The device was discovered more than a century ago by sponge divers from the Aegean island of Symi.
In 1900, after a gale blew them off course, they took shelter by a barren islet called Antikythera.
When the storm abated, they went diving. Instead of sponges, the divers found a large heap of
bronze and marble statues. They had happened upon an ancient shipwreck.
In all the excitement, nobody noticed a corroded lump of rock dumped in a crate in the courtyard of
the National Archaeological Museum in Athens. That changed a few months later when it cracked open,
revealing traces of gearwheels, precisely marked circular scales and inscriptions in ancient Greek.

Some scholars thought it was a hoax, others that it had come from a modern ship that sank on
the ancient wreck site by chance. The only clues to its purpose were a reference to the signs
of the zodiac – used for astronomy as well as astrology – and the word “Pachon”, which was a
month name used by the ancient Greeks. As the years passed, the mechanism sank into obscurity.
With no answers, historians of technology tended to mention it as an afterthought, if at all.

In recent decades, however, a series of researchers have dedicated large parts of their lives to
studying the mechanism. From their combined efforts, including X-raying its internal workings, we
at last have a fairly complete picture of what the Antikythera mechanism did. It turns out that it
was a hand-wound clockwork device used to calculate the motions of the sun, moon and planets
as seen from Earth, as well as to predict solar and lunar eclipses.
Archimedes and the 2000-year-old computer