Off the coast of the Greek island of Antikythera in 1900, sponge divers came across a shipwreck filled with ancient treasures. Hidden among flashier finds like marble statues and jewelry was a mysterious device known today as the Antikythera mechanism.

Dated to more than 2,000 years ago, the device “is probably the most exciting artifact that we have from the ancient world,” says Jo Marchant, author of the 2008 book Decoding the Heavens: Solving the Mystery of the World’s First Computer. More than a millennium before 13th-century Europeans invented the first mechanical clocks, the Antikythera mechanism employed similarly complex technology—including gear wheels, dials and pointers—to chart the cosmos. The ancients used it to predict eclipses, track the movement of the sun and the moon, and even see when sporting events like the Olympics were scheduled to take place.

Contrary to what Indiana Jones and the Dial of Destiny, the latest installment in the epic franchise, suggests, the Antikythera mechanism won’t transport you back in time—not literally, at least. Every Indiana Jones adventure needs an exotic MacGuffin; in the new outing, which arrives in theaters this week, the hero chases after the Archimedes Dial, a fictionalized version of the Antikythera mechanism that predicts the location of naturally occurring fissures in time.

Indiana Jones and the Dial of Destiny | Official Trailer

In the film’s 1944-set prologue, Indy (Harrison Ford) captures a train loaded with Nazi plunder, including the titular Dial of Destiny. The movie then jumps ahead to 1969. Indy is set to retire from teaching archaeology, and the world is celebrating the safe return of the Apollo 11 crew. One of the men most responsible for the United States’ victory in the space race is Jürgen Voller (Mads Mikkelsen), a former Nazi who was given sanctuary by the Allies in exchange for his expertise, much like the real-life NASA engineer Wernher von Braun. When Indy learns that Voller wants to use the Archimedes Dial to travel for nefarious purposes, he reluctantly dusts off his old hat and bullwhip to (again) keep a potentially devastating weapon out of Nazi hands.

At the time of its discovery, the actual historical device was encased in a corroded clump of metal. Experts only began to realize the object’s significance in 1902, when the clump—by then housed at the National Archaeological Museum in Athens—broke apart to reveal an intricate network of gears.

In the decades since, scholars have used X-rays, CT scans and other tools to study the 82 surviving fragments of the mantel clock-sized object, which is believed to date to between roughly 200 and 60 B.C.E. Observers originally speculated the mechanism might be a navigation device, or perhaps a modern object dropped at the Antikythera wreck site centuries after the ship sank. A more far-fetched interpretation suggested the device was “alien technology used on alien spaceships,” Marchant says.

In 2021, a team writing in the journal Scientific Reports presented a computational model of the mechanism, offering the clearest sense yet of how the device might have worked. Still, much about the mechanism remains unknown, from its creator (one theory, apparently picked up by the movie’s creative team, attributes the technology used in the device to Greek mathematician Archimedes), to the meaning of the inscriptions scattered across its surface, to its overall purpose.

Decoding the Heavens: Solving the Mystery of the World's First Computer

Jo Marchant tells the story of the 100-year quest to understand the Antikythera mechanism.

“It’s by far the most sophisticated technological device that survives [from that era],” says Marchant. “It’s essentially a pocket universe, like a model of the cosmos.”

To learn more about the real Archimedes Dial, Smithsonian chatted with Marchant, a frequent contributor to the magazine who has written extensively about the Antikythera mechanism. Read a condensed and edited version of the conversation below.

What is the Antikythera mechanism? Why is it unique?

This is the most sophisticated example we have of ancient Greek technology. This is the pinnacle. We know of nothing else as complex as this. There’s nothing even close.

The mechanism was held in a wooden case, a bit like a clock that might go on the mantelpiece. Inside, it was made of bronze gear wheels, and there was a big dial on the front. Instead of telling you the time, it showed you the motions of the sun, the moon and the planets in the sky.

The Antikythera mechanism on view at the National Archaeological Museum in Athens
The Antikythera mechanism is on view at the National Archaeological Museum in Athens. Marcus Cyron via Wikimedia Commons under CC BY 2.0

You turned the handle on the side to move the gear wheels and wind forward and backward in time. It drove these mathematical pointers, showing you the positions of celestial bodies, the date, the timing of athletic games. There’s a calendar, there’s an eclipse prediction dial, and there are inscriptions giving you information about what the stars are doing. The dials and the pointers are telling you everything you need to know about the state and workings of the cosmos.

At least 30 bronze gear wheels survive. But there were probably many more than that originally. I’m not sure there’s even one other gear wheel that survived from the ancient world. There are no other devices like this, before or after the Antikythera, until we come to the invention of modern mechanical clocks in medieval Europe.

How was the mechanism discovered?

Sponge divers who were working in the Mediterranean discovered the shipwreck in 1900. The ancient vessel’s crew members were blown off course by a storm, and they sheltered in this little island of Antikythera, which is beautiful but very treacherous. It’s a barren island, with jagged rocks and sheer cliffs that fall down straight into the sea.

The sponge divers sheltered there, and when the storm passed, they dived down. The first diver to go down came back up terrified, talking about how he’d seen a pile of rotting corpses on the seabed—men, women, horses. It turned out that these were not corpses but the remains of statues. They had discovered a shipwreck that was full of treasure.

Divers examine objects from the Antikythera shipwreck
Divers examine objects from the Antikythera shipwreck. Brett Seymour / EUA / WHOI /ARGO

The sponge divers then recovered as much of the cargo as they could. Working for the Greek government and directed by archaeologists, they spent about ten months hauling up marble and bronze statues, gold and jewelry, pieces of furniture like a throne, weapons, beautiful glass bowls, amphorae that would have been full of wine and olive oil.

The ship set sail between 70 and 60 B.C.E. It was coming back west from the Asia Minor coast, the eastern Mediterranean. Initially, it was thought to be a Roman vessel bringing looted treasures home. Further analysis of the wreck suggests it was actually a Greek trading vessel that was carrying this luxury cargo back home. Either way, it didn’t make it.

Did Archimedes create the Antikythera mechanism?

Cicero was a writer and politician around the first century B.C.E. He wrote descriptions of devices that sound quite similar to the Antikythera. But they don’t have any technological detail about how the machines would have worked, so historians have never really been able to take them that seriously. Cicero talked about bronze machines, globes that turn to show the motions of the heavens. And one of them he attributed to a philosopher named Posidonius, who lived on Rhodes in the first century B.C.E. at exactly the time scholars think the Antikythera ship would have stopped off at the island. The main theory is the device was made in a workshop on Rhodes, perhaps Posidonius’ workshop, perhaps as a commission for a wealthy buyer who lived in northern Greece, and was being shipped from Rhodes to northern Greece when the ship sank.

Benjamin West, Cicero Discovering the Tomb of Archimedes, 1805
Benjamin West, Cicero Discovering the Tomb of Archimedes, 1805 Public domain via Wikimedia Commons

Cicero also wrote about another device he said was constructed by Archimedes, the legendary mathematician and inventor. Archimedes lived a couple of centuries too early to have made this particular Antikythera mechanism. But he could easily have invented this idea of representing the universe or celestial motions in a machine using bronze gear wheels. It probably would have started off a bit simpler and then been refined, incorporating the latest astronomical thinking over the centuries. We don’t know for sure. But Archimedes would be our prime suspect for the person who invented this entire line of technology.

How did the ancient Greeks use the device?

What I really like about the mechanism is just how many different functions you’ve got packed into one device. You could almost think of it as the iPad of the ancient world, because you’ve got all these different apps: the dial on the front that’s showing you the sun, moon and planets around the sky; eclipse predictions on the back; and Olympics predictions. Depending on which display you’re looking at, you’re seeing all of these different functions.

The Greeks didn’t use the device to do work. They weren’t making a steam engine or industrial machinery. They were modeling the heavens. Why? What were they trying to do? It doesn’t seem that this was a navigational device. There’s nothing it could do that you couldn’t accomplish much more easily with other well-known types of navigational instruments.

Astrology is another option. Could you have used it for casting horoscopes? Because you could turn it to a particular date and see everything that was going on in the sky at that point. There are actually some astrological hints on the mechanism. On the eclipse prediction dial, there are mentions of colors and directions associated with different predicted eclipses, perhaps a direction the wind was supposed to be blowing or maybe the direction the disk would be blocked from.

But again, it would have been a lot easier to cast horoscopes using astronomical tables that would have been available at the time. You wouldn’t need something like the Antikythera mechanism. So the explanation most scholars have converged on, and the one that makes the most sense to me, is this is more of a philosophical device or a teaching device. It’s encapsulating the knowledge of what the universe is and how it works, and it was a way of sharing that knowledge with other people.

Some of the inscriptions on it are almost like captions you might see at a museum exhibition. They’re aimed at laypeople. They’re not instructions for a professional. They’re explaining to you what’s happening as the machine is working. The idea the mechanism was expressing ultimately was of the universe as a machine, as something that works according to predictable mathematical rules that we can study and understand.

For a lot of human history, the universe would have been seen as a divine being, or perhaps a plaything of the gods, something quite magical. The planets moved in unpredictable ways, and often they were seen as gods themselves. This device represents a shift to an understanding of the universe as something much more mathematical, something scientific, where there are these numerical principles behind what’s happening, and you can model that in a machine.

Another aspect that’s actually mentioned by Cicero is this idea of a divine creator of the universe. Cicero said something along the lines of, “Look at a machine of the cosmos, and you know it must have had a creator, a designer.” The device was making the point that the universe itself must have a creator, so there are a lot of deep religious and philosophical principles embodied in it.

What does the mechanism tell us about the ancient Greeks?

One of the things it tells us is we don’t know the half of it in terms of what people were capable of in the ancient world, because so little survives. We’ve just got this one device. If this mechanism hadn’t survived on a shipwreck, and we hadn’t been lucky enough to find it, there would have been this whole branch of technology, the heights of what the ancient Greeks were able to do, that we would have had absolutely no idea about. And it just makes you wonder what else we have no idea about. Relying solely on archaeology means there’s always going to be a huge underestimate of what these ancient people were capable of.

The mechanism also represents a really impressive tale of human ingenuity. This machine was under the sea for more than 2,000 years, so as you can imagine, it is not in a good state. It’s in pieces, it’s battered and corroded, and different layers of it are all smushed together. About two-thirds of it is lost, actually. So you’ve got these very uninspiring pieces until you look at them closely, at the very different, dense layers. It’s really inspiring how scientists have studied the layers and used technology as it becomes more advanced—so initially cleaning them, studying the device by eye, and then you’ve got the first X-rays that were done. Next, they’re using X-ray tomography to try and pick apart different layers, conducting CT scans, and trying different lighting techniques to bring out details of the surface. Today, we’ve ended up with quite a big international team of people in different disciplines, all working together to try to figure out what this thing was.

Exploded model of the Cosmos gearing of the Antikythera mechanism
Exploded model of the Cosmos gearing of the Antikythera mechanism © 2020 Tony Freeth

Why do you think the Dial of Destiny team decided to feature the Antikythera mechanism?

The Antikythera mechanism really fascinates people. It’s one of those things that when you first hear about it, and this was certainly my reaction, you think, “How did I not know that this existed? How could there be an ancient Greek mechanical computer that predicted eclipses that was found on a shipwreck?” It sounds unbelievable. It’s just so outside what we would expect to find and what we previously knew about the ancient Greeks. There are these natural connections that we make with something almost magical or supernatural. The device is a natural choice if you’re looking for something that actually exists, but you want to give it a slightly magical spin.

It’s also absolutely bound up with time. It’s a time machine in a sense. When you turn the handle on the side, you are moving backward in time, you’re controlling time. You’re seeing the universe either being fast-forwarded or reversed, and you’re choosing the speed and can set it to any moment in history that you want.

What mysteries does the mechanism still hold?

We know quite a lot about how it worked and what it did. But certainly in terms of exactly how that front dial worked and what it showed, a lot of that is missing. We know it showed the planets, but how did it show them? Were there pointers? Were there rings that were moving around? These are debates that scholars are having about the details of the mechanism.

The other main mystery is that it would just be really nice to find more devices like this. We only have one, so there’s nothing to compare it against. But it seems pretty likely this was not the only device of its kind. It’s just too well made, too sophisticated, too complex. It’s quite small, as small as you could make something like this without needing magnifying glasses to see all the components, and generally with a piece of technology like this, you would start off making it bigger and simpler. This is such a confident design. It’s clearly the product of decades or generations worth of development.

Divers have been going back down to the Antikythera shipwreck since around 2012. One of the things they would love to find is either more pieces of this mechanism or more devices like it. For me, that would be the most exciting way in which we could take the story forward.

Interpretations of inscriptions on the Antikythera mechanism
Interpretations of inscriptions on the Antikythera mechanism Freeth et al. via Wikimedia Commons under CC BY 4.0

Can the public view the device anywhere?

The Antikythera mechanism is on display at the National Archaeological Museum in Athens. It’s an incredible thing to see. It’s much smaller than you would expect, but it’s beautiful and so intricate. It’s really haunting to see, because you’re looking at these corroded, battered pieces. You can see they’re ancient, you can see they’ve been lying there for thousands of years. And yet, when you look closely, it’s familiar. It looks like the inside of a pocket watch or alarm clock. It’s a form of technology we have all around us today. It’s an incredible feeling to recognize that connection and see an invention that has been so influential in shaping human history right back at its starting point.

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