An X-ray image of the Antikythera mechanism

What are we seeing? An X-ray image of the mechanism made by Allan George Bromley. The picture represents the main fragment of the mechanism. The mechanism is divided in two main parts: front and back. According to Prices’ interpretation, the front part represents the movements of the Sun and Moon, the back part of other planets. A crank handle can be seen on the right of the picture. The crank handle was used to activate the movement of the gears.

A first reconstruction of the mechanism




This is a schematic reconstruction by Derek De Solla Price of the main gears of the mechanism viewed from the above. The crank handle can be seen on the left of the picture.

3 steps in the work of one scientist who studied the Antikythera mechanism

Prologue: Whom am I talking about? Derek J. De Solla Price (1922-1983), Professor of history of science at Yale University.

The first step: restoration. Price restored the remans of the mechanism, trying to clean it from incrustations and corrosions.

The second step: translation. Many Greek incriptions were translated. In the inscriptions the Sun is nominated a number of times. The planet Venus is also mentioned. An inscription mentioned 76 years (the Calippic cycle.), another 19 years (the Metonic cycle). It was then clear for those in the know that the mechanism was related to the study of the movements of celestial bodies.

The third step: X-rays. Price used X-rays to penetrate in the interior of the mechanism and find relevant features of it.

5Ws about the discovery of the Antikythera mechanism

Who discovered it? A team of sponge divers led by Captain Dimitrios Kondos.

What was discovered? A shipwreck, at first described as a heap of rotting corpses and horses lying on the sea bed. The sponge divers salvaged numerous artifacts from the waters, such as statues of a philosopher's head, a young boy, a discus thrower, the bronze Ephebe of Antikythera of c. 340 B.C., a Hercules, a marble bull and a bronze lyre. Many other small and common artifacts were also found. And finally a piece of rock with a gear wheel embedded in it….

Where was it discovered? In the sea near the coast of Antikythera .

When? In October 1900.

Why was it discovered? To enable us to probe deeper into the wisdom of the Ancients.

5Ws about the Antikythera mechanism

Who made it? Nobody knows for sure. It could have been made by the Greek Stoic philosopher Posidonius (ca. 135 BC – 51 BC) or by a student of him.

What is it? It is an orrery. A mechanical device that illustrates the relative positions and motions of the planets and the moon in the solar system in a heliocentric model.


Where was it made? If the Posidonius theory is correct it was made in Rhodes.

and so When? ca. 80 BC.

Why was it made? To track celestial bodies for astrologically important occasions such as religious events or births or possibly as an elaborate display of knowledge.