The Source and Mode of Solar Energy Throughout the Universe

by Isaac W. Heysinger

In Miller’s “Romance of Astronomy” we read, “Encke’s comet, which possesses the smallest orbit of any connected with our system, is sensibly drawing nearer and nearer to the sun at every revolution.” In Professor Proctor’s “Cometic Mysteries,” the author says, “We hear it stated that the nucleus of a comet is made up of meteoric stones (Professor P. G. Tait says—for unknown reasons—that they resemble ‘paving stones or even bricks’) as confidently as though the earth had at some time passed through the nucleus of a comet, and some of our streets were now paved with stones which had fallen to the earth on such an occasion. As a matter of fact, all that has yet been proved is that meteoric bodies follow in the track (which is very different from the tail) of some known comets, and that probably all comets are followed by trains of meteors. These may have come out of the head or nucleus in some way as yet unexplained; but it is by no means certain that they have done so, and it is by many astronomers regarded as more than doubtful. The most important point to be noticed in the behavior of large comets as they approach the sun is, that usually the side of the coma which lies towards the sun is the scene of intense disturbance. Streams of luminous matter seem to rise continually towards the sun, attaining a certain distance from the head, when, assuming a cloud-like appearance, they seem to form an envelope around the nucleus. This envelope gradually increases its distance from the sun, growing fainter and larger, while within it the process is repeated and a new envelope is formed. This, in turn, ascends from the nucleus, expanding as it does so, while within it a new envelope is formed. Meanwhile the first one formed has grown fainter, perhaps has disappeared. But sometimes the process goes on so rapidly (a day or two sufficing for the formation of a complete new envelope) that several envelopes will be seen at the same time,—the outermost faintest, the innermost most irregular in shape and most varied in brightness, while the envelope or envelopes between are the best developed and most regular. The matter raised up in these envelopes seems to have undergone a certain change of character, causing it no longer to obey the sun’s attractive influence, but to experience a strong repulsive action from him, whereby it is apparently swept away with great rapidity to form the tail. ‘It flows past the nucleus,’ says Dr. Huggins, ‘on all sides, still ever expanding and shooting backward until a tail is formed in the direction opposite to the sun. This tail is usually curved, though sometimes rays or extra tails sensibly straight are also seen.’ ”

In “The Sun as a Perpetual Machine,” Professor Proctor says, “Take, again, the phenomena of comets, which still remain among the greatest of nature’s mysteries. We have reason to believe … that the nucleus of a comet consists of an aggregation of stones similar to meteorites. Adopting this view, and assuming that these stones have absorbed somewhere gases to the amount of six times their volume (taken at atmospheric pressure), we may ask, What will be the effect of such a mass of stones advancing towards the sun at a velocity reaching in perihelion the prodigious rate of three hundred and sixty-six miles per second (as observed in the comet of 1843), being twenty-three times our orbital rate of motion?” Professor Ball says, “One of the most important results of the great shower of 1866 was the demonstration that the swarm of little bodies to which that shower owed its origin was connected with a comet. The swarm was found, in fact, to follow the exact track which the comet pursued around the sun …. Of this connection between the cometary orbits and revolving swarms of meteors many other instances could be cited. I may refer to the remarkable lists published by the British Association, in which, beside the name of the comet or the designation which astronomers had affixed to it, the meteoric swarm with which the comet is associated is also given …. On these grounds it appears to be perfectly certain that the origin of the shooting stars which appear in swarms cannot be disassociated from the origin of the comets by which those swarms are accompanied.” The author makes a distinction between such ordinary shooting stars and meteorites, and attributes the appearance of the latter on earth to masses thrown forth from some volcano somewhere, but this has nothing to do with the special phenomena to be interpreted. It may be said, however, that the presence of olefiant gas as one of the occluded gases in a meteorite (four and fifty-five-hundredths per cent., as stated by Professor Proctor, in his article “The Sun as a Perpetual Machine”), and the remarkable fact, stated in the article “Spectrum Analysis” in Appleton’s Cyclopædia, that, in Winnecke’s comet of 1868, “the bands agree in position with those obtained as the spectrum of carbon, by passing the electric spark through olefiant gas, “would lead one to consider a cometic origin, for this particular meteorite at least, to be highly probable. Professor Ball further says, “There have been several instances in which a comet has approached so close to a planet that the attraction between the two bodies must have had significant influence on the planet, if the cometary mass had been at all comparable with that of the more robust body. The most celebrated instance is presented in the case of Lexell’s comet, which happened to cross the track of Jupiter. The effect upon this body was so overwhelming that it was wrenched from its original path and started afresh along a wholly different track.” The same writer, speaking of the tails of comets, says, “I have no intention to discuss here the vexed question of the tails of comets. I do not now inquire whether the repulsion by which the tail is produced be due to the intense radiation from the sun, or to electricity, or to some other agent. It is sufficient for our present purpose to note that, even if the tails of comets do gravitate towards the sun, the attraction is obscured by a more powerful repulsive force …. Nor do the directions in which the comets move exhibit any conformity; some move round the sun in one direction, some move in the opposite direction. Even the planes which contain the orbits of the comets are totally different from each other. Instead of being inclined at only a very few degrees to their mean position, the planes of the comets hardly follow any common law; they are inclined at all sorts of directions. In no respect do the comets obey those principles which are necessary to prevent constitutional disorder in the planetary system …. Now, all we have hitherto seen with regard to comets tends to show that the masses of comets are extremely small. Attempts have been made to measure them, but have always failed, because the scales in which we have attempted to weigh them have been too coarse to weigh anything of the almost spiritual texture of a comet. It is unnecessary to go as far as some have done, and to say that the weight of a large comet may be only a few pounds or a few ounces. It might be more reasonable to suppose that the weight of a large comet was thousands of tons, though even thousands of tons would be far too small a weight to admit of being measured by the very coarse balance which is at our disposal.” In the chapter “Visitors from the Sky,” the same author says, “As such a comet in its progress across the heavens passes between us and the stars, those stars are often seen twinkling brilliantly right through the many thousand miles of cometary matter which their rays have to traverse. The lightest haze in our atmosphere would suffice to extinguish the faint gleam of these small stars; indeed, a few feet of mist would have more power of obstructing the stellar light than cometary material scores of thousands of miles thick. It is true that the central portions of many of these comets often exhibit much greater density than is found in the exterior regions; still, in the great majority of such objects there is no opacity, even in the densest part, sufficient to put out a star. In the case of the more splendid bodies of this description, it may be supposed that the matter is somewhat more densely aggregated as well as more voluminous; still, however, it will be remembered that the great comet of 1858 passed over Arcturus, and that the star was seen shining brilliantly, notwithstanding the interposition of a cometary curtain millions of miles in thickness. So far as I know, no case is known in which the nucleus of a really bright and great comet has been witnessed in the act of passage over a considerable star. It would indeed be extremely interesting to ascertain whether in such case the star experienced any considerable diminution in its lustre.”

CHAPTER VIII.

THE PHENOMENA OF COMETS.

From the extracts thus cited we may form a fairly clear idea of the phenomena which comets present, and these facts represent about all that we know of these mysterious objects. They approach the sun in a nearly radial direction, thus cutting the planetary orbits transversely. They approach the sun from all directions and at all angles, without reference to the common plane in which all the planetary orbits lie. They have no rotation on their own axes, as the planets have, but, like an aggregated mass of meteorites or cosmical dust, rush inward from the exterior realms of space, so that their course is diametrically opposite that of the planets and the other cosmical bodies which constitute our solar system. Such a body as a comet, in fact, would present in its approach to our solar system very much the phenomena of an approaching exterior sun, corresponding far more closely in appearance and behavior to our own sun than to any of the planets. Such a body could not generate positive electricity, as the planets do, but, on the contrary, must have an electrosphere of negative, or at least neutral, polarity. On its approach to our planetary system the batteries of all the planets would be at once turned upon the intruder, and it would be rapidly thrown into the same state of active electrical polarity as the sun. The aqueous vapor condensed around its nucleus by gravity in its approach through space, or buried among the meteoric particles constituting the comet, would be necessarily decomposed into its constituent gases, just as in the case of the sun, by the positive electrical currents from the planetary electrospheres, and the disassociated hydrogen would form the negative electrosphere of the comet, glowing with its own luminosity, by gaseous incandescence. “We should then observe, during its continued approach to the sun, phenomena similar to those which we might expect to manifest themselves during the approach of a minute solar body towards the sun, characterized by a rapid increase of velocity, due to attraction of gravity, and tremendous mutual repulsion between the solar and cometic electrospheres. We should see the luminous hydrogen and associated gases boiling upward, and thence drawn forward from the nucleus by the combined gravity of the sun’s mass, that of the planetary masses, and the opposite polarity of the planetary electrospheres, while they would be, at the same time, repelled backward by the enormous repulsive force of the negative electrosphere of the sun. As a result, we should find these gases in a state of ebullition, forced forward under great excitement and disturbance, boiling, eddying about, driven to and fro in all directions until the sun’s repulsive force had overcome the different attractions, when these luminous clouds or envelopes would be swept swiftly off to the rear, as by a powerful current of wind, around the margins of the nucleus, and they would be seen to stream backward from the sun as an elongated envelope or tail. New volumes of gas would pour to the front, attracted from deeper depths, and these, on reaching the cometary electrosphere, would be again repelled by the solar activity and driven to the rear, while the gases thus driven backward, themselves similarly electrified, would mutually repel each other as they streamed backward around the margins of the nucleus.

Repulsion of glow in partial vacuum compared with phenomena of sun and comet.—C, charged electrical conductor; A, electrical discharge in partial vacuum, repelled by like electricity of C; B, Henry’s comet, C representing the sun.

Let us now see what these gases are: if they are such as appear in the sun’s electrosphere, we will know that such must be their action; if, on the contrary, they are such as appear in planetary electrospheres, we will find any such attempted explanation to be a failure. Quoting largely from Dr. Huggins, Professor Proctor, in his “Cometic Mysteries,” says, “The spectrum of the brightest comet of that year was partly continuous, and on this continuous spectrum many of the well-known Fraunhofer lines could be traced. This made it certain that part of the comet’s light was reflected sunlight, though Dr. Huggins considers also that a part of the continuous spectrum of every comet is due to inherent light. On this point some doubt may be permitted. It is one thing for special bands to show themselves, for some substances may become self-luminous under special conditions at very moderate temperatures; it is quite another thing that the solid parts of a comet’s substance should become incandescent. I venture to express my opinion that this can scarcely happen, except in the case of comets which approach very near to the sun. Besides the continuous spectrum with dark lines, the photograph showed also a spectrum of bright lines. ‘These lines,’ says Dr. Huggins, ‘possessed extreme interest, for there was certainly contained within this hieroglyphic writing some new information. A discussion of the position of these new lines showed them to be undoubtedly the same lines which appear in certain compounds of carbon. Not long before Professors Liveing and Dewar had found from their laboratory experiments that these lines are only present when nitrogen is also present, and that they indicate a nitrogen compound of carbon,—namely, cyanogen. Two other bright groups were also seen in the photograph, confirming the presence of hydrogen,—carbon and nitrogen.’ It is worthy of notice that only a few days later Dr. H. Draper succeeded in obtaining a photograph of the same comet’s spectrum. It appeared to him to confirm Dr. Huggins’s statements, except only that the dark Fraunhofer lines were not visible, the photograph having probably been taken under less favorable conditions …. But the latest comet has brought with it fresh news. Its spectrum is not like that given by the comets we are considering. The bright lines of sodium are seen in it, and also other bright lines and groups of lines which have not yet been shown to be identical with any belonging to the hydrocarbon groups, but probably are so …. The cyanogen groups are not seen …. But it is manifest that this comet underwent important changes…. In April was found simply a faint continuous spectrum; in May the three bands associated with carbon were present, though faint, while there was no trace whatever of the sodium band. On the contrary, in June the nucleus of the comet gave a very strong and extended continuous spectrum with an excessively strong bright line in the orange-yellow identical with the well-known double sodium line of the solar spectrum. On this … it is necessary to conclude that during the last fortnight of May the spectrum of Wells’s comet had changed in a manner of which the history of science furnishes no precedent.”

It should be observed that the elements carbon and hydrogen closely resemble each other, not only in their multifarious chemical affinities and reactions, but in their electric polarities, and the hydrocarbon compounds, like their constituents, carbon and hydrogen, are electrically similar to each other, an example of this similarity of the elements being found in the identical action of the carbon arc and hydrogen envelope in the heating and lighting experiments with electrical currents hereinbefore described.