The arms and faces of ancient statuary litter the seabed at the site of a shipwreck off the coast of Greece. But that's not the most interesting find. Encrusted with over 2,000 years of mineral deposits are highly engineered gears clearly visible as part of a mysterious device dating back to about 50 BCE. Using X-ray technology and working off of the realization that the gears' teeth are prime numbers relating to astronomy, the device is revealed to be the earliest known computer used for predicting eclipses and demonstrating planetary motion.
Nova
Examining an ancient Greek astronomical calculator and eclipse predictor that is believed to be from the workshop of Archimedes.