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Special techniques used to study waves in the universe may have helped researchers solve an ancient mystery.

Statistical modeling methods that were developed to study gravitational waves have been used to predict the structure of a broken section of a millennia-old artifact, according to a new paper in The Horological Journal.

These techniques allowed the researchers to tell how many holes were in one of the broken rings of the Antikythera Mechanism, the ancient computer featured in Indiana Jones and the Dial of Fate.

The Antikythera Mechanism is an ancient Greek analog device dating between 100 and 200 BC that is believed to be the world’s first known computer. Discovered in 1901 in a shipwreck off the coast of the Greek island of Antikythera, the device is believed to have been used to predict astronomical positions and eclipses for calendrical and astrological purposes.

The mechanism is composed of a complex system of bronze gears and dials housed in a wooden case. It has 30 gears, which is an incredibly advanced design for its time.

Its complexity suggests that the ancient Greeks developed an advanced knowledge of gear-based technology far more advanced than previously thought for that era.

Modern imaging techniques, such as X-ray computed tomography, have been used to study the internal structure and functions of the mechanism. It slowly became clear that it was used to calculate the positions of the planets, predict eclipses, and keep track of the months and years.

Thanks to X-ray images in 2020, it was discovered that one of the device’s rings has regularly spaced holes. Because the ring was broken, it is unclear how many rings it originally had, but researchers have estimated between 347 and 367.

According to the new paper, the ring likely had 354 holes corresponding to the cycle of the moon. According to their calculations, a ring with 354 holes is hundreds of times more likely than a ring with 360 holes.

“We present a new analysis of the positions of the holes under the calendar ring of the Antikythera mechanism,” the researchers wrote in the paper. “We significantly refine their estimate of the number of holes that were present throughout the ring.” Our 68 percent confidence estimate for this number, taking all data into account, is 355.24 [plus or minus about 1.4].

“If holes adjacent to fractures are removed from the analysis, our estimate becomes 354.08. A ring of 360 holes is highly unfavorable, and one of 365 holes is not plausible given the assumptions of our model.”

This mystery was solved using similar statistical modeling techniques to those used to study gravitational waves, which are ripples in the fabric of spacetime created by the motion of massive objects traveling outward from a source.

“Towards the end of last year, a colleague pointed me to data acquired by YouTuber Chris Budiselic, who wanted to make a replica of the calendar ring and was investigating ways to determine exactly how many holes it contained,” paper co-author Graham Vaughan, professor in the School of Physics and astronomy at the University of Glasgow, said in a statement.

“This struck me as an interesting problem, and I thought I might be able to solve it in a different way over the Christmas holidays, so I set out to use some statistical techniques to answer the question.”

After using this technique, the scientists found that the number of holes was probably 354 or 355.

“Previous studies suggested that the calendar ring probably tracked the lunar calendar, but the dual techniques we applied in this part of the work greatly increase the likelihood that this is the case,” co-author Joseph Bailey, also a researcher at the University of Glasgow, said in the statement.

“It gave me a new appreciation for the Antikythera mechanism and the work and care Greek craftsmen put into making it – the precision of the positioning of the holes would have required extremely precise measuring techniques and an incredibly steady hand to drill them.”

Although we will never know how many holes the ring actually had, the analysis provides pretty strong evidence that there were 354.

“It’s a neat symmetry that we’ve adapted the techniques we use to study the universe today to understand more about a mechanism that helped people track the heavens almost two millennia ago,” said Vaughan.

“We hope that our discoveries of the Antikythera mechanism, while less supernaturally spectacular than those made by Indiana Jones, will help to deepen our understanding of how this remarkable device was made and used by the Greeks.”

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