LESSON VI.
THE STARRY HEAVENS.
“Sit, Jessica: Look how the floor of heavenIs thick inlaid with patines of bright gold;There’s not the smallest orb, which thou beholdest,But in his motion like an angel sings,Still quiring to the young-eyed cherubim.”
“Sit, Jessica: Look how the floor of heavenIs thick inlaid with patines of bright gold;There’s not the smallest orb, which thou beholdest,But in his motion like an angel sings,Still quiring to the young-eyed cherubim.”
“Sit, Jessica: Look how the floor of heavenIs thick inlaid with patines of bright gold;There’s not the smallest orb, which thou beholdest,But in his motion like an angel sings,Still quiring to the young-eyed cherubim.”
“Sit, Jessica: Look how the floor of heaven
Is thick inlaid with patines of bright gold;
There’s not the smallest orb, which thou beholdest,
But in his motion like an angel sings,
Still quiring to the young-eyed cherubim.”
—Merchant of Venice, Act 5.
The kitten plays with its tail, the lamb nibbles the grass, the chick scratches on the ground for a living, and none of them feel any curiosity about the reason of things around them. But the smallest child begins to ask questions, especially about the natural objects that surround it. It is notsatisfied with having water to drink; it wants to know from whence water comes. Fruit is good, but how do fruits grow? No doubt the first human beings felt this same curiosity, or rather desire for knowledge, the food of the mind. As soon as there was a man to observe natural objects, what they were, and how they came to be, were questions that early presented themselves to his attention, and afforded theme for the first legends and fables.
The wonders of the heavens were among the primary subjects of human thought. The rising and setting of the sun, and his splendid way through the sky; the milder beauty of the moon; the marshalled hosts of the stars aroused the admiration, interest, even worship, of the earliest representatives of our race. Men concluded that the heavenly bodies were gods or men, who for great deeds had been taken to shine in deathless glory in the skies. With enlarging ideas they understood that the stars are worlds, but they had no means of determining how large or how distant they might be. The first students of the skies thought that the earth was the largest of the heavenly bodies, and stood still, while the others moved. They considered also that the earth was flat, and that the skies above it were a vast hemispherical dome. Such notions are instinctive even at the present time.
How natural it is for us to believe that the earth is the lower half of the universe, and the skies the upper half! We speak as if the heavens and the earth were two separate creations. We are slow to recognize the fact that the earth is merely one little part of the heavens. The heavens are about us on every side. By the heavens we mean that partof space which seems to be star filled. In these heavens our world is as a globe suspended, and every star that we see is another globe suspended in space. Of these globes we can, with the unaided eye, see countless thousands; millions more are reached only by powerful telescopes; very likely myriads still exist which no glass is strong enough to bring into human sight.
In ancient times people fancied that the stars ruled the lives of men, and from them came good or evil influences, wars, famines, plagues. They foretold the events of years by the stars that showed highest and brightest, and cast the horoscopes of individuals by dividing the sky into “houses” or sections, and considering the appearances of these houses at the hour when a child was born. This pursuit was called astrology, and it extended to the study of comets, eclipses, and all the appearances of the skies. This astrology was an elaborate science, and one of the most ancient studies of men, and by degrees led the way to the present noble science of astronomy.
When we look at the skies they seem to be crowded with shining bodies sown thickly together without any particular order. Looking more carefully, we see that in parts of the sky the stars are thickly clustered, and that there seem to be empty spaces. We observe too that there are differences in the size, brightness, and color of the stars. Some stars are red, some white, some blue, some green or yellow: some shine with a clear, steady ray, some quiver, tremble, disappear, reappear.
During the day we cannot see the stars, because of thegreater brightness of the sunshine. When the moon is full and bright at night the stars seem dim, but on a cloudless, moonless night the stars are well displayed.
The early observers divided the stars into constellations, and traced upon the sky fanciful figures of chairs, dragons, sheep, crowns, bears, persons, each of these constellations having some few prominent stars and a number of smaller ones. While the outlines of these objects are entirely fanciful, the arrangement is of great use in helping us to find or describe stars.
Distant in the starry space are vast shining clouds, which were once supposed to be whirling masses of vapor or “star dust,” and received the name of nebulæ, or clouds. Better telescopes have revealed the true character of the nebulæ, and we find that they are thickly crowded stars, so immensely distant that their light mingles as one mass, and the spaces between them are not seen. It is also true that there are some nebulæ which are really “cloud-masses of glowing gas.”
Wandering among the stars are seen at times brilliant bodies with long trains or tails of glowing vapor. These are comets. Once their appearances caused great terror, as indicating disaster to the human race, and even now some persons are alarmed lest one of these sky wanderers should, in his frantic flight, run against our earth and dash the poor little globe to pieces! But these comets are not such vagrants as they seem. Law reigns in all the universe, and even comets are subject to it, and come and go on a distinct track. The motion of many comets has been determined, and their return into the range of our vision is accurately foretold. Thereare some comets which always remain in our own solar system; others come from the depths of space, pass about our sun, and dash away into infinite distance to return no more.
Various opinions are held as to the material of comets. Some consider that they are composed of myriads of small bodies like tiny meteors; others consider them made of gas. The head or nucleus is doubtless more solid than the tail, and it has been found that tails of comets differ in composition; they contain hydrogen, carbon, iron, chlorine, and other kinds of matter, such as we have in our world. The tails of comets always turnfromthe sun, and as the comet nears the sun in its circuit the tail expands; as it leaves the sun the tail decreases in size.
Some comets have no tails, some have several. It is supposed that the tails of comets diminish and finally disappear, from destruction of their expanded material by the sun’s heat as they repeatedly draw near to the centre of our system.
Some comets go and come in their orbits in three or four years, others roam for centuries before they sweep again into our range of sight.
As marvellous as the comets, are the temporary stars. Several instances are on record where stars have suddenly appeared where no star had been seen before. They shone for a time with splendor, then faded away. In November, 1572, a magnificent new star shone in the constellation of Cassiopeia. In eighteen months it vanished. During the seventeenth century “Kepler’s Star” appeared in the constellation of The Serpent Bearer, and surpassed all the fineststars near it in brightness. It gradually lessened, and in two years was lost to view.
Other wonders of the heavens are the variable stars. The light of these stars changes greatly. Week after week they brighten as the sun brightens from dawn to noon; then for an equal period they pale and fade, to revive in splendor and again to wane.
There are also stars that fix our attention by being binary or double. These are twin stars situated very close together, and revolving around each other. After the binary stars were discovered, it was found that there were also multiple stars; that is, three or four stars similarly situated in relation to each other, and circling about each other. These binary and multiple stars are usually of different colors, as a green and a red, an orange and a blue, or blue, green, orange, and red in a four-fold star.
Most of the stars are so very far from us that we cannot learn much about them. What we call our own solar system embraces our sun and a certain number of planets, which depend on our sun for heat and light, and constantly move about the sun in great and nearly circular paths. By means of telescopes and other instruments we are able to study our own sun and his system of dependent planets. When we examine distant stars they seem to us to be like our sun, and so we conclude that like him they may be centres of systems and have planets wheeling about them.
If there were such planets we could not see them, owing to the greatness of the distances. Planets are dark in themselves, as our world is, and shine only by reflected lightfrom their suns. These suns are the stars of the field of heaven. Suns are stationary with respect to their accompanying planets, but with respect to other systems it is probable that each system is in motion and moves about some distant centre, led by its sun along some path which no mind can calculate.
As we look upon the heavens we can consider that all these glowing bodies are moving on some majestic path through infinite space. The star Alcyone, in the Pleiades, has been conjectured by Mädler of Dorpat to be the centre of gravity, or central sun of all the known universe.[16]The Pleiades, often called “The Seven Stars,” are a grape-shaped cluster, of which six stars are large and beautiful, while many smaller ones appear like a soft, golden haze.
Ancient poets said that once there were seven Pleiads, but one wept itself out at the fall of the city of Troy. That is a pretty fancy; but if one of those so distant stars had gone out when Troy fell, its light might yet be shining for us, and certainly would have shone on Ovid, who told the tale. A poet has written truly:—
“Were a star quenched on high,For ages would its lightStill travelling downward through the sky,Fall on our mortal sight.”
“Were a star quenched on high,For ages would its lightStill travelling downward through the sky,Fall on our mortal sight.”
“Were a star quenched on high,For ages would its lightStill travelling downward through the sky,Fall on our mortal sight.”
“Were a star quenched on high,
For ages would its light
Still travelling downward through the sky,
Fall on our mortal sight.”
So vast are these star-distances that it takes hundreds of years for the light of a star to reach us, and yet light movesone hundred and eighty-six thousand miles a second! This is much faster than Puck, who could “put a girdle roundabout the earth in forty minutes!”
What an immensity is this about us! All that void amid the starry systems we call stellar or inter-stellar space. Lit by so many splendid suns, is it not then glowing with the light of high noon a million times multiplied? No. The higher we rise above the earth, the darker becomes the color of the sky, until it hangs like a pall of unspeakable blackness. Why is this? Why is light not light? Why this absolute darkness among so many, many suns? It is simply lack of dust! There must be something to throw back and scatter the rays of light before it can be visible. Unless far up in stellar space there is dust, star-dust, a whirl of motes or stones to seize and throw back the light, then all must be very dark. Here on our own little globe the glorious sunbeams lighten us, thanks to dust in our atmosphere. The sunshine reveals to us the dust, but the dust makes the sunshine visible. Sunbeams and dust, each one invisible without the other!
FOOTNOTES:[16]This, of course, is merely a conjecture, which it would need ages of observation to confirm.
[16]This, of course, is merely a conjecture, which it would need ages of observation to confirm.
[16]This, of course, is merely a conjecture, which it would need ages of observation to confirm.