The Antikythera Mechanism
John H. Seiradakis
Aristotle University of Thessaloniki, Department of Physics, Laboratory of Astronomy
The Antikythera Mechanism was found by chance, in a shipwreck, close to the small Greek island of Antikythera (between Crete and Peloponnese) in April 1900, by sponge divers. The shipwreck was dated between 86 and 67 B.C. (coins from Pergamon). The Mechanism has been dated, by epigraphologists, around the second half of the 2nd century B.C. (100 – 150 B.C.). About this time the great Greek astronomer Hipparchos (190 – 120 B.C.) lived in Rhodes. It was a portable (laptop-size), geared artifact which calculated and displayed, with high precision, the movement of the Sun and the Moon on the sky, the phase of the Moon for a given epoch and could predict eclipses. It had one dial on the front and two on the back. Its gears were driven by a manifold, with which the user could set a pointer to any particular epoch (at the front dial). While doing so, several pointers were synchronously driven by the gears, to show the above mentioned celestial phenomena on three accurately marked annuli. It contained an extensive user’s manual. The exact function of the gears has finally been decoded and a large portion of the manual has been read after 2000 years by a major new investigation, using state of the art equipment.