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 runitself 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 thispresentation 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 successivechanges 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,convergingin 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 thelarger 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 theslightest 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, atleast, 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 thevis 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 atatmospheric 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.The fact that the orbital planes of very many of these asteroids are greatly inclined to the common planetary plane, and still more greatly inclined to one another, points almost unerringly to the existence during their stage of formation of some powerful force either of internal repulsion or external attraction. That no sufficiently large body could have been present to exercise such attraction so far outside the general planetary plane is self-evident, andif there had been such source of attraction, while the orbital planes of the asteroids might have been deflected from the common plane, they could not have been forced apart so as to differ largely among themselves. Certainly nothing pertaining to the nebular hypothesis could have produced any such effects under any conceivable circumstances, and especially at so late a period of its progress, after all the principal planets had been completed. The only alternative is self-repulsion, and this could only have been due to the causes and their mode of operation already described in this work. In a modified degree these planes exhibit the same irregular orbital deflections as are so conspicuously visible in the orbits of comets, and they must have been unquestionably produced in the same manner. The barren bands or stripes in the area occupied by these asteroids, like the dark or vacant rings of the planet Saturn, may have been largely affected by the perturbing attraction of the neighboring planet Jupiter; but certainly no influence of that great planet (himself in the common planetary plane) could have operated to cast these forming planetoids into planes of diverse inclinations among themselves or to that of his own. On the contrary, his whole force must have been exerted to bring them into the closest harmony with his own orbital movements.Omitting discussion of the technical difficulties in the application of the nebular theory to demonstrated facts, which may be found in the books, we may again repeat that this theory is not essential toaccount for the heat of the sun, which finds its real source elsewhere, while, nevertheless, the theory in itself is not incompatible with the views which we have endeavored to present and demonstrate. Certain phenomena, however, have been considered in prior quotations in this work which may aid us to roughly indicate the successive processes by which the evolution of solar systems and galaxies may be explained on another basis which requires no violent assumptions to be made and no suspension of any of nature’s universal laws. The same operations which we see around us at the present time in our own system, if extended to the dimensions of a nebular aggregation, would probably present the same phenomena as those we find partially disclosed in the gaseous nebulæ, particularly the spiral, and these would naturally determine the final production of solar systems such as our own. The gaseous nebulæ, not spiral, and the mixed nebulæ also, would fall into their appropriate categories in the same general plan, and a consistent mode of formation would be presented from the beginning to the end of the different processes.Spiral nebulæ, reduced from Nichol, after drawings of Lord Rosse. Fig. 1 is from Plate XV., Fig. 2 from Plate XII., and Fig. 3 from frontispiece of Nichol’s “Architecture of the Heavens;” Fig. 4 is from same work, showing a similar development, from a spiral nebula, of a solar system with a double star for its central sun.It should be observed that the spiral required by Laplace’s nebular theory is essentially a centripetal spiral. The spiral nebulæ we see in the heavens, however, arecentrifugalspirals. This is clearly shown in Plates XV., XII., and the frontispiece of Nichol’s “Architecture of the Heavens,” as well as in Plates XIII. and XIV. Plate XV.—the open spiral—is directly contradictory of any phenomena which could occur in accordance with the nebulartheory of Laplace. The frontispiece shows the only form which such a nebula could assume at any stage of its career,—that is, a close spiral with nearly circular convolutions. But while this particular form is not only in entire accordance with the hypothesis which we are about to suggest,being in fact one of the later and necessary stages in its progress, any such spiral as that shown in Plate XV. is utterly out of the question in the application of the nebular theory of Laplace or in any of the more recent modifications thereof.The only hypothesis by which the various phenomena can be adequately explained must almost certainly be based upon the combined action of gravitation and electrospheric repulsion. We find in the corona of our own sun such phenomena manifested in the most striking degree, even in a completed system, and we can well understand that during the early stages of systemic development such phenomena would vastly transcend anything which we could now hope to observe around our own sun. We see this repulsion still more highly developed in the formation of the tails of comets. While these coronal rays are not visible to a distance of more, perhaps, than five million miles from the sun’s disk, we have seen that the tail of Newton’s comet was shot forth to a distance of ninety million miles in a few days, as it were in a moment, by the tremendous electrical repulsion of the solar electrosphere, and that this enormous tail, which, if composed of hydrogen gas alone (it was, of course, enormously more attenuated), would have contained a mass much more than equal to the weight of the sun, was swung around over an arc of one hundred and eighty degrees, giving a radial sweep of the tail over a distance of two hundred and eighty millions of miles in less than four days. And the tails of many other comets have largelytranscended in dimensions that of Newton, above cited. We have learned much of the laws which regulate the development of storms, cyclones, whirlwinds, water-spouts, and other vortical phenomena in the atmosphere of our own earth, and can readily apply these principles to phenomena of vastly greater magnitude. We know that the matter of comets’ tails is self-repulsive, as shown in multiple tails, as well as that it is repelled by an adjacent similarly electrified electrosphere,—that of the sun, for example,—as with pith-balls in the familiar class-room experiments; so that we can gather a very fair and complete idea of the processes of nature when dealing with such phenomena on a vastly more extended scale, in which our moments are measured by millions of years and our miles by the almost infinite distances of sidereal and nebular space.
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 runitself 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 thispresentation 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 successivechanges 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,convergingin 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 thelarger 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 theslightest 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, atleast, 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 thevis 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 atatmospheric 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.The fact that the orbital planes of very many of these asteroids are greatly inclined to the common planetary plane, and still more greatly inclined to one another, points almost unerringly to the existence during their stage of formation of some powerful force either of internal repulsion or external attraction. That no sufficiently large body could have been present to exercise such attraction so far outside the general planetary plane is self-evident, andif there had been such source of attraction, while the orbital planes of the asteroids might have been deflected from the common plane, they could not have been forced apart so as to differ largely among themselves. Certainly nothing pertaining to the nebular hypothesis could have produced any such effects under any conceivable circumstances, and especially at so late a period of its progress, after all the principal planets had been completed. The only alternative is self-repulsion, and this could only have been due to the causes and their mode of operation already described in this work. In a modified degree these planes exhibit the same irregular orbital deflections as are so conspicuously visible in the orbits of comets, and they must have been unquestionably produced in the same manner. The barren bands or stripes in the area occupied by these asteroids, like the dark or vacant rings of the planet Saturn, may have been largely affected by the perturbing attraction of the neighboring planet Jupiter; but certainly no influence of that great planet (himself in the common planetary plane) could have operated to cast these forming planetoids into planes of diverse inclinations among themselves or to that of his own. On the contrary, his whole force must have been exerted to bring them into the closest harmony with his own orbital movements.Omitting discussion of the technical difficulties in the application of the nebular theory to demonstrated facts, which may be found in the books, we may again repeat that this theory is not essential toaccount for the heat of the sun, which finds its real source elsewhere, while, nevertheless, the theory in itself is not incompatible with the views which we have endeavored to present and demonstrate. Certain phenomena, however, have been considered in prior quotations in this work which may aid us to roughly indicate the successive processes by which the evolution of solar systems and galaxies may be explained on another basis which requires no violent assumptions to be made and no suspension of any of nature’s universal laws. The same operations which we see around us at the present time in our own system, if extended to the dimensions of a nebular aggregation, would probably present the same phenomena as those we find partially disclosed in the gaseous nebulæ, particularly the spiral, and these would naturally determine the final production of solar systems such as our own. The gaseous nebulæ, not spiral, and the mixed nebulæ also, would fall into their appropriate categories in the same general plan, and a consistent mode of formation would be presented from the beginning to the end of the different processes.Spiral nebulæ, reduced from Nichol, after drawings of Lord Rosse. Fig. 1 is from Plate XV., Fig. 2 from Plate XII., and Fig. 3 from frontispiece of Nichol’s “Architecture of the Heavens;” Fig. 4 is from same work, showing a similar development, from a spiral nebula, of a solar system with a double star for its central sun.It should be observed that the spiral required by Laplace’s nebular theory is essentially a centripetal spiral. The spiral nebulæ we see in the heavens, however, arecentrifugalspirals. This is clearly shown in Plates XV., XII., and the frontispiece of Nichol’s “Architecture of the Heavens,” as well as in Plates XIII. and XIV. Plate XV.—the open spiral—is directly contradictory of any phenomena which could occur in accordance with the nebulartheory of Laplace. The frontispiece shows the only form which such a nebula could assume at any stage of its career,—that is, a close spiral with nearly circular convolutions. But while this particular form is not only in entire accordance with the hypothesis which we are about to suggest,being in fact one of the later and necessary stages in its progress, any such spiral as that shown in Plate XV. is utterly out of the question in the application of the nebular theory of Laplace or in any of the more recent modifications thereof.The only hypothesis by which the various phenomena can be adequately explained must almost certainly be based upon the combined action of gravitation and electrospheric repulsion. We find in the corona of our own sun such phenomena manifested in the most striking degree, even in a completed system, and we can well understand that during the early stages of systemic development such phenomena would vastly transcend anything which we could now hope to observe around our own sun. We see this repulsion still more highly developed in the formation of the tails of comets. While these coronal rays are not visible to a distance of more, perhaps, than five million miles from the sun’s disk, we have seen that the tail of Newton’s comet was shot forth to a distance of ninety million miles in a few days, as it were in a moment, by the tremendous electrical repulsion of the solar electrosphere, and that this enormous tail, which, if composed of hydrogen gas alone (it was, of course, enormously more attenuated), would have contained a mass much more than equal to the weight of the sun, was swung around over an arc of one hundred and eighty degrees, giving a radial sweep of the tail over a distance of two hundred and eighty millions of miles in less than four days. And the tails of many other comets have largelytranscended in dimensions that of Newton, above cited. We have learned much of the laws which regulate the development of storms, cyclones, whirlwinds, water-spouts, and other vortical phenomena in the atmosphere of our own earth, and can readily apply these principles to phenomena of vastly greater magnitude. We know that the matter of comets’ tails is self-repulsive, as shown in multiple tails, as well as that it is repelled by an adjacent similarly electrified electrosphere,—that of the sun, for example,—as with pith-balls in the familiar class-room experiments; so that we can gather a very fair and complete idea of the processes of nature when dealing with such phenomena on a vastly more extended scale, in which our moments are measured by millions of years and our miles by the almost infinite distances of sidereal and nebular space.
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.
“There sinks the nebulous star we call the Sun,If that hypothesis of theirs be sound.”—Tennyson.
“There sinks the nebulous star we call the Sun,If that hypothesis of theirs be sound.”—Tennyson.
“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 runitself 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 thispresentation 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 successivechanges 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,convergingin 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 thelarger 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 theslightest 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, atleast, 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 thevis 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 atatmospheric 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.The fact that the orbital planes of very many of these asteroids are greatly inclined to the common planetary plane, and still more greatly inclined to one another, points almost unerringly to the existence during their stage of formation of some powerful force either of internal repulsion or external attraction. That no sufficiently large body could have been present to exercise such attraction so far outside the general planetary plane is self-evident, andif there had been such source of attraction, while the orbital planes of the asteroids might have been deflected from the common plane, they could not have been forced apart so as to differ largely among themselves. Certainly nothing pertaining to the nebular hypothesis could have produced any such effects under any conceivable circumstances, and especially at so late a period of its progress, after all the principal planets had been completed. The only alternative is self-repulsion, and this could only have been due to the causes and their mode of operation already described in this work. In a modified degree these planes exhibit the same irregular orbital deflections as are so conspicuously visible in the orbits of comets, and they must have been unquestionably produced in the same manner. The barren bands or stripes in the area occupied by these asteroids, like the dark or vacant rings of the planet Saturn, may have been largely affected by the perturbing attraction of the neighboring planet Jupiter; but certainly no influence of that great planet (himself in the common planetary plane) could have operated to cast these forming planetoids into planes of diverse inclinations among themselves or to that of his own. On the contrary, his whole force must have been exerted to bring them into the closest harmony with his own orbital movements.Omitting discussion of the technical difficulties in the application of the nebular theory to demonstrated facts, which may be found in the books, we may again repeat that this theory is not essential toaccount for the heat of the sun, which finds its real source elsewhere, while, nevertheless, the theory in itself is not incompatible with the views which we have endeavored to present and demonstrate. Certain phenomena, however, have been considered in prior quotations in this work which may aid us to roughly indicate the successive processes by which the evolution of solar systems and galaxies may be explained on another basis which requires no violent assumptions to be made and no suspension of any of nature’s universal laws. The same operations which we see around us at the present time in our own system, if extended to the dimensions of a nebular aggregation, would probably present the same phenomena as those we find partially disclosed in the gaseous nebulæ, particularly the spiral, and these would naturally determine the final production of solar systems such as our own. The gaseous nebulæ, not spiral, and the mixed nebulæ also, would fall into their appropriate categories in the same general plan, and a consistent mode of formation would be presented from the beginning to the end of the different processes.Spiral nebulæ, reduced from Nichol, after drawings of Lord Rosse. Fig. 1 is from Plate XV., Fig. 2 from Plate XII., and Fig. 3 from frontispiece of Nichol’s “Architecture of the Heavens;” Fig. 4 is from same work, showing a similar development, from a spiral nebula, of a solar system with a double star for its central sun.It should be observed that the spiral required by Laplace’s nebular theory is essentially a centripetal spiral. The spiral nebulæ we see in the heavens, however, arecentrifugalspirals. This is clearly shown in Plates XV., XII., and the frontispiece of Nichol’s “Architecture of the Heavens,” as well as in Plates XIII. and XIV. Plate XV.—the open spiral—is directly contradictory of any phenomena which could occur in accordance with the nebulartheory of Laplace. The frontispiece shows the only form which such a nebula could assume at any stage of its career,—that is, a close spiral with nearly circular convolutions. But while this particular form is not only in entire accordance with the hypothesis which we are about to suggest,being in fact one of the later and necessary stages in its progress, any such spiral as that shown in Plate XV. is utterly out of the question in the application of the nebular theory of Laplace or in any of the more recent modifications thereof.The only hypothesis by which the various phenomena can be adequately explained must almost certainly be based upon the combined action of gravitation and electrospheric repulsion. We find in the corona of our own sun such phenomena manifested in the most striking degree, even in a completed system, and we can well understand that during the early stages of systemic development such phenomena would vastly transcend anything which we could now hope to observe around our own sun. We see this repulsion still more highly developed in the formation of the tails of comets. While these coronal rays are not visible to a distance of more, perhaps, than five million miles from the sun’s disk, we have seen that the tail of Newton’s comet was shot forth to a distance of ninety million miles in a few days, as it were in a moment, by the tremendous electrical repulsion of the solar electrosphere, and that this enormous tail, which, if composed of hydrogen gas alone (it was, of course, enormously more attenuated), would have contained a mass much more than equal to the weight of the sun, was swung around over an arc of one hundred and eighty degrees, giving a radial sweep of the tail over a distance of two hundred and eighty millions of miles in less than four days. And the tails of many other comets have largelytranscended in dimensions that of Newton, above cited. We have learned much of the laws which regulate the development of storms, cyclones, whirlwinds, water-spouts, and other vortical phenomena in the atmosphere of our own earth, and can readily apply these principles to phenomena of vastly greater magnitude. We know that the matter of comets’ tails is self-repulsive, as shown in multiple tails, as well as that it is repelled by an adjacent similarly electrified electrosphere,—that of the sun, for example,—as with pith-balls in the familiar class-room experiments; so that we can gather a very fair and complete idea of the processes of nature when dealing with such phenomena on a vastly more extended scale, in which our moments are measured by millions of years and our miles by the almost infinite distances of sidereal and nebular space.
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 runitself 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 thispresentation 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 successivechanges 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,convergingin 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 thelarger 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.
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 theslightest 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, atleast, 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 thevis 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 atatmospheric 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.
The fact that the orbital planes of very many of these asteroids are greatly inclined to the common planetary plane, and still more greatly inclined to one another, points almost unerringly to the existence during their stage of formation of some powerful force either of internal repulsion or external attraction. That no sufficiently large body could have been present to exercise such attraction so far outside the general planetary plane is self-evident, andif there had been such source of attraction, while the orbital planes of the asteroids might have been deflected from the common plane, they could not have been forced apart so as to differ largely among themselves. Certainly nothing pertaining to the nebular hypothesis could have produced any such effects under any conceivable circumstances, and especially at so late a period of its progress, after all the principal planets had been completed. The only alternative is self-repulsion, and this could only have been due to the causes and their mode of operation already described in this work. In a modified degree these planes exhibit the same irregular orbital deflections as are so conspicuously visible in the orbits of comets, and they must have been unquestionably produced in the same manner. The barren bands or stripes in the area occupied by these asteroids, like the dark or vacant rings of the planet Saturn, may have been largely affected by the perturbing attraction of the neighboring planet Jupiter; but certainly no influence of that great planet (himself in the common planetary plane) could have operated to cast these forming planetoids into planes of diverse inclinations among themselves or to that of his own. On the contrary, his whole force must have been exerted to bring them into the closest harmony with his own orbital movements.
Omitting discussion of the technical difficulties in the application of the nebular theory to demonstrated facts, which may be found in the books, we may again repeat that this theory is not essential toaccount for the heat of the sun, which finds its real source elsewhere, while, nevertheless, the theory in itself is not incompatible with the views which we have endeavored to present and demonstrate. Certain phenomena, however, have been considered in prior quotations in this work which may aid us to roughly indicate the successive processes by which the evolution of solar systems and galaxies may be explained on another basis which requires no violent assumptions to be made and no suspension of any of nature’s universal laws. The same operations which we see around us at the present time in our own system, if extended to the dimensions of a nebular aggregation, would probably present the same phenomena as those we find partially disclosed in the gaseous nebulæ, particularly the spiral, and these would naturally determine the final production of solar systems such as our own. The gaseous nebulæ, not spiral, and the mixed nebulæ also, would fall into their appropriate categories in the same general plan, and a consistent mode of formation would be presented from the beginning to the end of the different processes.
Spiral nebulæ, reduced from Nichol, after drawings of Lord Rosse. Fig. 1 is from Plate XV., Fig. 2 from Plate XII., and Fig. 3 from frontispiece of Nichol’s “Architecture of the Heavens;” Fig. 4 is from same work, showing a similar development, from a spiral nebula, of a solar system with a double star for its central sun.
Spiral nebulæ, reduced from Nichol, after drawings of Lord Rosse. Fig. 1 is from Plate XV., Fig. 2 from Plate XII., and Fig. 3 from frontispiece of Nichol’s “Architecture of the Heavens;” Fig. 4 is from same work, showing a similar development, from a spiral nebula, of a solar system with a double star for its central sun.
It should be observed that the spiral required by Laplace’s nebular theory is essentially a centripetal spiral. The spiral nebulæ we see in the heavens, however, arecentrifugalspirals. This is clearly shown in Plates XV., XII., and the frontispiece of Nichol’s “Architecture of the Heavens,” as well as in Plates XIII. and XIV. Plate XV.—the open spiral—is directly contradictory of any phenomena which could occur in accordance with the nebulartheory of Laplace. The frontispiece shows the only form which such a nebula could assume at any stage of its career,—that is, a close spiral with nearly circular convolutions. But while this particular form is not only in entire accordance with the hypothesis which we are about to suggest,being in fact one of the later and necessary stages in its progress, any such spiral as that shown in Plate XV. is utterly out of the question in the application of the nebular theory of Laplace or in any of the more recent modifications thereof.
The only hypothesis by which the various phenomena can be adequately explained must almost certainly be based upon the combined action of gravitation and electrospheric repulsion. We find in the corona of our own sun such phenomena manifested in the most striking degree, even in a completed system, and we can well understand that during the early stages of systemic development such phenomena would vastly transcend anything which we could now hope to observe around our own sun. We see this repulsion still more highly developed in the formation of the tails of comets. While these coronal rays are not visible to a distance of more, perhaps, than five million miles from the sun’s disk, we have seen that the tail of Newton’s comet was shot forth to a distance of ninety million miles in a few days, as it were in a moment, by the tremendous electrical repulsion of the solar electrosphere, and that this enormous tail, which, if composed of hydrogen gas alone (it was, of course, enormously more attenuated), would have contained a mass much more than equal to the weight of the sun, was swung around over an arc of one hundred and eighty degrees, giving a radial sweep of the tail over a distance of two hundred and eighty millions of miles in less than four days. And the tails of many other comets have largelytranscended in dimensions that of Newton, above cited. We have learned much of the laws which regulate the development of storms, cyclones, whirlwinds, water-spouts, and other vortical phenomena in the atmosphere of our own earth, and can readily apply these principles to phenomena of vastly greater magnitude. We know that the matter of comets’ tails is self-repulsive, as shown in multiple tails, as well as that it is repelled by an adjacent similarly electrified electrosphere,—that of the sun, for example,—as with pith-balls in the familiar class-room experiments; so that we can gather a very fair and complete idea of the processes of nature when dealing with such phenomena on a vastly more extended scale, in which our moments are measured by millions of years and our miles by the almost infinite distances of sidereal and nebular space.