The Antikythera mechanism is a 2100+ year old computer that could predict eclipses using the 235-month Metonic cycle. Similar machines didn’t reappear again for 1500 more years, and the Antikythera device is more compact than the much later models. Advanced imaging techiques have revealed even more anachronistic awesomeness from this sucker:
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.
The true genius of the mechanism goes beyond even the complex calculations and craftsmanship of a mechanical calendar. For example, the ancients didn’t know that the moon has an elliptical orbit, so they didn’t know why it sometimes slowed or sped up as it moved through the zodiac. The mechanism’s creator used epicyclic gears, also known as planetary gears, with a “pin-and-slot” mechanism that mimicked this apparent shifting in the moon’s movement. This use of epicyclic gears is far ahead of what anyone suspected ancient technology was capable of. [io9]
There’s a video below showing a replica of the Antikythera in action. Somebody living in 150 B.C. built this thing and I can’t even get my laptop to stop asking me to buy McAfee. Then again, I don’t wipe with rocks and clay, so who’s the genius now, mysterious ancient Greek inventor?