The Source and Mode of Solar Energy Throughout the Universe

by Isaac W. Heysinger

CHAPTER XII.

THE NEBULAR HYPOTHESIS: ITS BASIS AND ITS DIFFICULTIES.

“There sinks the nebulous star we call the Sun,

If that hypothesis of theirs be sound.”—Tennyson.

While the nebular theory of Laplace is now the generally accepted scientific hypothesis of the formation of our solar system and of all solar systems, it finds its strongest support in the mode in which it seeks to account for the heat and light of the sun,—that is, that the central orb, gradually condensing down from an original volume as large as the orbit of Neptune, at least, after disengaging the planetary rings, continued to condense to its present volume, and still so continues, the molecular motions arrested by condensation under gravity reappearing in the form of the energy of light and heat, and that this process of degradation will continue until, finally, the sun becomes a solid inert mass, incapable by further condensation of exciting the ethereal undulations in space which constitute heat and light, when the whole process will finally cease, the sun will die out, the planets continue to rotate in darkness, and the whole machinery be left running through an eternal night, like a vast mill in the hands of a negligent watchman (or rather no watchman at all), left to run itself alone, dark, empty, lifeless, and deserted, through the long and silent watches of the night. While the source and mode of solar energy set forth in this work are to be as readily accounted for if we accept as valid Laplace’s nebular hypothesis as by any other theory, yet such basis is not essential for its support; for while the planetary rotations and the central sun are the necessary consequence, according to Laplace’s hypothesis, of their mode of formation,—are, in fact, just what we actually find them to be under any hypothesis,—electrical generation and transformation will proceed just the same whether the planets and sun were formed originally in one mode or in another. But, since this generally accepted hypothesis accounts for the light and heat of the sun, to a certain extent at least, and for a certain relatively brief period, while no other hypothesis has been able to sufficiently account for it at all, and while this hypothesis also finds both support and contradiction in many observed phenomena of our solar system, it may well occur that this hypothesis itself, based upon the necessity of accounting for the sun’s light and heat, and which latter afford it its strongest basis of support, may, if the basis upon which the theory rests be found to be otherwise explicable, still remain as an end, while originally presented only as a means, and thus be held as an obstacle to the acceptance of the widely different interpretation of known facts herein presented, in the absence of any other hypothesis capable of explaining the same facts in accordance with this presentation of planetary electrical generation and the solar transformation of this energy into light and heat. Herbert Spencer mentions an instance of such perversion of means into an end as occurring during the agitation for the repeal of the corn laws in England, which extended over many years, during which organized efforts were made to influence Parliament. A permanent commission was established, with official head-quarters permanently located in London, with clerks, secretaries, higher officers, and all the paraphernalia of a first-class establishment. The purpose of this institution was to act in behalf of the popular interests upon Parliament by every available means to secure this great reform. After years of effort, he says, a clerk one day rushed, breathless, into the office from the House of Commons and shouted, in accents of despair, “We are ruined; the bill has passed!”

The nebular hypothesis, while generally accepted in lieu of a better one, has no actual primary basis beyond that of mere assumption. Of it Professor Ball says, “The nebular theory … seems, from the nature of the case, to be almost incapable of receiving any direct testimony.” We have already quoted from Professor Newcomb that it must be accepted, with all its difficulties, until a different and sufficient explanation of solar energy shall be presented. As set forth in Appleton’s Cyclopædia, the theory is as follows: “Assuming, for the sake of the argument, a rare, homogeneous, nebulous matter, widely diffused through space, the following successive changes will, on physical principles, take place in it: 1, mutual gravitation of its atoms; 2, atomic repulsion; 3, evolution of heat by overcoming this repulsion; 4, molecular combination at a certain stage of condensation; followed by, 5, sudden and great disengagement of heat; 6, lowering of temperature by radiation and consequent precipitation of binary atoms, aggregating into irregular flocculi and floating in the rarer medium, just as water when precipitated from air collects into clouds; 7, each flocculus will move towards the common center of gravity of all; but, being an irregular mass in a resisting medium, this motion will be out of the rectilinear,—that is to say, not directly towards the common center of gravity, but towards one or the other side of it,—and thus, 8, a spiral movement will ensue, which will be communicated to the rarer medium through which the flocculus is moving; and, 9, a preponderating momentum and rotation of the whole mass in some one direction, converging in spirals towards the common center of gravity. Certain subordinate actions are to be noticed also. Mutual attraction will tend to produce groups of flocculi concentrating around local centers of gravity and acquiring a subordinate vortical movement. These conclusions are shown to be in entire harmony with the observed phenomena. In this genetic process, when the precipitated matter is aggregating into flocculi, there will be found here and there detached portions, like shreds of cloud in a summer sky, which will not coalesce with the larger internal masses, but will slowly follow without overtaking them. These fragments will assume characteristics of motion strikingly correspondent to those of the comets, whose physical constitution and distribution are seen to be completely accordant with the hypothesis.” During this process, it is further stated, successive rings of nebulous matter will be thrown off and left behind, which are supposed to have coalesced into planets and their satellites, and the motion of rotation will become more and more rapid as condensation proceeds, until, finally, the last planet, Mercury, will be left behind in annular form, and the sun will then become the central orb of all the planets, and condensation afterwards will proceed without further delivery of planetary rings. Professor Ball says, “If we go sufficiently far back, we seem to come to a time when the sun, in a more or less completely gaseous state, filled up the surrounding space out to the orbit of Mercury, or, earlier still, out to the orbit of the remotest planet.”

Great spiral nebula in Canes Venatici. (See Fig. 156 of Guillemin’s “The Heavens.”) The small nebula to the right is also, according to M. Chacarnac, a spiral, though with the telescopic power used the figure above does not show it.

There is nothing in the actively developing nebula illustrated on the following page which shows the slightest analogy, either in structure or the forces at work, to what is demanded by the nebular hypothesis. On the contrary, these radiating, spiral convolutions, springing from a center and extended, with interstratified dark spaces, out to the periphery, are entirely incompatible with that theory. There have not, so far, been observed in all the heavens any gaseous nebulæ which lend the slightest support to the nebular hypothesis. We should expect to find, if it were true, that many of the nucleated planetary nebulæ show exterior concentric rings of luminous matter, clearly defined, two, three, or a dozen in number, left behind by the contracting volume of the nebula, and coalescing into planets, and, within, the glowing disk from which new external rings are about to be left as a residuum. On the contrary, these nebulæ gradually fade away towards their margins, and imperceptibly disappear in the blackness of space. If they terminated abruptly, we might suppose that here, at least, was the orbit of a newly forming planet, but the regular and delicate gradation of luminosity from maximum to zero shows that no such sudden breaking off has occurred. In all these nebulæ we find every definitely marked structure to exhibit the operation of combined forces of gravity and internal repulsion nearly equally balanced, but each acting independently of the other. These phenomena are as universal as the forces of cohesion and repellent polarity in the “attraction particles” of cell-life which determine the segmentation, growth, and development of the living organism. We find here the primal modification and differentiation of material structure under the stress of directly opposite and interacting primitive forces, and it is doubtless the same whether in a cell or a system. It is not a residuum, but the vis a tergo.

It is well known that there are many and great difficulties involved in the nebular hypothesis. As for the genesis of comets, it will be at once seen that the theory will only account for such comets as never venture much beyond the orbit of Neptune, as well as those which have an orbital plane nearly coincident with that of the planets. But most comets come from illimitable space, far, far beyond Neptune’s circle and at all angles to the plane of the planetary orbits; and we have already seen that a disk of space of the diameter of Neptune’s orbit and half as thick (see Proctor’s “Familiar Essays”) would, to contain all the matter of our solar system equally distributed, have a density of only one four-hundred-thousandth that of hydrogen gas at atmospheric pressure,—that is to say, such a volume of the lightest substance we know of would make four hundred thousand solar systems like our own. This author inquires if such a mass could, under any circumstances, rotate as a whole, and adds, “Has it ever occurred, I often wonder, to those who glibly quote the nebular theory as originally propounded, to inquire how far some of the processes suggested by Laplace are in accordance with the now well-known laws of physics?” But the great primal difficulty is in the first assumption of the theory, which is not only entirely gratuitous, but physically impossible. It is that this great plasma of nebulous material—in the case of our own solar system not less than six thousand million miles in diameter—should have in someway become aggregated into a homogeneous mass of the requisite tenuity, complete and perfect, and ready for the succeeding stages of the process, in which, however, the law of gravity has hitherto had no active operation whatever; for, if gravitation existed and operated therein, such homogeneous mass could never have been formed, nor ever existed even if formed. The very forces which alone could have brought this vast mass together must have been the identical forces which afterwards broke it up into the sun and planets, and the operation of the same force must have prevented its original formation at all. According to the theory, it was like a horse-race, in which all the participants stood silent and motionless until the judge cried, “Go!” But the judge was the great creative force itself, and if the fiat reached to this extent, the same power could just as readily—nay, far more readily—have shot the sun and planets forth into rotation, as children scatter dough-balls, instead of holding in abeyance the control of universal law so as to (as a humorous writer speaks of the operations of a child in his investigation of a watch) “see the wheels go round.” This is not nature’s plan, so far as human knowledge goes. Of course these masses gathering to this great nebulous center, if acted upon by gravitation, would have at once condensed around the center as a nucleus, and if rotation ever commenced, it must have commenced then, millions of years, doubtless, before the outlying masses had even got within hailing distance. When masses of people assemble at a camp-meeting, the first comers take the best places, and the late arrivals have to circulate around in the woods; they do not all gather in a circle and then make a grand rush. That would be fair, perhaps, but it is not nature. And this, unquestionably, is how, if ever formed at all, these nebulæ must have formed into systems.