The Antikythera Mechanism: An Ancient Greek Computer
A lump of corroded bronze from an ancient shipwreck turned out to hold 30 gearwheels that modelled the Sun, Moon and planets.
In 1901 a corroded lump of bronze was recovered from an ancient shipwreck off the Greek island of Antikythera. For decades no one understood what it was.
Today it survives in 82 fragments, only about a third of the original machine, including 30 bronze gearwheels.
In 2005 researchers scanned the fragments with high-resolution imaging and X-ray tomography. They read thousands of tiny inscriptions and worked out what the gears did: the mechanism was an astronomical calculator built around the end of the second century BCE.
Its inscriptions describe the motions of the Sun, the Moon and all five planets known in antiquity. Its gears turned those motions into machinery, combining cycles from Babylonian astronomy with mathematics from Plato's Academy.
Evidence
- X-ray tomography revealed the internal gears and thousands of inscription characters hidden inside the fragments.
- A 2006 study in Nature dated the device to around the end of the second century BCE and reconstructed how its gears worked.
- A 2021 study proposed a model of the front display matching the inscriptions about the five planets.
What do you think happened?
You have the evidence. Stamp your verdict before you read ours.
Verdict
CONFIRMEDBacked by strong, verifiable evidence.
Confirmed: a real ancient Greek geared calculator. Some of its lost parts are still being reconstructed.
How readers voted
Theories vs evidence
An astronomical calculator built by Greek engineers
SUPPORTEDIts inscriptions, gear counts and astronomical cycles all fit this, and match Greek astronomy of the time.
Made with help from outside the ancient world
RULED OUTIts design follows known Babylonian cycles and Greek mathematics, and its inscriptions are in Greek.
Sources
- Freeth et al. (2006), Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism, Nature 444
- Freeth et al. (2021), A Model of the Cosmos in the ancient Greek Antikythera Mechanism, Scientific Reports
Image credits
- Antikythera Fragment A (Front).webp. Logg Tandy, CC BY 4.0
Published 2026-10-25. Spotted an error? Email provenmysteries@gmail.com.
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