So, I have questions.
About what? Well, by now you’ve heard about this wonderful machine that was found 100 years or so ago, which after a lot of research, has been found to be a remarkably sophisticated mechanical computer designed and built in ancient Greece about 2,100 years ago. There’s a nice LA Times story on it by Thomas H. Maugh II here, and a New York Times story* by John Noble Wilford here and a Reuters article by Patricia Reaney here. (The image to the right (click for larger) is from the University of Cardiff.)
From the articles you can learn that the machine was able to perform computational tasks 1400 years or so before the time when machines of this sort (but less sophisticated) were thought to have appeared. What sort of tasks? Well, using 37 gears or so it can do subtractions, multiplications and divisions to show the cycles of the moon, predict eclipses, etc. From the LA times article:
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 positions of the heavenly objects on that day.
It is called the Antikythera mechanism, after the Greek island near which it was found in a wreck of a Roman ship in 1901, on a major ancient trade route between Rhodes and Rome. Mike G. Edmunds and Tony Freeth of Cardiff University in Wales led the team that did the recent X-ray tomography work on the artifact to indentify and analyze its innards.
Such a sophisticated Astronomical computer is not really supposed to have existed so early, and so this is rather exciting. Nobody knows who made it, but it is supposed that it is by the Greek astronomer Hipparchus or a follower of Hipparchus, perhaps the philosopher Posidonius. The LA Times article quotes the Roman Cicero who
later wrote 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.”
and speculates that perhaps these words, thought to be somewhat fanciful, were indeed true, and this is the device of which he spoke. Very exciting indeed.
So my questions. Well, the obvious one is whether this device was unique… but some of the follow up questions are – Why was it on a ship between Rome and Rhodes? Was it a gift? A prize? A working tool or a curiosity? Perhaps it was not unique and there were several others, and so it was not a big deal for it to be being transported away from one place to another.
Either way, it does make one wonder if the technology had been used in other ways, and we just have not found more examples yet.
-cvj
(*Thanks Nick!)
why does everyone posting on this article write in slightly off english?
Ptolemy’s “Almagest” (Greek-Arabic title meaning “The Greatest Compilation”) is a continuation and amplification of the earlier work of Hipparchus, where Ptolemy contributed detailed mathematics. If anyone has that book, in original Greek or translated, that would help answer what was the link was between Hipparchus and the mechanical device. I have only a short English-translated excerpt in a History of Physics encyclopedia, where he barely mentions eclipses. Doesn’t it seem reasonable in the full Almagest that there be a mention of the mechanical device that makes the following eclipse predictions (gathered from a site that collects eclipse quotes: http://www.mreclipse.com/Special/quotes.html) ?
*”*Hipparchus tries to demonstrate the Moon’s distance by guessing at the Sun’s. First he supposes that the Sun has the least perceptible parallax, in order to find its distance, and then he uses the solar eclipse which he adduces; at one time he assumed that the Sun has no perceptible parallax, at another that it has a parallax big enough [to be observed]. As a result, the ratio of the Moon’s distance came out different for him for each of the hypotheses he put forward; for it is altogether uncertain in the case of the Sun, not only how great its parallax is, but even whether it has any parallax at all.*”*
From: Ptolemy, /Almagest/, V, 11.
*”*So Hipparchus, being uncertain concerning the Sun, not only how great a parallax it has but whether it has any parallax at all, assumed in his first book of ‘On Sizes and Distances’ that the Earth has the ratio of a point and centre to the Sun [i.e. the Sun’s sphere]. And at one time using the eclipse he adduced, he assumed that it had the least parallax, and at another time a greater parallax. Hence the ratios of the Moon’s distances came out different. For in Book 1 of ‘On Sizes and Distances’ he takes the following observation: an eclipse of the Sun, which in the Hellespontine region was an exact eclipse of the whole Sun, such that no part of it was visible, but at Alexandria in Egypt approximately four-fifths of the diameter was eclipsed. By means of the above he shows in Book 1 that, in units of which the radius of the Earth is one, the least distance of the Moon is 71, and the greatest 83. Hence the mean is 77. . . Then again he himself in Book 2 of ‘On Sizes and Distances’ shows from many considerations that, in units of which the radius of the Earth is one, the least distance of the Moon is 62, the mean 67-1/3 and the Sun’s distance 490. It is clear that the greatest distance of the Moon will be 72-2/3.*”*
From: Pappus, /Commentary on the Almagest/
*”*Moreover, such an observation has been made in the case of an eclipse of the Sun. Once the Sun was wholly eclipsed in the Hellespont, it was observed in Alexandria to be eclipsed except for the firth part of its diameter, which is, according to the sight, except for two digits and a little more. . . Now since it is 5000 stades from Alexandria to Rhodes; besides, proceeding hence to the Hellespont, this will also decrease in proportion, since when the Hellespont is reached, it will entirely vanish.*”*
From: Cleomedes, /De Motu Circularis Corporum/, II, 3.
These three quotations probably refer to a total solar eclipse of 20 November 129 BC. Quoted in /Historical Eclipses and Earth’s Rotation/, by F Richard Stephenson, Cambridge University Press, 1997, page 351.
Clifford: – Trying to put all the shipwreck items together and reassembling their positions on the ship is a great idea. Unfortunately, according to the archeological record, the sponge divers exctracted several of the artifacts by themselves in 1900; the first trained archeologist, Valerios Stais, reached the site in 1902. Also, chances are that as the ship capsized(?) and was sinking, the artifacts dispersed somewhat anyway (42 meters of water will make artifacts with flat surfaces spread/plane in random directions).
The next best thing might be to walk around the Athens Archeological Museum and identify/photograph the artifacts. This provides a nice context. I suspect sooner or later, the museum officials might assemble them all in one area. Actually, there is a really impressive bronze statue of a beautiful woman wearing a long cape and sandals (in the same wing of the museum, but not in the same room, as the mechanism), that was just restored and put on display in the last year or so. Unofortunately, I did not take photos of it. I might do that next summer. I believe there are more artifacts not (yet?) on display, but I suspect nothing as substantial.
My opinion is that this was a salvage (re-cycling) ship. Fortunately (for us) it sunk.
By the way, it is said that the complete quote from Cicero is almost the origin of ID theory.
Indeed Clifford I would to like how they conjeture that the philosopher is Bion the Borysthenite; I would fit a lot better if it were Bion of Abdera.
Clifford, If you study the astrolabe, the astronomical device the Arabs used in the medieval period for navigating the stars, there are (clear, I think) similarities to the Antikythera mechanism. The libraries in Fez (?) and Toledo have thousands of Arab translations of Greek scientific works, from which the Moors built their technical civilization and flourished. If you really want to see (further) evidence of the Greek technical civilization, then look at the Arab archeological sites in Andalucia Spain.
Regarding the melting of Bronze, the Romans did that with the Etruscans too. The Romans (and others) valued the exceptionally fine Etruscan military gear, which sometimes included a gorgeous filigree technique on bracelets, rings, armbands. Usually at the end of a battle, the Etruscans were stripped of their bronze breastplates, shields, shin guards, helmets, weapons, and chariots, and gold armbands (from which hung one or more small orbs of solid gold) and gold rings. A Roman victory over Etruscans was often followed by a command:
“Bring me their arms!”
after which the commanding general received carts filled with gold-laden arms and hands … (1)
(1) Holder, Philancy, Etruscans: A Beginning, Cortona: HP Publishing, 2002, pgs 105, 118, who references Bonfante, Larissa, ed. Etruscan Life and Afterlife. Detroit: Wayne State University Press, 1986, pg. 249, who further quotes Livy I. You can see many of these gold filigree and bronze military pieces in the Villa Giulia National Etruscan Musceum in Rome.
Bill: – I wonder what we might notice if we were able to put all the shipwreck items together and try to reassemble their postions on the ship. Maybe there is a story they might tell us.
-cvj
Here are photos of the mechanism I took last summer:
http://manaris.wordpress.com/
The interesting thing is that it is placed in a side area, out of context (i.e., away from the other artifacts it was discovered with). I took photos of some of the other artifacts found on the shipwreck. They are hard to find because they are dispersed thought the (rather large) museum.
Question: But if the Greeks had access to such powerful calculating technology, why don’t we see other useful artifacts of technical sophistication? Well, we do have the massive, architecturally intricate buildings they left behind (many still standing). But what about other technological gizmos, like the Antikythera one?
Answer: According to the Nature article (http://www.nature.com/nature/journal/v444/n7119/full/444534a.html)
“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.’ ”
Bronze was a preferred medium for weapon making because of its strength and ease of casting. Romans also used bronze for casting statues of their gods. Why preserve a conquered, disgraced nation’s statues of philosophers and of strange delicate artifacts with no apparent practical use? The bronze used in these artifacts was far more valuable to the conqueror.
Alejandro, you make a good point! If the Antikythera Mechanism truly carried extraordinary weight (so to speak), it only seems reasonable that a prominent writer, such as Cicero or Hipparchus, would’ve – at the very minimum – cited this instrument, somewhere/somehow, in their documents.
I’d say, simply from the looks of your comments, you appear to have a rather strong grasp on Greco-Roman culture/civilization. In contrast, my knowledge base of the period is grossly sketchy. Nonetheless, I still retain a child-like fascination with this period.
Once again, thanks for showering Asymptotia with your insights into Greco-Roman history:)
Other possibility is that it were related to the geographic efforts of Posidonious and his school. But how? The determination of longitude suggested by Hiparchus was via the timing of moon eclipses, so they did not really need to know the position of the planets, they just need a table of the next five or six eclipses and to agree to measure (using clepsidras or similar tricks) the time of start and end of the eclipse at each laboratory.
Feynman’s hint, about the measurement of moon and sun distances, could be interesting, but again I do not see why do they need to predict on site, instead of just sending the results of the calculations in Rhodes to the interested teams in Rome.
Hmm but on the other hand Posidonius was in Rome, as ambassador, during 87-86 BC. So the machine could be an agreed exchange, sent next year to someone there.
The Nature article is impresive, compulsory read. It is fascinating that the monetary evidence plus the cargo of the ship point towards Hipparchus. Still, the report of Cicero is disconcerting because he was in Rhodes between 79 and 77 BC; the shipwreck happened some years before, about 85 BC. So if Cicero saw the machine, it was a different one. And if he was reporting on the lost machine, it is strange he does not elaborate on the dramatic circunstance of the loss or even who was the man in charge.
I tend to be somewhat skeptical when hearing about accounts of lost treasures from the ancient world just awaiting to be rediscovered so that history can be rewritten for all to behold in amazement. There are, for instance, a number of ‘Classic Scholars’ determined to see that Archimedes receive sole credit for inventing calculus.
One can’t deny that Archimedes is a key figure in calculus, perhaps even the first figure in a long line of predecessors. However, to elevate the man to the status of absolute originator of calculus is not only a bit of a stretch, but is a flagrant exaggeration of the facts.
Doubtlessly, Archimedes is responsible for formulating some of the underpinnings of calculus. But one mustn’t loss sight of the fact that it took the brilliance of both Newton and Liebniz to capture and harness calculus in its entirety.
Looking back though, the Antikythera Mechanism might be regarded as a monumental precursor to modern astronomy. In a similar vien, Archimedes’ method of exhaustion is viewed as a forerunner to calculus.
After Stefan so kindly created a link to that above-mentioned article in ‘Nature’, I’ll paraphrase a tidbit from it: the Greeks designed machines with the purpose of achieving a “deeper understanding of cosmic order”. Well, then, I guess it’s quite conceivable that the secrets of quantum gravity are embedded within the interlocking gear wheels of the Antikythera Mechanism.;)
Given that the parts of this device are supposed to have been smoothly and finely engineered, this argues against it being a single example. To make finely-calibrated machine parts is the mark of someone undertaking repeated efforts at the construction task, suggesting there were other similar devices made at the same time.
Carl Brannen: Your post makes me wonder if you are aware that the beautiful Libyan desert glass, could very well be the result of an asteroid impact.
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Aaron F.: You might like this. If you go to the National Archaeological Museum, Naples, you’ll find The Farnese Atlas, which is a late Roman (second century AD) sculpture and copy of a Greek original, that depicts the Titan Atlas holding a sky globe on his shoulder. The statue’s sky globe shows 41 Greek constellations, as well as the celestial equator, tropic and ecliptic. Bradley Schaefer, an astronomer who presented work on the Farnese Atlas last year, says that the constellations are accurately depicted, and represent one of the earliest star catalogs by Hipparchus. Most of the books of Hipparchus have not survived. Hipparchus’ lost star catalog is only known through the references of later astronomers, and in the work: Almagest, by influential Greek astronomer and geographer: Ptolemy, who lived around AD 85 to AD 165. A chi-square analysis shows the date of the constellations to be 125 BC, a date which points directly at Hipparchus as being the observer. Other analysis supports the idea that the Farnese Atlas being the depiction of Hipparchus’ lost star catalog.
http://www.pma.edmonton.ab.ca/human/archaeo/faq/_images/medwhls.jpg
Maybe what we had thought less then intelligent(?) because of some idea of time and culture we see here, that they may have “seen” the earth in different ways in which we are not accustom?
Where the landscape had interesting associations. Places that may have it’s idea of physics attached, while we only viewed the waterfall, the mountains, or volcanoes? Winds? An eye on the sun, as a spot on the earth?
This is a very ancient idea too?
John Baez column had some perspective on travelling through the ruins? 🙂 I enjoyed it as I travelled through them, and of course am biased with my own research. The rock art, as if Plato has his hand on the shadows on the wall, advanced other thinking beyond the cave?
Very coooooooool! Naked-eye astronomy never fails to amaze me; it’s one thing everyone in the world has in common. We share it with people we know nothing else about; we will never speak their languages, hear their stories, live in their cities or believe in their g-ds, but we can read their pictures of the stars. 🙂
I’ve always been impressed by the stonework of the ancients, some of which cannot be easily reproduced today:
Egyptian lathed stone tableware
Also see the beautiful agate bowl at the Getty museum:
Getty bowl
The amazing thing about the above bowl (manufactured before AD 200) is that it is fully microwave and freezer compatible, is durable, and has less chemical interaction with food than any common modern tableware. Ancient Roman glass was similarly beautiful, but since glass (even most modern glass) dissolves in water, what we have left from that era looks like hell. People get the impression that ancient glass was ugly, but this is not the case.
I was working on the project of making modern tableware with a quality approaching that ancient Getty musem bowl when my efforts were rudely interrupted by my realizing that I could rewrite the foundations of physics. When I get done with this, I’ll return to the problem of making the world’s finest tableware.
To me the key question is was the device built based stictly on empirical observation of the eclipses/cycles or did the builder have to have an understanding of celestial mechanics which was not developed until thousands of years later. Either way it is quite amazing.
Perhaps more evidence for ancient visits by extraterrestials…;)
Elliot
Amara, presumably if a ship had got safely to Rome with that sort of calculator on board, the Romans would have copied it and developed it further (as they did of other Greek inventions, such as architecture), kick-starting mechanical calculators long before Pascal’s machine.
Hence by Susskind’s application of the anthropic principle, for the world to be as we observe it, all Antikythera mechanisms must have sunk before reaching Rome.
Clifford, your question: “Why was it on a ship between Rome and Rhodes?”
Some clues might be the following. The ship that was carrying it was specifically a Roman trading vessel, which was also holding many other valuables: marble and bronze statues, gold jewlery, silver tabel utensils. And the ancient civilization of Rhodes was one of the last Greek city-states to fall to the Roman Empire.
And of your comment: “Such a sophisticated Astronomical computer is not really supposed to have existed so early, and so this is rather exciting.”
There are other complex mechanical devices (not as sophisticated, but still impressive) from that period: The “polylobos”, or machine-gun catapult, which could continuously fire arroves without reloading, Archimedes’ odometer, which could accurately measure the distance traveled by a rolling carriage, “Archimedes’ screw”, which could draw water from the Nile, “Archimedes’ water clock, to measure time, the machines by Ctesibios to exploit compressed air, such as the piston pump,and his compressed air weapons, and Heron of Alexandria’s aeolipile, which moved objects by the power of steam (a precursor of the steam engine).
I read about this in a fascinating letter in one of Feynman’s books (“What Do You Care What Other People Think?). He saw the thing in a very boring museum and was fascinated as it was the only mechanical device there, so he asked the curator about it. She replied, Of all the beautiful things in this museum, why does he pick out that particular item? What is so special about it?
Feynman’s letter is at http://www.giant.net.au/users/rupert/kythera/kythera6.html
“Yesterday morning I went to the archeological museum. . . . Also, it was 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. The
teeth are very regular and many wheels are fitted closely together. There are graduated circles and Greek inscriptions. I wonder if it is some kind of fake. There was an article on it in the Scientific American in 1959. . . .
“I asked the archeologist lady about the machine in the museum — whether other similar machines , or simpler machines leading up to it or down form it, were ever found — but she hadn’t heard of it. So I met her and her son of Carl’s age (who looks at me as if I were a heroic ancient Greek, for he is studying physics) at the museum to show it to her. She required some explanation from me why I thought such a machine was interesting and surprising because, “Didn’t Erastosthenese measure the
distance to the sun, and didn’t that require elaborate scientific instruments?” Oh, how ignorant are classically educated people. No wonder they don’t appreciate their own time. They are not of it and do not understand it. But after a bit she believed maybe it was striking, and she took me to the back rooms of the museum– surely there were
other examples, and she would get a complete bibliography. Well, there were no other examples, and the complete bibliography was a list of three articles (including the one in the Scientific American) — all by one man, an American from Yale!
“I guess the Greeks think all Americans must be dull, being only interested in machinery when there are all those beautiful statues and portrayals of lovely myths and stories of gods and goddesses to look at.
“(In fact, a lady from the museum staff remarked, when told that the professor from America wanted to know more about item 15087, “Of all the beautiful things in this museum, why does he pick out that particular item? What is so special about it?”)”
Mostly I though the trade routes in the ancient Mediterranean were along the coast lines? I don’t think these things were very abundant—I saw something on the History or Discovery channel and it looks pretty intricate. It seems to me to be an ancient desk toy sort of things for very wealthy people to bring out at dinner parties. Once one person had one, I’m sure that very wealthy Greeks and Romans could pay someone to build one for them. I just can’t imagine these things being produced in any great amount.
Maybe the same space aliens who built te pyramids left this novelty behind?
Well, i do know that across much of North America, dating back up to 2500 years ago (and earlier in a couple of questionable cases), there were numerous (hundreds) of astronomical instruments made of stone and wood. From Kivas and temple pyramids in the Southwest and Mexico, to mountain-tops (hilltops in northern Canada) throughout most of the US and Canada, earth-based tools kept very accurate track of stars (interestingly not planets) to determine exact dates of solstices and equinoxes, as well as propitious moments during the seasons for planting, monsoons, and other important cyclical phenomena (these may have involved planets and certainly moon cycles). It is likely that if the Greeks and other “civilized” cultures in Asia (China and India especially) required instruments for navigation, astronomical timekeeping, and so forth, they must have been plentiful and abundant.
I just hope it’s not another “Sokal affair” in the brewing? 🙁 There are to many nice people that could be hurt.
Hi ,
there is quite a long article in this week’s Nature about this thing, and it is free access for all:
http://www.nature.com/nature/journal/v444/n7119/full/444534a.html
I am also quite puzzled by this machine, and hope to find some reading time over the weekend.
Best, stefan
It’s called OOPArt
I read this back when Omni magazine was in production. Back then, it was not the kind of science magazine that we have today around us.
Also, how can we control our speculations faced with new information? Shall we change our views on the quantum gravity mechanism’s of John Baez’s? Or is there an added dimension to it?:)
Derek J. de Solla Prince.
Can it be used to measure the meridian or so?
Also, I think that I had a mistake in ‘Rice’s’ name.. should be Price!
Hi Clifford, The Antikythera Mechanism is pretty cool. In 2001, the Frankfurt Bookfair honored Greece (every year it is a different country), and among their very cool displays were a number of Greek instruments … it is not hard for me to imagine that such a device as this was made for the purpose that is proposed now.
A couple of years ago, I offered this project to my Astro 100 students.. So you see that Wright’s work has been going on for some years… Amara
——————————————————————-
X. The Antikythera Mechanism
In 1900, a Greek sponge diver named Elias Stadiatos discovered the wreck of a cargo ship off the tiny island of Antikythera. In his valuable finds, were a few green coroded lumps, which were the last remnants of an elaborate mechanical device, now known as the Antikythera Mechanism. New analysis of the device has indicated that the device was designed to model a particular form of epicyclic motion. Please answer the following questions.
1) Describe the discovered wreck.
2) Describe the original (1950s) analysis by Derek Rice, now known to be wrong.
3) Describe the results of the new (2002) analysis by M. Wright, the curator of mechanical engineering at the Science Museum in London. Sketch the motion that this device models.
4) Who was the ancient Greek that first modelled epicyclic motion?
5) Did the ancient Greeks have a tradition of mechanical technology? If yes, then please give the name of another one of their devices.
Useful References:
* Engineering and Technology in Ancient Greece by Christos Lazos.
* Derek Rice, “An Ancient Greek Computer?”, Scientific American, June 1959.
* The Economist, “The Clockwork Computer, September 19, 2002.