Astronomy for Amateurs

space. [Pg 20] Fig. 2.—The earth in space. June solstice, midday. Since the Sun can only illuminate one side of our globe at one moment, that is to say one hemisphere, it follows that Night is nothing but the state of the part that is not illuminated. As the Earth revolves upon itself, all the parts successively exposed to the Sun are in the day, while the parts situated opposite to the Sun, in the cone of shadow produced by the Earth itself, are in night. But whether it be noon or midnight, the stars always occupy the same position in[Pg 21] the Heavens, even when, dazzled by the ardent light of the orb of day, we can no longer see them; and when we are plunged into the darkness of the night, the god Phœbus still continues to pour his beneficent rays upon the countries turned toward him. The sequence of day and night is a phenomenon belonging, properly speaking, to the Earth, in which the rest of the Universe does not participate. The same occurs for every world that is illuminated by a sun, and endowed with a rotary movement. In absolute space, there is no succession of nights and days. Upheld in space by forces that will be explained at a later point, our planet glides in the open heavens round our Sun. Imagine a magnificent aerostat, lightly and rapidly cleaving space. Surround it with eight little balloons of different sizes, the smallest like those sold on the streets for children to play with, the larger, such as are distributed for a bonus in large stores. Imagine this group sailing through the air, and you have the system of our worlds in miniature. Still, this is only an image, a comparison. The balloons are held up by the atmosphere, in which they float at equilibrium. The Earth is sustained by nothing material. What maintains her in equilibrium is the ethereal void; an immaterial force; gravitation. The[Pg 22] Sun attracts her, and if she did not revolve, she would drop into him; but rotating round him, at a speed of 107,000 kilometers[2] (about 66,000 miles) per hour, she produces a centrifugal force, like that of a stone in a sling, that is precisely equivalent, and of contrary sign, to its gravitation toward the central orb, and these two equilibrated forces keep her at the same medium distance. This solar and planetary group does not exist solitary in the immense void that extends indefinitely around us. As we said above, each star that we admire in the depths of the sky, and to which we lift up our eyes and thoughts during the charmed hours of the night, is another sun burning with its own light, the chief of a more or less numerous family, such as are multiplied through all space to infinity. Notwithstanding the immense distances between the sun-stars, Space is so vast, and the number of these so great, that by an effect of perspective due solely to the distance, appearances would lead us to believe that the stars were touching. And under certain telescopic aspects, and in some of the astral photographs, they really do appear to be contiguous. The Universe is infinite. Space is limitless. If[Pg 23] our love for the Heavens should incite in us the impulse, and provide us with the means of undertaking a journey directed to the ends of Heaven as its goal, we should be astonished, on arriving at the confines of the Milky Way, to see the grandiose and phenomenal spectacle of a new Universe unfold before our dazzled eyes; and if in our mad career we crossed this new archipelago of worlds to seek the barriers of Heaven beyond them, we should still find universe eternally succeeding to universe before us. Millions of suns roll on in the immensities of Space. Everywhere, on all sides, Creation renews itself in an infinite variety. According to all the probabilities, universal life is distributed there as well as here, and has sown the germ of intelligence upon those distant worlds that we divine in the vicinity of the innumerable suns that plow the ether, for everything upon the Earth tends to show that Life is the goal of Nature. Burning foci, inextinguishable sources of warmth and light, these various, multi-colored suns shed their rays upon the worlds that belong to them and which they fertilize. Our globe is no exception in the Universe. As we have seen, it is one of the celestial orbs, nourished, warmed, lighted, quickened by the Sun, which in its turn again is but a star. [Pg 24] Innumerable Worlds! We dream of them. Who can say that their unknown inhabitants do not think of us in their turn, and that Space may not be traversed by waves of thought, as it is by the vibrations of light and universal gravitation? May not an immense solidarity, hardly guessed at by our imperfect senses, exist between the Celestial Humanities, our Earth being only a modest planet. Let us meditate on this Infinity! Let us lose no opportunity of employing the best of our hours, those of the silence and peace of the bewitching nights, in contemplating, admiring, spelling out the words of the Great Book of the Heavens. Let our freed souls fly swift and rapt toward those marvelous countries where indescribable joys are prepared for us, and let us do homage to the first and most splendid of the sciences, to Astronomy, which diffuses the light of Truth within us. To poetical souls, the contemplation of the Heavens carries thought away to higher regions than it attains in any other meditation. Who does not remember the beautiful lines of Victor Hugo in the Orientales? Who has not heard or read them? The poem is called "Ecstasy," and it is a fitting title. The words are sometimes set to music, and the melody seems to complete their pure beauty: [Pg 25] J'étais seul près des flots par une nuit d'étoiles. Pas un nuage aux cieux, sur les mers pas de voiles; Mes yeux plongeaient plus loin que le monde réel, Et les bois et les monts et toute la nature Semblaient interroger, dans un confus murmure, Les flots des mers, les feux du ciel. Et les étoiles d'or, légions infinies, A voix haute, à voix basse, avec mille harmonies Disaient, en inclinant leurs couronnes de feu; Et les flots bleus, que rien ne gouverne et n'arrête, Disaient en recourbant l'écume de leur crête: ... C'est le Seigneur, le Seigneur Dieu! Note: Free Translation I was alone on the waves, on a starry night, Not a cloud in the sky, not a sail in sight, My eyes pierced beyond the natural world... And the woods, and the hills, and the voice of Nature Seemed to question in a confused murmur, The waves of the Sea, and Heaven's fires. And the golden stars in infinite legion, Sang loudly, and softly, in glad recognition, Inclining their crowns of fire;... And the waves that naught can check nor arrest Sang, bowing the foam of their haughty crest... Behold the Lord God—Jehovah! [Pg 26] The immortal poet of France was an astronomer. The author more than once had the honor of conversing with him on the problems of the starry sky—and reflected that astronomers might well be poets. It is indeed difficult to resist a sense of profound emotion before the abysses of infinite Space, when we behold the innumerable multitude of worlds suspended above our heads. We feel in this solitary contemplation of the Heavens that there is more in the Universe than tangible and visible matter: that there are forces, laws, destinies. Our ants' brains may know themselves microscopic, and yet recognize that there is something greater than the Earth, the Heavens;—more absolute than the Visible, the Invisible;—beyond the more or less vulgar affairs of life, the sense of the True, the Good, the Beautiful. We feel that an immense mystery broods over Nature,—over Being, over created things. And it is here again that Astronomy surpasses all the other sciences, that it becomes our sovereign teacher, that it is the pharos of modern philosophy. O Night, mysterious, sublime, and infinite! withdrawing from our eyes the veil spread above us by the light of day, giving back transparency to the Heavens, showing us the prodigious reality, the shining casket of the celestial diamonds, the innumerable stars that succeed each other interminably in immeasurable space![Pg 27] Without Night we should know nothing. Without it our eyes would never have divined the sidereal population, our intellects would never have pierced the harmony of the Heavens, and we should have remained the blind, deaf parasites of a world isolated from the rest of the universe. O Sacred Night! If on the one hand it rests upon the heights of Truth beyond the day's illusions, on the other its invisible urns pour down a silent and tranquil peace, a penetrating calm, upon our souls that weary of Life's fever. It makes us forget the struggles, perfidies, intrigues, the miseries of the hours of toil and noisy activity, all the conventionalities of civilization. Its domain is that of rest and dreams. We love it for its peace and calm tranquillity. We love it because it is true. We love it because it places us in communication with the other worlds, because it gives us the presage of Life, Universal and Eternal, because it brings us Hope, because it proclaims us citizens of Heaven. [Pg 28]