The Antikythera Mechanism
One spring day in 1900, a party of Greek sponge divers took shelter from a storm near the island of Antikythera, which lies about 50 kilometres northwest of the western tip of Crete. After the storm, one of the group, Elias Stadiatis, decided to dive in search of giant clams to eat for their dinner. On a shelf about 43 metres below the surface of the water, he chanced upon the wreck of an ancient ship. Fragments of statues, looking like body parts, covered this ledge. The diver returned to the surface, bearing an arm made of bronze as proof of what he had discovered. He reported his find to the authorities and, in the autumn, he and his companions returned to dive on the Antikythera wreck on behalf of the Greek government. They spent the next ten months bringing up pieces of marble and bronze statues, amphorae, lamps and coins, all of which were sent to the National Museum in Athens for cleaning and restoration.
Among the artefacts retrieved from the shipwreck was a rather unprepossessing lump of bronze inside what seemed to be a wooden casing. This object was covered in barnacles and badly corroded by seawater, and didn’t attract much attention at first. It wasn’t until May 1902 that the leading Greek archaeologist Valerios Stais noticed that the wooden covering had dried out and split open, and the fused lump of metal inside it had separated into several pieces. The largest of these fragments was a dial about 14cm in diameter, with some inscriptions on it. Some other fragments also appeared to be parts of dials with perfectly formed triangular teeth, like gear wheels.The evidence seemed to point to this being part of a kind of mechanical clock, but the researchers ultimately rejected this possibility as the wreck had been dated to the first century BCE, and it was known that precise gears like these had not existed until fourteen centuries after that.
Little progress on identifying either the purpose or origins of the mechanism was made until the late 1950s, when the device attracted the attention of a British-born polymath, Derek de Solla Price, who was working at Princeton University in the United States. Price realised that the inscriptions on the large dial indicated days, months and zodiac signs and theorised that the device used gears to trace the paths of the sun, moon and other planets in relation to the earth and to indicate their position at any given moment by means of pointers that had since been lost. Although his interpretation was basically sound, further research was hampered by the fact that only a few of the gears appear on the surface of the fused metal fragments of the mechanism.
In 1971, the National Museum in Athens gave permission for Price, working with a Greek radiographer, to X-ray the fragments of the Antikythera mechanism. These two-dimensional images revealed many of the hidden gears and allowed Price to develop schematic drawings of how the mechanism must have worked. What he discovered confounded all previous theories of technology in the Hellenistic era and indicated that the ancient Greeks’ mechanical know-how and knowledge of astronomy came close to that of modern times. However, despite positive scholarly reviews of Price’s work, his idea that the Antikythera mechanism is an ancient analogue computer, published in his 1974 book “Gears from the Greeks”, fell on deaf ears where mainstream historians were concerned. This may have been due, at least in part, to the contemporaneous popularity of books by the Swiss writer Erich von Daniken, who postulated that ancient aliens had brought advanced technology to earth; Price’s work may have inadvertently become associated with fringe theories and UFO-hunters as a result.
Whatever the reason, little more official research was conducted on the mechanism until the 2005 launch of the Antikythera Mechanism Research Project, an international, multi-disciplinary study that operates under the supervision of the Hellenic Ministry of Culture. The project examined the fragments of the Antikythera mechanism using state-of-the-art imaging equipment. One machine, nicknamed BladeRunner, was originally designed to detect cracks in aircraft turbine blades by means of three dimensional X-ray technology. This project is ongoing and new findings are being constantly made and revealed. Enough has already been discovered to vindicate Price.
This modern research places the construction of the mechanism towards the end of the second century BCE and confirms that its bronze dials and gears would have been housed in a wooden box roughly the size of a modern shoebox. Like the clocks our grandparents’ generation kept on the mantelpiece, the mechanism had a circular dial at the front with rotating hands. Rather than showing hours and minutes, however, these hands indicated the positions of the sun and the moon in the sky at any given time, as well as of Mercury, Venus, Mars, Jupiter and Saturn, the five planets that are visible to the naked human eye. In addition, the mechanism also allowed for the fact that the orbit of some planets around the sun appears to go backwards, or “retrograde”, at certain times during the celestial cycle. It has also been discovered that there were two dials on the back of the mechanism, one of which was a calendar and the other which showed when solar and lunar eclipses would take place. A number of breathtaking models of the mechanism have been produced, including one made out of Lego blocks. These reveal the outstanding mechanical skills and astronomical knowledge of whoever built the Antikythera mechanism two thousand years or more before we developed the technological skills to start unlocking its secrets.