Technology & Medicine › Ancient world › Greek and Roman engineering
Antikythera mechanism
c. 150–100 BC (date debated)· Book, artwork, monument or document· Communication & computing
Mostly agreedGood evidence; some details, dates or numbers uncertain.
A hand-cranked bronze gear device from about 150–100 BC that modelled the sky, often called the first analog computer.
See it on the Technology & Medicine map →How it works
Sponge divers found it in a shipwreck off the Greek island of Antikythera in 1901. About 30 interlocking bronze gears survive in 82 corroded fragments. Turning a handle moved dials showing the positions of the sun and moon, the moon's phase, a calendar, the four-year cycle of athletic games, and predicted eclipses; it probably showed the planets too. Inscriptions on it served as a built-in user manual.
Why it mattered
It shows Greek craftsmen made precision gearing more than a millennium before anyone thought possible, forcing a rethink of ancient technology.
How we know
The fragments, in Athens's National Archaeological Museum, studied by Derek de Solla Price from the 1950s and by X-ray CT scans since 2005, which revealed hidden gears and text.
Still unknown or debated
Who built it (Rhodes, Corinth or Syracuse?), its exact date, and how the lost planet gearing worked are debated; nothing similar survives from antiquity.
Connections (2)
▸Archimedes may have inspired the gearing of the Antikythera mechanismDebated
The connection
Cicero wrote that Archimedes built a sphere showing the sun, moon and planets, carried to Rome after Syracuse fell in 212 BC. The Antikythera mechanism does the same with gears, and its calendar uses month names from Corinth and its colonies, including Syracuse. Some scholars suspect a workshop tradition descending from Archimedes.
When and how
Syracuse in the 200s BC; the mechanism dates to about 150–100 BC and sank in a shipwreck around 70–60 BC.
How sure are we?
Cicero's Republic describes Archimedes' sphere; Corinthian month names on the mechanism hint at Syracuse. No direct evidence links the two.
Debates and open questions
Others credit Hipparchus's astronomy or a workshop on Rhodes; whether Archimedes' sphere even used gears is unknown.
▸Antikythera mechanism was not matched in complexity until the Mechanical clockMostly agreed
The connection
The Antikythera mechanism shows Greek craftsmen could cut precise gear trains to model the heavens. Nothing equally intricate survives for over a thousand years. Geared astronomical displays reappear in simpler Byzantine and Islamic devices, then in Europe's astronomical clocks of the 1300s, such as Richard of Wallingford's and Giovanni de Dondi's.
When and how
Greece about 150–100 BC; St Albans, England (1327–1336) and Padua, Italy (1364).
How sure are we?
A Byzantine geared sundial-calendar (about AD 500, Science Museum, London) and al-Biruni's geared calendar (about 1000) show the skill survived in simpler form.
Debates and open questions
Whether a continuous craft tradition linked the mechanism to medieval clocks, or the know-how was lost and reinvented, is debated.