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posted by janrinok on Tuesday January 18, @04:53AM   Printer-friendly [Skip to comment(s)]

martyb and aristarchus both made submissions about:

An Ancient Greek Astronomical Calculation Machine Reveals New Secrets:

In modern terms, all the moving astronomical bodies have orbits close to the plane of Earth's motion around the sun—the so-called ecliptic—meaning that they all follow much the same path through the stars. Predicting the positions of the planets along the ecliptic was very difficult for early astronomers. This task, it turns out, was one of the primary functions of the Antikythera mechanism. Another function was to track the positions of the sun and moon, which also have variable motions against the stars.

[...] The second key figure in the history of Antikythera research was British physicist turned historian of science Derek J. de Solla Price. In 1974, after 20 years of research, he published an important paper, "Gears from the Greeks." It referred to remarkable quotations by Roman lawyer, orator and politician Cicero (106–43 B.C.E.). One of these described a machine made by mathematician and inventor Archimedes (circa 287–212 B.C.E.) "on which were delineated the motions of the sun and moon and of those five stars which are called wanderers ... (the five planets) ... Archimedes ... had thought out a way to represent accurately by a single device for turning the globe those various and divergent movements with their different rates of speed." This machine sounds just like the Antikythera mechanism. The passage suggests that Archimedes, although he lived before we believe the device was built, might have founded the tradition that led to the Antikythera mechanism. It may well be that the Antikythera mechanism was based on a design by Archimedes.

[...] It seems that the device could be used to predict the positions of the sun, moon and planets on any specific day in the past or future. The maker of the machine would have had to calibrate it with the known positions of these bodies. A user could then simply turn a crank to the desired time frame to see astronomical predictions. The mechanism displayed positions, for instance, on a "zodiac dial" on the front of the mechanism, where the ecliptic was divided into a dozen 30-degree sections representing the constellations of the zodiac. Based on the x-ray data, Price developed a complete model of all the gearing on the device.

[...] A third key figure in the history of Antikythera research is Michael Wright, a former curator of mechanical engineering at London's Science Museum. In collaboration with Australian professor of computer science Alan G. Bromley, Wright carried out a second x-ray study of the mechanism in 1990 using an early 3-D x-ray technique called linear tomography. Bromley died before this work bore fruit, but Wright was persistent, making important advances, for example, in identifying the crucial tooth counts of the gears and in understanding the upper dial on the back of the device.

[...] We proposed that any method the Antikythera creators used would have required three criteria: accuracy, factorizability and economy. The method must be accurate to match the known period relations for Venus and Saturn, and it must be factorizable so the planets could be calculated with gears small enough to fit into the mechanism. To make the system economical, different planets could share gears if their period relations shared prime factors, reducing the number of gears needed. Such economy is a key feature of the surviving gear trains. Based on these criteria, our team derived the periods 462 and 442 using the idea from Parmenides and employed the same methods to discover the missing periods for the other planets where the inscriptions were lost or damaged.

[...] We now understood how the front display matched the description in the back-cover user's manual, with the sun and planets shown by marker beads on concentric rings. The front cover also displayed the moon's phase, position and age (the number of days from a new moon), and the dragon hand that showed eclipse years and seasons.

With the concentric rings for the planets, we realized that we could now make sense of the front-cover inscription as well. This writing is a formulaic list of the synodic events of each planet (such as its conjunctions with the sun and its stationary points) and the intervals in days between them. On the back plate, the eclipse inscriptions are indexed to markings on the saros dial. On the front plate, inscriptions about the risings and settings of stars are indexed to the zodiac dial. Our insight was that the inscriptions on the front could refer to index letters on the planetary rings: if the sun pointer is at one of these letters, then the corresponding inscription entry describes the number of days to the next synodic event. Because the left-hand side of the inscription, where we would expect these index letters to be, is missing, we cannot prove the hypothesis—but it is a compelling explanation.


Original Submission #1Original Submission #2

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  • (Score: -1, Troll) by aristarchus on Tuesday January 18, @07:30AM (8 children)

    by aristarchus (2645) on Tuesday January 18, @07:30AM (#1213540) Journal

    Nice that my original sub, done with great craftsmanship, gets squashed in with a robo sub from an editor? Am I supposed to be getting a message, like no subs about ancient Greeks? Nicely done, SoylentNews, nicely done.

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    #Freearistarchus, again!!!!!1!!
    • (Score: 5, Funny) by janrinok on Tuesday January 18, @04:29PM (5 children)

      by janrinok (52) Subscriber Badge on Tuesday January 18, @04:29PM (#1213594) Journal

      You complain if we don't use your subs and you complain if we do. Are we supposed to be getting a message - that you whine and whinge a lot?

      like no subs about ancient Greeks

      We've published it! It is right there in front of your eyes. What is your complaint now?

      If you are going to act like a child I'll send you some crayons and you can spend your time colouring in the o, b, p's etc

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      • (Score: 0, Troll) by aristarchus on Tuesday January 18, @08:23PM (4 children)

        by aristarchus (2645) on Tuesday January 18, @08:23PM (#1213656) Journal

        I was thinking it was to avoid giving the karma points. But then, I receive this message from janrinok:

        This account is being investigated for possible moderation abuse.

        Cryptic, incomplete, ambiguous. Maybe I am committing, or maybe I am the victim, of moderation abuse? I have some idea, since I am privy to my karma score, I cannot tell if I was granted karma for this (sort of) accepted submission. But dealing with SN administration is a bit like being in a Kafka novel. Not sure if it is Das Schloß or Der Proceß, perhaps aristarchus is becoming a large beetle, a sort of a "Die Verwandlung".

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        #Freearistarchus, again!!!!!1!!
        • (Score: 3, Informative) by takyon on Tuesday January 18, @08:37PM (3 children)

          by takyon (881) <{takyon} {at} {soylentnews.org}> on Tuesday January 18, @08:37PM (#1213661) Journal

          Investigation? It's not like you're even trying to hide that you're using your sock accounts to upmod your main account.

          https://soylentnews.org/~Mockingbird/ [soylentnews.org]

          Moderations performed by Mockingbird
          Datestamp Was Now Val Reason Moderatee
          01-18 00:35 [soylentnews.org] -1 -1 +1 Interesting aristarchus (2645)
          01-17 21:03 [soylentnews.org] 2 -1 +1 Insightful aristarchus (2645)
          01-17 21:02 [soylentnews.org] -1 -1 +1 Informative aristarchus (2645)
          01-17 00:14 [soylentnews.org] 1 -1 +1 Informative aristarchus (2645)
          01-11 06:22 [soylentnews.org] -1 0 +1 Insightful Frigatebird (15573)
          01-11 06:17 [soylentnews.org] 4 5 +1 Insightful aristarchus (2645)

          On this one [soylentnews.org] you went ahead and upmodded it with two sock accounts.

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          • (Score: -1, Troll) by Mockingbird on Tuesday January 18, @09:23PM (1 child)

            by Mockingbird (15239) Subscriber Badge on Tuesday January 18, @09:23PM (#1213676) Journal

            Are you saying that those submissions by aristarchus were not insightful, interesting, or informative? I certainly found them to be, since I modded them so. Who are you accusing of being a sock, just from their moderations of fellow soylentils?

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            • (Score: 1, Funny) by Anonymous Coward on Tuesday January 18, @11:54PM

              by Anonymous Coward on Tuesday January 18, @11:54PM (#1213716)

              Are you saying that you're not mocking all of us?

          • (Score: 0, Interesting) by Anonymous Coward on Wednesday January 19, @07:41AM

            by Anonymous Coward on Wednesday January 19, @07:41AM (#1213800)

            Interesting. Can we see who takyon has been modding up, or down? Should be, well, revealing.

    • (Score: 0) by Anonymous Coward on Wednesday January 19, @03:32PM (1 child)

      by Anonymous Coward on Wednesday January 19, @03:32PM (#1213855)

      done with great craftsmanship

      Well, good day Mr. Kruger!

      • (Score: -1, Troll) by Mockingbird on Thursday January 20, @09:57AM

        by Mockingbird (15239) Subscriber Badge on Thursday January 20, @09:57AM (#1214110) Journal

        Are you Dunning with that? I'm sure you are.

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        "It is a sin to kill a mockingbird" Atticus Finch
  • (Score: 0, Informative) by Anonymous Coward on Tuesday January 18, @12:45PM (8 children)

    by Anonymous Coward on Tuesday January 18, @12:45PM (#1213564)

    See Original Submission #1 which I prefer.

    There is a fascinating (and long) series of building a replica of the machine, based on x-rays and the good sense of clever modelmaker/machinist "Clickspring", first episode at https://www.youtube.com/watch?v=ML4tw_UzqZE [youtube.com]

    • (Score: -1, Offtopic) by Anonymous Coward on Tuesday January 18, @12:52PM (1 child)

      by Anonymous Coward on Tuesday January 18, @12:52PM (#1213565)

      And digging deeper, the full article text -- https://soylentnews.org/submit.pl?op=viewsub&subid=53364 [soylentnews.org]

      • (Score: 3, Insightful) by aristarchus on Tuesday January 18, @08:26PM

        by aristarchus (2645) on Tuesday January 18, @08:26PM (#1213657) Journal

        This is what the link to the full text article is for. There are issues with scraping the entire thing.

        --
        #Freearistarchus, again!!!!!1!!
    • (Score: 0) by Anonymous Coward on Tuesday January 18, @02:07PM (5 children)

      by Anonymous Coward on Tuesday January 18, @02:07PM (#1213574)

      Isn't it easier to stay logged in to bitch? Why log in, post, log out, then post again?

      • (Score: 1, Informative) by Anonymous Coward on Tuesday January 18, @02:53PM (4 children)

        by Anonymous Coward on Tuesday January 18, @02:53PM (#1213581)

        I started this topic and I'm not Ari, but I'll admit that I often enjoy Ari's posts. Hell, I'm not even from the same century as Ari!

        Also, I'm logged in, posting AC.

        • (Score: 0) by Anonymous Coward on Tuesday January 18, @11:55PM (3 children)

          by Anonymous Coward on Tuesday January 18, @11:55PM (#1213717)

          No, I started this topic, and I am an ari sock, so you go stuff yourself back in the drawer!

          • (Score: 1, Interesting) by aristarchus on Wednesday January 19, @12:57AM (2 children)

            by aristarchus (2645) on Wednesday January 19, @12:57AM (#1213736) Journal

            Seems anybody who mods me up must be a sockpuppet, and is mod-banned. So there will be no one to mod poor aristarchus up, and only those who mod him down. I wonder where this will all end up? Crickets? In an echo chamber?

            --
            #Freearistarchus, again!!!!!1!!
            • (Score: 0) by Anonymous Coward on Wednesday January 19, @02:58AM

              by Anonymous Coward on Wednesday January 19, @02:58AM (#1213763)

              You've been living in an echo chamber for years. So, nothing will change for you.

            • (Score: 0) by Anonymous Coward on Wednesday January 19, @03:01AM

              by Anonymous Coward on Wednesday January 19, @03:01AM (#1213765)

              Tell us about your echo chamber with all of your sock puppets repeating you day in and day out.

  • (Score: 0, Redundant) by aristarchus on Tuesday January 18, @10:54PM

    by aristarchus (2645) on Tuesday January 18, @10:54PM (#1213707) Journal

    This part is especially interesting.

    It took months to understand these gears. When I did, the results were astonishing. These gears turned out to calculate the variable motion of the moon in a very beautiful way. In modern terms, the moon has variable motion because it has an elliptical orbit: when it is farther from Earth, it moves more slowly against the stars; when it is closer, it moves more quickly. The moon’s orbit, however, is not fixed in space: the whole orbit rotates in a period of just under nine years. The ancient Greeks did not know about elliptical orbits, but they explained the moon’s subtle motion by combining two circular motions in what is called an epicyclic theory.

    Most people today are unaware of the changes in the Moon, other than when there is a Super Blood Wolf Extra Blue Cheesy Moon!

    --
    #Freearistarchus, again!!!!!1!!
  • (Score: 2) by garfiejas on Wednesday January 19, @10:33AM

    by garfiejas (2072) on Wednesday January 19, @10:33AM (#1213817)

    I've been following the Tony Freeth et al for a while on this, it pays to watch the youtube videos i.e. https://www.youtube.com/watch?v=xWVA6TeUKYU [youtube.com] to see parts of it in motion, especially its user interface, the interpretation of which has changed from the 1990's/early 2000's. The things that strike me, some of which are given a few lines in the linked article;

    There must have been hundreds of devices for all kinds of uses, as whilst it may have been a "halo" product, the thing relies on a metric ton of research going back a few thousand years before it was made and incorporates the latest Greek theorems/algorithms;

    Folk from 2300 years ago would have been just fine with our machines, perhaps a gentle nudge to get them to point, as opposed to winding it, but the user interface is very complex - and it moves; pretty sure it would get annoying when they keep asking for the user manual though...

    The total loss of this technology for 900 years, for precision gears and for nearly 1800 years before machines as complex turned up surprises me; it was described by the Romans but they clearly didn't know how to replicate it (and then sell it to the known world)

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