By: Felix Xie

A new study published in the Horological Journal challenges old ideas about the Antikythera mechanism. Instead of a solar calendar, the study proposes that the mechanism is a lunar calendar.

Ever since the Antikythera mechanism was retrieved from a shipwreck close to a Greek island in 1901, the Antikythera mechanism—an inventive calculator created 2,200 years ago—has inspired wonder and enchantment. Though much is still unknown, generations of researchers have deciphered many mysteries pertaining to the device, which is frequently described as the world’s first analog computer.

The study upends the traditional beliefs of the perplexing timetable’s purpose. Instead of using the usual tools of archaeology, Graham Woan and Joseph Bayley, the two authors of the study, have resorted to using the techniques of gravitational wave astronomy, a field that tunes into subtle ripples in space-time that result from cosmic disruptions.

The two authors, Dr. Woan, a professor of astrophysics at the University of Glasgow, and Dr. Bayley, a research associate there as well, stated that the Antikythera mechanism’s rings contained 354 holes, corresponding to a lunar calendar with 354 days, in contrast to the previous count of 365 holes, which suggested a solar calendar.

“It’s a slightly contentious idea,” said Dr. Woan, who accepted that he and Dr. Bayley are not experts on the device. “However, the evidence is rather clear.”

“It’s just wrong,” said Tony Freeth, an honorary professor at University College London and an expert on the Antikythera mechanism. He noted that there was already a much more precise lunar calendar, based on the 19-year Metonic cycle, embedded in the machinery.

“Why put a second lunar calendar on the mechanism when you’ve already taken a lot of trouble to construct a lunar calendar of great accuracy and sophistication?” Dr. Freeth had said.

Controversy and speculation about the use of the machine have been the entire history of the mechanism. Its history of controversy is partly due to the advanced astronomical and astrological knowledge required to build such a machine. The machine is a complicated and elegant mess of gears, dials, and plates that produce a model of the sun, moon, planets, and constellations while also predicting the cosmic events that happen when the planets, sun, and moon interact with each other.

The artifact also inspired the titular “dial of destiny” in the latest Indiana Jones movie.