High tech from Ancient Greece: Archaeology

The Antikythera Mechanism, salvaged 100 years ago from an ancient shipwreck, was long known to be some sort of mechanical calendar. But modern analysis is only now revealing just how sophisticated it was. Planetary gears The Antikythera Mechanism is an intricate bronze construction discovered damaged and fragmented in the wreck of a cargo ship off the Greek island of Antikythera in 1900. Made towards the end of the second century BC , it contains 30 bronze gear wheels and many astronomical inscriptions. The mechanism is technically more complex than any known device for at least a millennium afterwards. It acted as a lunar–solar calendar, but its specific functions have remained controversial. Now a joint British–Greek team has reconstructed the device based on surface imaging and X-ray tomography of the surviving fragments. The reconstruction shows how the gears worked, and doubles the number of deciphered inscriptions. The Mechanism seems to have been a sophisticated predictor for the Sun/Moon/Earth system, and can justifiably be claimed as the world's oldest known analogue computer.