Physical phenomenon

“ And beyond his form no physical progress seems possible, for he fulfills what we conceive to be Nature's design, viz., to husband force by the fullest avoidance of gravity and friction, to decrease weight to the lowest available point consistent with the size and strength necessary to best adapt him to surrounding conditions, and to produce the utmost susceptibility to impression of natural force—to attain a form, in fact, having the greatest excess of available energy, and best adapted to gain experiences of the conditions of nature. ”

“ We must answer in the negative. The objects of the natural sciences of the physical world arc of a material and spatial nature. A physical body has weight, occupies a certain portion of space, so has the molecule, the atom. ”

“ The persistency of force means also the persistency of motion. All forms of physical energy—as light, heat, sound, electricity, magnetism, chemical action, gravity and sensible motion—he says, are different manifestations of force. ”

“ And the whole circle of the Physical Sciences, or Physical Science in its widest extent, confines itself to explaining the appearances of the material world by the properties of matter, and to reducing what is complex and manifold to the operation of a few simple but all-pervading laws. ”

“ Every motion which the accurate search of the experimentalist has traced, every principle or power which the physicist has discovered, every combination which the chemist has detected, every form which the naturalist has recorded, involves reflections of an exalting character, which constitute the elements of the highest poetry. The philosophy of physical science is a grand epic, the record of natural science a great didactic poem. ”

“ But it is in the study of the constitution of matter and the evolution of the elements, the deepest and most critical problem of physics and chemistry, that the extremes of pressure and temperature in the heavenly bodies, and the prevalence of other physical conditions not yet successfully imitated on earth, promise the greatest progress. ”

“ 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. ”

“ Out of everything that the world brings to the totality of our senses, there remains nothing more than mere movements, with certain changes of rate, direction, and so on. The picture of the world received by such an observer is a purely kinematic one. And this is, indeed, the character of the world-picture of modern physical science. For in the scientific treatment of natural phenomena all the qualities brought to us by our other senses, such as colour, tone, warmth, density and even electricity and magnetism, are reduced to mere movement-changes. ”

“ The position which I seek to establish in this essay is, that the various imponderable agencies, or the affections of matter which constitute the main objects of experimental physics, viz., heat, light, electricity, magnetism, chemical affinity, and motion, are all correlative, or have a reciprocal dependence;—that neither, taken abstractedly, can be said to be the essential or proximate cause of the others ”

“ On the remaining pages of this paper I desire to direct attention to some of the facts connected with the main subject of my present inquiry—the concept force.
Physical forces are distributed by modern science into two classes, molecular and molar forces. Molecular forces are those which determine the internal changes of a body, while molar forces cause the motion of the entire mass. ”

“ Having now defined the use of the term force, and shown that forces are correlated which are convertible 44and mutually dependent, we go on to study the evidences of such correlation among the motions of inorganic nature usually called physical forces; and to ask what proof science can furnish us that mechanical motion, heat, light, and electricity are thus mutually convertible. ”

“ By it we find that the air has weight and pressure, color, density, elasticity, compressibility, and some other properties with which we shall endeavor to make the young reader acquainted by many pleasing experiments, earnestly impressing upon him to lose no opportunity of making physical science his study. ”

“ But how “mechanical happening” comes to have this marvellous inwardness, which we call sensation, feeling, perception, thought and will, which is neither mechanical nor derivable from anything mechanical; and, further, how physical and psychical can condition one another without doing violence to the law of the conservation of the sum of energy, is an absolute riddle. ”

“ By influences external to this earth the balance of these forces is continually disturbed; and in the effort to restore the equilibrium, we have the production of all the varied forms of matter, and the manifestation of each particular physical principle or power. As motion and attraction, balanced against each other, maintain the earth in her elliptical orbit, so the opposition of forces determines the existence of the amorphous rock, the light-refracting crystal, the fixed and flowering plant, and the locomotive animal.
An eternal round of chemical action is displayed in nature. ”

“ The matter that surrounds us is divided into two great classes, living and dead; the latter is governed by physical laws, such as attraction, gravitation, chemical affinity; and it exhibits physical properties, such as cohesion, elasticity, divisibility, &c. Living matter also exhibits these properties, and is subject, in great measure, to physical laws. ”

“ It will now be evident that in all chemical phenomena we have the combined exercise of the great physical forces, and evidences of some powers which are, as yet, shrouded in the mystery of our ignorance. ”

“ Thus the march onward proceeds, and when some general law of Nature—like, for instance, gravitation, the correlation of the physical forces, or, even, with a more limited bearing, reflex spinal action—is discovered, a gain is made which, through reflected influence, has the effect of at once immensely enlarging and perfecting the understanding. ”

“ Physical Science is nothing more than the perceptions of our five bodily senses registered and methodized. But what are these five senses? According to physical science itself, nerves in a certain stage of evolution. Why then should it be assumed that their account of the universe, or of our relations to it, is exhaustive and final? Why should it be assumed that these are the only possible organs of perception, and that no other faculties or means of communication with the universe can ever in the course of evolution be developed in man? ”

“ What has been called matter is, so far as we know now, simply a complex of energies, and he has sought to extend the "energetic" principle from physical or chemical to biological, psychical, and social phenomena. ”

“ In these speculations, the force of gravity is resolved into the pressure or impulse of solids or fluids. On the other hand, hypotheses have been propounded, in which the solidity, and other physical qualities of bodies, have been explained by representing the bodies as a collection of points, from which points, repulsive, as well as attractive, forces emanate. ”

“ In those hard bodies, indeed, the particles of which are in actual contact, and which are closely united, how is it possible to conceive, that air, cold, or heat, can act upon one of these particles, even exteriorly, without the motion being communicated to those which are most intimate and minute in their union? Without motion, how should we be able to comprehend the manner in which our sense of smelling is affected, by emanations escaping from the most solid bodies, of which all the particles appear to be at perfect rest? ”

“ How strangely it obeys the impulses of heat—mysterious are the influences of light upon it—electricity wonderfully excites it—and still more curious [Pg 3] is the manner in which it obeys the magic of chemical force. These are phenomena which we have seen; we know them, and we can reproduce them at our pleasure. We have advanced a little way into the secrets of nature, and from the spot we have gained, we look forward with a vision somewhat brightened by our task ”

“ The physical philosopher has it for his business to trace clouds to the laws of evaporation and condensation; to determine the magnitude and mode of action of the forces of cohesion and crystallization by which the materials of the earth are made solid and firm. ”

“ Hence, if we remember that the ultimate object of all physical science is the successful formulation of such practical rules for action, we can see that it is a logical consequence of the character of the interests which dominate our scientific descriptions, that the physical sciences should adopt a rigidly mechanical view of the physical order. ”

“ In conservation of matter, energy, what you will, in plenitude, in motion as only relative and so as always under a principle of uniformity and constancy or even immobility, in motion too as inclining to vibration, which suggests poise or tension, or to rotation, in which we see rest as well as motion, and finally, not to extend what might be a long list, in the infinity of space and time or of quantity, the physical sciences have hidden entrances for the silent, usually unnoticed admission of what is psychical. ”

“ But to avoid undue suspension of the argument, I content myself with saying that when the respective effects of gravitation, heat, light, &c., are studied, as well as the respective effects, physical and chemical, of the matters forming the media, water and air, it will be found that while more or less operative on all bodies, each modifies organic bodies to an extent immensely greater than the extent to which it modifies inorganic bodies. ”

“ We believe in the Conservation of the physical forces, in the Law of Evolution as it is at present and for a limited past time found to express the facts of nature, and in the fact of the Dissipation of Energy. All this we believe as the scientifically probable view, and we do so on the authority of certain students of physical science, who, having examined the facts, seem to agree upon so much as capable of popular exposition. ”

“ If the properties of such a system of bodies are found to correspond to those of gases, an important physical analogy will be established, which may lead to more accurate knowledge of the properties of matter. ”

“ But the physical phenomena of contraction, expansion, absorption, undulatory and vibratory motions accompanying our sensations of light, heat and sound, as well as many other physical phenomena, all point to the fact that volumes of matter which are apparently continuous are really porous: the molecular structure of perceptible matter is an accepted physical theory ”

“ Every form, whether inorganic or organic, which we can discover within the limits of human search, is composed of atoms, which are capable of assuming, under the influence of certain physical forces, conditions essential to the physical state of that body of which they constitute a part. [1] The known forces, active in pro [Pg 5] ducing these conditions, are modes of motion; gravitation and aggregation, heat, light; and associated with these, actinism or chemical radiation; electricity, under all its conditions, whether static or dynamic ”

“ Thus physical quantities are aggregates of physical vibrations, and physical vibrations are the expression among the abstractions of physical science of the fundamental principle of æsthetic experience. ”

“ Under the head of physics we have the theory of the elements, of sound, heat and cohesion, and finally of chemical affinity—presenting the phenomena of material change and interchange in a series of special forces which generate the variety of the life of nature. ”

“ Physics treats of substances which move as masses, or which vibrate and rotate as molecules, without undergoing any appreciable change of structural integrity;5 they show changes of position and state, without corresponding changes in their elements. ”

“ Every condition of organised forms is due to the external excitation of light and heat, and in the chemical changes which take place, an equivalent of these principles, or powers—it signifies but little according to which view we may regard them—is absorbed, and retained as essential to the condition of the matter formed. ”

“ Not until the necessity arose for distinguishing between different forms of energy, and the conditions for developing them, did it become clear to all that a change in the form of energy implied a change in the form of motion that embodied it. ”

“ For it has always been the task of this line of investigation to extend the sphere within which physical and chemical laws can be validly applied in interpreting vital processes, and the results reached along this line will always be so numerous and important that even on psychological grounds the mechanical point of view has the best chance for the future. ”

“ All branches of physical science demonstrate the fact that every completed manifestation, of whatever kind and on whatever scale, is started by the establishment of a nucleus, infinitely small but endowed with an unquenchable energy of attraction, causing it to steadily increase in power and definiteness of purpose, until the process of growth is completed and the matured form stands out as an accomplished fact. ”

“ This appears to be the proper place for correcting an error too prevalent, relative to the formation of crystals, the development of cells, and the yet more fatal falsehood of referring the great phenomena of Life to any of the physical forces with which we are acquainted. ”

“ The history of science in the nineteenth century offers some interesting examples. The discovery of the conservation of energy and its transformations has revealed to us the unity Page 372 of force. It has shown, for example, that the phenomenon of heat could be explained by molecular motions. ”