Anti-cythera machine

The Antikythera machine, also known as the Antikythera mechanism, is the oldest known mechanical calculator, dated between 150 and 100 BC. or, according to more recent hypothesis, to 250 aC It is a sophisticated planetarium, driven by cogwheels, which was used to calculate the sunrise, the lunar phases, the movements of the five known planets, the equinoxes, the months, the days of the week and - according to a study published on Nature - the dates of the Olympic games. The name derives from the Greek island of Anticitera (Cerigotto) where the wreck of Anticitera was found, remains of a shipwreck that occurred in the second quarter of the 1st century BC, containing, together with numerous objects of that time, also the "machine ". It is kept in the National Archaeological Museum of Athens.

Discovery and first analysis

The mechanism was found in 1900 thanks to the signaling of a group of sponge fishermen who, having lost their route due to a storm, had been forced to take refuge on the rocky island of Cerigotto. Off the island, at a depth of about 43 meters, they discovered the wreck of a ship, shipwrecked in the second quarter of the first century BC. and used for the transport of prestigious objects, including bronze and marble statues.

On 17 May 1902 the archaeologist Valerios Stais, examining the finds recovered from the wreck, noticed that a block of stone had a gear incorporated inside. With a more in-depth examination, it was discovered that what initially appeared to be a stone was in fact a strongly encrusted and corroded mechanism, of which three main parts and tens of minor fragments had survived.

It was a whole series of toothed wheels, covered with inscriptions, forming part of an elaborate clockwork mechanism.

The machine was about 30 cm by 15 cm in size, the thickness of a book, made of copper and originally mounted in a wooden frame. It was covered by over 2,000 characters of writing, about 95% of which was decrypted (the full text of the inscription has not yet been published).

The mechanism is preserved in the bronze collection of the National Archaeological Museum of Athens, together with its reconstruction.

Some scholars argued that the mechanism was too complex to belong to the wreck and some experts retorted that the remains of the mechanism could be traced back to a planetarium or an astrolabe. The controversy followed for a long time, but the question remained unresolved. Only in 1951 doubts about the mysterious mechanism began to be revealed. That year, in fact, Professor Derek de Solla Price began to study the device, scrupulously examining each wheel and each piece and succeeding, after about twenty years of research, to discover its original functioning.

In June 2016, a team of scientists, using high-resolution X-ray scans, was able to read the letters of an inscription engraved inside it, finding indications on the specific use: to detect astronomical events, eclipses and dates of the Olympic games .

Function and operation

The mechanism turned out to be a very ancient calculator for the solar and lunar calendar, whose toothed wheels could reproduce a relationship close to that necessary to reconstruct the motion of the Moon in relation to the Sun (the Moon makes 254 sidereal revolutions every 19 solar years).

The extreme complexity of the device was also due to the fact that this ratio was reproduced with the use of twenty toothed wheels and a differential, a mechanism that allowed to obtain a rotation at a speed equal to the sum or difference of two rotations. at your place. In addition to the lunar lunar months, its purpose was to show the lunations, obtained by subtracting the solar motion from the sidereal lunar motion. Based on his research, Price concluded that, contrary to what was hitherto believed, in Greece in the 2nd century BC. there actually existed a tradition of high technology.