Antikythera Mechanism (the World's Oldest Computer) — What It Did and How It Worked | Early European History And Religion

ANTIKYTHERA MECHANISM

Fragment A of Antikythera mechanism is comprised of a complex system of 30 wheels and plates with inscriptions relating to signs of the zodiac, months, eclipses and pan-Hellenic games

The Antikythera Mechanism is the earliest known device to contain an intricate set of gear wheels. It was discovered by sponge divers on a shipwreck of a Greek cargo ship off Antikythera, a Greek island north of Crete, in 1901 but until recently no one knew what it did. Using X-ray tomography, computer models and copies of the actual pieces, scientists from Britain, Greece and the United States were able to reconstruct the device, whose sophistication was far beyond what was though possible for the ancient Greeks.

In November 2006, in an article published in Nature, team of researchers lead by Mike Edmunds of the University of Cardiff announced they had pieced together and figured out of the functions of the Antikythera Mechanism — an ancient astronomical calculator made at the end of the 2nd century B.C. that was so sophisticated it has been described as the world’s first analog computer. The devise was more accurate and complex than any instrument that would appear for the next 1,000 years. [Source: Reuters]

The shoe-box-size device was comprised of a maze 37 hand-cut, interlocking, bronze gear wheels packed together sort of like the gears in a watch and was housed in a wooden case with mysterious inscriptions on the face, cover and bronze dials. Originally thought to be a kind of navigational astrolabe, archaeologists continue to uncover its uses and have come to realize that at the very least is an extremely sophisticated astronomical calendar. Edmunds told Reuters, What is extraordinary is that they were able to make such a sophisticated technological device and be able to put that into metal.” Edmunds said the device is unique and nothing like as sophisticated would appear until the Middle Ages, when the first cathedral clocks were put into use.

What the Antikythera Mechanism Could Do

The Antikythera Mechanism could add, multiply, divide and subtract. It was also able to align the number of lunar months with years and display where the sun and the moon were on the zodiac. On top of all that it also had a dial that indicated when solar and lunar eclipses were likely to occur; it tracked the dates of the ancient Olympics and other sporting events; it took into account the elliptical orbits of the moon; and it may have had extra gears that predicted the motions of the planets.

On the discovery that the Antikythera Mechanism tracked Olympic days Yanas Bitsakis, a Greek researcher involved with project told AP. “We were astonished because this is not an astronomic cycle but an Olympian cycle, one of social events. One does not need a piece of high technology to keep track of a simple four-year cycle .” He said the mechanics might have been seen as “microcosm illustrating the temporal harmonization of human and divine order.”

The device also has a function related to the Metonic calendar, which was used to reconcile a day difference between the lunar months and solar year. Researchers believe the Olympic tracking system gives the Antikythera Mechanism a connection to the colonies of Corinth, possible Syracuse in Sicily, where Archimedes lived and this in turn hints of a connection with Archimedes himself. Archimedes, who lived in Syracuse and died in 212 B.C. He invented a planetarium that calculated motions of the moon and the known planets and wrote a lost manuscript on astronomical mechanisms.

How the Antikythera Mechanism Worked

model of the Antikythera Mechanism

When it was used the Antikythera Mechanism would have appeared as a box housing dozens of finely-cut bronze gear wheels. By manually rotating a handle on its side, the positions of the sun, moon, Mercury and Venus could be determined for any chosen date. Inscriptions show that the device could also calculate the positions of five planets known at that time. When the handle was turned gears spun dials on the exterior showing the phases of the Moon, the timing of lunar eclipses, and the positions Mercury, Venus, Mars, Jupiter, and Saturn at different times of the year, even accounted for their retrograde motion — an illusionary change in the movement of planets through the sky. [Source: Gareth Dorrian, Post Doctoral Research Fellow in Space Science, University of Birmingham and Ian Whittaker, Lecturer in Physics, Nottingham Trent University, The Conversation, April 24, 2020]

Jo Marchant wrote in Smithsonian Magazine: “The Antikythera mechanism was similar in size to a mantel clock, and bits of wood found on the fragments suggest it was housed in a wooden case. Like a clock, the case would’ve had a large circular face with rotating hands. There was a knob or handle on the side, for winding the mechanism forward or backward. And as the knob turned, trains of interlocking gearwheels drove at least seven hands at various speeds. [Source: Jo Marchant, Smithsonian Magazine, February 2015 |||]

Instead of hours and minutes, the hands displayed celestial time: one hand for the Sun, one for the Moon and one for each of the five planets visible to the naked eye—Mercury, Venus, Mars, Jupiter and Saturn. A rotating black and silver ball showed the phase of the Moon. Inscriptions explained which stars rose and set on any particular date. There were also two dial systems on the back of the case, each with a pin that followed its own spiral groove, like the needle on a record player. One of these dials was a calendar. The other showed the timing of lunar and solar eclipses.

Antikythera Mechanism Instructions?

Alexander Jones, a historian of ancient science at New York University's Institute for the Study of the Ancient World, has helped a great deal to figure out what the Antikythera Mechanism is all about. Sarah Kaplan wrote in the Washington Post: “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." [Source: Sarah Kaplan, Washington Post, June 14, 2016 +++]

“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. Edmunds compared it to the long label beside an item in a museum display. He told 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. 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. +++

History of the Antikythera Mechanism

sideview of Antikythera Mechanism gears

The fact the Antikythera Mechanism contains dates of a relatively minor athletic competition held in the city of Rhodes, wrote Kaplan, 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). [Source: Sarah Kaplan, Washington Post, June 14, 2016 +++]

“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. The elegant complexity of the mechanism – and the use its makers designed it for – are emblematic of the values of the ancient world:

Jo Marchant wrote in Smithsonian Magazine: ““The tradition of making such mechanisms could be much older. Cicero wrote of a bronze device made by Archimedes in the third century B.C. And James Evans, a historian of astronomy at the University of Puget Sound in Tacoma, Washington, thinks that the eclipse cycle represented is Babylonian in origin and begins in 205 B.C. Maybe it was Hipparchus, an astronomer in Rhodes around that time, who worked out the math behind the device. He is known for having blended the arithmetic-based predictions of Babylonians with geometric theories favored by the Greeks.” ||| [Source: Jo Marchant, Smithsonian Magazine, February 2015 |||]

Importance of the Information on the Antikythera Mechanism

Sarah Kaplan wrote in the Washington Post: 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.” [Source: Sarah Kaplan, Washington Post, June 14, 2016 +++]

“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."” +++

Antikythera Mechanism’s Missing Pieces and Clues

Computer graphic representing the front of Antikythera mechanism

Only about a third of the Antikythera Mechanism has survived and that is in more than 80 fragments. The back of the mechanism — which features a description of the cosmos display, which shows the motion of the five planets that were known at the time — was solved by earlier studies, but the nature of its complex gearing system at the front has remained a mystery. [Source: BBC, March 13, 2021]

Jo Marchant wrote in Smithsonian Magazine: ““Experts have been working to decipher inscriptions hidden inside the mechanism, in particular to understand the mechanism’s missing pieces, some destroyed, some probably still at the bottom of the sea. Though the pointers on the front face don’t survive, Jones, the historian in New York, says an inscription reveals that they carried colored balls: fiery red for Mars, gold for the Sun. [Source: Jo Marchant, Smithsonian Magazine, February 2015 |||]

“Also missing are the parts that drove the planetary pointers, leading to debate about exactly how they moved. Because planets orbit the Sun, when viewed from Earth they appear to wander back and forth in the sky. The Greeks explained this motion with “epicycles”: small circles superimposed on a larger orbit. According to Michael Wright, a former curator at London’s Science Museum who has studied the mechanism longer than anyone, it modeled epicycles with trains of small gears riding around larger ones. Though some experts have dismissed this as beyond the Greeks’ abilities, Jones says he will publish evidence supporting the idea later this year. |||

“Other inscriptions hint at where the mechanism was made. Paul Iversen, a classicist at Case Western Reserve University in Cleveland, reports that the calendar includes month names used in Corinth and its colonies in northwest Greece. A dial that displayed the timing of major athletic festivals, including the Olympics, lists Naa, a festival held in northwest Greece, and Halieia, held to the south on the island of Rhodes. Perhaps the mechanism hailed from Rhodes and was being shipped north. The ancient philosopher Posidonius had a workshop in Rhodes that could have been the source; according to Cicero, Posidonius made a similar model of the heavens in the first century B.C. |||

Antikythera Mechanism Followed Greek Lunar Calendar

In June 2024, scientists announced that the Antikythera mechanism followed the Greek lunar calendar, not the solar one used by the Egyptians, as was previously thought. Live Science reported: One piece of the mechanism, known as the "calendar ring," was used to track the days of the year, with one hole per day. While the ring has been known about for some time, it’s only partially preserved, so it's unclear how many days it was meant to track.

In 2020, a team led by independent researcher Chris Budiselic used new X-ray images of the device, combined with measurements and mathematical analysis, to determine that the mechanism likely didn't cover a full solar calendar year but rather 354 days, as would be used in a lunar calendar. On June 27 2024, another paper in The Horological Journal found a similar result. A team from the University of Glasgow used statistical techniques developed for the Laser Interferometer Gravitational-Wave Observatory to detect gravitational waves — ripples in space-time produced by the collisions of massive celestial objects such as black holes. These statistical methods are sensitive enough to detect the faint signals from a potentially very noisy background. [Source: Owen Jarus, Live Science, June 29, 2024]

When the researchers trained the powerful statistical technique on the Antikythera mechanism, they were able to use the positioning of the known holes, as well as the likely way the fragments of the mechanism fit together, to deduce the number and placement of the lost holes. They ultimately determined that the mechanism likely had 354 or 355 holes. This meant it likely followed the 354-day lunar calendar used in Greece at the time, rather than the 365-day calendar used by the ancient Egyptians.

The team was impressed with the device creators' attention to detail. "The precision of the holes' positioning would have required highly accurate measurement techniques and an incredibly steady hand to punch them," study co-author Graham Woan, an astrophysics professor at the University of Glasgow, said in the statement. "It's a neat symmetry that we've adapted techniques we use to study the universe today to understand more about a mechanism that helped people keep track of the heavens nearly two millennia ago."

Was the Antikythera Mechanism 'Started Up' on December 22, 178 B.C.?

The Antikythera mechanism was first "started up" on December 22, 178 B.C., archaeologists said on March 28, 2022 on the preprint database arXiv. Live Science reported: the researchers specify a number of reasons why they think Dec. 22, 178 B.C. was the mechanism's start date, which is the earliest date on which all calculations made on the mechanism are based. It's sort of like the temperature absolute zero on the kelvin scale. [Source Owen Jarus, Live Science November 5, 2022]

For one, there was a solar eclipse on that day, one that lasted over 12 minutes. Secondly, the following day, Dec. 23, was the winter solstice, an important day among many ancient peoples. They also note that the Isia festival — celebrating the Egyptian goddess Isis — was celebrated in both Egypt and Greece at this time. Additionally, the phases of the moon started Dec. 22 of that year, the team wrote in their paper.

This combination of events created a "very rare coincidence" that would make for a memorable starting day, the researchers wrote. The starting date "should be very characteristic, important and easily detected," Aristeidis Voulgaris, the lead author of the paper and team leader of the Functional Reconstruction of Antikythera Mechanism-The FRAMe Project, told Live Science.

It's possible that whoever made the Antikythera Mechanism — another unresolved question, with some experts suggesting Archimedes was the engineer who crafted the marvel — witnessed this day and remembered the cosmic events, but there is no way to be certain. "Usually, in order to perform time calculations, it is more common to select a date from the recent past rather than one in the future," the researchers wrote.

A hypothetical schematic representation of the gearing of the Antikythera Mechanism

This initiation date matters because it is the date in which all calculations using the mechanism would be based on. "In order to use a measuring instrument, a reference point is needed, before the measuring procedure," the researchers wrote in the paper. Like a calendar which needs a fixed date — such as A.D. 1 — whoever used the mechanism would need a starting date on which to base all calculations.

Many scholars were skeptical about the claim. "It's not a paper that would withstand competent peer-review," Jones in New York said."There are a lot of problems with it, ranging from major issues to minor ones that nevertheless are symptomatic of lack of good grounding in the broad context of ancient astronomy and science," Jones said. For instance, Jones pointed out that this start date would put Kraneios, a season inscribed on the Antikythera mechanism that is associated with wine, in the month of February, which is "not a particularly good month for ripe grapes," Jones said. Two papers published in 2014 showed that the starting date was in 204 B.C., Jones added. Those two papers showed "that the eclipse prediction sequence had been computed for a unique 223-lunar-month interval beginning in 204 B.C.," Jones said. This was timed to start on May 12 204 B.C. and start and end with a lunar eclipse.

Discovery of the Antikythera Mechanism

The Antikythera Mechanism was lost when the cargo ship carrying it was shipwrecked off the coast of the small Greek Island of Antikythera (which is located between Kythera and Crete) and found again in 1901. Sponge divers discovered the device in the wreckage. The ship appears to have been headed to the western Mediterranean carrying commercial goods, including high-end luxury objects, when it sank around 65 B.C. [Source Megan Gannon, Live Science , August 17, 2022]

Candida Moss wrote in the Daily Beast: After Greek sponge divers found an encrusted greenish lump they brought the mechanism, which they believed to be a rock, to archaeologist Valerios Stais at the National Archaeological Museum in Athens. Over the ensuing decades the site was looted, trampled on by explorers, and, in 1976, the famous French explorer Jean-Jacques Cousteau inadvertently destroyed much of what remained of the ship’s hull. [Source: Candida Moss, Daily Beast, November 13, 2018]

Initially no one knew want the lump was. Two millennia had eaten away at the ship and its cargo. Stais’ cousin, Spyridon Stais, a former mathematician, was the first to identify the gears in the mechanism. It was only with the development of advanced x-ray technology and the collaboration of numerous individuals (from Cousteau to modern historians of science like Alexander Jones) that the heavily corroded rock was revealed to be a technologically advanced calculator.

American and Greek marine archaeologists are continuing to excavate the Antikythera wreck site. In 2012, almost 50 years after Cousteau’s excavations, a new team of underwater archaeologists discovered hundreds of previously unnoted artifacts, including bronze and marble statues, furniture, coins, and a sarcophagus lid. But last year, on the seabed, they discovered something else: an encrusted corroded disk about 8cm in diameter. X-ray analysis has revealed that the disk bears an engraving of the zodiac sign Taurus, the bull. Some suggested the disk may have been a missing part of the Antikythera Mechanism but those suggestions were quickly dismissed by experts.

Using 3D computer modelling, scientists from University College London (UCL) have recreated the entire front panel of Antikythera Mechanism, and are building a full-scale replica of the devise using modern materials. In paper published in March 2021 in Scientific Reports these scientists revealed a new display of the gearing system that showed its fine details and complex parts. “The, Moon and planets are displayed in an impressive tour de force of ancient Greek brilliance," the paper's lead author, Professor Tony Freeth, said. “Ours is the first model that conforms to all the physical evidence and matches the descriptions in the scientific inscriptions engraved on the mechanism itself," he added. [Source: BBC, March 13, 2021]

Image Sources: Wikimedia Commons, The Louvre, The British Museum

Text Sources: Internet Ancient History Sourcebook: Greece sourcebooks.fordham.edu ; Internet Ancient History Sourcebook: Hellenistic World sourcebooks.fordham.edu ; BBC Ancient Greeks bbc.co.uk/history/; Canadian Museum of History, Perseus Project - Tufts University; perseus.tufts.edu ; MIT Classics Online classics.mit.edu ; Gutenberg.org, Metropolitan Museum of Art, National Geographic, Smithsonian magazine, New York Times, Washington Post, Live Science, Discover magazine, Natural History magazine, Archaeology magazine, The New Yorker, Encyclopædia Britannica, "The Discoverers" and "The Creators" by Daniel Boorstin. "Greek and Roman Life" by Ian Jenkins from the British Museum, Wikipedia, Reuters, Associated Press, The Guardian, AFP and various books and other publications.

Last updated September 2024