Dan Snow's History Hit - The Ancient Greek Computer: The Antikythera Mechanism

Episode Date: August 20, 2023

In the recent Indiana Jones: The Dial of Destiny movie, the Antikythera Mechanism is used for time travel but in reality it was actually more of a celestial calculator- to track and predict astronomical phenomena. It was discovered by a group of Greek sponge divers in 1901 as they explored the site of an ancient shipwreck that dated back to the first century BCE. Among the wreckage on the bottom of the Mediterranean Sea, they found a complex arrangement of gears, wheels, and dials housed in a wooden case. It has astounded archaeologists, scientists and historians for years. It challenges our previous understanding of ancient technological capabilities and reveals the sophisticated level of scientific knowledge possessed by the ancient Greeks.Dan is joined by Professor Tony Freeth, a man who understandings this astonishing object better than most- he is a founding member of the Antikythera Mechanism Research Project and an Honorary Professor at University College, London. He believes that the Antikythera Mechanism, may be an iteration of something designed by the great Greek inventor Archimedes, decades earlier...Discover the past on History Hit with ad-free original podcasts and documentaries released weekly presented by world renowned historians like Dan Snow, Suzannah Lipscomb, Lucy Worsley, Matt Lewis, Tristan Hughes and more.Get 50% off your first 3 months with code DANSNOW. Download the app or sign up here.If you want to get in touch with the podcast, you can email us at [e-mail], we'd love to hear from you!You can take part in our listener survey here.Produced by Mariana Des Forges and edited by Dougal Patmore.

Hi everybody, welcome to Dan Snow's History Hit. The other day, it was raining. And on rainy days, we often go for bicycle rides in the nearby forest. So imagine my children's surprise when I ran into the kitchen and announced we were going to the movies. It was a Sunday, we were going to drive to the nearest theatre and we were going to watch a film. And my wife was like, what's going on? I said, Indiana Jones has just landed and we went going to watch a film. And my wife was like, what's going on? I said, Indiana Jones has just landed. And we went to watch the Indiana Jones movie. Imagine my

excitement when the Antikythera mechanism made an appearance in the most recent Indiana Jones film. The Antikythera mechanism is one of the most fascinating and important objects ever recovered from an archaeological site dating back to ancient Greece. It is a mind-blowing, hugely advanced bit of mechanical engineering. It's a testament to the ingenuity, the intellectual achievements of the ancient Greeks. continuity the intellectual achievements of the ancient greeks in the early 20th century a lump of metal had been recovered from a shipwreck burst open in an athenian museum and tiny mechanical gears fell out everyone was astonished they were the size of a fingernail the teeth on them were around a millimeter long nothing like this had ever been found from an ancient Greek site.

After years of speculation and scientific papers, we now think we know what it is. It is a system of gears and dials that accurately calculates astronomical positions of the sun, the planets, the moon, and predicts celestial events such as upcoming solar and lunar eclipses. six celestial events such as upcoming solar and lunar eclipses. It is a mechanical calculator of extraordinary sophistication. The one thing the Indiana Jones movie got right about it, because I don't want to put too many spoilers in it, the one thing it may have got right about it is it may be connected with one of history's greatest mathematicians, Archimedes himself, as you'll hear in this podcast. It is certainly one of the most exciting objects ever to come out of a shipwreck,

and that's against pretty stiff competition. So here to tell us all about this device is Professor Tony Freeth. He's honorary professor of the Department of Mechanical Engineering at UCL. He's part of the Antikythera research team. And he points out to me in this podcast that nothing more advanced than this mechanism was produced in the west of Eurasia until the astronomical clocks of the 14th century, 1500 years.

This is the ancient Greek computer, folks. Enjoy. T minus 10. Atomic bomb dropped on Hiroshima. God save the king. No black-white unity Enjoy. Tony, thank you very much for coming on the podcast. You're very welcome. When did you first hear that this was going to be in an Indiana Jones film? First of all, let's get down to brass tacks here.

Maybe a month ago, something like that. Really? No one told you? No one told me. Firstly, let me say, it's the Antikythera mechanism. It's not the Antikythera mechanism. That's how they pronounce it in the film. They spent $295 million making it, and they couldn't bother to ask a Greek person how to pronounce it. It's pronounced Antikythera.

When was it discovered? The discovery is so exciting. Well, in 1900, a party of Greek sponge divers chanced on a wreck near the island of Antikythera, which is between Crete and mainland Greece. And the youngest diver went down to look for sponges. And he is said to have come back up shaking in fear, saying he'd seen a heap of dead naked people on the seafloor. saying he'd seen a heap of dead naked people on the seafloor. And so the captain of the ship, Captain Condos, went down and he discovered that the dead naked people were sculptures,

bronze sculptures, marble sculptures, and so on, scattered on the seafloor. And he brought up a bronze arm. And then they proceeded off to their normal Spanish fishing grounds, which by this time were in North Africa. The sponges had been fished out of the Mediterranean, went back to the island they'd come from, which is Simi in the eastern Mediterranean, not far from Rhodes. And they debated as to whether they should go back the next year and plunder the wreck or whether they should tell the authorities. And I don't know why, but they told the authorities. And then the Greek government, in collaboration with the Greek Navy, organized

from autumn 1900, a dive on the wreck with a Greek naval gunboat standing by to loot us. And they had bad weather in 1900. But in early-ish 1901, they started to bring up huge amounts of stuff from this. It was a real treasure ship. It was a huge ship for the times. And it was just stuff full of Greek treasure. It had superb bronzes on it, marble sculptures, superb bronzes on it, marble sculptures, glassware, jewelry, a lot of pottery of different sorts. And they brought up really thousands of objects. And you can imagine they're diving in those days that were in these great big brass and copper helmets and these canvas suits and they're pumped there. They're said to have only been able to spend about five minutes on the bottom, but they still managed to bring up some of this glasswork completely intact. And they also recovered this lump,

which was not regarded as anything important at all at the time. It's about the size of a very large dictionary. Everything was taken back to the National Archaeological Museum in Athens. And this lump lay somewhere in a store of stuff to be examined later. It was probably recovered because it would look greenish, so it might have contained bronze. And some months later, it split apart. And a visiting former Minister of education, Spyridon Stice, noticed that inside the split parts, there were these tiny gear wheels, you know, about the size of coins, teeth about a millimeter long. And this was a complete shock for ancient Greece, because such gear wheels simply shouldn't have existed in those times. These are precision gears, mathematical gearing. They knew gears for

water mills and windmills, crude mechanical gears, but these sorts of precision gears really were astonishing for them. And there was a lot of early controversy about what it was. You know, some people thought it was a navigation instrument because it had come from a ship, which it wasn't. Some people thought it was an astrolabe, which is a device for tracking the stars, which again it wasn't, though that was closer. No real progress was made until a German philologist,

language expert, Albert Riem, started to study it in 1905. And he really began to get some insights into what the mechanism was. He found some numbers, it's covered in inscriptions, all the external surfaces covered in tiny inscriptions, It covers in tiny inscriptions, typically 1.6 millimeter high letters there. And he found some numbers which related to known cycles, some from Babylonian astronomy, some from Greek astronomy. For example, he found the number 19, which is a known cycle of the moon from Babylonian astronomy, a 19-year cycle of the moon. He discovered the number 76, which was a Greek improvement on this lunar cycle.

And he discovered the number 223, which is a number well known to people who study ancient astronomy as a number relating to a very important eclipse cycle called the Saros Cycle, which is 223 lunar months, just over 18 years. And he started to theorize that this was an astronomical calculating machine. He was the first to realize the real essence of the Antikythera mechanism as a calculating machine. And he started to do diagrams of models which had extraordinary aspects to them. They had things like epicyclic gearing. Well, people will be used to gears in, say, a normal clock, like a 19th century clock, where the gears have axles which go into plates and they're fixed. In epicyclic gearing, the gears are mounted on

other gears and the axes move around with them. This was just, in a sense, a ridiculous suggestion for that era. Just ridiculous. Not known until, I don't know when it was known, later 18th century maybe. But Rem was proved right in a very, very fascinating way. He was proved to be right. So he was the first person who really started to understand it, but he didn't have enough good data and all his models, none of them are correct, but he got the essence of it right, you know. And then there was a long period where nothing much progressed until a British physicist called Derek the Solar Price started to look at it in the 1950s. And he published a well-known article in Scientific American, 1959. And he again started to make real progress. He

started to measure everything and he started to understand what it was like. He discovered that it had a big dial system at the front and two dial systems at the back. And he started to hypothesize about what these dials were for and how the mechanism worked. and how the mechanism worked. And he wrote a very famous paper called Gears from the Greeks in 1974, which was, I think, what he felt he'd sort of solved the mechanism. This device that he had contained what he called a differential gear. That's not the same as a car differential. There are parallels, but differential was a gearing system that calculated the difference between two rotations. And this used epicyclic gearing from REM.

And it was very clever. And it was completely wrong. And he became famous for this discovery of this differential. And because it was so clever, and because he became so famous with it, he couldn't challenge it. He couldn't sort of say, maybe I got this wrong. And this, in a way, is where I came in. In the year 2000, I was introduced to the device by a professor of astronomy that I knew. I'd never heard of it until the year 2000.

And subsequently, I published a paper called Challenging the Classic Research, which really demolished Price's major paper, though I have great respect for Price. I have huge respect for Price. You don't just make progress in science by getting everything right. You make progress by getting things wrong in an interesting way, in a way that stimulates other people to pick up the threads and the pieces and the clues, you know. But by the time Price saw it, the mechanism was split into, well, now it's split into 82 different fragments. It came out of the sea in one fragment, and it's now 82 pieces.

So you have to put it all back together. So it's an incredible sort of fiendish 3D jigsaw puzzle, really reconstructing what it was and what it did. And you've spent 20 years doing that fiendish 3D jigsaw puzzle. I became passionate about it, or what my wife calls obsessive about it. So, it. So yes. And the thing is that it throws up these very hard problems, but it also gives you clues, intriguing clues, which enables you to solve them. So you have this great feeling of, you know, achievement. You will spend thousands of hours with the data we have. And perhaps I should talk a bit about the data we have, and you come up with solutions which are just astonishing solutions,

you know, that what they did, the cleverness of this device is quite unbelievable. You're listening to Dan Snow's History. We're talking about the Antikythera Mechanism, the ancient Greek computer. More coming up. Thanks for downloading this episode of Dan Snow's History It. If you don't already, you're going to want to sign up to our subscription service for this podcast,

either on Apple or by heading over to History It and taking out a subscription there. And you're going to have to do it because we have an exclusive series in August unravelling the well-known, the unknown and the should-be-known stories of great explorers who traversed uncharted territory seeking fame, fortune, riches, or just satisfying their curiosity. From the first Polynesian wayfarers who used the stars to make their way across the dark Pacific, to James Beckworth, a former slave who lived all the drama of the American frontier. And Nellie Bly, the investigative journalist who attempted to traverse the world in less than 80 days. And finally, we're going to debunk the many myths and legends of Marco Polo.

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We're talking Vikings, Normans, Kings and Popes, who were rarely the best of friends, murder, rebellions, and crusades. Find out who we really were by subscribing to Gone Medieval from History Hit, wherever you get your podcasts. so tony you are more than 2 000 years after these people but you must have climbed into their heads you must feel like you know the the engineers and scientists who helped create this. I mean, could they walk into a lab today and engage you in a conversation and know their way around science in the way that you do? Or would they be blown away? Well, that's a complex question.

A very distinguished British professor now working in the States said to me, we should never believe that we understand how they thought. And I think that's a good caution that you start to think that you understand. And obviously, you do start to understand because you see what they've done, you see how they put the thing together. But you shouldn't really believe you understand how they thought. I think for anybody from those times who saw modern science, they would simply be astonished, bowled over. And even the great Archimedes would have been absolutely astonished by modern science because the advances in 2000 years have been really unbelievable and so on. I think he would have got very interested and he would have started to have a lot of conversations with current scientists, you know, about astronomy and mathematics and so on.

But the difference between what the ancient Greeks did and what we did in terms of science and technology is there's a huge gap. The Antikythera Mechanism doesn't use advanced mathematics. It uses very simple mathematics, multiplication, division, addition, and subtraction, and things like that. But the final machine calculates very sophisticated motions. Because if you look at the solar system, you know, you've got the moon goes around the earth.

You think, well, does it go around in a circle at a constant rate? The answer is no. It actually goes around in an ellipse. Not that the ancient Greeks knew this. And it has a variable motion. When it's further away from us, it appears to be going slower. When it's closer to us, it appears to be going faster. And the Babylonian astronomers knew

this and the ancient greek astronomers knew this and had a very nice neat theory for it and one thing that i discovered was that this theory is built into the anti-kythra makers into the gearing in a way that is completely unbelievable completely completely astonishing, work of genius, actually. It's just very beautifully realized in the gearing and so on. Because the mechanism doesn't just show constant motions, it shows variable motions. And with the planets, you need those. Because the planets, you know, if you look at them from Earth,

they travel through the zodiac in so-called prograde motion. They reach a stationary point. They do little loops backwards, and then they resume their prograde motion. Because we're seeing them from Earth, and they go around the sun, that's the reason for this complex motion. But you can't just make a machine that makes the planets go around the Earth at a constant rate because it doesn't model what the planets evidently do in the sky.

Does your work and the mechanism itself, has it changed the way that you and your colleagues see science and engineering and maths in ancient Greece? Oh, I think it's transformed how people see science and technology in ancient Greece. I mean, we knew of clever mathematics, very good mathematics from ancient Greece, excellent geometry, you know, some stunning and beautiful mathematics from ancient Greece. But in terms of technology, this is high technology where we would have thought of rather simple devices from ancient Greece, you know, but this is extremely sophisticated. You know, our latest model has 69 gears in it. And the outputs of the mechanism are, many of them are variable motions, not all of them,

but many of them are variable motions. And every single aspect of the machine is very, very clever, very ingenious. Do we know anything about who might have made it, where it was made, where it was on the way to? We do know, but the evidence is not a one-line answer. If you're talking about when it was made, there are arguments about this still. And the arguments are that it was made somewhere. The earliest would be towards the end of the 3rd century BC and the latest middle of the 1st century BC. And people still disagree about this. I tend to think of it as an earlier date for technical reasons related to the way it predicts eclipses.

Who made it? Well, we don't know, but we have this remarkable evidence from some texts by Cicero. Cicero was a very distinguished lawyer, politician, and orator in first century BC Rome. And he took a lot of interests, much wider than politics and philosophy and so on. And he describes two devices that Archimedes made, which sound just like the Antikythera mechanism. They follow the sun, the moons, the planets, and eclipses. And it's explicitly said in his texts. The texts don't even tell you that they used gear wheels to do this, but it's hard to see how they would have worked without gear wheels. And he describes a device made by Posidonius on the island of Rhodes in the first century BC. Posidonius was head of the school of Stoic philosophy on Rhodes,

and Cicero was one of his pupils. So this was almost certainly a first-hand account. The accounts of the Archimedes machines were not first-hand accounts, but the account of the Posidonius machine was. So if you ask what the link is, say, between Archimedes and the Antikythera mechanism, well, Archimedes was killed in the siege of Syracuse in 212 BC, run through by a Roman soldier. And it's a bit early for the Antikythera mechanism. The earliest date that's been suggested is 205 BC. That's seven years later. that's been suggested is 205 BC, that's seven years later. But if you look at the mechanism and its ingenuity and its cleverness and so on, what I believe, and it's very speculative actually, but what I believe is that Archimedes may well have founded the tradition of making these devices.

And then if you've got a good device like that, later generations are going to copy it, because Archimedes was famous, even in the ancient world, he was famous. So people would have copied Archimedes' designs in later mechanisms, you know, just as you have a great temple, the Parthenon in Athens, and many temples that came afterwards copied the design, you know, it's reproduced all over the ancient Greek world. So I think it's quite likely the Antikythera Mechanism, its basis is a design by Archimedes, but it was made by people just a bit later after he died.

What strikes me, Tony, is if they were so advanced in this area, why do we not see comparable advances in other departments? Like, they were so close. They were so close leading from this to a scientific and industrial revolution. Is it just the nature of science that sometimes it takes these giant strides in one area and that doesn't necessarily mean it advances another? For example, health sciences didn't advance in this period as rapidly as clearly mechanical engineering did. Well, there's difficult questions about the history of technology, I think, in there.

And one thing that's interesting is that technology almost seems to have gone backwards after the Antikythera Mechanism. There are devices mentioned by Vitruvius, a bad poet called Nonnus in the 4th century AD, and there's various devices that sound similar, but nothing that's more advanced to it until the great astronomical clocks of the 14th century. This is sort of at least 1,500 years later. And what you're really asking is, why didn't they exploit these ideas to advance technology

far more quickly at that time, you know. And the great writer and scientist Arthur C. Clarke wrote that if the Greeks had understood the implications of what they made in the Antikythera Mechanism, they would have reached the moon by about 300 AD. And we'd now be exploring the nearest stars, you know, as if they didn't understand the potential of this technology for using it in other ways. I mean, why didn't they make calculating machines, for example, just to multiply and divide numbers?

These come in in the 17th century, and they are simpler than the Antikythera mechanism. And they use, you know, in that case, probably brass gear wheels. But in principle, the technology could have been used for that. I just think that they didn't make that leap. A calculating machine calculates abstract numbers. This machine calculated very concrete cycles of the sun, moon, and stars. And I think they looked around their world and they thought, well, nothing else has these regular cyclic motions. The solar system has. These cycles keep going on and on, and we can model them.

But everything else in the rest of our world is rather chaotic and random and disordered. And they didn't think of using the technology for, say, making calculating machines or other purposes. But I'm not a historian of technology, but these are very good questions that you ask. And I think we're still learning the lessons of how you know, how you can invent the Antikythera mechanism and why is there such a long time before the apparent consequence of this technology? You know, we have to wait until the 13th century for mechanical clocks, 14th century for these astronomical dogs.

And then after that, you get scientific instruments and you get the whole technological and scientific revolutions, 16th, 17th, 18th century onwards, and you get the Industrial Revolution as a consequence. And none of that happened for another 1,500 years, you know. If you got the Antikythera, you're not a million miles away from a steam engine. You're not a million miles away. Well, they did have a... Heron had a steam engine in ancient Greece, which had a sort of cylinder with two nozzles that stack out, and you sort of heated

it up, and the nozzles squirted out steam, spun the cylinder. So there was a sort of steam engine in ancient Greece. They did have these little devices they liked, pneumatic devices and things, which had sort of animated birds that flapped their wings and that opened temple doors and so on. But compared to the Antikythera makers, they were all simple children's toys, really. Yeah, and I love the arguments.

We won't get into it here, but I love the arguments of historians of technology talk about how maybe it required the kind of horny handed dust covered lads from the North of England and Scotland who weren't interested in toys and the movement of the heavens, but interested in making a bit of cash and moving coal around a bit quicker. Required a little more of that sort of that attitude. That's the more working class attitude perhaps. I guess the last thing is what, if we can find this,

are you open to the idea that one day shipwrecks or other finds could be made with other astonishing things that can rewrite what we understand about the ancient Greeks? I'm certainly open to the idea that more devices may be discovered in ancient Greek shipwrecks because they keep discovering new Greek shipwrecks, because they keep discovering new Greek shipwrecks in the Mediterranean, thousands of them down there, and many of them very deep. But modern technology, you know, we may be able to bring up some of these wrecks. And I think it's

quite possible that one or two of these similar devices may be found on some of these wrecks. I think they were certainly rare in their time because they're hugely labor-intensive. They're like a modern astronomical watch, very expensive devices, really, you know, so that it wasn't a common device. But I think that they might well find, we might find other things, you know, and we just don't know. But I'm always hoping. It's so exciting, isn't it? Yeah.

Tony, have you seen the Indiana Jones film? I have. Could you enjoy it, or were you swearing and shouting all the way through? Well, the actual device in the film, which they call the Dial of Destiny, or they call it the anti-Kythera, as I said, mechanism, not the anti-Kythera mechanism. It's about the same size as the real thing. And it's got some pointers and concentric dials on the front, which is correct,

but everything else about it isn't. I didn't kind of mind that. You know, Indiana Jones is hokum and fantasy and everything. And the extra elements that they've got is that it finds fissures in time. And this enables them to time travel in a rather magic way. You know, it turns out the device is split into two halves. You have to put the two halves together and put the thing in the middle. And then you get magically transported in time. Well, they don't show any of the mechanics of time travel. And we know how to do time travel nowadays. You need a DeLorean sports car with a flux capacitor. and you need Marty and Doc and a lot of electricity, and then you can dial up where you go, and you can create the great Back to the Future films

with their wonderful scripts. Tony, I love the historical story of you and the Antikythera mechanism. Thank you very much for coming on the podcast and talking about it.