Reaction force

“ The conceptions of force and matter, of action and reaction, of momentum and inertia, with the reasonings in which they are involved, cannot be evaded by any substitution of lines or symbols for the conceptions. Any attempts at such substitution would render the study of Mechanics useless as a preparation of the mind for physical science; and would, indeed, except counteracted by great natural clearness of thought on such subjects, fill the mind with confused and vague notions, quite unavailing for any purposes of sound reasoning. ”

“ When they say that action is equal to reaction, they mean not only that the instantaneous intensity of the moving forces, or pressures opposed to each other, are necessarily equal, but conceive also a species of accumulated force residing in a moving body, which is capable of resisting pressure during a time that is proportional to its momentum or quantitas motus. ”

“ Newton’s Law of Motion is a law of maya: “To every action there is always an equal and contrary reaction; the mutual actions of any two bodies are always equal and oppositely directed.” Action and reaction are thus exactly equal. “To have a single force is impossible. There must be, and always is, a pair of forces equal and opposite.” ”

“ Every function, as representing a state of more or less perfect, moving equilibrium, may be regarded either as the final form issuing from a long process of action and reaction or, as determined at present, by such a comparative constancy of all its conditions as makes the line followed by the resultant approximately a repetition of that which it has followed before; and we may lay stress upon either the inferior resistance in this line or the continual application of superior force, the accumulation of energy, in its direction. Use or exercise is function ”

“ It is recognized that every effect has a sufficient and a commensurate cause, not en bloc, but in matter, energy, mind, and spirit. Action and reaction are definite mathematical processes. The parallelogram of force tends everywhere to equilibrium and secures further action and new processes under universal law. ”

“ We have now to consider the effect of the forces acting on the particles. These may be divided into two categories; we have first, the extraneous forces exerted on the various particles from without, and, secondly, the mutual or internal forces between the various pairs of particles. It is assumed that these latter are subject to the law of equality of action and reaction. If the equations of motion of each particle be formed separately, each such internal force will appear twice over, with opposite signs for its components, viz. ”

“ Chemistry teaches us that matter, as a cause, has matter for its effect; but we may say with equal justification that to force as a cause corresponds force as effect. Since c = e, and e = c, it is natural to call one term of an equation a force, and the other an effect of force, or phenomenon, and to attach different notions to the expression force and phenomenon. In brief, then, if the cause is matter, the effect is matter; if the cause is a force, the effect is also a force. ”

“ And so far as the action is propagated by the intervening instruments, and at last impressed upon the resisting body, the ultimate determination of the action will be always contrary to the determination of the reaction. ”

“ When a force is brought to bear upon it, it dances up and down, flings itself wildly from side to side, performs the most astonishing and rapid gyrations, but the three fundamental motions incessantly persist. ”

“ Using the phraseology of physical science may help a good deal to understand what we mean. Of the total force of every action of a man–including thought and word also in the word action–one part goes off as kinetic energy and that is represented by its visible effects that appear immediately the action is ended. ”

“ And thus we have a positive force active at one extremity of a line of particles, corresponding to a negative force at the other extremity, all the intermediate particles reciprocally neutralizing each other’s action. ”

“ It was then shown that the forces by which chemical effects are produced necessarily involve the Idea of Polarity,—they are polar forces; the particles tend together in virtue of opposite properties which in the combination neutralize each other. Hence, in attempting to advance to a theory of Causes in chemistry, our task is by no means to invent laws of mechanical force, and collections of forces, by which the effects may be produced. ”

“ The opinion is rapidly gaining ground that even chemical action is a mode of motion, and Professor Norton does not hesitate in affirming that "all the phenomena of material nature result from the action of force upon matter." [169] All that we mean by a Material Force "is a force which acts upon matter, and produces in matter its own appropriate effects." ”

“ It follows that, when a gas is under pressure, what prevents it from collapsing is not any repulsion between the particles, since there is none. Now, there are only two modes of force known to us, force of position or attractions and repulsions, and force of motion. ”

“ The first great agent which the analysis of natural phenomena offers to our consideration, more frequently and prominently than any other, is force. Its effects are either, 1st, to counteract the exertion of opposing force, and thereby to maintain equilibrium ”

“ My contention then is—and in this contention I am practically speaking for my brother physicists—that whereas life or mind can neither generate energy nor directly exert force, yet it can cause matter to exercise force on matter, and so can exercise guidance and control ”

“ Force being the cause, and motion the effect produced by it on matter, to say that matter is inert, or has inertia, as it is termed, is only to say that the cause is expended in producing its effect, and that the same cause cannot (without renewal) produce double or triple its own proper effect. ”

“ Yet in mechanics, whatever the mechanicians might think, both energies acted as interchangeable forces on man, and by action on man all known force may be measured. Indeed, few men of science measured force in any other way. ”

“ Have not the small particles of bodies certain powers, virtues, or forces, by which they act at a distance? .... What I call 'attraction' may be performed by impulse, or by some other means unknown to me. I use that word here to signify only in general any force by which bodies tend toward one another, whatsoever be the cause. ”

“ For every one of these impulses, not being the result of a force locally existing in some other form, implies the creation of force; and the creation of force is just as inconceivable as the creation of matter. ”

“ Cause then becomes the synonym of force. But physical science defines force only by its effects:—movement, or work done. So, too, the biologist rejects the notion of “vital force”; non-metaphysical psychology will have none of the “faculties,” intervention of “the soul,” and the like. Is the notion thus discarded, totally suppressed? Nay,—for even in mechanics and physics it cannot be entirely eliminated. It is there as a postulate, a residuum, an unknown factor covering lacunæ. ”

“ In like manner, the conversion of one form of energy into another, as indicated in the law of the persistence of force, illustrates the constant reciprocity of the two chief types of substance, ether and mass. ”

“ It is, however, certain that we must regard all manifestations of chemical force as dependent upon some secret principles common to all matter, diffused throughout the universe, but modified by the influences of the known imponderable elements, and by the mechanical force of aggregative attraction. ”

“ Thus, instead of beginning our reasonings, as in the last section we supposed them to commence, with the case in which forces act upon different points of the same body in the same line of force, and counteract each other in virtue of the intervening matter by which the effect of force is transferred from one point to another; we may suppose different forces to act at the same point, and may thus commence our reasonings with a case in which we have to contemplate force, without having to take into our account the resistance or rigidity of matter. ”

“ This is what we mean by causation, and this is what we call the manifestation of force. My next question is, How do we obtain the idea of force? The common answer to this question would be, that we obtain the idea of force through the manifestation of power by ourselves. We are conscious of using energy. We, ourselves, produce change in the objects about us. ”

“ We have learned that force is one, indestructible and uncreatable, and that all its manifestations are mutually convertible one into another. Either of the great modes of force may be active in affecting chemical composition; may cause chemical union or chemical separation; may be the motive of either analysis or synthesis. Now, in the direction here suggested, the main work of physics is being done. The chief object of the physicist to-day is to determine quantitatively the relations connecting all the different varieties of energy. Under what circumstances, and how, are forces transformed? ”

“ It is from our dynamic Activity also that we derive our conception of Force. Force, though it is studied scientifically in the measurement of the great natural forces which operate constantly, is originally known to us in the stress or pressure to which muscular exertion in contact with a material body gives rise. Such a force if it could be correctly measured, would record the rate at which Energy was undergoing transmutation, and it is from such experience of pressure that our idea of Force is originally derived. ”

“ The more chemistry, and electrology, and life, are searched into by the keenest and most remorseless experiment, the more do we find ourselves admitting that motive power and force, as manifested to us, is derived, is in its essence immaterial, is direct from Him in whom we live and move, and to whom, in a sense quite peculiar, belongeth power. ”

“ Force and matter, though presupposing each other in action, are fundamentally disparate; they are essentially distinct, and mutually irreducible entities. Matter, as such, is passive, dead; all motion or life is caused by force; and the only possible solution of the problems of physiology, no less than of physics and chemistry, consists in the enumeration of the forces acting upon the material particles, and in the exact quantitative determination of the effects produced by their action. ”

“ Every objective manifestation, whether it be the motion of a living limb, or the movement of some inorganic body, requires two conditions: will and force—plus matter, or that which makes the object so moved visible to our eye; and these three are all convertible forces, or the force-correlation of the scientists. ”

“ And from hence the expansive force will not be a particular force opposed to the attractive one, but an effect derived therefrom. I own, that we must suppose a perfect spring in every molecule, and in every atom of matter, to have a clear conception how this change of attraction into repulsion is performed. ”

“ Now, by this sense, we obtain a perception of force as pressure, distinct and unique, and not involving the variable element of distance, which enters into the perception of force as derived from the sense of sight alone. ”

“ Every such action must be composed of the effects of one particle in the system on another, and as this must invariably produce an equal and opposite reaction the total moment of momentum is unaltered. ”

“ As matter only rises step by step from plane to plane, and never two steps at a time, so also force, in its transformation into higher forms of force, rises only step by step. Physical force does not become vital except through chemical force, and chemical force does not become will except through vital force. ”

“ If it is a mechanical force, then the immediate effect is some distortion of the part—a distortion having for its limit that attitude in which the resistance of the structures to further change of position, balances the force tending to produce the further change; and the ultimate effect, supposing the force to be continuous or recurrent, is such a permanent alteration of form, or alteration of structure, or both, as establishes a permanent balance. ”

“ Force is that which is imagined to immediately produce, or tend to produce, motion. Why "immediately"? Because a particle of "matter"—attracting, as it does, every other particle of "matter"—may be said to "tend to produce motion." ”

“ That the primary force is a force of repulsion, and that the immediate source [Pg 223] of all the forces that are known to take effect upon ordinary matter is the action of recurring repulsive impulses upon the atoms of the universal ether, and their subsequent propagation and partial interception by the atoms which they encounter, I infer from the fact that this conception furnishes a rational explanation of all the known forces and phenomena of inanimate nature. ”

“ Every pair of atoms is, like a balance, delicately suspended, under the constant struggle which arises from the tendency to fly asunder, induced by one order of forces—centrifugal force—and the efforts of others, gravitation and cohesion, to chain them together. ”

“ Here we learn the important truth that two forces not in the same direction can be replaced by a single force. The process is called the composition of forces, and the single force is called the resultant of the two forces. ”

“ You have yet much to learn in connection with allied phenomena, but this study of the crude exhibition of force-disturbed matter, the manipulation of which is familiar to man under the above names, is an introduction to the more wonderful study destined yet to be a part of your field, an investigation of quiescent matter, and pure motion. ”

“ Since Newton's time we have made an advance in the definition of Force, and have come to consider Force as a kind of energy; the application of Force being the application of energy. Such terms as Mechanical Force, Chemical Force, Vital Force, are therefore out of date, and in their place the more definite ideas of energy are substituted. ”