A Physical Fraction

The Antikythera mechanism is an ancient mechanical calculator and is also described as the first known mechanical computer designed to calculate astronomical positions. It was recovered in 1901 from the Antikythera wreck but its complexity and significance were not understood until decades later. It is now thought to have been built about 150 – 100 BC. Technological artifacts of similar complexity did not reappear until a thousand years later.

Professor Michael Edmunds of Cardiff University who led the most recent study of the mechanism said: "This device is just extraordinary, the only thing of its kind. The design is beautiful, the astronomy is exactly right. The way the mechanics are designed just makes your jaw drop. Whoever has done this has done it extremely carefully... in terms of historic and scarcity value, I have to regard this mechanism as being more valuable than the Mona Lisa."



The device is remarkable for the level of miniaturization and for the complexity of its parts, which is comparable to that of 18th century clocks. It has over 30 gears, although it has been suggested as many as 72 gears, with teeth formed through equilateral triangles. When a date was entered via a crank, the mechanism calculated the position of the Sun, Moon, or other astronomical information such as the location of other planets. Since the purpose was to position astronomical bodies with respect to the celestial sphere, with reference to the observer's position on the surface of the earth, the device was based on the geocentric model.

On 30 July 2008, scientists reported new findings in the journal Nature showing that the mechanism tracked the Metonic calendar, predicted solar eclipses, and calculated the timing of the Ancient Olympic Games. Inscriptions on the instrument closely match the names of the months on calendars from Illyria and Epirus in northwestern Greece and with the island of Corfu.