Mean motion

“ Free motion, arrested motion, the effort, the speed, and the direction of motion, such are the sensorial elements, which, in all probability, constitute the foundation of our ideas on space and its properties. ”

“ Motion itself, however, is not twofold in character; it is unity, but the result of duality. In time we have to distinguish the polar act of position, and the act of repeating this position, which is motion. ”

“ And again, motion in a straight line and in a curve are no otherwise distinct than that the one is motion continuing in the same direction, the other is motion which at each instant changes its direction. ”

“ Although the doctrine of motion in connexion with force, which is the subject of mechanics, is by far the most important form in which the consideration of motion enters into the formation of our sciences, the Pure Doctrine of Motion, which treats of space, time, and velocity, might be followed out so as to give rise to a very considerable and curious body of science. ”

“ All that we know about motion is that it is a [Pg 46] name for certain changes in the relations of our visual, tactile, and muscular sensations; and all that we know about matter is that it is the hypothetical substance of physical phenomena, the assumption of the existence of which is as pure a piece of metaphysical speculation as is that of the existence of the substance of mind. ”

“ If when once in motion its tendency is to continue in motion, then it could be used as an instrument by which intelligent power, putting it in motion, could extend the effects of its own action in time and space. ”

“ Simple modes of motion. To slide, roll, tumble, walk, creep, run, dance, leap, skip, and abundance of others that might be named, are words which are no sooner heard but every one who understands English has presently in his mind distinct ideas, which are all but the different modifications of motion. Modes of motion answer those of extension ; swift and slow are two different ideas of motion, the measures whereof are made of the distances of time and space put together ; so they are complex ideas, comprehending time and space with motion. ”

“ Many modern physicists mythologize in this manner about motion, being unable to distinguish motion as an abstract property, because motion is formulated in terms of space and force in terms of parallelograms. ”

“ The alteration of motion is ever proportional to the motive force impressed; and is made in the direction of the right line in which that force is impressed. ”

“ The general law that the change of motion is proportional to the moving force and takes place in its direction, provided we take care always to regard the reaction of curves, surfaces, obstacles, &c., as so many real moving forces of (for a time) unknown magnitude, will always help us out of any dynamical scrape we may get into. ”

“ That a body, once in motion, would continue for ever to move in the same direction with undiminished velocity unless acted upon by some new force, was a proposition which mankind found for a long time the greatest difficulty in crediting. ”

“ Motion depends upon certain external disturbing and directing forces acting upon all matter; and, consequently, as every mode of action is determined by some excitement external to the body moved, motion cannot, philosophically, be regarded otherwise than as a peculiar affection of matter under determinable conditions. “We find,” says Sir Isaac Newton, “but little motion in the world, except what plainly flows from either the active principles of nature, or from the command of the willer.” ”

“ In the physical world we are congnizant of but four elementary or primordial ideas, beside the inevitable Time and Space. They are Matter, Force, Position, and Motion. Of these, motion is simply change of position; and force is recognized as the agent in every change of motion. ”

“ Or rather, out of this primitive conception of Motion, the adult conception of it is developed simultaneously with the development of the conceptions of Space and Time: all three being evolved from the more multiplied and varied impressions of muscular tension and objective resistance. Motion, as we know it, is thus traceable, in common with the other ultimate scientific ideas, to experiences of force. ”

“ To cause a motion is the name for the action of our soul on matter—a thing shrouded in mystery. To be the antecedent in a chain of movements is the fact which we can observe about any movement in the external world. ”

“ To begin with the examination of motion; 'tis evident this is a quality altogether inconceivable alone, and without a reference to some other object. The idea of motion necessarily supposes that of a body moving. Now, what is our idea of the moving body, without which motion is incomprehensible? It must resolve itself into the idea of extension or of solidity; and consequently the reality of motion depends upon that of these other qualities. ”

“ The causes, as they exist at any moment, having produced a certain motion, that motion, becoming itself a cause, reacts upon the causes, and produces a change in them. By altering the distance and direction of the central body relatively to the planet, and the direction and quantity of the force in the direction of the tangent, it alters the elements which determine the motion at the next succeeding instant. ”

“ There is natural harmony in rapid motion over a long smooth line, and slow motion over a short jagged one. A simple case like this may help us to answer the question, When is the relation between velocity and direction harmonious? ”

“ In the currently accepted language of science, the cause of motion, in all such cases as this, when bodies tend to move towards or away from one or another, without any discernible impact of other bodies, is termed a 'force,' which is called 'attractive' in the one case, and 'repulsive' in the other. ”

“ Motion. A continued and successive change of place, either of a whole body, or of the particles of [Pg 211] which a body is composed; the earth in revolving upon its axis only, would not change its place as a body, but all the particles of which it is composed, would revolve round a common axis of motion. In revolving in its orbit, its whole mass is constantly occupying a new portion of space. ”

“ It is better form of speech to say that motion is absolute or relative when it is desired to call attention to one factor or the other, rather than to say that motion is an absolute or a relation.
The motion of particles is of such a nature that paths must impinge, and then collisions arise which give rise to impulse, or collision by which paths are deflected. ”

“ They seek an entity to account for the fact. Motion is a very definite conception, expressing precise experiences; we know what it means, and know that the laws of moving bodies admit of the nicest calculation. A similar precision belongs to Force when understood as “mass acceleration,” or M V2. But this does not content those191 metaphysicians who understand by Force “the unknown reality behind the phenomena”—the cause of Motion. ”

“ The communication of motion, its direction, the resistance it suffers, and its cessation, in a word, the whole doctrine of motion cannot be consistently explained or clearly understood without supposing the inertia of matter. Self-moving matter must have thought and design, because, whenever matter moves, it must move in some particular direction, and with some precise degree of velocity ”

“ On the other hand can motion be predicated of anything apart from and other than the bodies, and, if not, can we avoid predicating it of the bodies, and, if so, is it not their state, and so in some sense a state of each? ”

“ It is as much like it as the short, straight lines, substituted by the mathematician, are like the segments of the curve he is trying to solve. What is true of motion is true in a way of all our definitions, formulations, laws, and categories; they are not the real things, but merely handy surrogates. ”

“ All motion that awakens sublime ideas is such as conveys the notion of great force and power. Motions of this kind are generally in straight or angular lines. Such motions are seen in the working of machinery, and in the efforts of animal nature. Quick motion is more sublime than slow. Motions that awaken ideas {134} of beauty are generally slow and curving. ”

“ Everywhere motion, and everything is motion, and there is not the hundredth part of a second of rest.—How shall I seize actuality, how shall I recognize it, if I myself, at any given moment, am not what I was, am not what I shall be the following moment? ”

“ Motion is a fact seen by the eye, felt by the hand; it enters into us by the perception we have of the solid masses visible to the naked eye which exist in our field of observation, of their movements and their equilibrium and the displacement we ourselves effect with our bodies. ”

“ Move it in any manner, you still find motion or a change of relation. 'Tis absurd to imagine that motion in a circle, for instance, should be nothing but merely motion in a circle; while motion in another direction, as in an ellipse, should also be a passion or moral reflection ”

“ Motion, as studied in mechanics, is but an abstraction or a symbol, a common measure, a common denominator, permitting the comparison of all real movements with each other; but these movements, regarded in themselves, are indivisibles which occupy duration, involve a before and an after, and link together the successive moments of time by a thread of variable quality which cannot be without some likeness to the continuity of our own consciousness. ”

“ How illusive are our ideas of Motion, is thus made sufficiently manifest. That which seems moving proves to be stationary; that which seems stationary proves to be moving; while that which we conclude to be going rapidly in one direction, turns out to be going much more rapidly in the opposite direction. And so we are taught that what we are conscious of is not the real motion of any object, either in its rate or direction ”

“ Modern definition of Motion.
Nor have the modern philosophers, who have endeavoured to throw off the jargon of the schools, and speak intelligibly, much better succeeded in defining simple ideas, whether by explaining their causes, or any otherwise. The atomists, who define motion to be 'a passage from one place to another,' what do they more than put one synonymous word for another? ”

“ Not only is motion one of the most universal of all phenomena, it is also (as might be expected from that circumstance) one of those which, apparently at least, are produced in the greatest number of ways; but the phenomenon itself is always, to our sensations, the same in every respect but degree. [Pg 6] Differences of duration, or of velocity, are evidently differences in degree only; and differences of direction in space, which alone has any semblance of being a distinction in kind, entirely disappear (so far as our sensations are concerned) by a change in our own position ”

“ For that Motion which can continue long in one and the same part of a Body, can be propagated a long way from one part to another, supposing the Body homogeneal, so that the Motion may not be reflected, refracted, interrupted or disorder'd by any unevenness of the Body. ”

“ B. You perplex yourself by confounding the idea of circular motion, with that of motion in a right line; you must think only of the motion of a body round a fixed line, and you will find, that if the parts farthest from the centre had not the greatest velocity, those parts would not be able to keep up with the rest of the body, and would be left behind. Do not the extremities of the vanes of a windmill move over a much greater space, than the parts nearest the axis of motion? (plate 3. fig. 1.) ”

“ And this rudimentary consciousness of Motion, consisting of serial impressions of force, becomes inseparably united with the consciousness of Space and Time as fast as these are abstracted from further impressions of force. ”

“ Motion is the simple repetition of the polar, twofold act, or the ceaseless separation of poles; but, as in every polar line the two poles are in all cases together, so even is this mutual separation of poles only a repetition of polarity.
83. Motion also is not created, but has emerged directly from the Eternal, is the primary function itself repeated. Motion is the ever self-manifesting, consequently progressive God.
84. Motion is thought, which is manifested as speech. Thought polarizes the fingers. If the thought be powerful it moves them, and through them other bodies. ”

“ And it is most certain, if we consider ourselves for a moment as part of the vulgar (setting aside the fictions of astronomers and the school, who are wont undeservedly to attack the senses in many respects, and to affect obscurity) , that the apparent motion is such as we have said, a model of which we have sometimes caused to be represented. ”

“ Many of the most eminent thinkers of the present time are disposed to regard all the active principles of nature as “modes of motion,”—to look upon light, heat, electricity, and even vital force, as phenomena resulting from “change of place” among the particles of matter; this change, disturbance, or motion, being dependent upon some undefined mover. ”

“ Motion is nothing but the simultaneous change of matter in space and time. You see how blended all the factors are? You cannot deal with one without the others. And mark you this, Rob—you can subdivide matter until it becomes a mere vortex in empty space. ”

“ No object at rest alters its position without the intervention of some conditions extraneous to itself; and when once in motion, no object returns to a state of rest, or alters either its direction or its velocity, unless some new external conditions are superinduced. ”

“ In the other class of motions, as when bodies are thrown up in the air, they are, on the contrary, moving from their own place. Now, this conception of a body moving toward its own place may justly be considered inappropriate; because, though it expresses a circumstance really found in some of the most familiar instances of motion apparently spontaneous, yet, first, there are many other cases of such motion, in which that circumstance is absent; the motion, for instance, of the earth and planets. ”