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Scientists move closer to solving mystery of antikythera mechanism:
Researchers claim breakthrough in study of 2,000-year-old Antikythera mechanism[*], an astronomical calculator found in sea
[...] The hand-powered, 2,000-year-old device displayed the motion of the universe, predicting the movement of the five known planets, the phases of the moon and the solar and lunar eclipses. But quite how it achieved such impressive feats has proved fiendishly hard to untangle.
Now researchers at UCL[**] believe they have solved the mystery – at least in part – and have set about reconstructing the device, gearwheels and all, to test whether their proposal works. If they can build a replica with modern machinery, they aim to do the same with techniques from antiquity.
"We believe that our reconstruction fits all the evidence that scientists have gleaned from the extant remains to date," said Adam Wojcik, a materials scientist at UCL. While other scholars have made reconstructions in the past, the fact that two-thirds of the mechanism are missing has made it hard to know for sure how it worked.
The mechanism, often described as the world's first analogue computer, was found by sponge divers in 1901 amid a haul of treasures salvaged from a merchant ship that met with disaster off the Greek island of Antikythera. The ship is believed to have foundered in a storm in the first century BC as it passed between Crete and the Peloponnese en route to Rome from Asia Minor.
[...] Michael Wright, a former curator of mechanical engineering at the Science Museum in London, pieced together much of how the mechanism operated and built a working replica, but researchers have never had a complete understanding of how the device functioned. Their efforts have not been helped by the remnants surviving in 82 separate fragments, making the task of rebuilding it equivalent to solving a battered 3D puzzle that has most of its pieces missing.
Writing in the journal Scientific Reports, the UCL team describe how they drew on the work of Wright and others, and used inscriptions on the mechanism and a mathematical method described by the ancient Greek philosopher Parmenides, to work out new gear arrangements that would move the planets and other bodies in the correct way. The solution allows nearly all of the mechanism's gearwheels to fit within a space only 25mm deep.
According to the team, the mechanism may have displayed the movement of the sun, moon and the planets Mercury, Venus, Mars, Jupiter and Saturn on concentric rings. Because the device assumed that the sun and planets revolved around Earth, their paths were far more difficult to reproduce with gearwheels than if the sun was placed at the centre. Another change the scientists propose is a double-ended pointer they call a "Dragon Hand" that indicates when eclipses are due to happen.
[...] "Although metal is precious, and so would have been recycled, it is odd that nothing remotely similar has been found or dug up," Wojcik said. "If they had the tech to make the Antikythera mechanism, why did they not extend this tech to devising other machines, such as clocks?"
[*] Wikipedia entry.
[**] UCL: University College London.
Journal Reference:
Tony Freeth, David Higgon, Aris Dacanalis, et al. A Model of the Cosmos in the ancient Greek Antikythera Mechanism [open], Scientific Reports (DOI: 10.1038/s41598-021-84310-w)
Previously:
Evidence of a Lunar Calendar on the Antikythera Mechanism
Antikythera Shipwreck Yields Statue Pieces and Mystery Bronze Disc
Antikythera Discoveries Prove Luxury Cargo
(Score: 3, Insightful) by Immerman on Saturday March 13 2021, @07:28PM (3 children)
>"If they had the tech to make the Antikythera mechanism, why did they not extend this tech to devising other machines, such as clocks?"
Why on earth would they imagine the technology was remotely relevant to clocks?
Despite the name, clockwork mechanisms are virtually useless for measuring time - their only value is in displaying what is measured in some other way. And the display is mostly very straightforward. The big challenge is in the measuring. Pendulums can do that. Or well-regulated dripping water. Hand-cranked gears can't. Even spring-driven gears present some enormous challenges since the driving force is constantly changing. And pendulum clocks have some huge challenges in the form of continuously recharging the pendulum without disrupting its rhythm and throwing off its timekeeping.
Accurate timers of all kinds existed in ancient Greece and earlier: Hourglasses, water-clocks, candle-clocks, etc. As did the extremely simple and reliable (so long as it wasn't cloudy) sundial - though they didn't measure equal-length hours throughout the year until Arabic advances in trigonometry made it possible in the late 1300s.
But a mechanical clock needs to be able to run for a long time without intervention to have any value. And that takes some really clever innovations that weren't developed until the for for almost another 2000 years.
Though actually - perhaps the Antikythera mechanism actually WAS a clock. The motion of the planets keep accurate time, so if you have a mechanism that computes their positions accurately enough you could just wind it until it matches the current planet positions and know what time it is, within the limits of the accuracy of your measurements. Planets don't move much over the course of a day though, so maybe it would be more of a calendar. Which could still be extremely valuable on a trading ship. I believe the first astronomical clock useful for measuring time of day relied on telescopes and the much-faster motion of Jupiter's Galilean moons.
(Score: 0) by Anonymous Coward on Saturday March 13 2021, @09:58PM (1 child)
The point of such a device is most likely as an astronomical aid, so you can predict where and when you need to look to observe any given phenomenon. The ancient Greek philosophers would have been gravely insulted if such a device was used for any practical purpose. Pressure plate operated door for a temple? Wonderful. Design a roof that doesn't leak or improved tools for farming? Preposterous.
(Score: 2) by Eratosthenes on Sunday March 14 2021, @08:09PM
Clearly you have very little knowledge of ancient Greek philosophers. Thales has some futures options he might interest you in.
Ἀριθμητικὴ εἰσαγωγή
(Score: 1) by GerryA on Sunday March 14 2021, @08:27AM
To justify the work that went into this, and its likely enormous value, I'd guess there was a practical use at a strategic level, worth paying big money for. Suppose it was used to conduct world-class 'astrology' - just wind the handle to decide when best to invade neighbours, marry Princes, or expect death. So we've now understood the hardware, but we've long lost contact with the 'app'.