Page:Popular Science Monthly Volume 78.djvu/329

This page has been proofread, but needs to be validated.
319
THE GENESIS OF THE LAW OF GRAVITY

III. The system seemed adequate, was geocentric and appealed to the popular imagination.

Some of the more obvious criticisms of the system may be mentioned:

I. The ancients believed the sun to be larger than the earth—it would be more likely to be the center of the system.

II. The diurnal motion of the earth offered a simple explanation of the apparent motion of the heavens—the simple should prevail when opposed to the complex.

III. The Pythagorean system gave the same law of motion (the circle) to all the members of the system, while in the Ptolemaic system the moon and sun moved in circles and the rest in epicycles.

The cumbersome Ptolemaic system, having been adopted, became with the passage of time deeply rooted in the philosophy and religion of the race. Its complexity became greater and greater, for with more accurate observations came the necessity of adding "cycle on epicycle, orb on orb" to keep track of the required corrections. It is not surprising, therefore, to find Alphonso X., in the thirteenth century, when contemplating the system, exclaiming, "if the Deity had called him to His councils at the creation of the world, he could have given Him good advice." Indeed the system finally crumbled and fell from the very weight of its superstructure.

"We have spoken of the ravages of time and of war as hindering the progress of knowledge. We have now to note the greatest calamity that has in modern history overtaken the cause of human knowledge. In the third century before Christ, was founded the Alexandrian library with its treasures of art, of literature and of science collected from every part of the known world. Century by century it grew, and could it have survived what untold treasures would have been ours to-day! But in the seventh century a.d. the Caliph Omar in a day reduced to ashes this storehouse of wisdom, and by one act set the world back a thousand years. Perhaps this disaster can be overrated; perhaps, in the dissemination of copies of the old masters, the Alexandrian library had done its real work; but to me it seems otherwise; for many a priceless gem of literature and of science must have perished in the wanton Arab's destruction. As a single example, it is doubtless due to this cause that we have none of the astronomical writings of Hipparchus.

To Alphonso X., of Castile, belongs the honor of being the first European monarch to foster astronomy. In the thirteenth century he founded a college in Toledo, and gathered together savants from all parts of his realm. From the Arabs they acquired much both in mathematics and in astronomy. Original sources were also sought out in the Greek. Other schools were rapidly established and centers of