Volume 2

Popular science / edited by Arthur Mee.

Date:
1912-1913
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Popular science / edited by Arthur Mee. Source: Wellcome Collection.

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    motion of the planets, the order and uni formity of which he discovered. But his philosophic ideas were other than ours, and the views which we have rejected were just and necessary to him. It is recorded of him that, being asked by his wife what he had been doing all the hours of “ star-gazing,” he replied that he had been “ thinking the thoughts of God after Him.” A noble reply, yet, as per chance we shall duly see, not noble enough. His theory of the Universe involved the belief that the fixed stars were where God had put them ; and that the planets, the order of whose movement he had dis covered, were impelled and maintained in their orbits by heavenly beings, the agents of God, whose “ thoughts ” their movement expressed. It is the one decisive, incomparable step for the human mind to deny Kepler’s explanation ; to exclude the activity of any form of will or intention o r caprice from our explana tion of any part or fact of the Uni verse, partly on the ground that these ex planations do not explain, partly be cause, as we are about to see, other ex planations are possible ; and, above all, because to confine Deity to any part or fact of things is to exclude Him from the rest. Such are the reasons why the substitution of Newton’s law of gravitation for Kepler’s theory of the motion of the planets is typical and representative, on a great and illustrious scale, of the age-long processes, everywhere illustrated, whereby superstition, with its small idea of God, yields to science, whose idea of Him can never be less than infinite. Men whose idea of the Universe was as mean as Galileo’s was great were offended at his blasphemy in descrying spots upon the majestic face of the sun. Men of a similar type were entirely indisposed to consider any additions to the number of the sun’s family, because the perfect number is seven, and such must be the number of the planets. Vet again, just as the sun must be spotless, and the number of his family the perfect number, so their movement round him (if, indeed, we are to admit that the planets, including the earth, do move round him, and not all things round the earth) must at least be itself perfect. Now, there is only one perfect figure on this theory of perfec tion, and that is the circle. Therefore, the planets, perfect in number, must move round the spotless face of their perfect sun, in the perfect figure of circles, and with perfectly constant speed. It is, perhaps, easy to ridicule such assumptions to-day, especially since most of those who ridicule would then have been found among the number of the ridiculous. We must remember that, with all this folly and idleness of mind, there was in some cases, at any rate, a sincere desire to glorify God, and that the indignation of such men against those who controverted their evidence o f perfection was in part sincere and admirable in spirit. J ust so is the present indignation of many religious people, now quite content to accept Kepler and N e w t o n , against the work of modern men who seek, say in the study of heredity, to think the thoughts of God after Him, even though they appear, in dull eyes—perhaps their own—to sap the foundations of moral responsibility. Let us learn for the present from the past. Now, if the planets move in circles round the sun, at constant speeds, there is no more to be said. The thing is so, because it is so ; and has no meaning. Nothing deeper, nothing wider, is involved. But we may find a deeper and wider perfection even than that of the perfect figure, if we look into the facts, and discover that the figures described by the planets are not perfect at all—in this very imperfect sense. John Kepler was born in 1571, a delicate baby, belonging, like Newton himself, to the number of those very weakly children whom certain later mathematicians would THE CHANGING PACE OF THE EARTH ROUND ITS ORBIT This diagram illustrates one of Kepler's laws. A line drawn from the sun to the earth takes the same time to pass over the area No. 1 as it does to pass over the equal area No. 2, the motion of the earth being swifter between a and b than between c and L>.