The Antikythera Mechanism, an advanced clock-like device made of bronze gear was discovered in the 1st century BCE. The complexity of the mechanism, based on mathematical principles accredited to Hipparchus, highlights the advanced technological capabilities that are believed to have been far ahead of its time.
Discovery and History
One of history’s greatest discoveries, The Antikythera Mechanism was discovered purely by accident. In 1990, off the coast of the Greek Island of Antikythera sponge divers found an ancient Roman shipwreck. Numerous artefacts including coins, statues, and jewellery were retrieved over the following year. Among these treasures was lying a lump of degraded bronze and wood, broken calcified remnants, which went largely unnoticed at the beginning. Along with the other items, it was sent to the National Archaeological Museum of Athen for cataloguing. Its true significance remained undiscovered for many years. Researchers, upon closer inspection, noticed that the bronze fragments consisted of gears and dials, which gave the initial assumption that it was a navigational device or a clock. The level of complexity was deemed too advanced at first, but later with advanced imaging techniques, the incredible function of the mechanism was revealed.
Now recognized as the earliest known analog computer, the Antikythera mechanism is believed to have been constructed around 150 BCE. Scholars believe that the mechanism was supposedly developed in Rhodes, where well-known astronomers like Hipparchus and Poseidonios once thrived. The mechanism was believed to predict the positions of the sun, moon, and planets and even calculate lunar and solar eclipses. Furthermore, its capability extended to the determination of phases of the moon and predicting important events like the ancient Olympic Games. Its discovery highlights the sophistication of early astronomical tools and impacts our understanding of ancient Greek society.
Design and Functionality
The Antikythera Mechanism is considered a highly advanced device and comprises a design encased in a wooden box with dimensions 32 cm x 16 cm x 10 cm. The front and back of the mechanism were covered by bronze plates with intricate calendars and astronomical scale markings. At least 39 interlocking gears worked in unison to move the seven pointers simultaneously; this method allowed prediction of different astronomical events. The front side of the mechanism comprises two concentric circular scales, with the outer scale being divided into 365 subdivisions for the various days of the year. Similarly, the inner scale is comprised of 12 zodiac constellations. The device further consisted of Sun and Moon pointers that moved according to the position of the celestial bodies, which helped in the indication of the sun and moon’s location in the sky for a given day.
Functioning much like a clock, the Antikythera Mechanism used trains of gears to carry out complex calculations. The mechanism was operated manually, with a user entering a specific date, and the device displayed the positions of the planets, moon, and sun. Lunar and Solar eclipses were marked with specific symbols, Σ for a lunar eclipse and H for a solar eclipse, which were used to track eclipses using a spiral scale. With the incorporation of the Saros cycle, the mechanism predicted eclipses every 223 days, and even the 19 years spanning the Metonic cycle.
Scientific Significance
Standing as a testament to the extraordinary engineering skills of ancient Greek mechanicians, the Antikythera Mechanism used gear trains, including pin-and-slot gears, to model complex movements of Celestial bodies, for instance, the Moon’s elliptical orbit. The understanding of gear systems and the design of similar advanced mechanisms wouldn’t be replicated in Europe until the development of mechanical clocks in the 13th century. The Antikythera Mechanism was built around the expertise of at least 20 different scientific fields inclusive of mathematics, engineering, astronomy, and metallurgy. The device reflects an extraordinary achievement and Greek’s expertise in mechanics and theoretical astronomy.
The device, with its capability to accurately predict the positions of the Sun, Moon, and planets, included an Egyptian-inspired calendar system, a lunisolar calendar based on the Saros and Exeligmos eclipse cycle. Furthermore, it incorporated the 19-year Meton cycle, which later contributed to Christian and Hebrew calendars. The Antikythera Mechanism may have served as a teaching device in ancient schools, for instance, the philosopher Posidoinus’s school. It was believed to be even a luxury item for wealthy people to show as an accessory to impress. Some scholars further add to the significance of the device marking its use for geographical and navigational reasons.
Modern Studies
The modern studies of the Antikythera Mechanism involve an interdisciplinary approach. Since its discovery in 1990, experts from various scientific fields like physics, chemistry, archaeology, underwater excavation, and ancient language have shared their expertise to decode and reconstruct the device. With extensive use of modern technologies such as X-ray tomography and Polynomial Texture Mapping (PTM) imaging, the internal workings of the device have been revealed and the reading of the faded inscriptions on its fragments has been possible. These studies have assisted scientists in aligning the device’s use in important historical events, such as the Pythian games. This further stands as a testament to how ancient Greeks used their knowledge of mathematics and astronomy.
The discovery of the mechanism has dramatically reshaped our understanding of the ancient Greek technological advancements. The historical similarity between devices like Cecero, Pappus of Alexandria, and Proclus has confirmed that such mechanisms were in use in the ancient period. The revolutionary gears and predictive capabilities of the device make it the earliest known analog computer. The revelation of the Antikythera Mechanism has not only revolutionised our understanding of ancient engineering but also highlighted the advances made in Hellenistic science.
References:
Amabile, A. (2022) A New Look at the Antikythera Mechanism. thesis. Dipartimento di Fisica “E. Pancini”.
Efstathiou, K., Efstathiou, M. and Basiakoulis, A. (2023) ‘The artistic complexity of the Antikythera Mechanism: A Comprehensive Tutorial’, Proceedings of the European Academy of Sciences and Arts, 2. doi:10.4081/peasa.2.
Moussas, X. (2009) ‘The Antikythera mechanism: The oldest mechanical universe in its scientific milieu’, Proceedings of the International Astronomical Union, 5(S260), pp. 135–148. doi:10.1017/s1743921311002225.
