The Antikithira Machine

High Technology in Ancient Greece

In October of 1900, greek sponge divers discovered a shipwreck lying at a depth of 180 feet, just off the coast of the tiny island of Antikithira. Click on the maps below to see the exact location of this island.

Amongst the various items of the ship's cargo recovered, they found a heavily calcified lump of bronze which, upon closer inspection, revealed itself to be a truly awesome piece. After cleaning and re-assembling the artefact, it turned out to be a very sophisticated and complex mechanism with about 40 interlocking cog wheels of varying sizes, 9 adjustable scales, and 3 axes on a base plate. An indicator of the precision of this piece is the central cog which has 240 teeth, each only 1.3mm high. Non-intrusive photographic techniques of the different layers inside the device have revealed each layer to be only 2mm thick. Click the thumbnail below for a diagram of the design.

So how old is it? Ancient greek inscriptions on the device indicate a date of 82-65 BC, the ship's sinking, based on its cargo is dated to 83-75 BC, and the ship itself to 200 BC. However, we must be careful not to put too much weight on these dates - the machine could well have been inscribed at any time after its original manufacture, and it could also be a copy of an older device. One interesting fact is that it was constructed of bronze - this is unusual because bronze is much harder to work than copper, which was much more widespread during this time. In fact, this kind of precision construction in bronze should have been impossible during this period.

So what was it used for? Again, the answer here is still open to debate. Its label in the museum identifies it as a simple astrolabe, (a seafaring instrument used to take altitudes of the sun and stars), but if this is the case, it is over-engineered to a ridiculous degree. Its internal gears are linked on several differentials, incorporating the cycle of the sun, and the complex 19-year cycle of the moon. Professor Derek Price, who made an exhaustive study of the device in 1958, summarised his findings as follows: "It appears that this indeed was a computing machine that could work out and exhibit the motions of the Sun and Moon, and probably also the planets."

It is clear from the evidence that this machine indicates an advanced knowledge of astronomy and precision engineering that should not have been possible over 2000 years ago.