Early Work on Periodic Motion

Abstract

RECURRENT events hold an interest for the human mind through their appeal to a sense of order; in no other type of phenomenon is the insistent suggestion of law in Nature of a necessity which even “compels the gods” felt so forcibly. Certainly, from the empiricist point of view much might be made of the existence in Nature of manifold periodic recurrences, and the recognition of large- and small–scale rhythms has certainly played an important part in the origins of science. Pythagoras discovered the numerical key to the periodicities of musical notes and thus the abstract idea of periodicity entered mathematics (though the origin of this idea may lie far back with the Akkadian writers of about 2000 B.C. studied by Neugebauer). By the fifth century B.C. even the non-mathematical Aristotle looked on periodicity as almost the one sure indication of necessity in natural events: the only events of which absolute necessity could be predicated were those which formed part of a recurrent series such as the orbits of the heavenly bodies.