The Antikythera Mechanism, recovered in 1901 from a Roman-era shipwreck off the island of Antikythera, is a hand-cranked bronze device with dozens of interlocking gears, often called the oldest known analog computer. It calculated the positions of the sun and moon, the phases of the moon, eclipse cycles and the dates of the Panhellenic games.
The surviving fragments are corroded and incomplete, so researchers have built working reconstructions like this one to show how the gearing and dials may have looked and functioned.
