Scientists publish the principle of the so-called "Mechanism of Antikythera" - the world's first computer

Researchers at the University of London have made a digital model of the 2,150-year-old mechanical device Antikythera, the world's oldest known computer. The article includes breathtaking images and a detailed description of the working principle of the machine, which predicted with perfect accuracy the movements of the sun, moon and all five planets known to antiquity.
The first badly corroded parts of the machine were discovered by divers off the coast of the Greek island of Antikythera in 1900. It lay in the wreckage of a Roman merchant ship that sank around 70 BC. The shoebox-sized instrument was once filled with gears that were precisely made to perfectly accurately depict the movements of celestial bodies.

For the next 120 years, the cosmic mechanism both amazed and baffled generations of scientists. The fragments found were only one-third of the entire device - a highly sophisticated, hand-powered apparatus for accurately displaying the motions of the five planets, the sun, the phases of the moon, and their eclipses. The machine displayed these bodies in relation to the timing of major events, such as the Olympic Games.
Despite years of painstaking research, scientists have not yet been able to fully reconstruct the mechanism. Now, however, experts at University College London have created a replica of the jehi according to ancient methods of computation, computer modelling and modern knowledge to find out exactly how it works: "Our work reveals the Antikythera mechanism as a beautiful blending of cutting-edge engineering into an ingenious device," the 12 scientists wrote. "It disproves all our preconceptions about the technological capabilities of the ancient Greeks."

The scientists wanted to reassemble the device to try to explain all the mysteries surrounding the machine. No one has yet created a model of the so-called "Cosmos" that matches all physical phenomena: "The distance between the complexity of this device and other devices being made at the same time is infinite," Adam Wojcik, a UCL research fellow and co-author of the paper, told Live Science. "Frankly, nothing like this has ever been found before."
The complex gears that made up the device's mechanism are on a scale you might expect to find in an old clock. However, gears from this period tended to be much larger and coarser. They were used in devices such as ballistae, large crossbows and catapults. Such high precision raises many questions about the manufacturing process and why only one such device has been discovered - there is no equivalent anywhere in the world.

"What was it doing on that ship? We found only one-third; where are the other two [thirds]? Have they corroded? Did it ever work?" asked Wojcik. "These are questions we can only really answer through experimental archaeology. It's like answering the question of how people once built Stonehenge - it took 200 people with a rope and a big rock to try to move it across Salisbury Plain. We tried to do a similar thing here."
In creating the model, the researchers drew on all previous research and knowledge of the facilityincluding the work of Michael Wright, former curator of the Science Museum in London, who had previously constructed a partially working replica. Using inscriptions found on the mechanism and a mathematical model of planetary motion first defined by the Greek philosopher Parmenides, they were able toa computer model for a mechanism of overlapping gears set in a space of just 2.5 centimetres.

Their model translates each gear and rotating dial to show the movement of the planets, sun and moon through the Zodiac (an ancient map of the stars) on the front and the phases of the moon and eclipses on the back. It replicates the ancient Greek assumption that all celestial bodies revolve around the Earth.
Now that a computer model has been created, scientists want to create a real-life replica of it - first usingm modern technology to verify that the device works, and then using techniques that the ancient Greeks might have known: "We have no evidence that the ancient Greeks could build something like this. It's really a mystery," Wojcik said. "The only way to verify it is to try to build it using the methods of the time."

There's also a lot of debate about who the device served and who built it: "Some believe it was Archimedes himself," Wojcik said. "He lived around the same time the Antikythera was built, and no one else had the level of technical ability that he did. Moreover, it was a Roman ship on which the device was found, and Archimedes was killed by the Romans during the siege of Syracuse and his technology was stolen."

It is still a mystery whether the ancient Greeks used knowledge and techniques to produce similar, as yet undiscovered devices. Does a copy of the Antikythera mechanism exist anywhere? "It's a bit like having a TARDIS in the Stone Age," Wojcik said, referring to the spaceship from the popular British TV series Doctor Who that travels across space and time

Roman Nemec

Only about a third of the device has survived in more than 80 fragments

Scientists have created a digital model of the device's complex gear system

Sources: nature.com, livescience.com, bbc.com