CELESTIAL WORLDS.

Woodville Examiner, Volume XXXVI, Issue 5516, 24 October 1919, Page 4 (Supplement)

CELESTIAL WORLDS.

(By “Luna.”) Another mysterious law governs the sun spots. Their number fluctuates from year to year; hut it would seem that the epochs of. maximum sun-spots succeed each other with a certain degree of regularity. The observations of sun-spots for nearly three centuries show that the recurrence of a maximum takes place, on an average, every eleven years. The course cf f ae of these cycles is somewhat as follows:—For two or three years the sun-spots are both lai’ger and more numerous than on the average; then they begin to diminish, until in about five or six years from the maximum they reach a minimum: then the spots begin to increase, and in another five or six years the maximum is once more attained. The cause of this periodicity is a question of the most profound interest, but at present the answer must be regarded as unknown. It has, indeed, to be admitted that the real nature of sunspots is still a matter of uncertainty. No theory yet proposed will account in a thoroughly satisfactory manner for “all” the phenomena which they present, when viewed with the telescope and the spectroscope, as well as for their peculiar distribution over the sun, and the marvellous phenomena of periodicity. When the atmosphere will allow of a very good vision, we can see that the sun’s surface is mottled in a remarkable manner. A very remarkable granulated appearance is often presented by the sun. Indeed, photographs have been taken in which these brilliant granules seem disposed to arrange themselves in patterns of marvellous regularity. It would thus appear as if the luminous surface of the sun was composed of intensely bright clouds suspended in a darker atmosphere. Some observers have thought that these floating objects are, occasionally at all events, of a characteristic size and shape, variously known as “willow leaves” or “rice grains.” Near the edge are ortea seen some of those brighter streaks or patches which are called faculae (little torches). They are often of enormous dimensions, covering areas vastly larger than any of our continents.

The margin of the sun is fringed with objects of very great interest. They are so faint that in the full blaze of sunlight they cannot be seen, except wit:, the spectroscope. They are invisible for the same reason that stars are invisible in daylight. We see the stars at night when the sun is gone, and so we can see the fringe surrounding the sun when the brilliant central portion is obscured by the rare occurrence of a total eclipse. For an eclipse of the sun to occur, the moon must actually come between the earth and the sun. The recurrence of an eclipse will be more fully considered later on. The few minutes during which a total eclipse lasts are of the most priceless value to the astronomer. Darkness reigns over the earth, and in that darkness rare and beautiful sights can be witnessed.

During a total eclipse, we see some of those remarkable prominences which project from the surface of the s. n. . Objects of this character surround the sun at other times also, but their light is so faint that he great light of the sun renders them invisible. With the obscurity which currounds the sun during a total eclipse as a background, the phenomena starts into brilliancy. It has been demonstrated that these very curious objects are, as their appearance indicates, really mighty glowing masses of gas; and a most beautiful arrangement has been discovered by which it has been possible to view the prominences without waiting for the aid of an eclipse. Suffice it now to observe that the principle of the method depends upon the peculiarity of the light from the prominences, which the spectroscope enables us to isolate from the glare produced by the ordinary solar rays. We will explain more of this method in a later article. The prominences appear to be merely protuberant portions of a layer of red incandescent gas surrounding the sun. This gas has been shown to consist of hydrogen and probably other substances. Majestic indeed are the proportions of some of those mighty flames which leap from the surface of the sun; yet those flames flicker as do our terrestrial flames, when we allow them time comparable to their gigantic dimensions. Drawings of the same prominence often show great changes in a few hours, or even less. The magnitude of the changes could not be less than many thousands, and the actual velocity with which such masses move is often not less than 100 miles per second. Still more violent are the solar convulsions which some observers have been so fortunate as to behold, when from the sun’s surface, as from a mighty furnace, vast -incandescent masses are projected upwards. All indications point to the surface of the sun as the seat of the most frightful storms and tempests, in which the winds sweep along incandescent vapours. The remarkable power which the spectroscope places at our disposal of enabling the prominences to be seen without a total eclipse has been largely availed of in making drawings of these objects. These drawings show the red colour of the flame-like objects, not very happily described as prominences; and they also show, in the different pictures, the wondrous variety of aspect which these objects assume. The dimensions of the prominences vary; it is not unusual to view them of 80,000 to 100,000 miles in height. Muclv larger ones have been observed, but these are abnormal. These objects change rapidly. One observer recorded a mighty flame which rose to a height ten times as great as tue diameter of the earth in an interval no greater than twenty minutes. Drawings have also shown various instances of the remarkable spike-like prominences. These spikes usually attain altitudes not greater than 20,000 miles, but sometimes they stretch up to stupendous distances. We may quote one special object of this kind, whose remarkable history has been chronicled by Professor Young, who observed a prominence on the south-east limb (or eighth) of the sun. It was then an object of no unusual appearance, being about 40,000 miles high; but half an hour witnessed a wonderful transformation. During this brief interval the prominence became very brilliant, and doubled its length. For another half an hour the mighty flame still soared upwards until it attained the unprecedented elevation of 350,000 miles —a distance more than ons-third of the diameter of the sun. Here the energy of the mighty outbreak seems to have expended itself; the flame broke up into filaments, and, within two hours from the time w r hen it was first noticed, the huge prominence

had completely faded away. The velocity must have been 200,000 miles an hour—a rate which must have averaged nearly fifty miles a second. Tne facts we have recorded give a surprising indication of the violence of those fiery storms, by which the surface of the sun is occasionally disturbed. In all directions the sun pours, forth, with the most prodigal liberality, its torrents of light and heat. The greater part of tnat light and heat seems wasted in the depths ot space. Our ea.-ui intercepts only the merest fraction, less than the 2,000,000,000 th part of the whole. Our fellow planets and the moon also intercept a trifle; but what portion of the mighty flood can they utilise? Were the radiation of the sun to be intercepted all life on this earth must cease An immovable atmosphere would brood over the frozen ocean, and the silence of death over the surface of the earth would only be broken by the occasional groans of a volcano. Let us terminate this column by a brief recital of what we at present enjoy by the benign influence of the sun. His gracious beams supply the magic power that enables our corn to grow and ripen. It is the heat of the sun which r'-ises water from the ocean in the form of vapour and then sends down that vapour as rain to refresh the earth. It is the heat of the sun beating on the large continents which gives rise to the breezes and winds that waft our vessels across the deep; and when, in winter, we enjoy the invigorating rays of the fire, we are really only enjoying sunbeams which shone on the earth countless ages ago. The heat in those ancient sunbeams developed the vegetation of the coal epoch, and in the form of coal that heat has slumbered for millions of years, till we now call it again into activity. Therefore, thepporerw r er of the sun really urges on our steam engines, and gives light stored up in coal beams from our gas lights. For our power to live and move, and for tne plenty with which we are surrounded, for the beauty with which nature is adorned, we are immediately indebted to one body, and that body is the sun.