Divers Discover 2,000-Year-Old 'Computer' That Is Rewriting History

But to the astonishment of researchers, later this rusting chunk of ancient history turned out to be a highly sophisticated machine not far off a modern computer in its operation. This discovery went on to overturn many of our preconceptions about how well the ancients understood the universe in which they lived.

The ship was a cargo vessel, one of the many that plied their trade in Aegean Sea — part of the Mediterranean — around 2,000 years ago. Evidence from the many shipwrecks that have been discovered in these waters suggests that seaborne trade was at its peak at the time our wreck sunk, probably between 60 and 50 B.C.

Marine archeologists have gleaned much information from the remains of this ancient shipwreck. The Smarthistory website tells us, “It was a large freighter and… its wooden planks were lined with lead to insulate it from the water and wood-boring microorganisms.”

Smarthistory also lists, “bronze couches/beds, silver and glass vessels and utensils, red-slipped dish ware, and organic foods and substances” among the cargo. So this was quite some find, considering the diver who stumbled across it had only been looking for sponges!

Goods carried by the Antikythera wreck originated from various centers of the ancient Greek world such as Syria, Alexandria in Egypt, and Pergamon and Ephesus both in what is now Turkey. Smarthistory speculates that the ship may have “embarked from somewhere in the eastern Mediterranean and was bound for an Italian port, probably Puteoli [now Pozzuoli] near the modern city of Naples.”

In fact, it was a storm that caused the boats of the Greek sponge divers to be at the location where the ancient ship sank. The divers’ two small sailing boats, or caiques as the Greeks call them, were crewed by six divers and 20 oarsmen who were needed for windless days.

When they sailed into a severe Mediterranean storm, the skipper decided that the best thing to do was to anchor in the safe haven of a harbor on the island of Antikythera. There they’d wait until the winds had died down.

Impatient with their enforced break, Kontos decided to search for sponges in the shallower waters around the Antikythera. So the mariners sailed around the island to Cape Glyphadia and anchored about 60 feet off the cliffs there.

For the people of Symi, diving for sponges was an important and lucrative marine industry. In the 19th century the islanders operated the “the world’s largest sponge-diving fleet”, according to the AllAboutSymi website.

Until well into the 19th century divers reached the depths where the sponges were to be found without any sophisticated equipment. In the 1840s, divers were descending by clutching a heavy stone, one weighing as much as 30 pounds.

Stadiatis’ suit would have been made with layers of canvas material with the seams sealed by rubber. The copper helmets used in the early 20th century were so heavy that it took two men to put them in place over a diver’s head.

Stadiatis went over the side of the boat, hoping to find some sponges. But what he came across utterly terrified him. When he got back to the surface, he blurted out what had so severely disturbed him.

Hearing Stadiatis’ extraordinary claim, Captain Kontos decided there was only one thing for it: he’d have to clamber into a diving suit and go down to the seabed and take a look for himself. What he found was not quite what his diver had reported.

As Tourtas told it, there were varying versions of what Kontos and his men did next. The writer said that the official Greek version had it that the divers returned to their home port on Symi. Word soon spread around the island about their incredible find.

Tourtas noted, though, that there were other accounts of what the divers did after making their find. These cast Kontos and his men in a rather less favorable light. Some said that they had actually plundered what they could from the wreck’s treasures.

In any case we know that Kontos traveled to the Greek capital and met a University of Athens archaeology professor, one A. Oikonomou. He himself was a native of Symi and he acted as a go-between, linking the divers and the Greek authorities.

Kontos had two questions for the authorities. Firstly he requested permission to salvage the wreck. Secondly, he enquired as to what reward he might expect for this work and for the discovery his diving team had stumbled across.

The Greek government now sent a naval ship to the site of the wreck off the coast of Antikythera to assist the sponge-divers in their salvage task. Kourtos wrote, “The agreement was that Kontos and his divers would be the ones salvaging the cargo.”

Professor Oikonomou, who was to oversee the salvage operation, sailed to Antikythera aboard the Mycale, a naval transport vessel. Captain Kontos’ two boats sailed with the navy ship and by the end of November the operation was ready to start. 

Just to make matters worse — and perhaps unsurprisingly since it was November — the weather broke, making diving difficult and hazardous. But Kontos was keen to crack on with his mission and managed to make several dives.

As the salvage work continued through the winter in spite of the unfavorable conditions, more and more stunning artifacts were retrieved. These included a bronze lyre, marble statues of horses and men, and a massive marble bull.

As the divers continued their arduous work, they began to find the conditions intolerable. After months of continuous diving, in March 1901 the men demanded that they should be allowed a month’s break.

George Kritikos, one of the Symi divers, ascended too quickly from a dive. He had a severe attack of the bends, the painful condition caused when a diver comes up from the seabed too quickly to decompress properly. In fact this case of the bends proved to be fatal for the unfortunate Kritikos.

Eventually, the Symi men and the authorities managed to reach an agreement and diving recommenced. But later in the summer the project would come to a halt: it was felt that the divers had retrieved as much as they could from the wreck.

As Tourtas wrote, “Whatever the negative aspects of the operation, on the whole it was a success. A great success actually, and that is how it was treated by almost everyone. This was the first archaeological survey of a wreck, and it had yielded far more than anyone could have expected.”

Everything that had been salvaged from the sea off Antikythera was put in storage at the National Museum in Athens. There it would be examined, cataloged, and conserved. Bronze artifacts were bathed in clean water to desalinate them and treated with chemicals.

Tourtas quotes from a contemporary newspaper report from May 1902 which describes a visit to the museum store room by the senior politician we met earlier, Stais. The paper reported that, “Mr. Stais saw some scattered bronze fragments.”

The legendary Antikythera Machine had finally been discovered, although it would be decades before its true purpose would be recognized. But it immediately triggered a storm of interest among both researchers and the public.

Tourtas quoted the descriptive words of one of the earliest researchers to examine the Antikythera Machine. He was P. Rediadis, who noted, “The mechanism fragments were heavily corroded. The instrument’s surface was encrusted with seashells… much of the mechanism was already destroyed”.

Eventually 82 separate fragments of the machine were identified. According to Jennifer Ouellette writing in 2021 for the Ars Technica website, these parts “were originally housed in a wooden box roughly the size of a shoebox, with dials on the outside, containing a complex assembly of gear wheels within.”

Ouellette also noted that although the wrecked cargo ship was Roman, the machine was likely to have been made by Greeks. She speculated that it might have been made on the Greek island of Rhodes, which was known for its advanced engineering skills.

It wasn’t until 1951 that a British researcher — science historian Derek J. de Solla Price — began to seriously study the Antikythera machine’s purpose. Working with a physicist called Charalampos Karakalos, Price began to investigate the inner workings of the machine. 

Price and Karakalos suggested, “The mechanism had been used to calculate the motions of stars and planets — making it the first known analog computer.” That was a stunning claim. Here, according to their theory, was an analog computer that was more than two millennia old.

Another three decades would pass before more detailed information about the precise workings of the Antikythera machine emerged. In 2002 Michael Wright, a curator at London’s Science Museum, created finer X-ray images of the Antikythera Machine.

For the Greeks the movement of celestial bodies was centered on the Earth. It wasn’t until the great Polish astronomer Copernicus informed the world in 1514 that our planet actually rotated around the Sun, not the other way round. The term for that ancient Earth-centric view is epicyclic. 

But Wright noted that while the device could indicate the paths of the Moon, the Sun, Mercury, and Venus, it did not include the motions of Saturn, Mars, or Jupiter. This was a puzzle, since the existence of those planets was certainly known in the classical era. 

Wright also believed the Antikythera machine could be used to predict the time of eclipses. He went so far as to build “a reproduction of the Antikythera mechanism, stacking the gears like layers in a sandwich,” Ouellette wrote.

Since Wright’s seminal work of some 20 years ago further advances in scanning technology such as 3D X-ray imaging have emerged. These have given researchers more detailed knowledge of the workings of the Antikythera Machine.

If you really want to appreciate the complexity of the Antikythera machine, it might come as something of a surprise to learn that Lego can help. In 2010 the magazine Nature commissioned the building of a working replica of the machine using the plastic construction kit.