Divers found a 2,000-year-old computer in a Greek shipwreck.
In 1901, sponge divers pulled a lump of corroded bronze from a Roman-era wreck off the Greek island of Antikythera. Hidden inside were dozens of interlocking gears. The device could predict eclipses and track the Moon and Sun. Machines this complex don't reappear in western Europe until the 14th century.
Sponge divers from the island of Symi discovered the wreck in 1900, lying 45 metres down, and with the Greek navy recovered statues, pottery, glassware, coins and, probably in July 1901, the mechanism. It looked like a shapeless lump of bronze and wood and sat ignored for two years while museum staff reassembled the more obvious treasures. In May 1902 the archaeologist Valerios Stais and his cousin noticed a gear wheel embedded in it. Many scholars at first thought it far too complex to be ancient.
Serious study came later. Derek de Solla Price took X-ray and gamma-ray images of the fragments in 1971 and published his findings in 1974. In 2005 a Cardiff University team led by Mike Edmunds used X-ray tomography to look inside and read faint inscriptions. The mechanism appears to have had around 35 bronze gears, 30 of which survive, all turned by a hand crank. It survives today as 82 fragments in the National Archaeological Museum in Athens.
It is often called the oldest known analogue computer. Dials tracked the Sun and Moon through the zodiac and modelled the Moon's uneven speed, using a theory associated with the astronomer Hipparchus. A spiral dial based on the 18-year Saros cycle could predict eclipses, and another tracked the four-year cycle of the great athletic games, including the Olympics. Inscriptions deciphered in 2016 mention the cycles of Venus and Saturn, fuelling speculation that it also showed the planets.
Who made it, and when, is debated. Proposed construction dates range from about 205 BC to about 87 BC; the ship sank around 70 to 60 BC. Its calendar has been linked to Corinthian colonies in north-west Greece, which has prompted speculation about a connection to Archimedes, while others point to Rhodes, a centre of astronomy. Its sophistication suggests there were earlier devices that have not survived.
Source: Wikipedia — Antikythera mechanism · Text summarised from Wikipedia (CC BY-SA 4.0)
