A computer from 2,000 years ago

In 1901, divers pulled a lump of corroded bronze from a shipwreck off the island of Antikythera. It looked like scrap.

Decades of study revealed the truth: it was a geared machine more than 2,000 years old, capable of predicting eclipses and the positions of the planets. An analogue computer from ancient Greece.

Nothing of comparable complexity would be built again until more than a thousand years later.