The Antikythera Mechanism, an ingenious calculator made 2,200 years ago, has inspired wonder and fascination ever since it was recovered from a shipwreck near a Greek island in 1901. Generations of researchers have uncovered many mysteries about the device, which is often described as the world’s first analog computer, although much remains unknown.
A study published this month in The Horological Journal challenges a fundamental assumption about a mechanism that could overturn the understanding of the form and function of a complex timepiece. But rather than using the standard tools of archaeology, the researchers reached their conclusions by drawing on the methods of gravitational wave astronomy, a field that tunes in to the subtle ripples in spacetime that result from cosmic perturbations.
Graham Woan, professor of astrophysics at the University of Glasgow, and Joseph Bayley, a research fellow there, said the mechanism’s calendar ring, a circular structure that survives only in fragments, once contained 354 holes, corresponding to the lunar calendar. 354 days. This result contradicts earlier research that identified the ring as a solar calendar, lined with 365 holes.
“It’s a bit of a questionable idea,” said Dr. Woan, who acknowledged that he and Dr. Bayley are not experts on this device. “However, the evidence is fairly clear.
If the calendar ring represents the lunar year, this would invalidate current models of the mechanism. For this reason, some Antikythera scholars remain skeptical of the new study.
“It’s just wrong,” said Tony Freeth, an honorary professor at University College London and an expert on the Antikythera mechanism. He noted that a much more accurate lunar calendar already existed in the machinery, based on the 19-year Metonic cycle.
“Why put a second lunar calendar on the mechanism when you’ve already put a lot of work into creating a lunar calendar with great precision and sophistication?” said Dr. Freeth.
The Antikythera Mechanism is no stranger to controversy and speculation, in part because it was so ahead of its time in the second century BC Its intricate network of gears, dials and plates created a model of the universe that followed the cycles of the moon, the sun. , planets and constellations while also predicting eclipses and marking the timing of athletic games such as the ancient Olympics. The artifact also inspired the titular “dial of fate” in the latest Indiana Jones film.
For decades, scientists considered the calendar ring to be the solution to the mathematically refined solar year, which lasts 365.24 days. Just as leap years are built into our calendars, the holes in the ring allowed it to be manually rotated one day every four years to keep it from going off course.
The solar model was first challenged in a 2020 study by a team of researchers and enthusiasts. By analyzing X-ray images of the remaining holes in the mechanism, the study claimed to have “displaced the century-old assumption of a 365-day calendar on the Antikythera Mechanism and proposed instead that it is a 354-day lunar calendar”.
Dr. Woan and Dr. Bayley thought that the methods they used to analyze gravitational waves might place tighter constraints on the original number of holes.
“It’s such a well-defined and clear problem that we couldn’t resist analyzing it in the same way we would analyze an astronomical problem,” said Dr. Wow.
Through their astronomy software, they took measurements of the surviving holes, including size and spacing. The results strongly favored a complete ring with 354 holes.
Mike Edmunds, emeritus professor of astrophysics at Cardiff University in Wales and chair of the Antikythera Mechanism Research Project, said there appeared to be “no apparent reason to doubt” the 354-hole study’s estimate. Still, he was not convinced that the mechanism carried a redundant lunar calendar.
“The suggestion that 354 represents a lunar calendar does not seem to have any other support from within the mechanism – it is not at all clear how this would work and how it would relate to the markings on the face of the calendar ring,” said Dr. Edmunds said. “But perhaps the establishment of the count tells us something about the level of precision in construction that the builders of the mechanism felt was necessary and used.
Whatever the original nature of the calendar ring, a new study shows that the Antikythera mechanism is not a static relic, but a dynamic puzzle with many missing pieces that have yet to be found.
The mechanism “keeps giving us new things,” said Dr. Freeth. “It’s extraordinary. Year after year we find these amazing things in it.”