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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Antikythera mechanism | 11/12 | https://en.wikipedia.org/wiki/Antikythera_mechanism | reference | science, encyclopedia | 2026-05-05T09:39:59.175186+00:00 | kb-cron |
Pappus of Alexandria (290 – c. 350 AD) stated that Archimedes had written a now lost manuscript on the construction of these devices titled On Sphere-Making. The surviving texts from ancient times describe many of his creations, some even containing simple drawings. One such device is his odometer, the exact model later used by the Romans to place their mile markers (described by Vitruvius, Heron of Alexandria and in the time of Emperor Commodus). The drawings in the text appeared functional, but attempts to build them as pictured had failed. When the gears pictured, which had square teeth, were replaced with gears of the type in the Antikythera mechanism, which were angled, the device was perfectly functional. If Cicero's account is correct, then this technology existed as early as the third century BC. Archimedes' device is also mentioned by later Roman era writers such as Lactantius (Divinarum Institutionum Libri VII), Claudian (In sphaeram Archimedes), and Proclus (Commentary on the first book of Euclid's Elements of Geometry) in the fourth and fifth centuries. Cicero also said that another such device was built "recently" by his friend Posidonius, "... each one of the revolutions of which brings about the same movement in the Sun and Moon and five wandering stars [planets] as is brought about each day and night in the heavens ..." It is unlikely that any one of these machines was the particular Antikythera mechanism found in the shipwreck since both the devices fabricated by Archimedes and mentioned by Cicero were located in Rome at least 30 years later than the estimated date of the shipwreck, and the third device was almost certainly in the hands of Posidonius by that date. The scientists who have reconstructed the Antikythera mechanism also agree that it was too sophisticated to have been a unique device. Other relatively complex metal devices are known from Roman Greece. For example, a bronze combination lock from the Augustan or Hadrianic period was unearthed in the Kerameikos. The device operated on a primitive form of mechanical logic: the central bolt was physically blocked from retracting until the notches of two independent rotary dials were correctly aligned. The device also included a simple concealed bypass mechanism.
=== Eastern Mediterranean and others ===
This evidence that the Antikythera mechanism was not unique adds support to the idea that there was an ancient Greek tradition of complex mechanical technology that was later, at least in part, transmitted to the Byzantine and Islamic worlds, where mechanical devices which were complex, albeit simpler than the Antikythera mechanism, were built during the Middle Ages. Fragments of a geared calendar attached to a sundial, from the fifth or sixth century Byzantine Empire, have been found; the calendar may have been used to assist in telling time. In the Islamic world, Banū Mūsā's Kitab al-Hiyal, or Book of Ingenious Devices, was commissioned by the Caliph of Baghdad in the early 9th century AD. This text described over a hundred mechanical devices, some of which may date back to ancient Greek texts preserved in monasteries. A geared calendar similar to the Byzantine device was described by the scientist al-Biruni around 1000, and a surviving 13th-century astrolabe also contains a similar clockwork device. It is possible that this medieval technology may have been transmitted to Europe and contributed to the development of mechanical clocks there. In the 11th century, Chinese polymath Su Song constructed a mechanical clock tower that told (among other measurements) the position of some stars and planets, which were shown on a mechanically rotated armillary sphere.
== Popular culture and museum replicas ==