John Seiradakis
Dept. Astroph., Aristotle Univ. Thessaloniki (Thessalonique, Grèce)
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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| « The Antikythera Mechanism: decoding an astonishing 2000 years old astronomical computer » |
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John Seiradakis |
| A lecture that attempts to explain the functional details, the operation and the purpose of use of an ancient astronomical mechanism, built about 2000 ago. The Antikythera Mechanism was found by chance, in a shipwreck, close to the small Greek island of Antikythera, in April 1900, by sponge divers. The shipwreck was dated between 86 and 67 BCE (coins from Pergamon). Later the Mechanism was stylistically dated, around the second half of the 2nd century B.C. (200 – 100 BCE). It was a portable (laptop-size), geared mechanism which calculated and displayed, with good precision, the movement of the Sun and the Moon on the sky and the phase of the Moon for a given epoch. It could also calculate the dates of the four-year cycle of the Olympic Games and predict eclipses! Its 30, precisely cut, gears were driven by a manifold, with which the user could select, with the help of a pointer, any particular epoch. While doing so, several pointers were synchronously driven by the gears, to show the above mentioned celestial phenomena on several accurately marked spiral dials. 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. New astronomical results will be discussed, the construction of the spirals and the pointers will be presented and the ability of ancient Greeks to use hard metals and cutting tools will be examined. |
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vendredi 13 avril 2018 - 11:00 Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |