The island of Antikythera lies between Crete and Greece (the name means ‘opposite Kythera’, which is a large island adjacent to it). In 1900, a Greek diver found a wreck just off the coast of the island. Presumed to be a Roman vessel from the first century BC, it contained many remarkable artefacts that dated back as far as the fourth century BC. It’s possible that the boat was carrying booty from the sacking of Athens in 87–86 BC, or that the objects were being taken to Rome to be presented to Julius Caesar.
Many of the objects retrieved from the wreck were quickly identified, but the most mysterious and fascinating artefact – the Antikythera mechanism – puzzled historians for decades. It was a damaged remnant of a wooden box (about the size of a shoebox), which contained thirty interlinked gears and levers. The famous physicist Richard Feynman described it as ‘so entirely different and strange that it is nearly impossible ... it is some kind of machine with gear trains, very much like the inside of a modern wind-up alarm clock’.
It befuddled archaeologists and was more or less ignored until 1951, when the historian Derek de Solla Price became intrigued by it. After two decades of work, he published some preliminary thoughts, but he hadn’t fully understood the device before his death in 1983. However, the attention of academics was starting to focus on a mention in the writings of Cicero of a mechanical planetarium known as the ‘sphere of Archimedes’ that showed how the celestial objects in the solar system moved relative to the Earth. The inscriptions on the device, in Koine Greek, seemed to back up this theory, as did the fact that the dials and rings were inscribed with Greek zodiac signs and calendar days.
A model of the Antikythera machine.
In the past few decades it has been established that the mechanism is indeed a device for tracking the lunar calendar, and predicting eclipses and the position and phase of the Moon. In addition it shows the seasons, and marks festivals such as the Olympics. One of its most remarkable properties was that it could calculate the Moon’s period to a high degree of accuracy and model its elliptical orbit. As a result it has been called ‘the world’s first analog computer’, which might seem hyperbolic, but given that mechanical aids such as slide rules or tide predictors were in use before digital computers, and they can be described as analog computers, it is pretty accurate.
The remaining mysteries about the mechanism concern who owned it and who created it. One suggestion for the creator is Hipparchus, the second-century BC astronomer and mathematician who is remembered for compiling the first trigonometric table and for his rather accurate estimate of the distance from the Earth to the moon. Cicero suggests that Posidonius, who followed Hipparchus as the head of the school on Rhodes, built a planetary device, which might mean that the two men collaborated on its design.
That mystery may never be solved, and we can’t know whether this is the one surviving example of a machine that other people were also able to build. However, the mechanism (and modern recreations of it) shows us how remarkably sophisticated some Greeks of the period had become.
