The Antikythera Mechanism was discovered by Symiote sponge divers in 1900 off the Greek island of Antikythera between the Greek mainland and Crete.  Subsequent study of the 82 known fragments revealed details of some 30 gears in a compact mechanism dating to around 70BC, and further analysis showed that it was the oldest known astronomical computer which could calculate lunar and solar eclipses as well as the planetary positions. 

A BBC documentary on the mechanism prompted my interest, and led to me reading a scientific paper that proposed a scheme for the overall mechanism’s construction and functionality including an epicyclic gearbox with “pin-in-slot” mechanism to show planetary motion including retrograde motion.  As this was relatively complex, I decided to generate a CAD model of the device which then led to me building a modern reproduction of all the main parts in an exploded form so that the mechanism could be seen working in all of its complexity.

This presentation aims to describe in outline the lunar, solar and planetary movements that the mechanism tried to model and then show how this was implemented in both the original device and my modern reproduction.

 (This talk was due to be given in June 2020, but has been delayed by COVID.  It will now be presented on our Zoom channel 912 0723 6181)