The Antikythera Mechanism

One of the artefacts ranked among the Wonders of the Ancient World is the Antikythera Mechanism, the oldest extant complex geared device, also described as the first analogue computer. Its construction was variously estimated to about 87 BC; between 150 and 100 BC; to 205 BC; or finally, within a generation before the shipwreck, which has been dated to approximately 70-60 BC. It relied on the second-century BC Greek knowledge of astronomy and mathematics.

The main utility of the Antikythera mechanism was to calculate the exact position of the Sun, the Moon and possibly the planets in the sky as well the phases of the Moon and the prediction of eclipses. Apart from the prediction of astronomical events, the mechanism could also determine dates related to religious, social and agricultural rituals and events.

The Mechanism was accompanied by an extended “instructions manual” inscribed on one of its parts. The device was operated manually by a user, setting a date in a dial. All necessary calculations were made using a set of gears (at least 39), while the results were displayed on several scientific scales. Unfortunately, the specific purpose for which the Mechanism was made remains unknown.

The identity of its maker is also unknown, but the variety of skills and knowledge necessary for the creation of the Mechanism indicate that it required collaboration between an astronomer/mathematician and a mechanic.

With its discovery, the Antikythera Mechanism demonstrated that Greek engineers of the Hellenistic period had become far more fluent in designing and constructing geared devices than the surviving written sources infer. It is also notable that the knowledge transmitted by the mechanism was lost and similar technological works appeared much later in Byzantium (fifth-sixth century AD) and the Arab world, while complex ones like the Mechanism appeared in Western Europe in the fourteenth century.

The discovery and the prior scientific investigations

The Antikythera Mechanism was retrieved from the sea in 1901 near the coast of the Greek island of Antikythera. The divers retrieved also numerous large artefacts, including bronze and marble statues, pottery, unique glassware, jewellery and coins. A year later, the archaeologist Valerios Stais acknowledged that the curious artefact housed in the remains of the wooden box was an instrument composed by at least one gear. The device was found as one lump, which was subsequently divided into three main fragments during restoration. The Mechanism currently showcased at the National Archaeological Museum of Athens is divided into eighty-two separate parts.

Antikythera mechanism front view, model by Aristotle University of Thessaloniki, Thessaloniki Technology Museum. Gts-tg, CC BY-SA 4.0, via Wikimedia Commons.

As expected, the scholars who have been involved in the study of the Antikythera Mechanism were numerous, with specialization in various research fields. The first researchers who concentrated for over 30 years on the study of the function of the Mechanism published the most substantial and extensive article available today. A series of articles were also published dealing with the function of the mechanism and its calculations. The authors of the various papers formed eventually the core of the “Antikythera Mechanism Research Group” composed by researchers from Greece and the UK, supported in addition by an international team of astronomers, archaeologists, mathematicians, physicists, chemists, computer engineers, mechanical engineers, epigraphists and papyrologists. In September 2005 they undertook a major new investigation of the Antikythera Mechanism, using x-ray tomography and a PTM/RTI dome for the mapping of the texture of the fragments, which revealed internal details of the gears, as well as inscriptions previously undeciphered.

The importance of the Antikythera Mechanism has subsequently led to the formation of a research group at the Aristotle University of Thessaloniki, Greece, for its further study. Among the leaders of the research group in question was Prof. Kyriakos Efstathiou, currently holder of the “Mnemosyne” ERA Chair on Digital Cultural Heritage.

Mnemosyne’s research commitment

The complexity along with the universal reputation of the Antikythera Mechanism as a world-class Cultural Heritage asset makes of it a challenging, as well as an ideal case study to include among those, which will be delivered by the ERA Chair team. The work undertaken in the context of this case study will be planned and closely supervised by Prof. K. Efstathiou who has carried out extensive research on it over the last twenty years, and thus possesses extended knowledge on the asset. It is therefore expected that the new knowledge and data, which will be produced regarding the history of the Mechanism, will be integrated and connected to the already existing ones.


Essential Bibliography

The Construction of the Metonic Pointer and the Back Plate Spirals,” J. Hist. Astron., vol. 45, no. 4, pp. 418–441, Nov. 2014, doi: 10.1177/0021828614537185.

M. Anastasiou, J. H. Seiradakis, J. Evans, S. Drougou, and K. Efstathiou, “The Astronomical Events of the Parapegma of the Antikythera Mechanism,” J. Hist. Astron., vol. 44, no. 2, pp. 173-A10, May 2013, doi: 10.1177/002182861304400204.

K. Efstathiou, A. Basiakoulis, M. Efstathiou, M. Anastasiou, and J. H. Seiradakis, “Determination of the gears geometrical parameters necessary for the construction of an operational model of the Antikythera Mechanism,” Mech. Mach. Theory, vol. 52, pp. 219–231, Jun. 2012, doi: 10.1016/j.mechmachtheory.2012.01.020.

K. Efstathiou, A. Basiakoulis, M. Efstathiou, M. Anastasiou, and J. H. Seiradakis, “The reconstruction of the antikythera mechanism,” in Proceedings of Science, 2012, vol. 2012-June, no. 3, doi: 10.1260/2047-4970.2.3.307.

K. Efstathiou and M. Efstathiou, “Celestial Gearbox,” Mech. Eng., vol. 140, no. 9, pp. 31–35, Sep. 2018, doi: 10.1115/1.2018-SEP1.

T. Freeth et al., “Decoding the Antikythera Mechanism,” 2006.

A. Jones, Portable Cosmos. 2017.

J. H. Seiradakis and M. G. Edmunds, “Our current knowledge of the Antikythera Mechanism,” Nature Astronomy, vol. 2, no. 1. Nature Publishing Group, pp. 35–42, Jan. 01, 2018, doi: 10.1038/s41550-017-0347-2.

M. T. Wright, “Epicyclic Gearing and the Antikythera Mechanism–Part II,” Antiq. Horol., vol. 29, no. 1, pp. 51–63, 2005.