pencil of rays, brush, or cone,” the point of which is the point of discharge; the negative spark, on the other hand, is said to be a “star” (p. 396). A short spark is said to be always white, a long one usually reddish or purplish. (Wonderful nonsense of Faraday on the spark, p. 400.) The spark drawn from the prime conductor [of an electric machine) by a metal sphere is said to be white, by the hand – purple, by aqueous moisture – red (p. 405). The spark, i.e., light, is said to be “not inherent in electricity but merely the result of the compression of the air. That air is violently and suddenly compressed when an electric spark passes through it” is proved by the experiment of Kinnersley in Philadelphia, according to which the spark produces “a sudden rarefaction of the air in the tube,” and drives the water into the tube (p. 407). In Germany, 30 years ago, Winterl and others believed that the spark, or electric light, was “of the same nature with fire” and arises by the union of two electricities. Against which Thomson seriously proves that the place where the two electricities unite is precisely that where the light is least, and that it is two-thirds from the positive and one-third from the negative end! (Pp. 409-10.) That fire is here still something quite mythical is obvious.

With the same seriousness Thomson quotes the experiments of Dessaignes, according to which, with a rising barometer and falling temperature, glass, amber, silk, etc., become negatively electrified on being plunged into mercury, but positively electrified if the barometer is falling and the temperature rising, and in summer always become positive in impure, and always negative in pure, mercury; that in summer gold and various other metals become positive on warming and negative on cooling, the reverse being the case in winter; that they are “highly electric” with a high barometer and northerly wind, positive if the temperature is rising, negative if falling, etc. (p. 416).

How matters stood in regard to heat: “In order to produce thermo-electric effects, it is not necessary to apply heat. Any thing which alters the temperature in one part of the chain … occasions a deviation in the declination of the magnet.” For instance, the cooling of a metal by ice or evaporation of ether! (P. 419.)

The electro-chemical theory (p. 438) is accepted as “at least exceedingly ingenious and plausible.”

Fabroni and Wollaston had already long ago, and Faraday recently, asserted that voltaic electricity is the simple consequence of chemical processes, and Faraday had even given the correct explanation of the shifting of atoms taking place in the liquid, and established that the quantity of electricity is to be measured by the quantity of the electrolytic product.

With the help of Faraday, Thomson arrives at the law

“that every atom must be naturally surrounded by the same quantity of electricity, so that in this respect heat and electricity resemble each other“! [p. 454.]

Static and dynamic electricity. Static or frictional electricity is the putting into a state of tension of the electricity already existing in nature in the form of electricity but in an equilibrated, neutral state. Hence the removal of this tension – if and in so far as the electricity during propagation can be conducted – also occurs at one stroke, by a spark, which re-establishes the neutral state.

Dynamic or voltaic electricity, on the other hand, is electricity produced by the conversion of chemical motion into electricity. Under certain definite conditions, it is produced by the solution of zinc, copper, etc. Here the tension is not acute, but chronic. At every moment new + and - electricity is produced from some other form of motion. and not already existing ± electricity separated into + and-. The process is a continuous one, and therefore too its result, electricity, does not take the form of instantaneous tension and discharge, but of a continuous current which can be reconverted at the poles into the chemical motion from which it arose, a process that is termed electrolysis. In this process, as well as in the production of electricity by chemical combination (in which electricity is liberated instead of heat, and in fact as much electricity as under other circumstances heat is set free, Guthrie, p. 210),[243] the current can be traced in the liquid (exchange of atoms in adjacent molecules – this is the current).

This electricity, being of the nature of a current, for that very reason cannot be directly converted into static electricity. By means of induction, however, neutral electricity already existing as such can be de-neutralised. In the nature of things the induced electricity has to follow that which induces it, and therefore must likewise be of a flowing character. On the other hand, this obviously gives the possibility of condensing the current and of converting it into static electricity, or rather into a higher form that combines the property of a current with that of tension. This is solved by Ruhmkorff’s machine. It provides an inductional electricity, which achieves this result.

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A pretty example of the dialectics of nature is the way in which according to present-day theory the repulsion of like magnetic poles is explained by the attraction of like electric currents, (Guthrie, p. 264.)

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Electro-chemistry. In describing the effect of the electric spark in chemical decomposition and synthesis, Wiedemann declares that this is more the concern of chemistry.[244] In the same case the chemists declare that it is rather a matter which concerns physics. Thus at the point of contact of molecular and atomic science, both declare themselves incompetent, while it is precisely at this point that the greatest results are to be expected. 

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Friction and impact produce an internal motion of the bodies concerned, molecular motion, differentiated as warmth, electricity, etc., according to circumstances. This motion, however, is only temporary: cessante causa cessat effectus. At a definite stage they all become transformed into a permanent molecular change, a chemical change.