Antikythera, Antikythera mechanism, Archimedes, astronomical, astronomical clocks, astronomy, calculations, calendar, Callippic cycle, computer, Corinth, eclipses, engineering, Exeligmos, first computer, gears, Greek island, Hipparchus, Metonic cycle, Olympiad, Permagon, planets, Posidonius, Rhodes, Saros, solar year, synodic month
(originally published to Bubblews writing site, now gone)
The first computer was probably made before 100 BCE on the Greek island of Rhodes. Remains of a contraption that came to be known as the Antikythera mechanism was recovered from the wreck of a small ship off the island of Antikythera in 1900, which had sunk around 65 BCE. It was a small hand-powered device that aimed to automate complex astronomical and calendar calculations and is thought to date to around 100 BCE.
A total of 82 fragments were found, including seven major pieces that contained gears. It had a number of sun, moon and other gears to work out the number of sidereal, anomalistic and synodic months in a year with good accuracy. For example, a series of gears set the ratio of a solar year to a synodic month as 1 to 12.368.
The Antikythera mechanism was also used to calculate the Metonic cycle of about 19 years, the Olympiad, the Callippic cycle of about four Metonic cycles and more accurate than it, and the Saros and the Exeligmos, both used to predict eclipses. It was thought to have further gears, not recovered, to track the planets. The machine could be set to the Greek or the Egyptian calendar.
The computers were probably manufactured at an academy of astronomy and engineering run by the philosopher Posidonius at Rhodes. The design may be that of astronomer Hipparchus around 140-120 BCE. Another theory suggests the mechanism came from the Corinth area, home of Archimedes and his school. Or it may have come from Permagon whose library was noted for art and science.
The technology of the Antikythera mechanism is regarded as extraordinary for its time and not equalled until astronomical clocks were developed in Europe in the 14th century.