Ancient Machines - Antikythera Mechanism

The Antikythera mechanism is an ancient mechanical calculator, also described as the first known mechanical computer, designed to calculate astronomical positions.

Scientists have finally demystified the incredible workings of a 2,000-year-old astronomical calculator built by ancient Greeks.

A new analysis of the Antikythera Mechanism, a clock-like machine consisting of more than 30 precise, hand-cut bronze gears, show it to be more advanced than previously thought—so much so that nothing comparable was built for another thousand years.

"This device is just extraordinary, the only thing of its kind," said study leader Mike Edmunds of Cardiff University in the UK. "The design is beautiful, the astronomy is exactly right…In terms of historical and scarcity value, I have to regard this mechanism as being more valuable than the Mona Lisa."

 The new analysis reveals that the device's front dials had pointers for the sun and moon — called the "golden little sphere" and "little sphere," respectively—and markings, which coincided with the zodiac and solar calendars. The back dials, meanwhile, appear to have been used for predicting solar and lunar eclipses.

The researchers also show that the device could mechanically replicate the irregular motions of the Moon, caused by its elliptical orbit around the Earth, using a clever design involving two superimposed gear-wheels, one slightly off-center, that are connected by a pin-and-slot device.

The team was also able to pin down the device's construction date more precisely. Radiocarbon dating suggested it was built around 65 B.C., but newly revealed lettering on the machine indicate a slightly older construction date of 150 to 100 B.C. The team's reconstruction also involves 37 gear wheels, seven of which are hypothetical.

"In the face of fragmentary material evidence, such guesswork is inevitable. But the new model is highly seductive, and convincing in all of its detail," wrote Francois Charette, a researcher at the Ludwig-Maximilians University in Germany who was not involved in the study, in a related article in the journal Nature.