Mechanical Astronomy: A Route to the Ancient Discovery of Epicycles and Eccentrics

Document Type

Book Chapter

Publication Date


Publication Title

From Alexandria, through Baghdad: surveys and studies in the Ancient Greek and Medieval Islamic mathematical sciences in honor of J.L. Berggren




The ancient Greek art of spbairopoiia was devoted to the building of models of the universe such as celestial globes and annillary spheres. But it also included the construction of geared mechanisms that replicated the motions of the Sun, Moon, and planets, such as the famous orrery that Cicero attributed to Archimedes or the spectacular Antikythera mechanism, found in an ancient shipwreck of about 60 BC. Was sphairopoiia merely an imitative art, in which the modelers followed the precepts of the theoretical astronomers? Or could theoretical astronomy also learn something from the art of mechanics? In this paper, we examine the relation of astronomy to mechanics in the ancient Greek world, and argue that we should imagine astronomy and mechanics in conversation with one another, rather than in a simple, one-way transmission of influence.