Talk abstract details

The Antikythera Mechanism, astronomy and mathematics embedded in the gears

Abstract

The Antikythera mechanism is an ancient astronomical computer and astronomical device recently re-examined with modern methods by the Antikythera Mechanism Research Project, a joint program between Cardiff University (M. Edmunds, T. Freeth), the National and Kapodistrian University of Athens (X. Moussas, Y. Bitsakis), the Aristotle University of Thessaloniki (J.H. Seiradakis), the National Archaeological Museum of Athens (M. Zafeiropoulou, E. Mangou), X-Tek Systems UK and Hewlett-Packard USA, funded by the Leverhulme Trust and supported by the Cultural Foundation (A. Tselikas) of the National Bank of Greece.
A new reconstruction of the mechanism based on the high resolution X-ray tomography and 3D photos. This work doubled the amount of readable text of the ancient computerís manual. The inscriptions lead to a new dating of the Mechanism around 150 to 100 BC. It is evident that they contain a manual with an astronomical, mechanical and geographical section. The name ISPANIA (ΙΣΠΑΝΙΑ, Spain in Greek) in these texts is the oldest reference to this country under this form, as opposed to Iberia or Esperia. The inscriptions mention the stationary points of the planets. Two spiral scales (simple Archimedean spirals, with two centers) with sliding pointers indicated the state of two further important astronomical cycles: the Saros cycle, the period of approximately 18 years separating the return of the Sun, Moon and Earth to the same relative positions and the more accurate exeligmos cycle of 54 years and one day (essential in eclipse prediction, see Eclipse cycle). It also contains another spiral scale for the Metonic cycle (19 years, equal to 235 lunar months) and possibly the Callippic cycle that proposed a more accurate periodicity of 940 lunar months in approximately 76 years.
The Moon mechanism shows the position and phase of the Moon during the month. The velocity of the Moon varies according to the theory of Hipparchus, and to a good approximation follows Kepler's second law for the angular velocity, being faster near the perigee and slower at the apogee (see Kepler's laws of planetary motion).