A mystery

IO9 has a fascinating report by Ed Grabianowski, on the latest discoveries concerning a mystery device, called the Antikythera mechanism:

X-rays and advanced photography have uncovered the true complexity of the mysterious Antikythera mechanism, a device so astonishing that its discovery is like finding a functional Buick in medieval Europe.

Using nothing but an ingenious system of gears, the mechanism could be used to predict the month, day and hour of an eclipse, and even accounted for leap years. It could also predict the positions of the sun and moon against the zodiac, and has a gear train that turns a black and white stone to show the moon's phase on a given date. It is possible that it could also show the astronomical positions of the planets known to the ancients: Mercury, Venus, Mars, Jupiter and Saturn.

The Antikythera mechanism wasn't just a scientific tool – it also had a social purpose. The Greeks held major athletic competitions (such as the Olympics) every two or four years. A small dial within the Metonic dial showed the dates of these important events.