Antikythera 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 hypotheses, 250 BC It is a sophisticated planetarium, driven by gear wheels, which was used to calculate the sunrise, the lunar phases, the movements of the five planets then known, the equinoxes, the months, the days of the week and - according to a study published in Nature - the dates of the Olympic games. It takes its name from the Greek island of Anticitera (Cerigotto) where it was found in the wreck of Anticitera, the remains of a shipwreck that took place 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 analyzes

The mechanism was found in 1900 thanks to the report of a group of sponge fishermen who, 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, which was wrecked in the second quarter of the first century BC and used to transport prestigious objects, including bronze and marble statues.

On May 17, 1902, the archaeologist Valerios Stais, examining the finds recovered from the wreck, noticed that a block of stone had a gear incorporated inside. On closer examination it was discovered that what had initially appeared to be a stone was actually a heavily encrusted and corroded mechanism, of which three main parts and dozens of minor fragments had survived.

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

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

The mechanism is kept in the collection of bronzes 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 argued that the remains of the mechanism could be traced back to a planetary or an astrolabe. The controversies continued for a long time, but the question remained unresolved. Only in 1951 doubts about the mysterious mechanism began to be revealed. In fact, that year Professor Derek de Solla Price began to study the device, carefully examining each wheel and each piece and succeeding, after about twenty years of research, in discovering 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, finding indications on its 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 gear wheels could reproduce a ratio 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 about twenty gear wheels and a differential, a mechanism that allowed to obtain a rotation at a speed equal to the sum or the difference of two rotations at your place. Its purpose was to show, in addition to the sidereal lunar months, also the lunations, obtained by subtracting the solar motion from the sidereal lunar motion. Based on his research, Price concluded that, contrary to what had hitherto been believed, a tradition of very high technology actually existed in 2nd century BC Greece. aeronautical watch diver watch traveler watch