Antikythera Mechanism

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The Antikythera mechanism is an ancient Greek analogue computer used to predict astronomical positions and eclipses for calendar and astrological purposes decades in advance. It could also be used to track the four-year cycle of the ancient Olympic Games. The artefact was retrieved from the seabed off the coast of the Greek island Antikythera in 1901, and first identified by archaeologist Valerios Stais. The mechanism is believed to have been designed and constructed by Greek scientists and has been dated to about 100 BC.The device, housed in the remains of a 34 cm × 18 cm × 9 cm wooden box, was found as one lump, later separated into three main fragments which are now divided into 82 separate fragments after conservation works. Four of these fragments contain gears, while inscriptions are found on many others. The largest gear is approximately 14 cm in diameter and originally had 223 teeth.It is a complex hand cranked clockwork mechanism composed of 37 meshing bronze gears. A team led by Mike Edmunds and Tony Freeth at Cardiff University used modern computer x-ray tomography and high resolution surface scanning to image the inside fragments of the badly corroded mechanism and read the faintest inscriptions that once covered the outer casing of the machine.the mechanism was designed to follow the movements of the Moon, Sun and the then known planets (Mercury, Mars, Venus, Jupiter and Saturn) through the zodiac, and to predict eclipses. The design of the gears allowed the irregular orbit of the Moon to be accurately modelled, where the Moon's velocity is higher in its perigee than in its apogee. This motion was studied in the 2nd century BC by astronomer Hipparchus of Rhodes, and it is speculated that he may have been consulted in the mechanism’s construction.When it was discovered it was cited as proof that aliens had visited Earth because the workmanship and design complexity were beyond the ancient Greeks, but as usual this is very disingenuous to the intelligence of our forebears. In fact, a YouTuber called Clickspring has begun the re-construction of the Antikythera mechanism using only tools and techniques known the people of the time and has achieved great success.This model is based on the one created by Scott Shambaugh, see the readme file. I have taken the liberty of adding the two indicators and spiral grooves mentioned in point 3, without regard to the practicality of manufacture.