The Antikythera Mechanism – an ancient shoebox-sized device used to track the movements of the sun, moon and planets – followed the Greek lunar calendar, not the solar one used by the Egyptians as previously thought, new research reveals.
The Antikythera mechanism, discovered by divers off the Greek island of Antikythera in 1901, was created about 2,200 years ago. The device, which contains bronze gears, is sometimes called the world’s oldest computer.
One part of the movement known as the “calendar ring” is used to track the days of the year, with one hole per day. Although the ring has been known for some time, it is only partially preserved, so it is not clear how many days it was supposed to track.
In 2020, a team led by independent researcher Chris Budiselich used new X-ray images of the device, combined with measurements and mathematical analysis, to determine that the mechanism probably does not cover an entire solar calendar year, but rather 354 days. as it would be used in a lunar calendar.
On Thursday (June 27), another article 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 caused by the collisions of massive celestial objects such as black holes. These statistical methods are sensitive enough to detect weak signals from a potentially very noisy background.
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 infer the number and location of the lost holes. They eventually determined that the mechanism probably had 354 or 355 holes. This meant that it probably followed the 354-day lunar calendar used in Greece at the time, rather than the 365-day calendar used by the ancient egyptians.
It has been thought that he may have used the Egyptian solar calendar of 365, as it was more accurate than the 354-day lunar calendar.
“The Glasgow team’s results provide fresh evidence that one of the components of the Antikythera mechanism was most likely used to track the Greek lunar year,” the researchers said in statement from the University.
The team was impressed by the device creators’ attention to detail.
“The precision of positioning the holes would require extremely precise measuring techniques and an incredibly steady hand to drill them,” study co-author Graham Vaughan, professor of astrophysics at the University of Glasgow, said in the statement. “It’s pure symmetry that we’ve adapted the techniques we use to study the universe today to learn more about a mechanism that helped humans track the heavens almost two millennia ago.”
Andrew Tieni, co-author of the 2020 paper, praised the new research. “We are very happy that more scientists are now accepting and confirming our findings,” Thoeni told Live Science in an email.
Diomedes Spinellisa professor of software engineering at the Athens University of Economics and Business, who studied the mechanism but was not involved in either paper, was also impressed by the new work.
“The Antikythera Mechanism is a gift that keeps on giving,” Spinellis told Live Science in an email. “Despite its severe corrosion and many missing elements, the application of increasingly sophisticated technologies and innovative interdisciplinary analysis continue to provide impressive insights into this remarkable artifact.”
