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  • Το μυστικό του Μηχανισμού των Αντικυθήρων - Το τελειότερο τεχνολογικό επίτευγμα της αρχαιότητας έδειχνε και τον χρόνο τέλεσης των Πανελληνίων Αγώνων | The Antikythera Mechanism Research Project
    εμφανής η μεγάλη περιπλοκότητά του για μια τέτοια απλή χρήση Το ότι είχε σχέση με την Αστρονομία ήταν επίσης εμφανές καθώς από τις επιγραφές που ήταν ευανάγνωστες είχαν διαβαστεί τα ονόματα του Ηλιου και της Σελήνης Για τη λύση του γρίφου της λειτουργίας του τελειότερου γνωστού τεχνολογικού επιτεύγματος της Αρχαιότητας απαιτήθηκε η τελευταία λέξη της σύγχρονης απεικονιστικής τεχνολογίας αξιοποιώντας τις δυνατότητες της ψηφιακής ακτινογραφίας οι ερευνητές του προγράμματος του Μηχανισμού των Αντικυθήρων μπόρεσαν να συλλέξουν δεδομένα για το εσωτερικό του χωρίς να τραυματίσουν το ήδη κατακερματισμένο όργανο υπάρχουν 82 θραύσματα του μηχανισμού οι διαστάσεις του οποίου ήταν 32x20x10 εκατοστά Τα δεδομένα που συγκεντρώθηκαν με τη βοήθεια της ψηφιακής ακτινογραφίας πριν από τρία χρόνια βοήθησαν στη διαλεύκανση του ρόλου του μηχανισμού και κατέδειξαν τη μηχανική πολυπλοκότητά του σε όλο της το μεγαλείο Μπορεί να φανταστεί κανείς τον μηχανισμό σαν ένα επιτραπέζιο ρολόι με ένα μεγάλο καντράν στην πρόσθια και δύο στην οπίσθια όψη του Στο εσωτερικό του 31 γρανάζια ίσως και περισσότερα αλλά μόνο τόσα έχουν εντοπισθεί χρησιμοποιήθηκαν προκειμένου στις ενδείξεις των καντράν να συνοψισθούν όλες οι αστρονομικές γνώσεις της εποχής του 150 100 π Χ Ετσι το καντράν της πρόσθιας όψης ήταν ένα κλασικό ημερολόγιο 365 ημερών με δυνατότητα ρύθμισης για δίσεκτα έτη ενώ έδειχνε πιθανότατα τις σχετικές θέσεις των πλανητών Το οπίσθιο μέρος του μηχανισμού φιλοξενούσε δύο μεγάλα σπειροειδή καντράν το επάνω αντιπροσώπευε τον Μετονικό κύκλο και το κάτω τον κύκλο του Σάρου Ο Μετονικός είναι ένας κύκλος 19 ετών ή 235 σεληνιακών μηνών Ενας σεληνιακός ή συνοδικός μήνας είναι το διάστημα μεταξύ δύο ομοίων φάσεων της Σελήνης π χ από Πανσέληνο σε Πανσέληνο Ο κύκλος αυτός αντιπροσωπεύει την επιστροφή της Σελήνης στην ίδια φάση και στην ίδια ημερομηνία του έτους Με το κλείσιμο του κύκλου ο Ηλιος η Σελήνη και η Γη επιστρέφουν στους ίδιους περίπου σχετικούς προσανατολισμούς Ο κύκλος του Σάρου προβλέπει εκλείψεις αν μια ηλιακή ή σεληνιακή έκλειψη συμβεί σήμερα μια παρόμοια θα συμβεί ύστερα από 223 σεληνιακούς μήνες Και τα δύο μεγάλα οπίσθια καντράν έφεραν στο εσωτερικό τους μικρότερα Το μικρό καντράν στο εσωτερικό του κύκλου του Σάρου αντιπροσώπευε τον κύκλο του Εξελιγμού ο οποίος έχει διάρκεια 54 ετών Ο κύκλος αυτός επιτρέπει τον ακριβή προσδιορισμό του χρόνου των εκλείψεων διαδοχικές σεληνιακές εκλείψεις είναι μετατοπισμένες κατά 8 ώρες και διαδοχικές ηλιακές εκλείψεις οι οποίες γίνονται ορατές από συγκεκριμένα γεωγραφικά πλάτη είναι μετατοπισμένες κατά 120 μοίρες Ακριβείς επαναλήψεις σεληνιακών εκλείψεων λαμβάνουν χώρα ύστερα από τρεις κύκλους του Σάρου όταν οι οκτάωρες μετατοπίσεις συμπληρώσουν ένα 24ωρο και αυτό περιγράφεται από τον κύκλο του Εξελιγμού όπου διακρίνονται οι ενδείξεις 8 και 16 Η διαλεύκανση του ρόλου των οπισθίων καντράν του μηχανισμού η οποία είχε περιγραφεί λεπτομερώς σε άρθρο στην επιθεώρηση Νature 30 Νοεμβρίου 2006 ανέδειξε τον μηχανισμό ως εργαλείο τεραστίου αστρονομικού ενδιαφέροντος Κανείς όμως τότε δεν είχε υποπτευθεί ότι το εργαλείο αυτό θα μπορούσε να έχει και ρόλο στην καθημερινότητα των ανθρώπων Βλέπετε δεν είχε ακόμη διαλευκανθεί ο ρόλος του πάνω μικρού εσωτερικού καντράν στο οπίσθιο μέρος του μηχανισμού Για την ακρίβεια είχε θεωρηθεί ότι αυτό θα έπρεπε

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  • Ancient Greek Eclipse Calculator Marked Olympics - Antikythera mechanism linked to Archimedes' home of Syracuse | The Antikythera Mechanism Research Project
    to account for the fact that 12 lunar months add up to only 354 days 11 days shy of a solar year Gears located behind the dial face would have moved a pointer like the minute hand on a clock to refer a user to particular markings on the dial Writing in Nature the team was able for the first time to read the names of the months on the dial which match those of calendars once used in the Corinthian colonies of northwestern Greece suggesting that the mechanism was built in the area Seven of the month names match a calendar used in a part of Sicily believed founded by settlers from Syracuse in the fourth century B C Syracuse was home to Archimedes the polymath who in one apocryphal story leaped from a bath shouting Eureka I have it after figuring out how to tell if a royal crown was made of solid gold by submerging it in water and measuring the water it displaced Researchers assume that the Antikythera mechanism built in approximately 150 to 100 B C sank on its way from the Greek island of Rhodes to Rome then a major trading route Although Archimedes died in 212 B C too early to have built the Antikythera mechanism the Roman philosopher Cicero attributes a device to Archimedes that was similar to it There s a chance that it s a kind of descendent of his invention study author Alexander Jones a historian of ancient science at the Institute for the Study of the Ancient World at New York University says Whatever purpose Archimedes may have had in mind for his instrument Jones says the use of the Corinthian calendar indicates that the Antikythera mechanism was not built for scientists Instead it may have been for teaching nonspecialists about astronomy Bolstering that interpretation the researchers discovered that the markings on a smaller dial inside the Metonic one spelled out the locations of the names of Panhellenic games the highly popular sporting events of which the most famous is the Olympics The games were on a four year cycle and each quarter turn of the dial indicated which games took place that year in the cycle That s something of no scientific interest That s of human social interest Jones says One of the things the mechanism was well suited to teach was the predictability of eclipses the apparent task of a second four twist spiral dial on the instrument s back Its 223 divisions correspond to months in the Saros cycle another ancient calendar system this one an 18 year cycle for tracking eclipses Of these divisions researchers had previously identified 16 that were marked with glyphs or sets of characters indicating solar and lunar eclipses The team increased that number by two to 18 The pattern of glyphs was highly accurate it matched the start dates of 100 eclipses that occurred during the final four centuries BC as determined by NASA We could start the

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  • Fragmentary Knowledge - Was the Antikythera Mechanism the world’s first computer? | The Antikythera Mechanism Research Project
    had a tradition of great inventors beginning with Archimedes of Syracuse c 287 212 B C who in addition to his famous planetarium is believed to have invented a terrible clawed device made up of large hooks submerged in the sea and attached by a cable to a terrestrial hoist the device was capable of lifting the bow of a fully loaded warship into the air and smashing it down on the water the Greeks reportedly used the weapon during the Roman siege of Syracuse around 212 B C Philon of Byzantium who lived around 200 B C made a spring driven catapult Heron of Alexandria who lived around the first century A D was the most ingenious inventor of all He described the basic principles of steam power and is said to have invented a steam powered device in which escaping steam caused a sphere with two nozzles to rotate He also made a mechanical slot machine a water powered organ and machinery for temples and theatres including automatic swinging doors He is perhaps best remembered for his automatons simulations of animals and men cleverly engineered to sing blow trumpets and dance among other lifelike actions Although a book by Heron Pneumatica detailing various of these inventions has survived some scholars have dismissed his descriptions as fantasy They have pointed to the lack of evidence no trace of any of these marvellous machines has been found But as other scholars have pointed out the lack of archeological evidence isn t really surprising No doubt the machines eventually broke down and as the know how faded there was no one around who could fix them so they were sold as scrap and recycled Very few technical drawings or writings remained because as Paul Keyser observes the texts that survive tend to be the more popular texts i e those that were more often copied and textbooks not the research works or the advanced technical ones Eventually following the dissolution of the Roman Empire the technological knowledge possessed by the Greeks disappeared from the West completely But if the Greeks did have greater technological sophistication than we think they did why didn t they apply it to making more useful things time and work saving machines for example instead of elaborate singing automatons Or is what we consider important about technology which is above all that it is useful different from what the Greeks considered worthwhile amusement enlightenment delight for its own sake According to one theory the Greeks because they owned slaves had little incentive to invent labor saving devices indeed they may have found the idea distasteful Archimedes claws notwithstanding there was as Keyser notes cultural resistance to making high tech war machines because both the Greeks and the Romans valued individual bravery in war In any case in the absence of any obvious practical application for Greek technology it is easy to believe that it never existed at all In 1958 Derek de Solla Price a fellow at the Institute for Advanced Study in Princeton went to Athens to examine the Mechanism Price s interests fell between traditionally defined disciplines Born in Britain he trained as a physicist but later switched fields and became the Avalon Professor of the History of Science at Yale he is credited with founding Scientometrics a method of measuring and analyzing the pursuit of science The study of the Mechanism which incorporates elements of archeology astronomy mathematics philology classical history and mechanical engineering was ideally suited to a polymath like Price and it consumed the rest of his life Price believed that the Mechanism was an ancient computer which could be used to calculate astronomical events in the near or distant future the next full moon for example He realized that the inscriptions on the large dial were calendrical markings indicating months days and the signs of the zodiac and postulated that there must have been pointers now missing that represented the sun and the moon and possibly the planets and that these pointers moved around the dial indicating the position of the heavenly bodies at different times Price set about proving these theories basing his deductions on the fundamental properties of gearing Gears work by transmitting power through rotational motion and by realizing mathematical relationships between toothed gear wheels The Mechanism concentrates on the latter aspect Price seems to have assumed that the largest gear in the artifact which is clearly visible in Fragment A was tied to the movement of the sun one rotation equalled one solar year If another gear representing the moon was driven by the solar gear then the ratio of wheels in this gear train must have been designed to match the Greeks idea of the moon s movements By counting the number of teeth in each gear you could calculate the gear ratios and by comparing those ratios to astronomical cycles you can figure out which gears represented which movements However because only a few of the gears appear at the surface of the Mechanism and because many of the gear teeth are missing Price had to develop methods for estimating total numbers from partial tooth counts Finally in 1971 he and a Greek radiographer Dr C Karakalos were permitted to make the first X rays of the Mechanism and these two dimensional images showed almost all the remaining gear teeth Price developed a schematic drawing of a hypothetical reconstruction of the internal workings of the Mechanism In 1974 Price published his research in the form of a seventy page monograph titled Gears from the Greeks He had written Nothing like this instrument is preserved elsewhere Nothing comparable to it is known from any ancient scientific text or literary allusion On the contrary from all that we know of science and technology in the Hellenistic Age we should have felt that such a device could not exist Price expected his work on the Mechanism to change the history of technology The Mechanism requires us to completely rethink our attitudes toward ancient Greek technology he wrote and later added It must surely rank as one of the greatest mechanical inventions of all time Price also pointed out that the Mechanism cannot have been the only one of its kind no technology this sophisticated could have appeared suddenly fully realized Not only did the Mechanism demonstrate that our concept of ancient technology was fundamentally incomplete it also contradicted the neo Darwinian concept of technical progress in general as a gradual evolution toward ever greater complexity technological history being the last refuge of the nineteenth century belief in progress an idea firmly embedded in A P Usher s classic 1929 study A History of Mechanical Inventions As Price writes it is a bit frightening to know that just before the fall of their great civilization the ancient Greeks had come so close to our age not only in their thought but also in their scientific technology But Price s work though widely reviewed in scholarly journals did not change the way the history of the ancient world is written Otto Neugebauer s huge A History of Ancient Mathematical Astronomy which came out the year after Gears relegates the Mechanism to a single footnote Scholars and historians may have been reluctant to rewrite the history of technology to include research that had lingering doubts attached to it Also Price s book was published at the height of the popularity of Chariots of the Gods a 1968 book by the Swiss writer Erich von Däniken which argued that advanced aliens had seeded the earth with technology and Price got associated with U F O s and crop circles and other kinds of fringe thinking Finally as Paul Keyser told me Classical scholarship is very literary and focusses on texts such as the writing of Homer Sophocles Virgil or Horace or it is old fashioned and historical and focusses on leaders and battles through the texts of Herodotus and Thucydides or it is anthropological archeological and focusses on population distributions and suchlike So when an archeological discovery about ancient technology arrives it does not fit because it s new it s scientific and it s not a text Plus there is only one such device and unique items tend to worry scholars and scientists who quite reasonably prefer patterns and larger collections of data Whatever the reason as one scholar Rob Rice noted in a paper first presented in 1993 It is neither facile nor uninstructive to remark that the Antikythera mechanism dropped and sank twice once in the sea and once in scholarship The National Museum in Athens took no special pains in displaying the lumps of bronze Item 15087 wasn t much to look at When the physicist Richard Feynman visited in 1980 there was little information explaining what the Mechanism was In a letter to his family later published in the book What Do You Care What Other People Think the physicist wrote that he found the museum slightly boring because we have seen so much of that stuff before Except for one thing among all those art objects there was one thing so entirely different and strange that it is nearly impossible It was recovered from the sea in 1900 and is some kind of machine with gear trains very much like the inside of a modern wind up alarm clock When Feynman asked to know more about item 15087 the curators seemed a little disappointed One said Of all the things in the museum why does he pick out that particular item what is so special about it For the Greeks as for other ancient civilizations astronomy was a vital and practical form of knowledge The sun and the moon were the basis for calendars by which people marked time The solar cycle told farmers the best times for sowing and harvesting crops while the lunar cycle was commonly used as the basis for civic obligations And of course for mariners the stars provided some means of navigating at night Xenophon Moussas one of the two Greek astronomers who are part of the research project is a compact soft spoken man He grew up in Athens and as a boy visiting the museum he often pondered the Mechanism now as a professor of astrophysics he uses it to connect with his undergraduate students for whom ancient technology is often more compelling than ancient theory One evening in January Moussas led me on a memorable walk around the archeological park in central Athens which includes both the Greek and the Roman agoras As a quarter moon shone in the clear night sky illuminating the ruined temples and markets Moussas narrated the story of how the ancients slowly learned to recognize patterns and serial events in the movements of the stars and to use them to tell time and to predict future astronomical events It was a way of keeping track not of time as we think of it he told me but of the movement of the stars a deeper time For the Greeks like the Babylonians before them the year consisted of twelve lunations or new moon to new moon cycles each of which lasted an average of twenty nine and a half days The problem with a lunar calendar is that twelve lunar cycles takes about eleven days less than one solar cycle That means that if you don t make regular adjustments to the calendar the seasons soon slip out of synch with the months and after eighteen years or so the summer solstice will occur in December Finding a system that reconciled the lunar year with the solar year was the great challenge of calendar making Most ancient societies readjusted their calendars by adding a thirteenth intercalary month every three years or so although methods of calculating the length of these months and when they should be added were never precise Babylonian astronomers hit upon an improvement They discovered that there are two hundred and thirty five lunar months in nineteen years In other words if you observe a full moon on April 4th there will be another full moon in that same place on April 4th nineteen years later This cycle which eventually came to be known as the Metonic cycle after the Greek astronomer Meton of Athens was an extremely useful tool for keeping the lunar calendar and the solar calendar in synch The Metonic cycle is still used by the Christian Churches to calculate the correct day for celebrating Easter The Babylonians also established what would come to be known as the saros cycle which is a way of predicting the likely occurrence of eclipses Babylonian astronomers observed that eighteen years eleven days and eight hours after an eclipse a nearly identical eclipse will occur Eclipses were believed by many ancient societies to be omens that depending on how they were interpreted could foretell the future of a monarch for example or the outcome of a military campaign The Greeks in turn discovered the Callippic cycle which consisted of four Metonic cycles minus one day and was an even more precise way to reconcile the cycles of the sun and the moon But the Greeks real genius was to work out theories to explain these cycles In particular they brought the concept of geometry to Babylonian astronomy As Alexander Jones a professor of classics at the University of Toronto put it to me recently The Greeks saw the Babylonian formulas in terms of geometry they saw all these circles all spinning around each other in the sky And of course this fits in perfectly with the concept of gearworks the gears are making little orbits Some Greek inventor must have realized that it was possible to build a simulation of the movements in the heavens by reproducing the cycles with gears But who Price called the inventor simply some unknown ingenious mechanic Others have speculated that the inventor was Hipparchus the greatest of all ancient Greek astronomers Hipparchus who is also believed to have invented trigonometry lived on the island of Rhodes from about 140 to 120 B C He detailed a theory to explain the anomalous movements of the moon which appears to change speed during its orbit of the Earth Hipparchus is also thought to have founded a school on Rhodes that was maintained after his death by Posidonius with whom Cicero studied in 79 B C In one of his letters Cicero mentions a device recently constructed by our friend Posidonius which sounds very like the Mechanism and which at each revolution reproduces the same motions of the sun the moon and the five planets that take place in the heavens every day and night As Moussas and I headed uphill toward the Acropolis he pointed out the spot where Meton s astronomy school and solar observatory had been On our way back down we stopped at the famous Tower of the Winds the now gutted shell of what was the great central clock of ancient Athens Designed by the renowned astronomer Andronicus of Cyrrhus it is thought to have been an elaborate water clock on the inside and a sundial on the outside But in light of what we know about the Mechanism Moussas said I am beginning to wonder whether this was a much more complicated clock than we think When Derek Price died of a heart attack in 1983 his work on the Mechanism was unfinished Although his fundamental insights about the device were sound he hadn t figured out all the details nor had he succeeded in producing a working model that was correct in all aspects That year in London a Lebanese man walked into the Science Museum on Exhibition Road with an ancient geared mechanism wrapped in a handkerchief in his pocket Michael Wright one of the curators of mechanical engineering was summoned to examine the artifact which was in four main fragments The man said that he d bought the artifact in a street market in Beirut several weeks earlier The Science Museum eventually bought it from him and Wright and a colleague J Field showed that it was a geared sundial calendar that displayed the positions of the sun and the moon in the zodiac Wright also built a reconstruction of the sundial The style of lettering on the dial dated the device to the sixth century A D making it the second oldest geared device ever found after the Antikythera Mechanism In addition to his job as a curator Wright helped to maintain the old clocks exhibited in the museum Among them was a replica of the oldest clock that we have a clear account of constructed in the early fourteenth century by Richard of Wallingford the Abbot of St Albans It was a fantastic astronomical device called the Albion All by One Another reconstruction was of a famous planetarium and clock built by Giovanni de Dondi of Padua in the mid fourteenth century known as the Astrarium Like many students of mechanical history Wright had noted this odd upwelling of clockwork in Europe appearing in several places at around the same time He was familiar with the theory that many of the elements of clockwork were known to the ancients With the decline of the West goes this theory technical expertise passed to the Islamic world just as many of the Greek texts were translated into Arabic and therefore preserved from loss or destruction In the ninth century the Banu Musa brothers in Baghdad published the Book of Ingenious Devices which detailed many geared mechanical contrivances and the tenth century philosopher and astronomer al Biruni 973 1048 describes a Box of the Moon a mechanical lunisolar calendar that used eight gearwheels The more Wright looked into these old Islamic texts the more convinced he became that the ancient Greeks knowledge of gearing had been kept alive in the Islamic world and reintroduced to the West probably by Arabs

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  • Unearthing four new mysteries | The Antikythera Mechanism Research Project
    By Antikythera Mec Posted on 23 August 2013 Data Publication Date 12 12 2006 00 Media name BBC Radio 4 Media type Radio Country United Kingdom Author Aubrey Manning Link to the publication The Antikythera Mechanism is an intricate bronze device of wheels dials and gears created more than two thousand years ago by the Ancient Greeks Found at the bottom of the sea by sponge divers on the wreck of a Roman cargo ship it has fascinated astronomers mathematicians engineers and historians ever since Crafted with precision engineering and covered with astronomical symbols and inscriptions was it an early astronomical computer The sophisticated technology used to make it isn t seen until medieval clocks 1000 years later Could its existence mean the ancient Greeks knew the Earth moved round the Sun more than a millennia before Copernicus brought it to the world in the sixteenth century Aubrey goes in search of who made it what it was used for and why its existence might mean a rethink of our understanding of the history of science and technology Bookmark Search this post with Google Plus One Pinterest Login or register to post comments Tweets by antikytheradive Upgrade tasks Check upgrade

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  • Computer Provides More Questions Than Answers - Scientists Mystified by 2,100-Year-Old Device | The Antikythera Mechanism Research Project
    what purpose Why did the technology behind it disappear for the next thousand years What does the device tell us about ancient Greek culture And does the marvelous construction and the precise knowledge of the movement of the sun and moon and Earth that it implies tell us how the ancients grappled with ideas about determinism and human destiny We have gear trains from the 9th century in Baghdad used for simpler displays of the solar and lunar motions relative to one another they use eight gears said François Charette a historian of science in Germany who wrote an editorial accompanying a new study of the mechanism two weeks ago in the journal Nature In this case we have more than 30 gears To see it on a computer animation makes it mind boggling There is no doubt it was a technological masterpiece The device was probably built between 100 and 140 BC and the understanding of astronomy it displays seems to have been based on knowledge developed by the Babylonians around 300 700 BC said Mike Edmunds a professor of astrophysics at Cardiff University in Britain He led a research team that reconstructed what the gear mechanism would have looked like by using advanced three dimensional imaging technology The group also decoded a number of the inscriptions The mechanism explores the relationship between lunar months the time it takes for the moon to cycle through its phases say full moon to full moon and calendar years The gears had to be cut precisely to reflect this complex relationship 19 calendar years equal 235 lunar months By turning the gear mechanism which included what Edmunds called a beautiful system of epicyclic gears that factored in the elliptical orbit of the moon a person could check what the sky would have looked like on a date in the past or how it would appear in the future The mechanism was encased in a box with doors in front and back covered with inscriptions a sort of instruction manual Inside the front door were pointers indicating the date and the position of the sun moon and zodiac while opening the back door revealed the relationship between calendar years and lunar months and a mechanism to predict eclipses If they needed to know when eclipses would occur and this related to the rising and setting of stars and related them to dates and religious experiences the mechanism would directly help said Yanis Bitsakis a physicist at the University of Athens who co wrote the Nature paper It is a mechanical computer You turn the handle and you have a date on the front Building it would have been expensive and required the interaction of astronomers engineers intellectuals and craftspeople Charette said the device overturned conventional ideas that the ancient Greeks were primarily ivory tower thinkers who did not deign to muddy their hands with technical stuff It is a reminder he said that while the study of history often focuses on written texts

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  • Scientists unlock mystery of 2,000-year-old computer | The Antikythera Mechanism Research Project
    the mechanism worked This device is just extraordinary the only thing of its kind said Edmunds in announcing the results The design is beautiful the astronomy is exactly right The way the mechanics are designed just makes your jaw drop Whoever has done this has done it extremely well The researchers will be releasing their full findings of what they are regarding as a 2 000 year old computer at a two day international conference in Athens on Thursday and Friday Created between 150 BC and 100 BC the mechanism contained 37 gear wheels in a case of wood and bronze in a contraption that resembled a clock The gear wheels were designed to track the movements of the sun and moon and even track eclipses and the irregular orbit of the moon It may also have been able to follow some of the planets Also astonishing is the machine s use of a differential gear a device known to have been used in the 17th century but often speculated to have been invented years earlier The device is an arrangement of gears that permits the rotation of two shafts at different speeds It is most commonly associated in modern usage with automobiles which use a differential gear on their rear axle to allow different rates of wheel rotation on curves The intricacy of the device is also comparable to that of 18th century clocks State of the art in astronomy I m very surprised to find a mechanical representation of this Alexander Jones an astronomy historian who works at the University of Toronto told Nature Jones predicts the mechanism will have a profound impact on our view of the history of science This was absolutely state of the art in astronomy at the time The greater question puzzling scientists

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  • Greeks owned the skies - Their astronomical calculator was so sophisticated, it was unequaled for centuries | The Antikythera Mechanism Research Project
    reappearing in a less advanced form Much of the mind boggling technological sophistication available in some parts of the Hellenistic and Greco Roman world was simply not transmitted further he wrote in an editorial accompanying the team s report in the journal Nature The device was found by Greek sponge divers in 120 feet of water off the coast of the Greek island of Antikythera midway between the southern tip of Greece and Crete The site is on a major trade route between the island of Rhodes and Rome Coins on the ship suggest it sank shortly after 85 BC Other artifacts from the ship indicate it carried a cargo of luxury goods including statues and silver coins that probably originated in Rhodes and was bound for Rome s elite The new study suggests that the Antikythera mechanism predates the sinking by 15 to 20 years The late British science historian Derek de Solla Price was the first to use modern technology to study the device Over the course of two decades beginning in the 1950s he used X ray and gamma ray images to reveal gears inside the corroded pieces He concluded correctly that it was an astronomical calculator But the device as he reconstructed it was unduly complicated and there were many gaps in his explanation of how it worked Edmunds said his interest in the device was piqued several years ago by a student who pointed it out to him He began studying the published literature eventually producing a review article But truly understanding it he concluded would require a more detailed knowledge of its encrusted gears Edmunds team brought a 7 5 ton X ray tomography machine similar to that used to perform CT scans on human patients into the National Archeological Museum of Athens to examine the fragments in greater detail than was possible before They were able to image the bronze gears more clearly and deciphered twice as many inscriptions on the casing They concluded that the device contained 37 gears about 30 of which still survive It was originally housed in a wooden case slightly smaller than a shoebox Two dials on the front show the zodiac and a calendar of the days of the year that can be adjusted for leap years Metal pointers show the positions in the zodiac of the sun moon and five planets known in antiquity Two spiral dials on the back show the cycles of the moon and predict eclipses The complicated meshing of the gears is a physical representation of the so called Callippic and saros astronomical cycles In the Callippic cycle for example the sun moon and Earth return to the same relative orientations four times in 76 years minus one day The saros cycle predicts that following a solar or lunar eclipse a similar eclipse will occur 223 lunar months later By turning the gears with a hand crank the user could select a specific day in the past or future and observe the

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  • Mysteries of computer from 65BC are solved | The Antikythera Mechanism Research Project
    the stricken ship subsequently revealed 80 pieces of gear wheels dials clock like hands and a wooden and bronze casing bearing ancient Greek inscriptions Since its discovery scientists have been trying to reconstruct the device which is now known to be an astronomical calendar capable of tracking with remarkable precision the position of the sun several heavenly bodies and the phases of the moon Experts believe it to be the earliest known device to use gear wheels and by far the most sophisticated object to be found from the ancient and medieval periods Using modern computer x ray tomography and high resolution surface scanning a team led by Mike Edmunds and Tony Freeth at Cardiff University peered inside fragments of the crust encased mechanism and read the faintest inscriptions that once covered the outer casing of the machine Detailed imaging of the mechanism suggests it dates back to 150 100 BC and had 37 gear wheels enabling it to follow the movements of the moon and the sun through the zodiac predict eclipses and even recreate the irregular orbit of the moon The motion known as the first lunar anomaly was developed by the astronomer Hipparcus of Rhodes in the 2nd century BC and he may have been consulted in the machine s construction the scientists speculate Remarkably scans showed the device uses a differential gear which was previously believed to have been invented in the 16th century The level of miniaturisation and complexity of its parts is comparable to that of 18th century clocks Some researchers believe the machine known as the Antikythera Mechanism may have been among other treasure looted from Rhodes that was en route to Rome for a celebration staged by Julius Caesar One of the remaining mysteries is why the Greek technology invented for the

    Original URL path: http://www.antikythera-mechanism.gr/media/clips/668 (2016-02-11)
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