Pieces of the ancient calculating machine were discovered by sponge divers exploring the remains of an ancient shipwreck off the tiny island of Antikythera in 1900. For decades, scientists have been trying to figure out how the device’s 80 fragmented pieces fit together and unlock its workings. The team was able to pin down the device’s construction date more precisely. Radiocarbon dating suggested it was built around 65 BC, but newly revealed lettering on the machine indicate a slightly older construction date of 150 to 100 BC. The team’s reconstruction also involves 37 gear wheels, seven of which are hypothetical.
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. There is a dial dedicated to the four-year Olympiad Cycle of athletic games in ancient Greece. 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 research team has also deciphered all the months on the Mechanism’s 19-year calendar, revealing month names that are of Corinthian origin, probably from a Corinthian colony of the western Hellenic world.
The Antikythera mechanism seems to be an arithmetical counterpart of the much more familiar geometrical models of the solar system which were known to Plato and Archimedes and evolved into the orrery and the planetarium.