The Antikythera mechanism
The Antikythera mechanism was discovered in 1900 during the recovery of a shipwreck off of the Greek island, Antikythera, in waters 60 meters deep. It is a metallic device which consists of a complex combination of gears, and dates back to the 2 nd century BCE. X-rays have shown that there are at least 30 different types of gears used in the device, and on the mechanism’s door plates are about 2,000 letters that are considered to be something like a usage manual.
There are references of such mechanisms in the works of ancient writers. In his writing, Cicero mentions an instrument which reproduces the motions of the sun and the five planets. The device, he claimed, was built by Archimedes.
For the last few decades, scientists have utilized the latest technology in attempts to decipher its functionality; however, due to its complexity, they have previously been unable to explain its function.
Now theories are being proposed by researchers. Some consider the Antikythera mechanism to be the first human-made analogue computer, potentially used for purposes ranging from calculating the positions of celestial bodies to determining—with accurate precision—solar and lunar eclipses; however, the full functionality of the mechanism and its intended use are yet to be deciphered.
One of the research groups currently studying the artefact is the Antikythera Mechanism Research Project , which is an international collaboration of academic researchers and companies - Cardiff University, National University of Athens, Aristotle University of Thessaloniki, National Archaeological Museum of Athens, X-Tek Systems (UK) and Hewlett-Packard (USA).
An interesting note: this artefact is so famous that a fully functional replica was constructed by Lego pieces .