Astronomy From Constellations to Atoms

ASTRONOMY FROM CONSTELLATIONS TO ATOMS FRANK ALLEN "HE stretcheth out the north over empty space and hangeth the earth upon nothing." Thus eloquently the Patriarch J ob uttered his lofty panegyric on the works of the Almigh ty; and in one brief but majestic sentence, breathing limitless power ·and mystery, he comprehended the most significant astronomical knowledge of antiquity. The challenge of the stars has been answered with increasing insight and resourcefulness in a logical succession of four general eras of developing knowledge. Earliest of all came the pictorial or statical age, in which the singular idea of partitioning the sky in to fanciful constellations was boldly conceived and partly executed. The second, or kinematical, era embraced the rise, domination, and fall of the Ptolemaic system of the heavens and the Copernican restoration of the primitive heliocentric theory, and culminated in the discovery of the laws of planetary orbits. In the third, or dynamical, era, universal gravitation was established as the basic force of nature, and the consequences of its action were ' mathematically elucidated. The fourth and present era of physical astronomy has among its subjects of inquiry the composition, structure, and developmen t of the heavenly bodies and their relation to space. Each era has had a fairly definite epoch for its beginning, but the overlapping ages, except the first, have yet no periods to mark their close. I In the northern highlands of Asia Minor astronomy probably had its birth. At the inception of the pic'torial S6 ASTRONOMY FROM CONSTELLATIONS TO ATOMS , 'era, when, between four and five thousand years ago, the visible portion of the sky .was fancifully divided into constellations to depict the most memorable even ts in the earliest history of the race, only those stars were included which shone above the horizon in ,lati tudes five hundred miles north of Babylon. Perhaps, in the high antiquity of that pictorial age, the Akkadian shepherds in their mountain pastures thus splendidly relieved the watchful tedium of the night, and ' later brought ' their unique fancies wi th them, when in search of a softer climate and a more luxurious home they descended into the languorous plains of Mesopotamia. Of the forty-eight constellations earliest delineated, as the late Mr. Maunder of the Greenwich Observatory has noted, no less than fourteen are directly, and eight are indirectly, ,representative of incidents recorded in the first ten chapters of Genesis. The remainder depict events of which even the tradition has perished. The Serpent, Hydra, of Eden, winds its sinuous form along the celestial equator of that period for nearly onethird of its course. To emphasize the significance of its 'origin, another Serpent lies partly along the equator and then perpendicularly rears its front precisely to the zenith along the autumna.\ equinox; while the Man, the Serpentcholder, presses one foot On the head of the Scorpion which curves its venomous tail. to sting his other heel. With evident design, this bold constellation is situated so that the foot upon the Scorpion occupied the important triple point where, at that remote time, the celestial equator, the ecliptic, and the autumnal equinox in tersected. , Close by is Hercules, Or the Kneeler, as he was simply and most anciently called, with one foot on the great Northern Dragon. "1 will put enmity between thee and the woman," 57 THE UNIVERSITY OF TORONTO QUARTERLY was the condemnation of the serpent} "and between thy seed and her seed; it shall bruis~ thy head and thou shalt bruise his heel.') This great primeval prophecy, which aptly epitolnizes in the history of mankind, the aeanlc struggle of the forces of elevation against those of debasement , never more menacing than to-day, thus receives a . twofold representation in the resplendent pictures of the skies. Other striking events are simila~'ly commemorated. Near the Mountain lies the Ship, with the messenger Raven not far distan t. The bow in the cloud was the· past-dihivial token 9£ divine reconciliation; and in the cloud of smoke, the Milky Way) ascending from. the Altar of sacrifice, glitters the covenan,t Bow of Sagittarius. The most brilliant of all constellations, known to Job as the Foo! or the Impious One, bu t...