Machine of Anticythère

The machine of Anticythère (called sometimes the mechanism of Anticythère) is a archaeological Artifact ancient preserved at the archaeological National museum of Athens.
One of the multiple put forth assumptions, because of its presence on board a wreck, is that it was about part of a mechanism allowing in addition to calculation of the position of some Astre S, such as the Sun and the the Moon and to predict the eclipse S of them, but also a such Horloge of sophisticated ultra navy, to make the geographical point constantly to fix the Longitude observer, calculation redécouvert by the Christian occident only with the XVIIIe century, and still, only at the time of the passage of the sun to its zenith, thanks to the perseverance ofself-educated clock and watch maker John Harrison against the royal astronomers, around 1734.
The mechanism is based on the cycles of progression of the Babylonian Arithmétique. At the second century before J.C., Hipparque had developed a theory to explain the irregularities of the lunar movement because of its orbit elliptique.
She was discovered in 1900 by sponge fishermen, in a wreck close to the coasts of the Greek island of Anticythère, between Cythère and the Crete.
She is gone back to before 87 av J. - C. (see Origine and dating below) and it is the oldest mechanism with Engrenage S known.

History

Origin and dating

The first studies had identified the age of the mechanism to that of the ship, that is to say 87 av. J. - C., of new studies consider it older one century (see will infra). More precise datings are carried out in 2006 (on the wood of the ship and metals of the mechanism).

One is unaware of still his precise origin. According to the last studies the astronomer Hipparque (v. 190 av. J. - C. - 120 av. J. - C.), Posidonios (135 av. J. - C. - 51 av. J. - C.) or one their close relations in would be the originator.

The ship transporting the machine was Roman but its Greek cargo and most probably came from Rhodos or the close coasts.

Discovered

Little before Easter 1900, two caïques of Greek sponge fishermen (with the diving-suit) of Symi, Euterpe and Calliope, on the way towards North Africa, made stopover on the north-eastern coast of Anticythère. April 4th, 1900, one of the plungers, Elias Lykopantis (or Stadiatis) approximately discovered by chance the ancient wreck lying by 62 m basic. It went up an object of the cargo of it, the hand of a bronze statue - it belonged to the statue known as of the Philosopher. The fishermen did not modify their plans for all that of them, and it is only with the return, with the autumn, that they informed the Greek authorities - rather than the Othoman government on which Symi depended at the time - by Hellenic patriotism. The Greek government dispatched at once on the spot ships of its navy of war, on November 24th, 1900. The operations of reinflation of the wreck lasted until September 1901, and showed the accidental death of a fisherman and the paralysis of two others, struck by the evil depths. Many marble and bronze statues and statuettes were withdrawn from it, of which most famous is a beautiful young man often allotted to Euphranor or Lysippe (these discoveries currently fill three rooms of the archaeological National museum of Athens), as well as various objects (surgical instruments, bronze quadrant, etc).

It is considered that the discovery of the machine strictly speaking dated May 17th 1902 when the archeologist Valerios Stais realized that a piece of stone brought back of the site concealed encrusted inscriptions and gears. An examination revealed that in fact stone, it was about a rusted mechanism, of which there remained three important pieces and 82 smaller fragments.

First studies: first assumptions

The care and the address with which this machine was produced, as well as knowledge necessary in mechanics and astronomy the place to the row of the Hellenic enigmas but also Astronomique S or Mathématiques. Indeed, a firmly since anchored idea centuries stipulates that the Greek Aristocratie was famous for its dislike of the technical and applied arts often left to the Esclave S. They their preferred more abstract sciences, such as the Mathématiques or the Physique.

In the Fifties

A Calculator? It is what wanted to check Dr. Derek of Solla Price, Physicien and historian of sciences English. Using the electrolytic process of deoxidation, proves to be able to reconstitute and produce three-dimensional images with an accuracy of 50 Micron S.

Moreover, to complete this new scientific report, Edmunds caused, with the autumn 2005, a multidisciplinary team associating with the astronomers, the physicists, the mathematicians and the paleographers of the three universities most concerned, implying the following departments:

University of Cardiff, GB, school of Physics and Astronomy (82 people);
University of Athens: Section of Astronomy, Astrophysics and Mechanics. Director Pr Triberis Georges (Responsible: Pr Xénophon Foamed) (71 people);
University Aristote de Thessalonique: Section of Astrophysics, Astronomy and Mechanics of the department of Physics (72 people). (Person in charge: Pr John Seiradakis).

For Xénophon Foamed, directing of the laboratory of astrophysics of the university of Athens, which takes part in the investigations in progress on the disc: “The Greek part is much more complex than all known astrolabes, since one of the most sophisticated astrolabes that one knows, preserved at London, with the British Museum, does not comprise comparatively, which some gears and wheels with teeth.” . It indicates in this same article: “We could discover new inscriptions in Greek, on the parts of the mechanism or fragments of bronze sheets and thus decipher more than 2000 letters against only 900 for Price. These texts, which count a thousand of characters on the whole, are at the same time directions for use of the apparatus and a treaty of astronomy, referring to stars. Each week learns some to us a little more”, is filled with enthusiasm it. Four dials “at least” - and not three - indicate the positions of the Sun and the Moon, like, for smallest of the dials, the phases of our satellite.

“We are sure today that it was a question of a calculating machine the movements of the Sun and the Moon, perhaps also - we are not certain - those of some planets. However, the astronomical term of clock appears to me however inappropriate, the mechanism being apparently actuated by a crank.”

Although about this crank, it is still probable that it is about a simple mechanical winder. Other share, the form of the characters, compared with those of other inscriptions of the same time, leads the experts to date the part from the end of IIe century before our era.

Outlines

The team of the Research project communicated the results of the analyzes in progress at the time of an International Conference in Athens, on November 30th and on December 1st, 2006. The first publication was made by the scientific newspaper Nature. The experimental data (more than one terabyte) should be put in line during 2007.

Description of the machine

The mechanism

Thanks to the terabyte (10¹² bytes) of data on the internal structure, the mechanism is known in detail. Its operation is him less well-known.

This machine of Bronze, circular form, currently fragmented in 3 principal parts exposed to the Archaeological Museum of Athens, occupies the volume of small a 21 cm high, broad case of 16 and thick of 5 (dimensions of a book of intermediate size).

It is made up of more than 82 elements of which about thirty toothed wheels. It was to probably be actuated with the hand or by a hydraulic system. Its operation is based on the differential movements of the gears making it possible “to calculate” the position of the Astre S at a given time.

Inscriptions

They are made up of more than 2.200 Greek letters. These letters engraved on the bronze very small from 1,5 to 2,5 mm height are more or less eroded. Their form indicates the neighborhoods of 100 before J. - C..

The inscriptions are divided into two types:

an astronomical text “strange” in front of the mechanism (the words Venus, Hermes/Mercury, the zodiac appear there).
“directions for use” with the back, combining indications on the toothed wheels, the periods of these wheels and the phenomena astronomical.

This text is deciphered to 95%.

Interpretation

It seems to be the first machine able to restore data transformed after entry of other data. From this point of view, it can be regarded as true a Calculateur.

Similar objects in the ancient literature

Cicéron evokes two similar machines.

the first, built by Archimedes, was found with Rome thanks to the general Marcus Claudius Marcellus. The Roman soldier brought back it after the seat of Syracuse into 212 before JC, where the Greek scientist found death. Marcellus tested a large respect for Archimedes (perhaps due to the defensive machines used for the defense of Syracuse) and brought back only this object of the seat. Its family preserved the mechanism after her death and Cicéron examined it later 150 years. It describes it like able to reproduce the movements of the Sun, the the Moon and five planets:

“hanc sphaeram Gallus cum moveret, fiebat C soli luna totidem conversionibus in ventilated island quot diebus in ipso caelo succederet, ex quo and in will sphaera solis fieret eadem island defectio, and incideret luna tum in eam metam quae esset will umbra terrae, cum ground E regione” Cicero, Of Re Publica I 22 .

If Cicéron is not mistaken, that would like to say that this technology existed as of IIIe century before JC.

Cicéron also mentions a similar object built by his/her friend Posidonios ( Cicero, De Natura Deorum II.88 )

The two evoked mechanisms were in Rome, fifty years after the date of the shipwreck of the wreck of Anticythère. It is thus known that there existed at least three machines of this type. In addition, it seems that the machine of Anticythère proves too much sophisticated to constitute only one single work

Gallery

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