The Antikythera Mechanism: A Computer from the Ancient World
1901 · event
In 1900 sponge divers sheltering from a storm near the small Greek island of Antikythera found a Roman era shipwreck on the seabed. Over the following months they raised bronze and marble statues, glassware and coins, and among the crates of finds delivered to Athens was a shapeless lump of corroded bronze and wood. In May 1901 it split apart in the museum and revealed something no one expected from the ancient world, a precisely cut gear wheel.
The object is now known as the Antikythera mechanism and is dated to roughly the second century BC. It contained at least thirty interlocking bronze gears in a wooden case about the size of a large book, turned by a hand crank. Pointers on its faces showed the position of the sun and moon in the zodiac, the phase of the moon, the cycles used to predict eclipses, the alignment of the lunar and solar calendars, and even the four year cycle of the Panhellenic games including the Olympics.
For decades the corroded fragments resisted study. The physicist Derek de Solla Price used gamma ray images in the 1970s to count teeth and propose a gear train, and in 2005 and 2006 a team using high resolution X ray computed tomography and specialised imaging read inscriptions hidden inside the fragments and mapped the gearing in detail. Their work turned a curiosity into a documented astronomical calculator.
Nothing of comparable mechanical complexity is known again until the astronomical clocks of medieval Europe more than a thousand years later. The mechanism sits today in the National Archaeological Museum in Athens, small, green and broken, and it quietly corrects a common assumption about the ancient world. The Greeks did not only think about the heavens, they built a machine that could count them.