Antikythera Mechanism

It modeled the Metonic cycle, predicted solar and lunar eclipses using the Saros dial, and tracked the four-year Olympiad cycle. A 2021 study of fragment G confirmed its ability to track the 462-year cycle of Venus. The front face displayed the Greek zodiac and Egyptian calendar months.

It was recovered in 1902 from a Roman-era shipwreck off the coast of the Greek island of Antikythera, south of the Peloponnese. Sponge divers working the wreck also recovered bronze and marble statues, including the Antikythera Ephebe. The site dates to roughly the first century BC.

The surviving fragments are displayed at the National Archaeological Museum in Athens, where they are catalogued as part of the Bronze Collection. The largest fragment (Fragment A) is approximately 18 cm across. Reconstructions by researchers such as Michael Wright are also exhibited.

British physicist Derek de Solla Price published the first major reconstruction in 1959 in Scientific American, later expanded in his 1974 book Gears from the Greeks. Cardiff University's Michael T. Wright built a working model in 2005. The Antikythera Mechanism Research Project used CT scanning in 2005-2006 to read previously hidden inscriptions.