Embedded Files
Your Attention : Please visit the next web pages which are displayed at the left !.. Thank you.
Your Attention : Please visit the next web pages which are displayed at the left !.. Thank you.
and ... of course ... please scroll down ...
==========
*****************
This web page was created by the braintumorguy, in Athens, GREECE.
please make a Small Donation, in my fight against my Brain Tumor which is Growing, ((( for more information about me, please visit my MEDICAL web page
https://sites.google.com/site/niactec/homeenglish )))
==========
*****************
The Antikythera Mechanism - The World's Oldest Computer
More than two thousand years ago, one small yet remarkable device sank in heavy seas off the tiny Greek island of Antikythera.
Two millennia later, Greek sponge divers by happenstance discovered the sunken treasure and brought it to the surface.
In the course of months it weathered, dried, split open and revealed its hidden secret: a large number of corroded yet clearly discernible interlocking precision bronze gearwheels.
Amazingly, the Antikythera mechanism is nothing less than a 2000-year-old analogue computer of astounding sophistication. As Arthur C. Clarke wrote, “though it is more than 2,000 years old, the Antikythera Mechanism represents a level that our technology did not match until the eighteenth century, and must therefore rank as one of the greatest basic mechanical inventions of all time.”
Clarke also realised how much had been lost. It was unsettling to think that in the Antikythera mechanism the Greeks had come so close to our modern technology, only to fall back again for so long. He articulated his thoughts a few years later in a lecture on the limits of technology at the Smithsonian Institution in Washington DC. If the Greeks had been able to build on their knowledge, Clarke told his audience, the Industrial Revolution might have begun more than a millennium ago. ‘By this time we would not merely be pottering around on the Moon. We would have reached the nearer stars.
*****************
"Every nation is proud of his spiritual possession. But the Greek race standing taller than any other, because ithas the merit to be the mother of all civilization. "
Ulrich von Wilamowitz Mðllendorf, (1848-1931), German philologist, a leading interpreter of the ancient Greek civilization.
Whenever we speak of ancient Greece and the achievements of their civilization, we inevitably find ourselves asking the question “Why the Greeks?” What was it that led this numerically small people of the Mediterranean to emerge first from the Archaic stage, in which all other ancient peoples were at a standstill, and strive towards the accomplishments of the Classical period?
To explain the singularity of ancient Greek civilization, we identify something that no other people had at the time as the baseline value of the ancient Greeks: the capacity to question. That is to say, while the predominant values of other peoples could be summed up in the view that “we must hand down to our children the world we inherited from our forefathers,” the ancient Greeks were the first to challenge this perception, by submitting to judgment those ideologies and convictions that had been passed on to them. This is the common starting point for philosophy and democracy.
But such questioning at the time, unlike today, was far from the norm; it could not have appeared on its own, as it presupposes an inner tendency of people to wish to surpass certain limits. And this disposition for transcendence goes hand-in-hand with the element of competition: the desire to be tested, to confront, change, overturn and improve. In such a context, extrapolating our thoughts, one could say that a key concept for understanding and explaining ancient Greek civilization is the idea of agon (struggle, contest, competition).
Thus, questioning and agon were part of a single viewpoint, an overall life stance, which pervaded all manifestations of ancient Greek life, permeated all activities and was the driving force behind all expression of culture. In ancient Greek society, the concept of agon underlay the view that anything can be achieved as the result of effort, healthy rivalry and noble competition.
Often called the "birthplace of civilisation", Ancient Greece heralded numerous advances in philosophy, science, engineering and mathematics which have shaped our understanding of the modern world.
Western civilization has been influenced by many cultures, but his birth took place in ancient Greece. Apart from philosophers such as Aristotle and Socrates, Olympian gods, the beginnings of democracy and conquerors such as Alexander the Great, Greece brought as a contribution to mankind cool ideas that enriched the art of architecture and construction.
*****************
Heritage of history reflected in these postage 1890-1940
*****************
01. [ ENGLISH ] The Antikythera Mechanism -The BEST COLLECTION of PODCASTS and YOUTUBE VIDEOS for
for more information please visit the following web page
( please using the right click of your mouse, and Open Link in Next Private Window, )
********************
==============
Home » Technology » 2,000 Year Old Computer Discovered In Shipwreck
2,000 Year Old Computer Discovered In Shipwreck
2,000 Year Old Computer Discovered In Shipwreck
Posted on November 1, 2015 by Sean Adl-Tabatabai in Technology // 0 Comments
It appears that the advent of computing began before the birth of Christ, over 2000 years ago, after the discovery of a small bronze mechanism under the sea off Crete.
The Antikythera mechanism is thought to be the first ever programmable computer, and the oldest computer in existence.
Yahoo News reports:
Thanks to an intricate series of gears and dials, the mechanism could be used as a calendar, to track the phases of the moon, and to predict eclipses. It’s an object out of time: no other artefact as complex was built during the thousand years after the mechanism’s creation–that we know of.
The Antikythera mechanism was named after the shipwreck on which it was discovered. Having sunk to the bottom of the sea in the first century BCE taking the mechanism with it, the shipwreck lay undisturbed until 1900, when a group of Greek sponge divers discovered it and began bringing its treasures to the surface.
After the death of one diver and two others becoming paralysed, operations to recover the artefacts were brought to a halt, but not before statues, ceramics, and the mechanism itself were brought up.
In 1953 and 1976, marine explorer Jacques Cousteau led the next expeditions to the wreck, bringing an assortment of objects, including more statues, coins, and gemstones. Due to the depth of the wreck and the diving technology of the period, divers could only spend a handful of minutes investigating the ship at a time or risk the bends that proved fatal to the first expedition.
Now, after time and technology has moved on, the Greek government invited a team from theWoods Hole Oceanographic Institution (WHOI), headed by Dr. Brendan Foley, to begin the first significant excavation of the wreck since the Frenchman’s over 40 years ago. If Cousteau and his team made sprints to the Antikythera, the WHOI exploration is set to be more of a marathon.
“We’ve been taking this steady incremental approach to the shipwreck, building the foundation of knowledge about it, then posing specific research questions, trying to answer them, and seeing what the next phase brings. When we first got to Antikythera in 2012, one of the questions we had was, does the island hold a whole lot of submerged cultural resources or is this the only shipwreck out there?” Foley said.
Investigators had only scratched the surface of the Antikythera in the last nearly two thousand years. A second wreck–mentioned in passing by Cousteau’s team but never really explored–had been keeping the first, better-explored ship company all these years, practically untouched.
Foley team set about circumnavigating the island of Antikythera, off whose coast the wreck lay, carrying out technical dives over a period of eight days, where they mapped everything human-made from the sea’s surface down to its floor, 45 meters below.
When Cousteau’s team had spotted the second wreck, they saw amphorae that looked probably Roman in origin–meaning the wreck could date from any time up to the fourth century BCE.
“We were the first archaeologists to see this [second] site and immediately we recognised that it had the exact same ceramics as the treasure wreck just up the coast” where the mechanism had been found, said Foley. The similarities between the two wrecks raised questions. Was the second wreck, dubbed Antikythera B, another ship that had sunk around the same time as the first Antikythera wreck? A second ship travelling in convoy with the Antikythera? Or something else entirely?
The debris trail stretching the 300 meters between the two ships looked to be continuous, suggesting that the two wreck sites were part of one larger ship that had split into two parts. Foley’s team will be testing the hypothesis over the next few visits to the site, using technology to help them determine the true origins of the second wreck.
As it has every year since since 2012, the team returned to Antikythera this summer to probe the wreck further, examining the area between the two wrecks and using both human divers and robots.
The team is using an autonomous underwater vehicle equipped with stereo cameras. Using an algorithm called SLAM (simultaneous localisation and mapping), the imagery from the stereo cameras can be knitted together to make an extremely precise map of the seafloor. During a few days in June, the robot created 10,500 square meters of map, with a resolution of 2mm. A separate remotely operated vehicle (ROV) carrying metal detecting equipment is also being used to spot hints of bronze or iron-carrying objects lying in the water.
Information from the ROV will be overlaid on top of the data from the 3D map generated by the autonomous underwater vehicle to build up a heat map of where the team should direct their excavation efforts when they return to the site later this summer.
By focusing excavation efforts on areas that show a higher density of metal, the excavations could potentially turn up more fragments of the Antikythera mechanism (only half of the system has been recovered to date). While such a discovery would generate headlines, tiny flecks of lead may have equally fascinating stories to tell.
If any lead artefacts are recovered, the team will take microscopic samples from them and send them away for spectroscopic analysis. By comparing the lead’s isotope profile to other samples from around the world, the researchers will be able to hone in on where the ship was built, or where it sailed from.
“One of the goals will be to virtually excavate and re-excavate the site in the computer afterwards.” Brendan Foley
Potentially, more of the bronze statues recovered on previous trips–hands, feet and other fragments have been found and are on display in the National Museum in Athens–could be identified through the metal heat map.
Finding more of the statues “would be quite a big contribution to art history and culture but we also expect that in amongst the fragments of the statues will be other amazing things. What kind of things? We can’t even imagine. The possibilities are boundless. This ship sank carrying the finest material that was available in the entire eastern Mediterranean in the first century BC,” Foley said.
Like the mechanism that it carried, the Antikythera is unique for its time period. Its hull planks are some of thickest seen in antiquity, indicating the true size of the ship could be over 200 feet in length, putting it in the same ballpark as HMS Victory, the warship commanded by Admiral Lord Nelson during the Battle of Trafalgar–some 1700 years after the Antikythera sailed.
Why was the Anitkythera so large? The only other known ships of the era that were larger were the pleasure barges that the Roman emperor Caligula used to cruise across Lake Nemi. The Antikythera, however, may have been built for a mix of business and pleasure.
One hypothesis is that the Antikythera may both have carried early tourists and freight, thanks to the huge bronze and marble statues it transported as cargo.
If the ship had to carry statues, some up to three meters tall, they’d have to be packed well to prevent damage in transit. It’s been posited that sand or straw could be used as the packing material, but Foley suggests grain could be a more likely candidate: not only would the statues be protected but the grain could be sold on at the Antikythera’s destination, making it a far more economical option.
“The ancient grain carriers weren’t just cargo ships, they were more like RMS Titanic. They were more like luxury cruise liners,” Foley said.
“The couple of extant literary references to grain carriers refer to these floating palaces: mosaic floors, libraries, and amazing cabins, well appointed for the passengers–the 200 or 300 passengers that could be aboard from Rome to Egypt or the Black Sea. They would be sort of the world’s first tourists. As the ship was loaded up with grain, which could take a couple of months, they would tour around and then get back on the ship at the end of the season.”
Any artefacts, such as mosaic pieces, would lend credence to the theory, but more evidence could come from the bones of passengers that died when the ship sank.
“There’s other circumstantial evidence that points to this being the first grain carrier ever discovered, and that’s the luxury goods that were carried onboard and also the presence of skeletal remains of a young woman,” said Foley.
Remains of four people on the wreck have been found so far, and more may still be on the wreck. Should other bones be recovered, they will be subject to a vigorous recovery procedure to make sure there’s no DNA cross-contamination between the dive workers and the bones themselves. All workers on the boat will give cheek swabs to make sure their genetic material can be identified if it ends up on the bones accidentally.
WHOI is now looking for a company that can work with it to analyse the DNA from the bones, perhaps hinting at where those on the ship–be they sailors, high-roller tourists, or slaves–originated from.
The WHOI scientists have already got a handle on other aspects of the travellers’ lives, from their hygiene habits to their diets, thanks to the ceramic storage vessels found on the wreck site. The first Antikythera wreck has already yielded amphora, the “55 gallon drum of antiquity”, table jugs known as lagynos, and unguentaria–the small bottles that would hold medicines, cosmetics or perfumes.
“With all of these types of ceramic artefacts, they’re empty now, but we can take swabs and using police forensic techniques we can pull ancient trace DNA from the ceramic matrix of the original contents, down to the species level,” Foley said.
It’s not uncommon to find ancient ready meals in some of the jars–mixes of legumes or meats, herbs and spices–but the information from the jars can be far more valuable, giving an indication of what commodities were being traded between what locations, enabling archaeologists to get a better insight into the economy of a region than historical sources alone can provide.
“It’s fun for us,” said Foley, “because we feel like we’ve opened up a whole new vista on the past, and we can generate hard data on these early economies. What are they actually importing and exporting, what are they producing, what are they consuming? And it’s all right there in these ostensibly empty jars.”
Even traces of the ancient grain may still be hidden in the sands around the wrecks for those with the right tech to find it. While the grain is long gone, it will have decomposed to leave characteristic starches and structures called phytoliths, which can be detected with a powerful enough microscope.
WHOI’s team returned to the wreck site in the summer of 2015 with their metallic heat maps to begin the process of finding out if the Antikythera has more secrets go give up.
“We’re always analysing the data and updating the data, so this year, those wonderfully precise data from the maps produced by the robots, we’ll have those on iPads. Those iPads will be in housings and we’ll have interactive maps with us as we’re diving on the site,” Foley said.
The divers move through the water, iPad in hand, looking for the points of interest from the heat maps, and checking their position against those locations as they go. They carry handheld metal detectors too, to spot any metal artefacts buried under the seafloor surface, and are accompanied by professional photographers and videographers, as well as using the iPad cameras to gather snaps too.
“All those data at the end of the day are incorporated into the maps. In the best vision we have of this, we’ll have have a data manager incorporating everything we’re doing daily,” said Foley. “One of the goals will be to virtually excavate and re-excavate the site in the computer afterwards, by using our series of images over the trench we’re digging to be able to take it down and refill it in the computer afterwards, so we make sure we’re absolutely documenting every action we take.”
The divers use rebreathers to allow them to investigate the wrecks at depths that would normally prove fatal to humans in a matter of minutes. By keeping the gases they breath in and out inside a closed loop, adding oxygen where necessary and cleaning out the carbon dioxide, divers are able to spend a far longer time on site than they would be able to with conventional scuba gear.
“Putting humans in the water is always the option of last resort because we have to eat, we have to poop, we get tired and we’re really not that efficient underwater. With the rebreather, we increase that efficiency, but it’s still we’re only want to put people down when there’s no other way to do the job,” Foley said.
That’s why today’s underwater excavations will typically rely heavily on robots. They can spend far longer underwater and go to far deeper depths than humans. However, often they’re used as observers, with the most difficult work still done by humans.
Last year, WHOI experimented with a fusion of the two: an Iron Man-like exosuit. The exosuit is a small wearable submarine that keeps the diver’s air at the same atmospheric pressure as it is in the water.
While the WHOI team didn’t use the experimental suit for any work on the wreck site, it was tested out on the vicinity of the Antikythera, and the organisation is now considering whether to plough ahead with a development program.
“You can stay for hours and hours doing work or observing work, and then be winched right back up to the surface,” said Foley. “You won’t have to pay a decompression penalty. You just jump out of the suit and go have a cup of coffee.”
Foley called the oragnisation’s August 2015 diving and excavating trip “the most intensive period of activity on the Antikythera ever.” The results of the landmark excavation are still being revealed.
==============
The world’s oldest computer is still revealing its secrets
By Sarah Kaplan June 14 , 2016-06-16
An international team of archaeologists, astronomers and historians have spent the past 10 years deciphering the many mysteries of the Antikythera Mechanism, the world's first mechanical computer. (Thomas Johnson/The Washington Post)
Item 15087 wasn't much to look at, particularly compared to other wonders uncovered from the shipwreck at Antikythera, Greece, in 1901. The underwater excavation revealed gorgeous bronze sculptures, ropes of decadent jewelry and a treasure trove of antique coins.
Amid all that splendor, who could have guessed that a shoebox-size mangled bronze machine, its inscriptions barely legible, its gears calcified and corroded, would be the discovery that could captivate scientists for more than a century?
"In this very small volume of messed-up corroded metal you have packed in there enough knowledge to fill several books telling us about ancient technology, ancient science and the way these interacted with the broader culture of the time," said Alexander Jones, a historian of ancient science at New York University's Institute for the Study of the Ancient World. "It would be hard to dispute that this is the single most information-rich object that has been uncovered by archaeologists from ancient times."
Jones is part of an international team of archaeologists, astronomers and historians who have labored for the past 10 years to decipher the mechanism's many mysteries. The results of their research, including the text of a long explanatory "label" revealed through X-ray analysis, were just published in a special issue of the journal Almagest, which examines the history and philosophy of science.
The findings substantially improve our understanding of the instrument's origins and purpose, Jones said, offering hints at where and by whom the mechanism was made, and how it might have been used. It looks increasingly like a "philosopher's guide to the galaxy," as the Associated Press put it — functioning as a teaching tool, a status symbol and an elaborate celebration of the wonders of ancient science and technology.
[The key to these ancient riddles may lie in a father's love for his dead son]
In its prime, about 2,100 years ago, the Antikythera (an-ti-KEE-thur-a) Mechanism was a complex, whirling, clockwork instrument comprising at least 30 bronze gears bearing thousands of interlocking tiny teeth. Powered by a single hand crank, the machine modeled the passage of time and the movements of celestial bodies with astonishing precision. It had dials that counted the days according to at least three different calendars, and another that could be used to calculate the timing of the Olympics. Pointers representing the stars and planets revolved around its front face, indicating their position in relation to Earth. A tiny, painted model of the moon rotated on a spindly axis, flashing black and white to mimic the real moon's waxing and waning.
The sum of all these moving parts was far and away the most sophisticated piece of machinery found from ancient Greece. Nothing like it would appear again until the 14th century, when the earliest geared clocks began to be built in Europe. For the first half century after its discovery, researchers believed that the Antikythera Mechanism had to be something simpler than it seemed, like an astrolabe. How could the Greeks have developed the technology needed to create something so precise, so perfect — only to have it vanish for 1,400 years?
But then Derek de Solla Price, a polymath physicist and science historian at Yale University, traveled to the National Archaeological Museum in Athens to take a look at the enigmatic piece of machinery. In a 1959 paper in Scientific American, he posited that the Antikythera Mechanism was actually the world's first known "computer," capable of calculating astronomical events and illustrating the workings of the universe. Over the next two and a half decades, he described in meticulous detail how the mechanism's diverse functions could be elucidated from the relationships among its intricately interlocked gears.
"Nothing like this instrument is preserved elsewhere. Nothing comparable to it is known from any ancient scientific text or literary allusion," he wrote.
===
That wasn't completely accurate — Cicero wrote of a instrument made by the first century BCE scholar Posidonius of Rhodes that "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." But it was true that the existence of the Antikythera Mechanism challenged all of scientists' assumptions about what the ancient Greeks were capable of.
"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," Price said.
Still, the degree of damage to the ancient plates and gears meant that many key questions about the the instrument couldn't be answered with the technology of Price's day. Many of the internal workings were clogged or corroded, and the inscriptions were faded or covered up by plates that had been crushed together.
[Broken pottery reveals the sheer devastation caused by the Black Death]
Enter X-ray scanning and imaging technology, which have finally become powerful enough to allow researchers to peer beneath the machine's calcified surfaces. A decade ago, a diverse group of scientists teamed up to form the Antikythera Mechanism Research Project (AMRP), which would take advantage of that new capability. Their initial results, which illuminated some of the complex inner workings of the machine, were exciting enough to persuade Jones to jump on board.
Fluent in Ancient Greek, he was able to translate the hundreds of new characters revealed in the advanced imaging process.
"Before, we had scraps of the text that was hiding inside these fragments, but there was still a lot of noise," he said. By combining X-ray images with the impressions left on material that had stuck to the original bronze, "it was like a double jigsaw puzzle that we were able to use for a much clearer reading."
The main discovery was a more than 3,500-word explanatory text on the main plate of the instrument. It's not quite an instruction manual — speaking to reporters, Jones's colleague Mike Edmunds compared it to the long label beside an item in a museum display, according to the AP.
“It’s not telling you how to use it. It says, ‘What you see is such and such,’ rather than, ‘Turn this knob and it shows you something,’ " he explained.
An undated photo released by the Greek Ministry of Culture shows a diver wearing a robotic Exosuit while exploring the famous Antikythera shipwreck. (EPA/GREEK MINISTRY OF CULTURE)
Other newly translated excerpts included descriptions of a calendar unique to the northern Greek city of Corinth and tiny orbs — now believed lost to the sandy sea bottom — that once moved across the instrument's face in perfect simulation of the true motion of the five known planets, as well as a mark on the dial that gave the dates of various athletic events, including a relatively minor competition that was held in the city of Rhodes.
That indicates that the mechanism may have been built in Rhodes — a theory boosted by the fact that much of the pottery uncovered by the shipwreck was characteristic of that city. The craftsmanship of the instrument, and the two distinct sets of handwriting evident in the inscriptions, makes Jones believe that it was a team effort from a small workshop that may have produced similar items. True, no other Antikythera Mechanisms have been found, but that doesn't mean they never existed. Plenty of ancient bronze artifacts were melted down for scrap (indeed, the mechanism itself may have included material from other objects).
It's likely that this particular mechanism and the associated Antikythera treasures were en route to a Roman port, where they'd be sold to wealthy nobles who collected rare antiques and intellectual curiosities to adorn their homes.
Visualizations showing how researchers enhanced images of the eroded inscriptions on the Antikythera Mechanism. (Antikythera Mechanism Research Project)
The elegant complexity of the mechanism – and the use its makers designed it for – are emblematic of the values of the ancient world: For example, a dial that predicts the occurrence of eclipses to the precision of a day also purports to forecast what the color of the moon and weather in the region will be that day. To modern scientists, the three phenomena are entirely distinct from one another — eclipses depend on the predictable movements of the sun, moon and planets, the color of the moon on the scattering of light in Earth's atmosphere, and the weather on difficult-to-track local conditions. Astronomers may be able to forecast an eclipse years in advance, but there's no scientific way to know the weather that far out (just ask our friends at the Capital Weather Gang).
But to an ancient Greek, the three concerns were inextricably linked. It was believed that an eclipse could portend a famine, an uprising, a nation's fate in war.
"Things like eclipses were regarded as having ominous significance," Jones said. It would have made perfect sense to tie together "these things that are purely astronomical with things that are more cultural, like the Olympic games, and calendars, which is astronomy in service of religion and society, with astrology, which is pure religion."
That may go some way toward explaining the strange realization Price made more than 50 years ago: The ancient Greeks came dazzlingly close to inventing clockwork centuries sooner than really happened. That they chose to utilize the technology not to mark the minutes, but to plot out their place in the universe, shows just how deeply they regarded the significance of celestial events in their lives.
In a single instrument, Jones said, "they were trying to gather a whole range of things that were part of the Greek experience of the cosmos."
===
for more information,please visit the following web page ...
( please using the right click of your mouse, and Open Link in Next Private Window, )
==========
Greek Scientists Call Antikythera Mechanism ‘World’s First Computer’
The overall analysis of the inscriptions found inside the Antikythera Mechanism was presented on Thursday by the study group of the enigmatic object.
In an event held at the Katerina Laskaridis Historical Foundation Library. The findings are the result of an international scientific research effort over the past 10 years.
According to the new data from decoding the inscriptions inside the folds of the mechanism, the mechanism can be considered as the world’s oldest computer, which gave the user the ability to see exact times of eclipses of the moon and the sun and the motion of celestial bodies.
Specifically, on one side of the device was a handle which was starting the movement of the whole system. By turning the handle and rotating the gauges in the front and rear of the mechanism, the user could set a date that would reveal the astronomical phenomena that would occur around the Earth.
Physician Yiannis Bitsakis who did part of the presentation said that today the NASA website can detail all the eclipses of the past and those that are to occur in the future. “What we do with computers today, it was done with the Antikythera Mechanism about 2000 years ago,” he said.
By successfully reading 3,400 characters from the fragmented inscriptions, the research team has been able to recognize whole sentences that help in understanding the functional object and form something like a “manual” for the use of the instrument.
Space Physics professor Xenophon Moussas said that “today’s computers and mobile phones have their roots in the gears of the mechanism,” as evidenced by the inscriptions found on the object.
“The most important thing is that we see laws of physics applying inside the mechanism, and the proof is in the inscriptions and the numbers 76, 19, 223 that also show the name of the manufacturer, who tells us clearly ‘I am a Pythagorean,'” Moussas said.
As the professor argued, this machine is the root of all civilization and technology and in fact it is the oldest “tablet.”
The Mechanism also includes an astrological calendar, as the indicators seem to revolve around the zodiac revealing the movements of both the Moon and the planets. The movements of the planets are directly linked to specific observation sites, suggesting that the creator of the Antikythera Mechanism had provided for the use of the machine in more than one location. This is indicated by the fact that the words Dodona and Alexandria have been found in the engravings. The mechanism also included methods to estimate the time of sporting events held every four years, like the Olympic Games and the Isthmian games, claimed the researchers.
All scientists agreed that the Antikythera shipwreck is the most important wreck discovery in human history.
Further underwater excavations and research will be conducted in the hope to discover more fragments of the enigmatic mechanism and decode more secrets hidden in its gears.
- See more at:
( please using the right click of your mouse, and Open Link in Next Private Window, )
==========
News Feature
News Feature
Nature 444, 534-538 (30 November 2006) | doi:10.1038/444534a; Published online 29 November 2006
In search of lost time
In search of lost time
Jo Marchant1
- Jo Marchant is Natures News Editor.
The ancient Antikythera Mechanism doesn't just challenge our assumptions about technology transfer over the ages — it gives us fresh insights into history itself.
Hear the sound of the Antikythera Mechanism recreated on the 30 November Nature Podcast.
It looks like something from another world — nothing like the classical statues and vases that fill the rest of the echoing hall. Three flat pieces of what looks like green, flaky pastry are supported in perspex cradles. Within each fragment, layers of something that was once metal have been squashed together, and are now covered in calcareous accretions and various corrosions, from the whitish tin oxide to the dark bluish green of copper chloride. This thing spent 2,000 years at the bottom of the sea before making it to the National Archaeological Museum in Athens, and it shows.
But it is the details that take my breath away. Beneath the powdery deposits, tiny cramped writing is visible along with a spiral scale; there are traces of gear-wheels edged with jagged teeth. Next to the fragments an X-ray shows some of the object's internal workings. It looks just like the inside of a wristwatch.
This is the Antikythera Mechanism. These fragments contain at least 30 interlocking gear-wheels, along with copious astronomical inscriptions. Before its sojourn on the sea bed, it computed and displayed the movement of the Sun, the Moon and possibly the planets around Earth, and predicted the dates of future eclipses. It's one of the most stunning artefacts we have from classical antiquity.
J. MARCHANT/ANTIKYTHERA MECHANISM RESEARCH PROJECT
No earlier geared mechanism of any sort has ever been found. Nothing close to its technological sophistication appears again for well over a millennium, when astronomical clocks appear in medieval Europe. It stands as a strange exception, stripped of context, of ancestry, of descendants.
Considering how remarkable it is, the Antikythera Mechanism has received comparatively scant attention from archaeologists or historians of science and technology, and is largely unappreciated in the wider world. A virtual reconstruction of the device, published by Mike Edmunds and his colleagues in this week's Nature (see page 587), may help to change that. With the help of pioneering three-dimensional images of the fragments' innards, the authors present something close to a complete picture of how the device worked, which in turn hints at who might have been responsible for building it.
But I'm also interested in finding the answer to a more perplexing question — once the technology arose, where did it go to? The fact that such a sophisticated technology appears seemingly out of the blue is perhaps not that surprising — records and artefacts from 2,000 years ago are, after all, scarce. More surprising, to an observer from the progress-obsessed twenty-first century, is the apparent lack of a subsequent tradition based on the same technology — of ever better clockworks spreading out round the world. How can the capacity to build a machine so magnificent have passed through history with no obvious effects?
Astronomic leaps
To get an idea of what the mechanism looked like before it had the misfortune to find itself on a sinking ship, I went to see Michael Wright, a curator at the Science Museum in London for more than 20 years and now retired. Stepping into Wright's workshop in Hammersmith is a little like stepping into the workshop where H. G. Wells' time machine was made. Every inch of floor, wall, shelf and bench space is covered with models of old metal gadgets and devices, from ancient Arabic astrolabes to twentieth-century trombones. Over a cup of tea he shows me his model of the Antikythera Mechanism as it might have been in its pomp. The model and the scholarship it embodies have consumed much of his life (see 'Raised from the depths').
The mechanism is contained in a squarish wooden case a little smaller than a shoebox. On the front are two metal dials (brass, although the original was bronze), one inside the other, showing the zodiac and the days of the year. Metal pointers show the positions of the Sun, the Moon and five planets visible to the naked eye. I turn the wooden knob on the side of the box and time passes before my eyes: the Moon makes a full revolution as the Sun inches just a twelfth of the way around the dial. Through a window near the centre of the dial peeks a ball painted half black and half white, spinning to show the Moon's changing phase.
On the back of the box are two spiral dials, one above the other. A pointer at the centre of each traces its way slowly around the spiral groove like a record stylus. The top dial, Wright explains, shows the Metonic cycle — 235 months fitting quite precisely into 19 years. The lower spiral, according to the research by Edmunds and his colleagues, was divided into 223, reflecting the 223-month period of the Saros cycle, which is used to predict eclipses.
To show me what happens inside, Wright opens the case and starts pulling out the wheels. There are 30 known gear-wheels in the Antikythera Mechanism, the biggest taking up nearly the entire width of the box, the smallest less than a centimetre across. They all have triangular teeth, anything from 15 to 223 of them, and each would have been hand cut from a single sheet of bronze. Turning the side knob engages the big gear-wheel, which goes around once for every year, carrying the date hand. The other gears drive the Moon, Sun and planets and the pointers on the Metonic and Saros spirals.
To see the model in action is to want to find out who had the ingenuity to design the original. Unfortunately, none of the copious inscriptions is a signature. But there are other clues. Coins found at the site by Jacques Cousteau in the 1970s have allowed the shipwreck to be dated sometime shortly after 85 BC. The inscriptions on the device itself suggest it might have been in use for at least 15 or 20 years before that, according to the Edmunds paper.
The ship was carrying a rich cargo of luxury goods, including statues and silver coins from Pergamon on the coast of Asia Minor and vases in the style of Rhodes, a rich trading port at the time. It went down in the middle of a busy shipping route from the eastern to western Aegean, and it seems a fair bet that it was heading west for Rome, which had by that time become the dominant power in the Mediterranean and had a ruling class that loved Greek art, philosophy and technology.
The Rhodian vases are telling clues, because Rhodes was the place to be for astronomy in the first and second centuries BC. Hipparchus, arguably the greatest Greek astronomer, is thought to have worked on the island from around 140 BC until his death in around 120 BC. Later the philosopher Posidonius set up an astronomy school there that continued Hipparchus' tradition; it is within this tradition that Edmunds and his colleagues think the mechanism originated. Circumstantial evidence is provided by Cicero, the first-century BC Roman lawyer and consul. Cicero studied on Rhodes and wrote later that Posidonius had made an instrument "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". The discovery of the Antikythera Mechanism makes it tempting to believe the story is true.
And Edmunds now has another reason to think the device was made by Hipparchus or his followers on Rhodes. His team's three-dimensional reconstructions of the fragments have turned up a new aspect of the mechanism that is both stunningly clever and directly linked to work by Hipparchus.
ANTIKYTHERA MECHANISM RESEARCH PROJECT
Gearing up: this reconstruction shows, among other things, the offset wheels of the Moon's nine-year cycle (lower left). A labelled diagram is on page 551.
One of the wheels connected to the main drive wheel moves around once every nine years. Fixed on to it is a pair of small wheels, one of which sits almost — but not exactly — on top of the other. The bottom wheel has a pin sticking up from it, which engages with a slot in the wheel above. As the bottom wheel turns, this pin pushes the top wheel round. But because the two wheels aren't centred in the same place, the pin moves back and forth within the upper slot. As a result, the movement of the upper wheel speeds up and slows down, depending on whether the pin is a little farther in towards the centre or a little farther out towards the tips of the teeth (see illustration on page 551).
The researchers realized that the ratios of the gear-wheels involved produce a motion that closely mimics the varying motion of the Moon around Earth, as described by Hipparchus. When the Moon is close to us it seems to move faster. And the closest part of the Moon's orbit itself makes a full rotation around the Earth about every nine years. Hipparchus was the first to describe this motion mathematically, working on the idea that the Moon's orbit, although circular, was centred on a point offset from the centre of Earth that described a nine-year circle. In the Antikythera Mechanism, this theory is beautifully translated into mechanical form. "It's an unbelievably sophisticated idea," says Tony Freeth, a mathematician who worked out most of the mechanics for Edmunds' team. "I don't know how they thought of it."
"I'm very surprised to find a mechanical representation of this," adds Alexander Jones, a historian of astronomy at the University of Toronto, Canada. He says the Antikythera Mechanism has had little impact on the history of science so far. "But I think that's about to change. This was absolutely state of the art in astronomy at the time."
Wright believes that similar mechanisms modelled the motions of the five known planets, as well as of the Sun, although this part of the device has been lost. As he cranks the gears of his model to demonstrate, and the days, months and years pass, each pointer alternately lags behind and picks up speed to mimic the astronomical wanderings of the appropriate sphere.
Greek tragedy
Almost everyone who has studied the mechanism agrees it couldn't have been a one-off — it would have taken practice, perhaps over several generations, to achieve such expertise. Indeed, Cicero wrote of a similar mechanism that was said to have been built by Archimedes. That one was purportedly stolen in 212 BC by the Roman general Marcellus when Archimedes was killed in the sacking of the Sicilian city of Syracuse. The device was kept as an heirloom in Marcellus' family: as a friend of the family, Cicero may indeed have seen it.
So where are the other examples? A model of the workings of the heavens might have had value to a cultivated mind. Bronze had value for everyone. Most bronze artefacts were eventually melted down: the Athens museum has just ten major bronze statues from ancient Greece, of which nine are from shipwrecks. So in terms of the mechanism, "we're lucky we have one", points out Wright. "We only have this because it was out of reach of the scrap-metal man."
But ideas cannot be melted down, and although there are few examples, there is some evidence that techniques for modelling the cycles in the sky with geared mechanisms persisted in the eastern Mediterranean. A sixth-century ADByzantine sundial brought to Wright at the Science Museum has four surviving gears and would probably have used at least eight to model the positions of the Sun and Moon in the sky. The rise of Islam saw much Greek work being translated into Arabic in the eighth and ninth centuries AD, and it seems quite possible that a tradition of geared mechanisms continued in the caliphate. Around AD 1000, the Persian scholar al-Biruni described a "box of the Moon" very similar to the sixth-century device. There's an Arabic-inscribed astrolabe dating from 1221–22 currently in the Museum of the History of Science in Oxford, UK, which used seven gears to model the motion of the Sun and Moon.
But to get anything close to the Antikythera Mechanism's sophistication you have to wait until the fourteenth century, when mechanical clockwork appeared all over western Europe. "You start to get a rash of clocks," says Wright. "And as soon as you get clocks, they are being used to drive astronomical displays." Early examples included the St Albans clock made by Richard Wallingford in around 1330 and a clock built by Giovanni de'Dondi a little later in Padua, Italy, both of which were huge astronomical display pieces with elaborate gearing behind the main dial to show the position of the Sun, Moon, planets and (in the case of the Padua clock) the timing of eclipses. The time-telling function seems almost incidental.
It could be argued that the similarities between the medieval technology and that of classical Greece represent separate discoveries of the same thing — a sort of convergent clockwork evolution. Wright, though, favours the idea that they are linked by an unbroken tradition: "I find it as easy to believe that this technology survived unrecorded, as to believe that it was reinvented in so similar a form." The timing of the shift to the West might well have been driven by the fall of Baghdad to the Mongols in the thirteenth century, after which much of the caliphate's knowledge spread to Europe. Shortly after that, mechanical clocks appeared in the West, although nobody knows exactly where or how. It's tempting to think that some mechanisms, or at least the ability to build them, came west at the same time. As François Charette, a historian of science at Ludwig Maximilians University in Munich, Germany, points out, "for the translation of technology, you can't rely solely on texts". Most texts leave out vital technical details, so you need skills to be transmitted directly.
But if the tradition of geared mechanisms to show astronomical phenomena really survived for well over a millennium, the level of achievement within that tradition was at best static. The clockwork of medieval Europe became more sophisticated and more widely applied fairly quickly; in the classical Mediterranean, with the same technology available, nothing remotely similar happened. Why didn't anyone do anything more useful with it in all that time? More specifically, why didn't anyone work out earlier what the gift of hindsight seems to make obvious — that clockwork would be a good thing to make clocks with?
Serafina Cuomo, a historian of science at Imperial College, London, thinks that it all depends on what you see as 'useful'. The Greeks weren't that interested in accurate timekeeping, she says. It was enough to tell the hour of the day, which the water-driven clocks of the time could already do fairly well. But they did value knowledge, power and prestige. She points out that there are various descriptions of mechanisms driven by hot air or water — and gears. But instead of developing a steam engine, say, the devices were used to demonstrate philosophical principles. The machines offered a deeper understanding of cosmic order, says David Sedley, a classicist at the University of Cambridge, UK. "There's nothing surprising about the fact that their best technology was used for demonstrating the laws of astronomy. It was deep-rooted in their culture."
Another, not mutually exclusive, theory is that devices such as the Antikythera Mechanism were signifiers of social status. Cuomo points out that demonstrating wondrous devices brought social advancement. "They were trying to impress their peers," she says. "For them, that was worth doing." And the Greek élite was not the only potential market. Rich Romans were eager for all sorts of Greek sophistication — they imported philosophers for centuries.
Seen in this light, the idea that the Antikythera Mechanism might be expected to lead to other sorts of mechanism seems less obvious. If it already embodied the best astronomy of the time, what more was there to do with it? And status symbols do not follow any clearly defined arc of progress. What's more, the idea that machines might do work may have been quite alien to slave-owning societies such as those of Ancient Greece and Rome. "Perhaps the realization that you could use technology for labour-saving devices took a while to dawn," says Sedley.
There is also the problem of power. Water clocks are thought to have been used on occasion to drive geared mechanisms that displayed astronomical phenomena. But dripping water only provides enough pressure to drive a small number of gears, limiting any such display to a much narrower scope than that of the Antikythera Mechanism, which is assumed to have been handcranked. To make the leap to mechanical clocks, a geared mechanism needs to be powered by something other than a person; it was not until medieval Europe that clockwork driven by falling weights makes an appearance.
Invention's evolution
Bert Hall, a science historian at the University of Toronto in Canada, believes a final breakthrough towards a mechanical weight drive might have come about almost by accident, by adapting a bell-ringing device. A water clock could have driven a hammer or weight mechanism swinging between two bells as an alarm system, until someone realized that the weight mechanism would be a more regular way of driving the clock in the first place. When the new way to drive clocks was discovered, says Hall, "the [clockwork] technology came rushing out of the wings into the new tradition".
Researchers would now love further mechanisms to be unearthed in the historical record. "We hope that if we can bring this to people's attention, maybe someone poking around in their museum might find something, or at least a reference to something," says Edmunds. Early Arabic manuscripts, only a fraction of which have so far been studied, are promising to be fertile ground for such discoveries.
Charette also hopes the new Antikythera reconstruction will encourage scholars to take the device more seriously, and serve as a reminder of the messy nature of history. "It's still a popular notion among the public, and among scientists thinking about the history of their disciplines, that technological development is a simple progression," he says. "But history is full of surprises."
In the meantime, Edmunds' Antikythera team plans to keep working on the mechanism — there are further inscriptions to be deciphered and the possibility that more fragments could be found. This week the researchers are hosting a conference in Athens that they hope will yield fresh leads. A few minutes' walk from the National Archaeological Museum, Edmunds' colleagues from the University of Athens, Yanis Bitsakis and Xenophon Moussas, treat me to a dinner of aubergine and fried octopus, and explain why they would one day like to devote an entire museum to the story of the fragments.
"It's the same way that we would do things today, it's like modern technology," says Bitsakis. "That's why it fascinates people." What fascinates me is that where we see the potential of that technology to measure time accurately and make machines do work, the Greeks saw a way to demonstrate the beauty of the heavens and get closer to the gods.
- See more at:
( please using the right click of your mouse, and Open Link in Next Private Window, )
http://www.nature.com/nature/journal/v444/n7119/full/444534a.html
==========
ISAW Papers 4 (February, 2012)
ISAW Papers 4 (February, 2012)
The Cosmos in the Antikythera Mechanism
The Cosmos in the Antikythera Mechanism
Abstract: The Antikythera Mechanism is a fragmentarily preserved Hellenistic astronomical machine with bronze gearwheels, made about the second century B.C. In 2005, new data were gathered leading to considerably enhanced knowledge of its functions and the inscriptions on its exterior. However, much of the front of the instrument has remained uncertain due to loss of evidence. We report progress in reading a passage of one inscription that appears to describe the front of the Mechanism as a representation of a Greek geocentric cosmology, portraying the stars, Sun, Moon, and all five planets known in antiquity. Complementing this, we propose a new mechanical reconstruction of planetary gearwork in the Mechanism, incorporating an economical design closely analogous to the previously identified lunar anomaly mechanism, and accounting for much unresolved physical evidence.
Subjects: Antikythera mechanism (Ancient calculator), Astronomy, Greek.
- Introduction
- Evidence & Models
- Building the New Model
- Appendices
- Acknowledgements & Author Contributions
- References and Notes
for more information,please visit the following web page ...
for more information,please visit the following web page ...
( please using the right click of your mouse, and Open Link in Next Private Window, )
Abstract
Abstract
ADVERTISEMENT
A. WRIGHT
Model success: Michael Wright devoted his life to decoding and replicating the Antikythera Mechanism.
François Charette
ANTIKYTHERA MECHANISM RESEARCH PROJECT
Inside out: computer tomography of the main fragment allowed for accurate modelling.
Michael Wright
It's a popular notion that technological development is a simple progression. But history is full of surprises.
I find it as easy to believe that this technology survived unrecorded, as to believe that this was reinvented in so similar a form.
Antikythera Mechanism as it appears today, with x-rays superimposed;
from Jo Marchant's 'In search of lost time' (Nature)
A recent issue of the British scientific journal Nature (dated 2006-11-30) has several fascinating articles including a research report on the Antikythera Mechanism, in which a battery of powerful techniques including x-ray computed tomography, high-resolution surface examination together with much painstaking analysis have, more than a century after its discovery at the bottom of the sea, begun to reveal the fascinating secrets of this ancient device.
As Jo Marchant puts it in her companion piece “In search of lost time”: 1
It looks like something from another world — nothing like the classical statues and vases that fill the rest of the echoing hall. Three flat pieces of what looks like green, flaky pastry are supported in perspex cradles.
Within each fragment, layers of something that was once metal have been squashed together, and are now covered in calcareous accretions and various corrosions, from the whitish tin oxide to the dark bluish green of copper chloride. This thing spent 2,000 years at the bottom of the sea before making it to the National Archaeological Museum in Athens, and it shows.
But it is the details that take my breath away. Beneath the powdery deposits, tiny cramped writing is visible along with a spiral scale; there are traces of gear-wheels edged with jagged teeth. Next to the fragments an X-ray shows some of the object’s internal workings. It looks just like the inside of a wristwatch.
This is the Antikythera Mechanism. These fragments contain at least 30 interlocking gear-wheels, along with copious astronomical inscriptions. Before its sojourn on the sea bed, it computed and displayed the movement of the Sun, the Moon and possibly the planets around Earth, and predicted the dates of future eclipses. It’s one of the most stunning artefacts we have from classical antiquity.
No earlier geared mechanism of any sort has ever been found. Nothing close to its technological sophistication appears again for well over a millennium, when astronomical clocks appear in medieval Europe. It stands as a strange exception, stripped of context, of ancestry, of descendants.
Considering how remarkable it is, the Antikythera Mechanism has received comparatively scant attention from archaeologists or historians of science and technology, and is largely unappreciated in the wider world. A virtual reconstruction of the device, published by Mike Edmunds and his colleagues in this week’s Nature (see page 587), may help to change that.
With the help of pioneering three-dimensional images of the fragments’ innards, the authors present something close to a complete picture of how the device worked, which in turn hints at who might have been responsible for building it.
Now that close to a comprehensive understanding of the Antikythera Mechanism has emerged from these studies, the picture of the revealed machine is astounding:
Rear side, sideways view of reconstruction of Antikythera Mechanism;
from Francois Charette, 'High tech from Ancient Greece' (Nature)
Schematic diagram of gear trains, as per Price and Wright;
from T. Freeth et al. 'Decoding the ancient Greek astronomical calculator
known as the Antikythera Mechanism' (Nature)
Diagram showing position of principal dials and inscriptions;
from T. Freeth et al. 'Decoding the ancient Greek astronomical calculator
known as the Antikythera Mechanism' (Nature)
Reading the research report’s description of its analysis of the dials and inscriptions on the device is almost like reading an alternate history novel (a sequel to a book by L. Sprague de Camp, say, The Glory that Was), where science took off in antiquity and all this arcane technology that results is accompanied by an impressive Ancient Greek technical vocabulary… except that this is our timeline.
Prior to historians and archaeologists’ realization of what the Antikythera mechanism really was, scholars had no reason to think that ancients were aware of the principle of clockwork-like complex gearing at all.
Via the 1st century b.c. Roman architect writer Vitruvius, we know that simple dual gearing, for directional change, was in use following this time frame in a type of water-powered mill. There are still no instances known of the use of gears of any type predating the Antikythera mechanism, however, nor anything of comparable sophistication for beyond a thousand years after.
A revealing excerpt from the Nature report, “Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism,” by Tony Freeth (Cardiff University, School of Physics and Astronomy), et al., reads as follows: 2
Named after its place of discovery in 1901 in a Roman shipwreck, the Antikythera Mechanism is technically more complex than any known device for at least a millennium afterwards. Its specific functions have remained controversial because its gears and the inscriptions upon its faces are only fragmentary.
Here we report surface imaging and high-resolution X-ray tomography of the surviving fragments, enabling us to reconstruct the gear function and double the number of deciphered inscriptions. The mechanism predicted lunar and solar eclipses on the basis of Babylonian arithmetic-progression cycles. The inscriptions support suggestions of mechanical display of planetary positions, now lost. In the second century b.c., Hipparchos developed a theory to explain the irregularities of the Moon’s motion across the sky caused by its elliptic orbit.
We find a mechanical realization of this theory in the gearing of the mechanism, revealing an unexpected degree of technical sophistication for the period.
The bronze mechanism (Fig. 1), probably hand-driven, was originally housed in a wooden-framed case of (uncertain) overall size 315 × 190 × 100 mm (Fig. 2). It had front and back doors, with astronomical inscriptions covering much of the exterior of the mechanism. Our new transcriptions and translations of the Greek texts are given in Supplementary Note “glyphs and inscriptions”. 2
The detailed form of the lettering can be dated to the second half of the second century B.C., implying that the mechanism was constructed during the period 150-100 B.C., slightly earlier than previously suggested. This is consistent with a date of around 80-60 B.C. for the wreck from which the mechanism was recovered by some of the first underwater archaeology.
We are able to complete the reconstruction of the back door inscription with text from fragment E, and characters from fragments A and F (see Fig. 1 legend for fragment nomenclature). The front door is mainly from fragment G.
The text is astronomical, with many numbers that could be related to planetary motions; the word “sterigmos” (ΣΤΗΡΙΓΜΟΣ, translated as “station” or “stationary point”) is found, meaning where a planet’s apparent motion changes direction, and the numbers may relate to planetary cycles. We note that a major aim of this investigation is to set up a data archive to allow non-invasive future research, and access to this will start in 2007. Details will be available on www.antikythera-mechanism.gr 3
The back door inscription mixes mechanical terms about construction (“trunnions,” “gnomon,” “perforations”) with astronomical periods. Of the periods, 223 is the Saros eclipse cycle (seeBox 1 for a brief explanation of astronomical cycles and periods). We discover the inscription “spiral divided into 235 sections,” which is the key to understanding the function of the upper back dial.
The references to “golden little sphere” and “little sphere” probably refer to the front zodiac display for the Sun and Moon — including phase for the latter.
The text near the lower back dial includes “Pharos” and “from south (about/around)… Spain (ΙΣΠΑΝΙΑ) ten.”
These geographical references, together with previous readings of “towards the east,” “west-north-west” and “west-south-west” suggest an eclipse function for the dial, as solar eclipses occur only at limited geographical sites, and winds were often recorded in antiquity with eclipse observations. Possibly this information was added to the mechanism during use.
Turning to the dials themselves, the front dial displays the position of the Sun and Moon in the zodiac, and a corresponding calendar of 365 days that could be adjusted for leap years. Previously, it was suggested that the upper back dial might have five concentric rings with 47 divisions per turn, showing the 235 months of the 19-year Metonic cycle.
A later proposal augments this with the upper subsidiary dial showing the 76-year Callippic cycle. Our optical and X-ray micro-focus computed tomography (CT) imaging confirms these proposals, with 34 scale markings discovered on the upper back dial. On the basis of a statistical analysis analogous to that described for gear tooth counts below, we confirm the 235 total divisions.
We also find from the CT that the subsidiary dial is indeed divided into quadrants, as required for a Callippic dial. In agreement with the back door inscription, we also substantiate the preceptive proposal that the dial is in fact a spiral made from semicircular arcs displaced to centers on the vertical midline. In the CT of fragment B we find a new feature that explains why the dial is a spiral: a “pointer-follower” device (Fig. 3) traveled around the spiral groove to indicate which month (across the five turns of the scale) should be read.
From our CT data of the 48 scale divisions observed in fragments A, E and F, we establish 223 divisions in the four-turn spiral on the lower back dial, the spiral starting at the bottom of the dial. This is the Saros eclipse cycle, whose number is on the back door inscription. The 54-year Exeligmos cycle of three Saros cycles is shown on the lower subsidiary dial.
Between the scale divisions of the Saros dial we have identified 16 blocks of characters, or “glyphs” (see “glyphs and inscriptions”) at intervals of one, five and six months. These are eclipse predictions and contain either Σ for a lunar eclipse (from ΣΕΛΗΝΗ, Moon) or Η for a solar eclipse (from ΗΛΙΟΣ, Sun) or both.
A correlation analysis (analogous to DNA sequence matching) with historic eclipse data (all modern eclipse data and predictions in our work are from this reference) indicates that over a period of 400-1 b.c., the sequence of eclipses marked by the identified glyphs would be exactly matched by 121 possible start dates. The matching only occurs if the lunar month starts at first crescent, and confirms this choice of month start in the mechanism.
The sequences of eclipses can then be used to predict the expected position of glyphs on the whole dial, as seen in Fig. 4. The dial starts and finishes with an eclipse. Although Ptolemy indicates that the Greeks recorded eclipses in the second century b.c., the Babylonian Saros canon is the only known source of sufficient data to construct the dial. […]
Of particular note is the dual use of the large gear, e3, at the back of the mechanism, which has found no use in previous models. In our model, it is powered by m3 as part of a fixed-axis train that turns the Saros and Exeligmos dials for eclipse prediction, and also doubles as the “epicyclic table” for the gears k1, k2.
These are part of the epicyclic gearing that calculates the theory of the irregular motion of the moon, developed by Hipparchos some time between 146 and 128 b.c. (ref. 22) - the “first anomaly,” caused by its elliptical orbit about the Earth. The period of this anomaly is the period from apogee to apogee (the anomalistic month).
To realize this theory, the mean sidereal lunar motion is first calculated by gears on axes c, d and e and this is then fed into the epicyclic system. As explained in Fig. 6, a pin-and-slot device on the epicyclic gears k1 and k2, clearly seen in the CT, provides the variation. This was previously identified, but rejected as a lunar mechanism.
The remarkable purpose of mounting the pin-and-slot mechanism on the gear e3 is to change the period of variation from the sidereal month (that is, the time taken for the moon to orbit the Earth relative to the zodiac), which would occur if k1 and k2 were on fixed axes, to anomalistic month — by carrying the gears epicyclically at a rate that is the difference between the rates of the sidereal and anomalistic months, that is, at the rate of rotation of about 9 years of the Moon’s apogee.
Gears with 53 teeth are awkward to divide. So it may seem surprising that the gearing includes two such gears (f1, l2), whose effects cancel in the train leading to the Saros dial. But the gearing has been specifically designed so that the “epicyclic table” e3 turns at the rate of rotation of the Moon’s apogee — the factor 53 being derived from the calculation of this rotation from the Metonic and Saros cycles, which are the bases for all the prime factors in the tooth counts of the gears.
The establishment of the 53-tooth count of these gears is powerful confirmation of our proposed model of Hipparchos’ lunar theory. The output of this complex system is carried from e6 back through e3 and thence, via e1 and b3, to the zodiac scale on the front dial and the lunar phase mechanism. Our CT confirms the complex structure of axis e that this model entails.
The Antikythera Mechanism shows great economy and ingenuity of design.
It stands as a witness to the extraordinary technological potential of Ancient Greece, apparently lost within the Roman Empire.
'Pointer-follower' device for spiral dial as it appears in x-ray computed tomography;
from T. Freeth et al.
'Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism' (Nature)
Map of the Mediterranean, showing Antikythera area in inset;
from Jo Marchant, 'In search of lost time' (Nature)
by Jo Marchant
Nature 444, 534-538 (30 November 2006)
from Nature Website
In 1900 a party of Greek sponge divers sought shelter from a storm in the lee of the barren, rocky islet of Antikythera. Once the winds had eased, Elias Stadiatis dived 42 meters to a rocky shelf to look for late additions to his hard-earned haul. Instead of sponges nestled on the sea bed, the shape of a great ship loomed out of the blue.
After grabbing the larger-than-life arm of a bronze figure as proof of his find, he returned to the surface to inform his companions. The Antikythera wreck was to yield a stunning collection of bronze and marble statues, pottery, glassware, jewellery and coins; it was also to claim the life of one of the divers, not yet aware of the risk of the bends when diving with an oxygen hose.
As busy museum staff struggled to piece together statues and vases, a formless, corroded lump of bronze and wood lay unnoticed. But as the wood dried and shrivelled, the lump cracked open, and on 17 May 1902, archaeologist Valerios Stais noticed that there were gear-wheels inside.
The gears elicited interest, but it was not until investigations delved beneath the surface that the box started to yield its secrets. The British science historian Derek de Solla Price and the Greek nuclear physicist Charalampos Karakalos made X- and gamma-ray images of the fragments in 1971. Karakalos and his wife Emily painstakingly counted the visible teeth; in 1974 Price published a heroic 70-page account of the machine (D. de S. Price Trans. Am. Phil. Soc., New Ser.64, 1–70; 1974).
"Price really put the mechanism on the map," says Tony Freeth, co-author of a new reconstruction of the device (see page 587). "He understood the essence of what it was — an astronomical computer." But Price massaged some of the data (much to the annoyance of Karakalos and his wife), and his reconstruction was unnecessarily complicated — perhaps too complicated for historians and archaeologists. They largely ignored Price's work, and he died in 1983.
That same year, a Lebanese man walked into the Science Museum in London with the pieces of another ancient mechanism in his pocket. Curator Michael Wright realized the device was a Byzantine sundial from the sixth century AD, which also contained a simple geared mechanism that drove pointers showing the position of the Moon and Sun in the sky. Studying the astronomically enhanced sundial led Wright to Price's treatment of the Antikythera Mechanism, in which he saw serious holes.
Wright ended up working with Allan Bromley, a computer scientist at Sydney University in Australia who had become interested in the Antikythera Mechanism at around the same time. Bromley wanted to study the machine with X-ray tomography, which assembles a sheaf of cross-sections of its subject.
As the fragments could not be moved from the museum, and Bromley didn't have the money to ship a tomography machine to Athens, Wright used his tool-making skills to build a crude tomograph in situ. The two researchers took around 700 images of the fragments, and Wright has been working on a reconstruction that supercedes Price's ever since.
In the meantime, Mike Edmunds, an astrophysicist at Cardiff University, UK, and his friend Tony Freeth, a mathematician-turned-film-maker living in London, decided the mechanism would make a fantastic subject for a documentary. But their efforts soon turned to discovering more about how the device worked.
They contacted Hewlett-Packard, which had developed a method for reading eroded cuneiform tablets that involved building up a composite computer image from pictures taken under light from a wide variety of directions, to reveal more of the inscriptions.
They enlisted experts in computer-assisted tomography from British firm XTEC, which developed a new machine just for the Antikythera project.
In search of lost time M. KIRK
Derek de Solla Price tried to undo the Antikythera Mechanism's secrets
In autumn 2005, the Hewlett-Packard equipment and all 12 tonnes of XTEC's machinery were shipped to the museum. The results have allowed the team to confirm many of Wright's ideas, and extend them. "My main fear initially was that we'd throw all this technology at it and we wouldn't do more than dot the i's and cross the t's," says Freeth. "But we got more out of it than I dared hope."
One major new result came as much from chance as from technology; a key section of a dial found sitting unnoticed in the museum's store room helped reveal that one of the dials was used to predict eclipses. Another big discovery was the identification of a 'pin and slot' mechanism to model the varying speed of the Moon through the sky (see main story).
The inscriptions are also revealing novelties, although deciphering them is hard work: some of them are less than 2 millimetres high, and there are no spaces to show where each word starts and finishes. Agamemnon Tselikas, director of the Centre for History and Palaeography in Athens, spent a concentrated three months trying to decipher the wording, working from late at night into the early hours of the morning: "I needed the silence."
So far Tselikas and his colleague Yanis Bitsakis have more than doubled the number of legible characters on the mechanism, which seem to form a manual that explains how the mechanism was to be used.
It takes "imagination and intuition" to decipher the inscriptions, says Tselikas.
"We are just starting to penetrate the mentality of the user of this machine."
Jo Marchant
Intriguing questions demanded by the mere existence of an ancient device of the sophistication and elegance of the Antikythera mechanism, of course, include where did it come from, and who built it?
The wreck on which the toponymically named mechanism was found, had foundered off the island of Antikythera, lying at the western extremity of the Aegean Sea directly astride important trade routes connecting the Aegean — places like Rhodes, a principal trading entrepot, along with points east and north (e.g., Pergamon) — with the western Mediterranean, most importantly the city of Rome itself.
Given the cargo of luxury goods aboard (originating to the east of the ship’s final resting place), it seems very likely that the vessel was indeed bound west, quite probably for Rome, when it abruptly sank in 42 meters (138 feet) of water.
Where then did the mechanism originate and who might have made it?
A clue is provided by the fact that in addition to the famous mechanism the ship also carried luxury trade goods which have been identified as originating at Rhodes, as well as other goods that are from Pergamon but which may have been transshipped through Rhodes.
As noted before, the Antikythera device itself contains an algorithm built-in to express the “first anomaly” of lunar motion which was worked out in the 2nd century b.c. by the Greek astronomer Hipparchos — perhaps greatest of ancient Greek astronomers; who indeed did much of his work at Rhodes — and on which island afterwards the philosopher Poseidonius (contemporaneously regarded as the most learned man of his age; who did astronomical work himself, and at one point instructed Cicero at Rome) established a school.
Hence the hypothesis that Poseidonius’ school at Rhodes developed the technological traditions — that may have been directly influenced by Hipparchos himself, and which must have taken a good long while to gestate, as the Antikythera mechanism clearly didn't spring whole-cloth out of nowhere — leading to the construction of the machine and others like it; one of which was sent off to Rome.
It never made it, and the rest is (latter day) history.
Diagram of eight-geared lunisolar calendar
from al-Biruni's astrolabe treatise of 996 AD
Beyond its jaw-dropping technology and fascinating provenance, the question of what effect the discovery and decipherment of this ancient technology has on our understanding of history itself, as Jo Marchant observes in her Nature companion piece, is perhaps even more intriguing.
As she notes, prior to the Antikythera device it was believed that the advent of clockwork-type mechanisms in 14th century Medieval Europe represented the invention of this fundamental technology at around something like that time frame.
Since Antikythera, however, a geared 6th century a.d. Byzantine sundial with four surviving gears (and which probably originally incorporated at least eight) has turned up; 4, 5 while the Medieval Persian scholar/scientist al-Biruni described a “box of the Moon” that is quite like the Byzantine device. (See at right an illustration of an eight-geared lunisolar calendar from al-Biruni’s astrolabe treatise of 996 a.d.)
Such an augmented astrolabe from 13th century Iran is still extant today. The step from that to the clocks of 14th century Europe is chronologically and technologically short.
Thus, the history of gearing and clockwork is being revolutionized. Instead of originating late in the Medieval era, as previously assumed (in a form we now see as suspiciously like that of the Antikythera mechanism), now it appears likely that the tremendously sophisticated gear-work that we see reflected in this machine continued to survive in some form in the Greco-Roman world, as displayed in the 6thcentury Byzantine device; from whence it found a refuge somewhere during the early Medieval period — perhaps in the Baghdad Caliphate — and it may well be that (after say the Mongol destruction of Baghdad during the 13th century) this technology thereupon migrated with scholarly refugees and ended up influencing the West’s own technological trajectory a century or so later.
As François Charette observes in his Nature companion piece “High tech from Ancient Greece,” 6 all this is not unlike us one fine day discovering that steam engines had actually been invented during the Renaissance, and Newcomen and Watt’s invention of improved steam engines during the 1700’s unbeknownst to us had ultimately derived from that.
Archaeologist Martha Dane looks out over the Martian ruins;
in H. Beam Piper's 'Omnilingual' (Kelly Freas)
An echo with speculative literature is found in the way that the deciphering of the Antikythera mechanism utilized such details as the number of teeth in the assorted gears (unique ratios identifying which heavenly phenomena are being computed or charted on the dials of the machine) along with such things as historic eclipse patterns (the Saros canon) as important indicators of its meaning and function and aids in reconstruction of the design.
This sense of using natural law and natural history as one’s keys to the decipherment, is very much akin to a classic science fiction tale from half a century ago, in which scientists investigating the remains of a disappeared alien race and civilization on their home world (Mars), in attempting to decipher their language — which seemed inherently almost impossible due to lack of a “Rosetta stone” (like the original that assisted in the decipherment of Ancient Egyptian) — ultimately came to realize that science (natural law), knowledge of which was embedded in the technology and writings of the science-savvy aliens, would serve as their universal Rosetta stone.
That story is “Omnilingual” by H. Beam Piper, 7 first published just fifty years ago, in the February 1957 (1957-02) issue of the extremely influential science fiction magazine then known as Astounding Science Fiction, altered a few years later to the still-extant name of Analog.
Astounding/Analog for many years was under the inspired editorship of very well-regarded science fiction author John W. Campbell, Jr. — who has since become even better known as the “father of modern science fiction,” as a result of his tutelage and inspiration of a whole generation and host of talented writers — Heinlein, Asimov, Clarke, van Vogt, Poul Anderson, the list goes on and on…
Piper’s story, I’d venture to suggest, shows every sign of having profited from Campbell’s famous idea generation process vis-a-vis his authors.
(“Omnilingual” is no longer under copyright today, and can be accessed, with its original Kelly Freas illustrations from Astounding and blurb by John Campbell, at Project Gutenberg.)
The story concludes with the archaeologists reveling in having finally begun comprehending the rudiments of the structure of the Martians’ language, using the periodic table of the elements as a starting point — in the course of which Martha Dane compliments one of her colleagues:
“You said we had to find a bilingual,” she said. “You were right, too.”
“This is better than a bilingual, Martha,” Hubert Penrose said. “Physical science expresses universal facts; necessarily it is a universal language. Heretofore archaeologists have dealt only with pre-scientific cultures.”
As we see with the Antikythera mechanism, one need not go to Mars or Alpha Centauri to encounter a scientific culture in archaeology.
However, one can’t help but wonder…
- Had any of the scientists who deciphered the Antikythera machine read “Omnilingual,” lo these many years before or at some moment since?
- Did it influence their work, or even career; did they realize they were retracing the steps, in a sense performing the verification of a scientific hypothesis, which is implicit in the story?
Martian City in H. Beam Piper's 'Omnilingual'
in Feb. 1957 Astounding (Kelly Freas)
References
- Jo Marchant, “In search of lost time,” Nature, Vol. 444, Issue No. 7119 (issue dated 2006-11-30), pp. 534-538; doi:10.1038/444534a. See also Box 1: Raised from the depths.
- T. Freeth, Y. Bitsakis, X. Moussas, J. H. Seiradakis, A. Tselikas, H. Mangou, M. Zafeiropoulou, R. Hadland, D. Bate, A. Ramsey, M. Allen, A. Crawley, P. Hockley, T. Malzbender, D. Gelb, W. Ambrisco, and M. G. Edmunds, “Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism,” Nature, Vol. 444, Issue No. 7119 (issue dated 2006-11-30), pp. 587-591; doi:10.1038/nature05357. Also, Figures and Tables, Supplementary Information, and Box 1: Astronomical cycles known to the Babylonians.
- Antikythera Mechanism Research Project: http://antikythera-mechanism.gr/
- J.V. Field and M.T. Wright (both of The Science Museum, London, SW7 2DD, England), “Gears from the Byzantines: A portable sundial with calendrical gearing,” Annals of Science, Taylor & Francis, Vol. 42, Issue No. 2, issue dated 1985 March (1985-03), pp. 87-138; doi: 10.1080/00033798500200131.
- Francis Maddison (Curator of the Museum of History and Science, Oxford OX1 3AZ, UK), “Early mathematical wheelwork: Byzantine calendrical gearing,” Nature, Vol. 314, Issue No. 6009 (issue dated 1985-03-28), pp. 316-317; doi: 10.1038/314316b0.
- François Charette, “High tech from Ancient Greece,” Nature, Vol. 444, Issue No. 7119 (issue dated 2006-11-30), pp. 551-552; doi:10.1038/444551a.
- H. Beam Piper, “Omnilingual,” Astounding Science Fiction (subsequently Analog), February 1957 (1957-02) issue.
- See more at:
( please using the right click of your mouse, and Open Link in Next Private Window, )
https://www.bibliotecapleyades.net/ciencia/esp_ciencia_antikythera06.htm
==========
Tag: Antikythera mechanism
Tag: Antikythera mechanism
Kerry Kolasa-Sikiaridi - Sep 20, 2016
The second phase of the 2016 underwater excavation of the 1st century B.C. Antikythera shipwreck took place from August 28 to September 14 and...
Kerry Kolasa-Sikiaridi - Sep 1, 2016
The second phase of the 2016 underwater excavation of the 1st century B.C. Antikythera shipwreck will begin on Thursday, the head of the Hellenic...
Mary Harris - Jun 16, 2016
The Greek Ephorate of Underwater Antiquities and Woods Hole Oceanographic Institute returned to the Antikythera Shipwreck from May 22 through to June 11. The...
Kerry Kolasa-Sikiaridi - Jun 15, 2016
Although the artifact was recovered back in 1901, new technological advances have helped archaeologists learn even more about an ancient Greek analog computer that...
A. Makris - Jun 10, 2016
What do the Antikythera Mechanism, Nestor's golden cup and the marble statue of an athlete from Delos all have in common? The answer is...
Philip Chrysopoulos - Jun 10, 2016
The overall analysis of the inscriptions found inside the Antikythera Mechanism was presented on Thursday by the study group of the enigmatic object. In an...
Ioanna Zikakou - Nov 11, 2015
"Conspiracy theories did not exist in the antiquity. The ancient Greeks were rationalists and scientists with the original sense of the term. All scientific...
A. Makris - Oct 12, 2015
A new replica of the famous Antikythera Mechanism, whose remains are currently at Greece's National Archaeological Museum, has been built and put on display in...
Philip Chrysopoulos - Jun 22, 2015
The Ephorate of Underwater Antiquities, in collaboration with the American Woods Hole Oceanographic Institution, has completed the digital underwater surveying and dimensional precision display...
Philip Chrysopoulos - Nov 27, 2014
The Antikythera mechanism, the ancient clock like device that tracked the cycles of the solar system, is more ancient than it has been estimated...
Philip Chrysopoulos - Nov 17, 2014
A new video of the Antikythera ancient shipwreck has been released by kithera.gr showing the impressive underwater findings. The video is seven minutes long and...
Daphne Tsagari - Oct 6, 2014
Despite the official attempt to keep a lid on the discoveries of the latest Antikythera shipwreck expedition, some details from a video showing the new discoveries have...
- See more at: http://greece.greekreporter.com/tag/antikythera-mechanism/#sthash.ESZx9oP0.dpuf
==========
Tag: Antikythera mechanism
Tag: Antikythera mechanism
Ioanna Zikakou - Sep 30, 2014
On Sunday, October 5, Prime Minister Antonis Samaras will visit the area of the famous Antikythera shipwreck. The trip comes as a group of Greek, American and Swiss...
Ioanna Zikakou - Sep 16, 2014
The Antikythera Mechanish is known for being the world’s oldest computer device. It was used by ancient Greeks to track the solar system's cycles. The device...
Sotiria Nikolouli - Jun 6, 2014
Using the latest advances in technology and robotics, archaeology will strive to extract more secrets from an ancient shipwreck that once yielded the unique...
Ioanna Zikakou - Jan 1, 2014
The citizens of Chania, as well as the visitors of the city, have the opportunity to visit a unique exhibition during the holiday season. Costas...
Nicky Mariam Onti - Mar 22, 2013
The unique exhibition, The Antikythera Shipwreck: the Ship, the Treasures, the Mechanism, which is currently on show at the Archaeological Museum in Athens, will...
A. Makris - Oct 4, 2012
A new search has begun at a Greek island where an ancient device known as the world's "oldest computer" was found more than over...
Marianna Tsatsou - Jun 19, 2012
The Antikythera mechanism is regarded to be humanity's oldest computer. It dates back to the early 1st century BC and is designed so that...
- See more at: http://greece.greekreporter.com/tag/antikythera-mechanism/page/2/#sthash.yu5IGTxe.dpuf
*****************
01. [ ENGLISH ] The Antikythera Mechanism -The BEST COLLECTION of PODCASTS and YOUTUBE VIDEOS for
for more information please visit the following web page
( please using the right click of your mouse, and Open Link in Next Private Window, )
********************
************************************************************************
************************************************************************
***************************************************************
WEB RING
----------
and for more information, please switch to the same webpage in English -
( please using the right click of your mouse, and Open Link in Next Private Window, )
y para más información, cambie por favor a la misma página web enespañol -
(por favor usando el clic derecho de su ratón, y elvínculo abierto en la ventana privada siguiente,)
et pour plus d'information, commutez svp à la même page Web en français -
(svp utilisant le droit - clic de votre souris, et le lien ouvert dans la prochaine fenêtreprivée,)
und zu mehr Information, schalten Sie bitte zur gleichen Webseite auf Deutsch -
(bitte unter Verwendung des Rechtsklicks Ihrer Maus und öffnen Sie Link im Folgenden privatenFenster,)
e per più informazioni, commuti prego alla stessa pagina Web in italiano -
(per favore facendo uso del cliccare con il pulsante destro del mouse del vostro mouse e delcollegamento aperto in finestra privata seguente,)
e para mais informação, comute por favor ao mesmo Web page noportuguês -
(por favor usando o direito - clique de seu rato, e a relação aberta na janela privada seguinte,)
και για περισσότερες πληροφορίες, παρακαλώ μεταπηδήστε στην ίδιαιστοσελίδα στα ελληνικά -
( παρακαλώ χρησιμοποιώντας το δεξιό κλικ του mouse, ανοίξτε τον επόμενο σύνδεσμο
( ιστοσελίδα ) σε ξεχωριστό παράθυρο προς τα δεξιά, )
----------
***************************************************************
***************************************************************
***************************************************************
we WELCOME YOUR ADS, CLASSIFIEDS, ADVERTISING, CLASSIFIED ADS ...
OUR SITE IS YOUR PLACE ...
MAXIMIZE YOUR EXPOSURE BY USING THE HIGHLY EFFECTIVE SERVICES BELOW !
ARE YOU SEARCHING FOR THE PERFECT LOCATION FOR INTERNET ADVERTISING AND PROMOTION ?
Advertise your product or service using our WEB PAGE !
* All Traffic in our site consists of totally unique visitors for FULL CAMPAIGN PERIOD !
* You can DRAMATICALLY IMPROVE YOUR BUSINESS
* We offer wide selection of categories to select from ... including Business, Marketing, Shopping, Health, and much more !
* YOU CAN USE OUR SITE TO MARKET ALL OF YOUR PRODUCTS AND SERVICES !
* OUR SITE IS THE MOST COST-EFFICIENT WAY TO REACH THE MASSES THAT HAS EVER EXISTED !
* TARGETED TRAFFIC TO YOUR SITE GUARANTEED !
PLEASE CONTACT OUR ADS ASSISTANT. email IN ENGLISH LANGUAGE :
and please send a text message to my mobile phone 0030 6942686838
( 0030 is the international area code of Greece )
in order I connect into the INTERNET and to my www.gmail.com email account and to reply to your email, withing the next 24 hours.
***************************************************************
***************************************************************
*****************************************************
( English ) the StatCounter was installed on 2016-05-14, 17:30 p.m. GMT
( Greek ) ( Ελληνικά ) Ο μετρητής εγκαταστάθηκε την 14-05-2016 19:30 μ.μ. ώρα Ελλάδας
***************************************************************
***************************************************************
***************************************************************
***************************************************************
***************************************************************
***************************************************************
Page updated
Google Sites
Report abuse