From Cave Paintings to the Internet A Chronological and Thematic Database on the History of Information and Media The Earliest Analog Computer (Circa 150 BCE – 100 BCE)

The Antikythera Mechanism discovered off Antikythera, Greece in 1901, includes the only specimen preserved from antiquity of a scientifically graduated instrument, and also may also be thought of as the earliest extant mechanical calculator. "The Antikythera mechanism must therefore be an arithmetical counterpart of the much more familiar geometrical models of the solar system which were known to Plato and Archimedes and evolved into the orrery and the planetarium. The mechanism is like a great astronomical clock without an escapement, or like a modern analogue computer which uses mechanical parts to save tedious calculation . . . . It is certainly very similar to the great astronomical cathedral clocks that were built. . . ." in Europe beginning in the fourteenth century.

Applying high-resolution imaging systems and three-dimensional X-ray tomography, in 2008 experts deciphered inscriptions and reconstructed functions of the bronze gears on the mechanism. The results of this research, illustrated in a video available at this link, revealed details of dials on the instrument’s back side, including the names of all 12 months of an ancient calendar. Scientists found that the device not only predicted solar eclipses but also organized the calendar in the four-year cycles of the Olympiad, forerunner of the modern Olympic Games.

In December 2008, Michael Wright described a more complete reconstruction of the device which he built, in a video available at this link.

The new findings also suggested that the mechanism’s concept originated in the colonies of Corinth, possibly Syracuse, in Sicily. The scientists said this implied a likely connection with Archimedes, who lived in Syracuse and died in 212 B.C. Archimedes invented a planetarium calculating motions of the moon and the known planets, and wrote a lost manuscript on astronomical mechanisms. Some evidence had previously linked the complex device of gears and dials to the island of Rhodes and the astronomer Hipparchos, who had made a study of irregularities in the Moon’s orbital course.