PARIS: A clockwork machine hailed as the supercomputer of the ancient world may have provided a calendar for the Olympic Games and has even been linked to early mathematician, Archimedes.

The 2,100-year-old device has bemused and bedazzled experts ever since its corroded and calcified bronze wheels and dials were recovered from a Roman shipwreck by Greek sponge divers in 1901.

For decades, they speculated that the machine, called the Antikythera Mechanism, was an astronomical calendar, although how it worked was unclear.

Antikythera Mechanism

In 2006, experts using X-ray computed tomography confirmed the theory by getting a three dimensional (3-D) view of its 29 surviving gears and used high-resolution imaging to get a close up of tiny letters engraved on the surface (see, Enigma of ancient computer solved, Cosmos Online).

They figured it was able to estimate a 365-day calendar with the leap day ingeniously included; the 19-year Metonic calendar devised by the Babylonians; and a predictor of eclipses over a 223-month cycle, including a complex motion that became notorious as the "First Anomaly" of the Moon.

Now, in a new study, published today in the U.K. journal Nature, the sleuths say they have discovered that one of the dials recorded the dates of the ancient Olympics, possibly to provide a benchmark for the passage of time.

"Astonished"

"We were astonished," said Tony Freeth, author and member of the Antikythera Mechanism Research Project – a team of experts at the University of Cardiff in Wales, the universities of Athens and Salonika in Greece, and the National Archaeological Museum in Athens.

"The Olympiad cycle was a very simple, four-year cycle and you don't need a sophisticated instrument like this to calculate it. It took us by huge surprise when we saw this," said Freeth. "But the Games were of such cultural and social importance that it's not unnatural to have it in the Mechanism."

The gadget was so cleverly engineered that it could fit into a small box about the size of an encyclopaedia, enabling it to be transported. But what was it used for?

Freeth speculates that it may have helped the rich and powerful predict times for marriage and births – or for waging war or agreeing to peace. No evidence has ever emerged to back such ideas though, he said.

BladeRunner

Hi-tech imaging of the Mechanism was carried out by an eight-tonne leviathan known as BladeRunner (its usual job is to investigate jet turbine blades to see if they carry any microscopic cracks). It was transported to Athens for the operation, as the delicate relics are housed at the National Archaeological Museum.

BladeRunner found another novelty too – that the dial for the Metonic calendar has names for the Corinthian family of months. Corinth, in central Greece, established colonies in northwestern Greece, Corfu and Sicily, where Archimedes was established.

Archimedes, whose list of exploits included an explanation for the lever, the displacement of water and a screw pump that bears his name today, died there in 212 BC.

The Mechanism was "almost certainly made many decades" after his death though, said Alexander Jones, a professor at the Institute for the Study of the Ancient World in New York City, USA.

If the machine came from Syracuse, the dial could have been made by the school of scientists and instrument-makers Archimedes inspired. Instead of one Olympics as there is today, the ancient Olympiads, called the Panhellenic Games, comprised four games spread over four years.

Ancient tradition

The events comprised the Pythian Games, held every four years at Delphi in honour of the god Apollo; the Isthmian Games, held every two years in Corinth in honour of Poseidon; the Nemean Games, also held every two years, in Nemea in honour of Zeus; and the most important, the Olympic Games, held every four years in Elis, also in honour of Zeus.

Drawing competitors from across the Greek empire, which stretched from Sicily to Asia Minor, the Games were so important that they became the basis for Greek chronology, becoming the term for a four-year period – historians noted "the third year of the eighth Olympiad" and so on.

The first Olympiad, or four-year period, dated back to 776 BC, although the Games are believed to have a far longer history.

The last Games of the ancient world were recorded in 393 AD, but were outlawed by the Roman Empire as pagan. The tradition of counting in Olympiads persisted into the next century, however.