October 13, 2008

The Antikythera Mechanism

Prof Mike Edmunds

Report by: Mike Dryland

Prof Mike Edmunds (Pic Mike Dear)

In the year 1900, after a storm, sponge divers found the wreck of an ancient ship off the island of Antikythera in the Mediterranean. The wreck was notable for its hoard of statues and other articles dated to 100BC. Much was salvaged in 1900-1. The ship may have been sailing from Rhodes to Italy. Found among the treasures was a lump of bronze covered in marine accretion. On investigation it was found to be a geared mechanism containing fragments of more than 30 gear wheels — a mechanism the like of which was not known again until the medieval cathedral clocks of 1000 years later!

Mike Edmunds is currently a Professor of Astrophysics at Cardiff University, and a member of the Science and Technology Facilities Council of the UK. His research career has focussed on the chemical evolution of galaxies and the origin of interstellar dust. In recent years he has been the academic lead of an international team investigating the ancient Greek astronomical calculator. He has a long history of strategic involvement in the provision and running of international observatory facilities.

Mike has been closely involved with the recent investigation using the latest scanning technology and benefiting from new interpretation of the inscriptions on the machine. Mike’s tale is nothing short of a compelling detective story of how the 82 fragments have been identified, reconstructed, and the function and purpose of the device teased-out. The machine includes spiral dials and epicyclic gearing, devices not dreamed to have been used in Greece 100BC.

Analysis of the gearing and inscriptions reveals systematic use of the numbers 76, 19 and 223 — the fingerprints of the Callipic, Metonic, and Saros cycles, key ratios relating lunar months to solar years and eclipse cycles.

See the links in ‘Read More’ for full details of the functions of this amazing machine.

Mike’s team has thoroughly explored the possibilities that the machine is a fake or later artefact dropped on the wreck site, but the weight of different strands of evidence points relentlessly to 100BC.

A deterministic device dating from 100BC casts new light on the nature of Greek philosophical thinking.

Why is this machine so rare? It suggests a 500-year tradition of such mechanisms but very few similar, and nothing remotely comparable, have been found. Possibly most were melted down for the bronze. It was a complex and unusual device even in its own time, and later on, the material may have been regarded as more valuable than the device itself.