The Mysterious Antikythera Mechanism is the World’s Oldest Known Computer

The Mysterious Antikythera Mechanism is the World’s Oldest Known Computer

Khalid Elhassan - July 31, 2019

In the ancient and classical eras, the Mediterranean Sea was not much of a barrier between the lands bordering its shores. Instead, it was more of a convenient watery highway, facilitating seaborne trade and exchanges between the Mediterranean’s peoples. In the eastern part of that sea is the small island of Antikythera, between the Peloponnesus and Crete. It lies roughly halfway along the sea lanes used by ships plying the waters between Asia Minor and Italy. In antiquity as well as now, Antikythera’s jagged coastline was a hazard to ships, that could easily be dashed to destruction on its unforgiving rocks.

Such destruction was the fate of an unfortunate ship, presumably Roman, that was sailing to the western Mediterranean sometime around 65 BC. That year the ship and its cargo of commercial goods, including luxury items, sank off the island. The wreck lay forgotten at the sea bottom until 1900. In the spring of that year, fishermen diving for sponges off Antikythera, spotted a bronze hand sticking out of the sediment, at a depth of about 150 feet. They informed Greek officials, who then directed a search around what was identified as a sunken ship. It came to be known as the Antikythera Wreck.

The Mysterious Antikythera Mechanism is the World’s Oldest Known Computer
Antikythera. Pintrest

A Mysterious Find

In 1901, divers working the wreck recovered marble and bronze statues, coins, jewelry, glass artifacts, and over 200 amphorae, some of them intact. They also brought up some finely worked vases, other high end goods, and some of the era’s most prized works of art. Among the objects recovered was a wooden box 13.4 inches high, 7.1 inches wide, and 3.4 inches in depth. Inside the box was a severely corroded lump of bronze, that began disintegrating as soon as it was removed from the water. All items from the Antikythera Wreck were taken to a museum in Athens. There, the wooden box and its contents were initially ignored, while archaeologists focused on restoring the more identifiable treasures, such as the statues, jewels, and coins.

A year later, however, an archaeologist named Valerios Stais took a closer look at the wooden box’s contents, and was surprised to discover what he identified as a gear. Further examination was conducted into the corroded lump of bronze, which initially consisted of 4 main lump fragments. As researchers painstakingly cleared the corrosion and encrustation, the 4 main lumps became 82 distinct pieces, including many more gears. All in all, the box contained about 30 meshing bronze gears, the largest of which measured about 5.5 inches in diameter, and had 223 teeth.

Working together, the box’s contents amounted to a complex clockwork mechanism, and Valerios Stais figured it must have been some kind of astronomical calculation device. However, most scholars at the time reasoned that the device, which came to be known as the Antikythera Mechanism, was too complex to have been manufactured in the 1st century BC. Instead, they concluded that it must have been made centuries later, then been lost at sea, and came to rest by mere coincidence atop the earlier debris of the Antikythera Wreck.

The Mysterious Antikythera Mechanism is the World’s Oldest Known Computer
The Antikythera Wreck. Why Athens

As a result, further research into the Antikythera Mechanism was abandoned for decades. It did not resume until the 1950s, when Derek John de Solla Price, a Yale professor who specialized in the history science, took an interest in the device. Over the next two decades, he conducted intensive research into the mechanism, including the use of gamma-rays and x-rays, before publishing a 70 page paper on his findings in 1974. In it, professor Price demonstrated that the device did, indeed, date to the 1st century BC, and as Valerios Stais had guessed seven decades earlier, the mechanism was an astronomical clock.

After carefully examining the gears, professor Price figured out that the device had been used to predict where the planets and stars would be positioned in the sky, on any given calendar month. It worked by moving the biggest gear, which represented the calendar year. That gear, in turn, would move other, smaller gears, that represented the motions of the sun, the moon, plus those of several planets.

The Mysterious Antikythera Mechanism is the World’s Oldest Known Computer
A reconstruction of the Antikythera Mechanism. Global Spec

Lingering Doubts

From the way it was made and the manner in which it worked, the Antikythera Mechanism was effectively the earliest known analogue computer – manufactured over 2100 years ago. However, the mechanism’s very existence, and the complexity of its design and manufacture, argued that it must have had earlier predecessors before things reached the high quality of the discovered device. So the world’s earliest functioning analog computer could well have been made centuries earlier.

Once it was demonstrated that the Antikythera find was an analog computer, that predated Jesus, research turned to figuring out its purpose and how it was used. Professor Price’s paper had pointed the way, but at the time of his publishing in 1974, and for many years afterwards, his findings were persuasive to many, but not quite conclusive. Once researchers were able to take a good look at the device and its innards, it became clear that it had to be some kind of calculating device. However, whether it worked the way Price had deduced, was still up in the air.

We now know that the device enabled users to tell how the skies would look for decades to come. That included the positions of the sun and moon, lunar phases, the paths of planets, and even eclipses. Several writers from Antiquity, including Cicero, had mentioned the existence of such devices, but the Antikythera Mechanism is the only one ever recovered. Unfortunately, the technology was lost during the Roman era, and the only known sample we know of ended up at the bottom of the sea, its secrets forgotten for over two millennia.

The Mysterious Antikythera Mechanism is the World’s Oldest Known Computer
The Antikythera Wreck. Smithsonian Magazine

Current researchers have benefited greatly from the leaps and bounds that scanning technology has taken in recent years. In the first few decades after the Antikythera Mechanism’s discovery, the device’s advanced state of corrosion made it difficult for scholars to properly see what they were looking at, let alone decipher its significance. Most intriguing was that observers could see that some of the mechanism’s fragments contained what seemed to be Greek letters and words. However, they were so obscured by corrosion so as to be indecipherable.

As one scholar put it: “Before, we could make out isolated words, but there was a lot of noise —letters that were being misread or gaps in the textNow, we have something that you can actually read as ancient Greek. We can tell what these texts were saying to an ancient observer“. That is thanks to new imaging techniques such as 3-D X-ray scanning, that have finally enabled researchers to legibly read about 3400 characters that were inscribed on those parts of the device that were recovered. That is a lot, but it is only a fraction of the roughly 20,000 characters that scholars estimate had been inscribed on the mechanism when it was whole.

The Mysterious Antikythera Mechanism is the World’s Oldest Known Computer
Text on a fragment from the back of the Antikythera Mechanism, revealed modern scanning techniques. Smithsonian Magazine

Recovered Texts Unlocked the Final Mysteries

The texts recovered by modern scanning have proven extremely helpful in unraveling the final mysteries of the Antikythera Mechanism. As it turned out, much of what was written amounted to an ancient version of a user’s manual. For example, text inscribed on the device’s back is an inventory of all of its dials, and a description of what they are for and what they signify. It is from that text that we now know that the mechanism’s front had once contained a display of the planets, moving through the zodiac. There were pointers with small spheres, representing the sun, the moon, plus Mars, Jupiter, and Saturn, arranged in a manner that replicated their orbit around the earth.

That display had not survived survive the ravages of time and 2000 years’ worth of salt water corrosion. Some scholars had speculated that there might have been something along those lines in the device, but those were simply educated guesses, without any hard physical proof to back them up. It was not until the device’s text was finally revealed via modern scanning, that the guesses were transformed into concrete facts.

Other recovered texts describe the risings and settings of various constellations, on different dates throughout the year. That enabled researchers to confirm that the device’s maker – or the person who commissioned its making – was an astronomer. Researchers were also able to make out handwritten text from at least two different people. That suggests that the mechanism was not made by a single person, such as the astronomer who had recorded the sightings. Instead, it had most likely been commissioned by an astronomer, who contracted a workshop to make the device according to set specifications.

The Mysterious Antikythera Mechanism is the World’s Oldest Known Computer
Reconstruction of the Antikythera Mechanism and its innards. Research Gate

Scholars were also able to work out from the dates of celestial sightings described in the text just where that mechanism’s astronomer was located: somewhere around latitude 35 degrees north. That is too far north for the astronomer to have been in Egypt, and too far south for him to have been in northern Greece. However, 35 degrees is a near perfect match for somebody making observations from the Aegean island of Rhodes, just off the southwestern coast of modern Turkey. Knowing where the device was made (Rhodes), and where the vessel carrying it it sank (off Antikythera), an educated guess can be made that it had been destined for a buyer in northwestern Greece, when its ship went under.

As a result, the mystery of what the Antikythera Mechanism was has, by and large, been solved. However, there is no certainty yet about what the device was for. As described by a scholar: “We know what it did now pretty well, but why would someone want to have something like this made? For my part, I think this is something that is very likely to have been made as an educational device, something that was not for research but for teaching people about cosmology and all sorts of time-related things about our world“. Others speculate that the device was intended for use in astrology: predicting the movement of the stars and constellations, in an attempt to predict the future. The debate is ongoing.

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Where Did We Find This Stuff? Some Sources and Further Reading

Antikythera Mechanism Research Project – Project Overview

Live Science, June 23rd, 2016 – Ancient Greek ‘Computer’ Came With a User Guide

Mental Floss – 15 Intriguing Facts About the Antikythera Mechanism

Smithsonian Magazine, February, 2015 – Decoding the Antikythera Mechanism, the First Computer

Smithsonian Magazine, June 8th, 2016 – The World’s First Computer May Have Been Used to Tell Fortunes

Vox, May 17th, 2017 – The Antikythera Mechanism is a 2000 Year Old Computer

Wikipedia – Antikythera Mechanism

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