Part 3

Joule worked out the mechanical equivalent of heat by means of his now famous experiment of churning water. He reasoned that if the heat produced by friction, etc., is really energy in another form, then the same amount of heat must always be generated by the expenditure of a given amount of motion or mechanical work. And this must be true, no matter whether this work is expended in overcoming the friction between wood on wood, iron on iron, or in any other conceivable way. Accordingly, he devised an experiment in which paddle wheels were made to rotate in a vessel of water by means of falling weights somewhat like the weights of a clock. The amount of work represented by the falling of the weights was easily calculated, and so was the amount of rise in temperature of the water caused by the friction of the water with the rotating paddle wheels. In various other ways he measured the amount of heat generated by a measured amount of work; and as the result of all his experiments (with very slight corrections made since by means of more exact apparatus), we now know that 778 foot pounds of work produce heat enough to raise one pound of water one degree Fahrenheit; or stated in the metric system, 427 kilogram meters of work will produce a calorie of heat.

Since these record-making experiments by Joule, the matter has been verified over and over again in all sorts of ways; and almost every kind of display of energy has been measured with more or less exactness. Even the amount of food oxidized in the human body is now known to be capable of correlation with the other forms of energy, though necessarily very minute exactness of measurement is scarcely attainable in this case. But no scientist of to-day doubts that all the physiological processes of animals or of plants conform exactly to the law of the conservation of energy that energy is neither created nor destroyed by any means known to science. In other words, the amount of energy in our world, if science can at all determine such a matter, seems to be a fixed quantity, gradually being dissipated into space, it is true, but momently replenished from the sun at exactly the same rate now as hundreds or thousands of years ago. And while this energy is in our world it is always capable of exact correlation in all of its multitudinous forms, and is transformable back and forth without increase and without loss.

On the discovery of the radioactive substances in 1896, some persons hastily concluded that the law of the conservation of energy was contradicted by the astonishing way in which these substances acted. But further and more accurate experiments have set this matter at rest, as indeed might have been expected; for the law of gravitation itself is not more immovably established in the make-up of the universe than this magnificent law that energy cannot be created by any means which we call natural.

In all ages there have been men who have spent their lives in the vain effort to invent a machine out of which work could constantly be obtained without the expenditure upon it of an equal amount of work. But the United States patent office has got so tired of receiving applications for patents based on this idea of perpetual motion that they have long since refused to issue any such patent where this principle is the manifest object; and I suppose the governments of other countries have taken a similar stand. And why? Because they know that energy cannot now be created by any device, no matter how ingenious; and they refuse to become a party to any scheme that seems to imply that this modern creation of energy is within the bounds of possibility.

Yet what is all this but a confirmation of the declaration long ago made that "the works were finished from the foundation of the world" (Heb. 4:3)? True, the energy we are constantly employing seems to come to us from the sun; but we must remember that the sun and its family of the solar system, including the earth, were all made at the same time, that they are bound together as parts of an indissoluble whole. Accordingly, no one can say that the total amount of energy called into existence at the creation of our solar system is being added to at the present time. At any rate, so far as modern science can judge of the matter, the total amount of energy available for our world is a fixed quantity; and its amount and the terms on which it was to be available for our use were fixed or finished "from the foundation of the world." While it is a very significant fact in this connection that with all the multiform speculations which have been made as to the physical source of the sun's heat, no explanation wholly satisfactory has yet been made as to how this energy coming to us from the sun is constantly replenished or maintained.

The desire to find a material cause for all phenomena is instinctive in the human mind, and has proved the chief impetus in a thousand discoveries. And yet, unless we are on our guard, it is liable to be a source of real error whenever we are dealing with the deeper problems of thought. For when we have pushed our way into the inner sanctuary of any department of nature, we almost invariably come upon a deep chasm that we can pass over only by building a bridge of words. Some of these verbal bridges have been decorated with very dignified names, such as "the luminiferous ether," "gravity," "chemical affinity"; and when we have shifted from the one side of the chasm to the other we impose upon the credulity of the public (and even ourselves) by giving out the impression that these words represent the real objective bridge on which we crossed.

In how many ways do we by our theories dodge the crucial problem of how energy is really transmitted, that is, how matter can act on distant matter across seemingly vacant space. Gravity, and indeed all the forms of the attractive forces, come under this head. True, we observe certain regularities in the way in which these phenomena occur, and the phenomenon at one place seems to be somehow dependent on some exercise of force at another place. And so we invent an ingenious theory, and fortify it all around with ponderous algebraic artillery for defense against all attack. And by persistent use of such theories we hypnotize ourselves into the belief that we are truly scientific in method, and are dealing with objective realities, and that these learned theories are something more than pretentious masks to hide our ignorance of real nature; when in reality these theories seem to be only a material screen to shield us from an embarrassing near view of the immediate action of God in all the various phenomena of the world; for not many find it a comfortable thought thus to live continuously beneath the great Taskmaster's eye.

The theory of the luminiferous ether as the medium of the transmission of light is one of these pretentious bridges of words. Our advancing knowledge of electro-magnetic phenomena may some day drive us back to a modified form of the corpuscular theory of light, and then we can throw this of the ether to the winds. In that case we would at least have a real material cause for the phenomena with which we deal. While the current theory of the ether has so many inconsistencies, and attempts to bridge over so many real chasms in our thinking that it seems truly astonishing to see it taught so long. By the theory of the ether the problems are not solved, they are merely postponed or evaded; for while solving one difficulty it creates a multitude of its own. How then are we better off than before without any such theory?

Being at liberty to invent any sort of qualities for their ether, scientists have tried to imagine such a substance as they think they need. The ether must be a kind of matter; but unlike any matter that we know of it cannot have weight, or else it would gravitate together here and there, thus becoming more abundant in some places than in others; whereas the need is for a material absolutely uniform throughout space, even throughout the interiors of solid bodies, such as the earth and the bodies upon the earth.

Another reason for supposing the ether to be a plenum, filling absolutely all space, is that it must be perfectly frictionless; and for this reason it cannot be composed of particles with spaces between them. It must be frictionless, for otherwise the planets would be retarded in their motions through space. The earth, for instance, is moving along its orbit at the rate of eighteen miles a second; and yet the ether does not pile up in front of it, nor is it made rarer in the wake of the earth. Moreover, during the thousands of years during which astronomers have been making observations absolutely no retardation has been detected in the motions of the earth or of any of the heavenly bodies, even to the smallest fraction of a second.

It is necessary to make the ether absolutely elastic and absolutely rigid. We are acquainted with many materials that are elastic, and with some that are comparatively rigid. But the elastic substances that we are acquainted with are not rigid, and the rigid substances are not elastic; and to assume such contradictory qualities in the ether transports us far beyond the bounds of experimental science.

These are but a few of the difficulties raised by the assumption of the ether as a real entity; but as there is no means of demonstrating its existence, except by arguing the necessity of having such a medium to transmit radiant energy, it follows that no multiplication of objections to the theory is likely to refute it in the minds of those who feel this necessity. Those who refuse to admit the possibility of "action at a distance," who insist on inventing a connecting material medium between every observed effect and some material object with which it seems to be in causal connection, will, I suppose, have to be allowed to exercise their ingenuity in any way to satisfy their minds, even though they may have to revise their theory with every fresh discovery in optics or radioactivity.

There are many other ingenious mental devices, like this of the ether, which seem to me only materialistic efforts to postpone or to dodge the real vital lessons to be read from natural phenomena,--efforts to push the real Cause back one step farther into the shadow,--a last desperate effort, in the face of the constantly accumulating evidence of modern knowledge that the great First Cause is far more intimately connected with life and motion than many are willing to believe. We have already mentioned gravity and the other attractive forces, such as cohesion and adhesion; but seemingly very few people have ever paused to consider how utterly inexplicable they still remain in any physical or materialistic sense.

It is easy to explain any form of a push in a physical way; but gravity is not a push but a pull. And how are we to explain the method by which a body can act where it is not, how explain in detail the way by which it can reach out and pull in toward itself another separated body, and exert this pull across the immeasurably wide fields of space? The law of inverse squares may tell us very accurately the manner in which the results are accomplished, for our Creator is a God of order. But there is no materialistic theory of the why of gravitation that is worth employing the time of sensible, truth-loving people. And we can rest assured that there never will be any such real "explanation," save that this is the way which the great Jehovah has ordained. Since such theories only explain the known in terms of the unknown, they can serve only as a sort of mental buffer or shield between us and the conception of the direct working of a personal God, whose word must always be as effective throughout the remotest corners of His universe as near at hand, for the very simple reason that matter has no "properties" which He has not imparted to it, and accordingly it can have no innate inertia or reluctance to act which God's word would need to overcome in order to induce it to act, even when this word operates across the wide fields of space. On this explanation these phenomena of "action at a distance" are at least intelligible; while to me, and I speak now as a scientist, they are intelligible in no other way.

III

There is another line of thought which has to do with living organisms, but which I shall beg leave to anticipate and bring in here at the close of this chapter, since it follows as a direct corollary from the law of the Conservation of Energy. Indeed, we might even term it the biological aspect of that law.

As we have seen, we can neither create energy nor destroy it; though we can lose it,--so far as this earth is concerned. The vast fund of energy that daily comes streaming to us from the sun is transmuted back and forth in a thousand ways, though little by little it is dissipated off into space, and we are dependent upon a fresh supply from the ever replenished fountain.

Just so, though in a somewhat idealistic sense, is it with what we may term vital energy. Cells, organisms, even whole races, are subject to degeneration and decay. They cannot acquire higher powers, though they may gradually lose what they already have; as Bateson has recently told us that whatever evolution there is must be by loss and not by gain. Water very easily runs down hill; but cannot go up hill in and of itself. Just so with the types of organic life. It was not merely an idle sneer of the witty Frenchman, that science has not yet explained how an ancestor can transmit what he has not got himself. He cannot always transmit all that he himself actually possesses of nature's gifts. Vitality becomes lowered, and the type degenerates. Weismann has emphasized this idea in his doctrine of "panmixia," or the withdrawal of selection, which always results in degeneration. Selection, artificial or natural, may serve to counteract this universal tendency of organic life, but only approximately. As Sir William Dawson says, "All things left to themselves tend to degenerate." Little by little the endowment of vitality bestowed upon our world at the beginning has, like radiant energy, been returned to God who gave it; but, unlike the case of radiant energy, the Creator has not established any regular source of vital supply from without, no elixir of life for organic nature in general. There is no longer within easy reach a tree of life from which we may pluck and eat and live forever. And as the individual grows old and dies, so do species and even whole tribes degenerate and become extinct.

"From scarpéd cliff and quarried stone She cries, 'A thousand types are gone.'"

The glorious flood of vitality, so prodigally lavished upon our world in the beginning, has been ebbing lower and lower; and the theory of organic nature steadily advancing from the lower to the higher is manifestly just as puerile as the old hope of creating energy by a perpetual-motion machine,--and a mistake of precisely the same nature. Both are contradicted by the magnificent law of the Conservation of Energy, which, as we have said, is only the scientific expression of the Scriptural statement that Creation is completed, so far as our world is concerned; though, as the "wages of sin," death has been decreed upon the individual, and degeneration more or less marked upon every organic type. The fossils of the past, as well as our own experience within the historic period, confirm the view already arrived at on other grounds that Creation is a completed work and is not now going on; and the universal testimony from organic nature is that degeneration and decay have marked the history of every living form. Just as the individual grows old and dies, so do species degenerate and become extinct.

III

LIFE ONLY FROM LIFE

"No biological generalization rests on a wider series of observations, or has been subjected to a more critical scrutiny, than that every living organism has come into existence from a living portion or portions of a pre-existing organism."

"Was there anything so absurd as to believe that a number of atoms, by falling together of their own accord, could make a sprig of moss, a microbe, a living animal? ... It is utterly absurd.... Here scientific thought is compelled to accept the idea of creative power. Forty years ago I asked Liebig ... if he believed that the grass and flowers, which we saw around us, grew by mere mechanical force. He answered, 'No more than I could believe that a book of botany describing them could grow by mere chemical force.'"

"Let them not imagine that any hocus-pocus of electricity or viscous fluids would make a living cell.... Nothing approaching to a cell of living creature has ever yet been made.... No artificial process whatever could make living matter out of dead."

Ever since René Descartes, in his Holland laboratory, dissected the heads of great numbers of animals in order to discover the processes of imagination and memory, men have been seeking a physical or materialistic answer to such questions as, What is life? What is it to be alive? How shall we distinguish the living from the not-living?

No one of to-day, in the light of the correlation of vital processes with the general law of the conservation of energy, believes that life in plants and animals is a separate entity which may exist outside of and apart from matter. In a scientific sense, we only know life by its association with living matter, which in its simplest form is known as protoplasm. The latter has been termed the physical basis of life, and so far as we know every material living thing is composed wholly of protoplasm and of the structures which it has built up.

This grayish, viscid, slimy, semi-transparent, semi-fluid substance, similar to the white of an egg, is the most puzzling, the most wonderful material with which science has to deal. Chemically it is composed of various proteids, fats, carbohydrates, etc., and these in turn of but very few elements, all of which are common, and none of which are peculiar to protoplasm itself. And yet its essential properties, its mechanical as well as its chemical make-up, have baffled the resources of our wisest men with all their retorts and microscopes and other instruments of precision.