Antikythera

In 1900, sponge divers sheltering from a storm off the island of Antikythera discovered a Roman-era shipwreck dated to around 70–60 BCE, lying at a depth of around 45 metres. Among the recovered bronze and marble statuary was a corroded lump of bronze that, when it later fractured, revealed an intricate assembly of gears. Now known as the Antikythera mechanism, the device contains at least 30 interlocking bronze gears — some with teeth less than 2mm across — and could calculate the positions of the sun and moon, predict lunar and solar eclipses, and track the four-year cycle of the ancient Olympic Games.

X-ray and CT scanning of the fragments since the 2000s, conducted by the Antikythera Mechanism Research Project, has revealed inscriptions describing its functions and confirmed that no device of comparable mechanical complexity is known to have existed for over a thousand years afterward — the next comparable geared mechanisms appear in European astronomical clocks of the 14th century. The identity of its maker remains unknown, though its design has been linked to the tradition of Archimedes, and debate continues over whether it represents a unique masterpiece or evidence of a broader Hellenistic tradition of mechanical instrument-making that has otherwise left no trace. The wreck site has been the subject of ongoing underwater excavations since 2012, which continue to recover additional artefacts.