The Antikythera Mechanism

The Antikythera Mechanism, accidentally discovered in 1900 by a sponge diver off the Greek island of Antikythera, is an anomaly. After much study and reconstruction, it has been found to be a mechanical astromonical computer from 65 B.C. with technology and complexity not seen again until the 1800s. There are no other mechanisms of this type which have been found, described or even mentioned in ancient texts. It stands alone.

Using modern computer x-ray tomography and high resolution surface scanning, a team led by Mike Edmunds and Tony Freeth at Cardiff University peered inside fragments of the crust-encased mechanism and read the faintest inscriptions that once covered the outer casing of the machine. Detailed imaging of the mechanism suggests it dates back to 150-100 BC and had 37 gear wheels enabling it to follow the movements of the moon and the sun through the zodiac, predict eclipses and even recreate the irregular orbit of the moon. The motion, known as the first lunar anomaly, was developed by the astronomer Hipparcus of Rhodes in the 2nd century BC, and he may have been consulted in the machine's construction, the scientists speculate.

Remarkably, scans showed the device uses a differential gear, which was previously believed to have been invented in the 16th century. The level of miniaturisation and complexity of its parts is comparable to that of 18th century clocks.

Some researchers believe the machine, known as the Antikythera Mechanism, may have been among other treasure looted from Rhodes that was en route to Rome for a celebration staged by Julius Caesar.

One of the remaining mysteries is why the Greek technology invented for the machine seemed to disappear. No other civilisation is believed to have created anything as complex for another 1,000 years.