At the beginning of the 20th century, divers off the island of Antikythera came across this clocklike mechanism, which is thought to be at least 2,000 years old, in the wreckage of a cargo ship. The device was very thin and made of bronze. It was mounted in a wooden frame and had more than 2,000 characters inscribed all over it. Though nearly 95 percent of these have been deciphered by experts, there as not been a publication of the full text of the inscription.
Today it is believed that this instrument was a kind of mechanical analog computer used to calculate the movements of stars and planets in astronomy. It has been estimated that the antikythera mechanism was built around 87 B.C and was lost in 76 B.C. No one has any idea about why or how it came to be on that ill-fated cargo ship. The ship was Roman though the antikythera mechanism was developed in Greece. One theory suggests that the reason it came to be on the Roman ship could be because the instrument was among the spoils of war garnered by then Roman emperor Julius Caesar.
“This is as important for technology as the Acropolis is for architecture,” said Professor John Seiradakis of the Aristotle University of Thessaloniki in Greece, and one of the team. “It is a unique device.”
Researchers believe these would have been housed in a rectangular wooden frame with two doors, covered in instructions for its use. The complete calculator would have been driven by a hand crank. Although its origins are uncertain, the new studies of the inscriptions suggest it would have been constructed around 100-150 BC, long before such devices appear in other parts of the world. Writing in Nature, the team says that the mechanism was “technically more complex than any known device for at least a millennium afterwards”.
“When you see it your jaw just drops and you think, ‘bloody hell that’s clever” – Mike Edmunds, Cardiff University
Using bespoke non-invasive imaging systems, such as three-dimensional X-ray microfocus computed tomography, the team was able to take detailed pictures of the device and uncover new information.
The major structure they describe, like earlier studies, had a single, centrally placed dial on the front plate that showed the Greek zodiac and an Egyptian calendar on concentric scales.
On the back, two further dials displayed information about the timing of lunar cycles and eclipse patterns. Previously, the idea that the mechanism could predict eclipses had only been a hypothesis.
Other aspects are less certain, such as the exact number of cogs that would have been in the complete device. The new research suggests 37 gears could have been used.
However, what is left gives an insight into the complexity of the information the mechanism could display.