The ancient Greeks built a mechanical computer — then the idea vanished for a millennium

The Antikythera mechanism, recovered from a shipwreck and dated to roughly the 2nd century BC, used dozens of precision bronze gears to predict eclipses and track planetary cycles. Nothing of comparable mechanical complexity appears again in the historical record for well over a thousand years.

— Tony Freeth et al., Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism — Nature, 2006