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A Lego Replica of the Antikythera Mechanism 74

Posted by timothy
from the hard-to-get-enough-antikythera dept.
vbraga writes "The Antikythera Mechanism is the oldest known scientific computer, built in Greece at around 100 BCE. Lost for 2000 years, it was recovered from a shipwreck in 1901. But not until a century later was its purpose understood: an astronomical clock that determines the positions of celestial bodies with extraordinary precision. In 2010, a fully-functional replica out of Lego (YouTube video) was built."
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A Lego Replica of the Antikythera Mechanism

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  • I must have this!! (Score:4, Interesting)

    by erroneus (253617) on Saturday January 29, 2011 @03:13AM (#35041360) Homepage

    I need a parts list and build instructions. Anyone know if they did this? All we got was a Youtube video...

    • That was the first thing I thought as well.... Want to build one myself!
    • by JaZz0r (612364) on Saturday January 29, 2011 @04:01AM (#35041510)
      Andrew Carol is the designer. His website has more information - http://acarol.woz.org/antikythera_mechanism.html [woz.org] If the site is down, try the Google cache [googleusercontent.com]
      • by TheMidget (512188) on Saturday January 29, 2011 @08:32AM (#35041982)
        .... which also shows that it is not a replica of the Antikhera mechanism. It achieves the same purpose (predicting eclipses), but using a different mechanism, because they needed to work with gear ratios achievable with available Lego pieces, and thus needed to add differentials, whereas the Greeks had no such needs (making their own gears, so being able to directly use whatever ratio was needed). Moreover, display differences (4-wind spirals versus 5) introduced more differences in the multiplicative constants, and thus the mechanism:

        Because it would be difficult to fit the information for 223 lunar months in a single rotation of a dial, the original machine used a 5 wind spiral to encode the information. This made more space available for the markings required for the eclipse information.

        My version of the machine uses a 4 wind spiral. This provides the same benefit as a 5 wind spiral but matches the Full Moon Cycle which may permit future enhancements to accuracy.

        This change results in the formula:

        Saros4 = Y * 4 * 235 / (223 * 19)

        I decided to not use the Corinthian calendar and instead use the standard Gregorian civil calendar in a four wind spiral representing the four year leap year cycle.

        Noting that 235 is 5 * 47 and 254 is 2 * 127, the important constants for the construction are:

        4, 5, 19, 47, 127, and 223.

        The readily available high quality LEGO gear ratios are combinations of 1, 3, and 5. With some challenge 4 is available. With these combinations we can get to gear ratios which are multiplicative combinations of these values. The easy ratios we can get to include: 1, 3, 4, 5, 9, 12, 15, 20, 25, 27, etc.

        Ratios of 19, 47, 127, and 223 are impossible to achieve with simple gear ratios because they are prime numbers. We have to look beyond simple gears to differentials.

    • by AmberBlackCat (829689) on Saturday January 29, 2011 @10:29AM (#35042366)
      It would be nice if I walked into a toy store and saw a Lego set with this on the front of the box instead of a Star Wars ship.
  • If I find a bug in this, I can hack any computer ever released in History?

  • by wiredlogic (135348) on Saturday January 29, 2011 @03:19AM (#35041386)

    Not to be missed is the time lapse video [youtube.com] of the process of creating the video which was as fascinating as the model itself.

  • non-scientific computers? So is there an even earlier computer that was in some way un-scientific?
  • by Tumbleweed (3706) * on Saturday January 29, 2011 @03:39AM (#35041460)

    "A device is not truly understood until its function can be duplicated by Legos."
    - Tumbleweed's Observation

    • Re: (Score:2, Funny)

      by jcr (53032)

      I think I understand how an oxy-acetylene torch works, but I don't think I could duplicate its function with legos...

      -jcr

      • Re: (Score:2, Funny)

        by Anonymous Coward

        I think I understand how an oxy-acetylene torch works, but I don't think I could duplicate its function with legos...

        Well, you can duplicate its function with bacon [popsci.com]. That also counts.

      • by jbeaupre (752124)

        There is a pneumatic set. I don't recommend it, but you could build an oxy-acetylene torch using the pressure vessel, tubes, connectors, and valves.

    • by Xyrus (755017)

      "A device that cannot be replicated by legos is not worth understanding."

      • by Tumbleweed (3706) *

        "A device that cannot be replicated by legos is not worth understanding."

        Excellent. And now I think we can get a nice research grant.

  • More Information (Score:4, Interesting)

    by breser (16790) on Saturday January 29, 2011 @04:25AM (#35041554) Homepage
    Built by Andrew Carol who is an engineer for Apple.
    He had a website about his building complex lego machines at: http://acarol.woz.org/ [woz.org]
    And specifically information about this one at: http://acarol.woz.org/antikythera_mechanism.html [woz.org]

    Unfortunately, the site seems to be down but Google still has a good cache:
    http://google.com/search?q=cache:acarol.woz.org/antikythera_mechanism.html [google.com]
    http://google.com/search?q=cache:acarol.woz.org/acarol.woz.org [google.com]
    • Unfortunately, the site seems to be down but Google still has a good cache

      Ahh, yes. The slashdot front page effect. Funny how that works.

      • by madmayr (1969930)

        Ahh, yes. The slashdot front page effect. Funny how that works.

        maybe we should build a slashdot-effect-machine out of LEGO

    • by Tablizer (95088)

      Built by Andrew Carol who is an engineer for Apple.

      Steve Jobs is going to purchase Lego Inc. and shorten the name to Ego.

  • by Anonymous Coward on Saturday January 29, 2011 @05:36AM (#35041664)

    This has as much to do with the Antikythera mechanism as a software simulation. The mechanism has no differential gears, which are used on this lego construct because its creator played with them during his experiments with Babbage's Difference Engine. The beauty of the Antikythera machine lies in its pin-and-slot mechanism for modelling epicyclic trajectories which are of course nowhere to be found in this "reconstruction".

    • by TheMidget (512188)

      This has as much to do with the Antikythera mechanism as a software simulation. The mechanism has no differential gears, which are used on this lego construct because its creator played with them during his experiments with Babbage's Difference Engine.

      Nope, the main reason for using differential gears is that with normal Lego gear pieces only certain ratios are achievable... which unfortunately do not include those needed by the Antikythera mechanism. So they had to obtain those by averaging two obtainable rations. And, in order to perform this "averaging" you need differential gears.

      So this is a mechanism achieving the same purpose as Antikythera, but implemented using a completely different way due to different constraints.

      See Building complex machin [woz.org]

  • NOT a replica (Score:2, Informative)

    by Gravis Zero (934156)

    it's an implementation of the same math that that the Antikythera mechanism does but it's done in a completely different fashion.

    Woz explains the device on his own page as well as the math behind it: http://acarol.woz.org/antikythera_mechanism.html [woz.org]
    There is also an article about his LEGO device: http://www.fastcodesign.com/1662831/how-one-engineer-redesigned-an-ancient-greek-mechanical-computer-out-of-legos [fastcodesign.com]

    more information about the Antikythera mechanism can be found here: http://en.wikipedia.org/wiki/Antiky [wikipedia.org]

    • It implements some of the same math, but misses some features of the original. For example, I don't see the pin and slot drive used to approximate the varying angular velocity of the moon due to its elliptic orbit. Nor the spherical phase of the moon display on the front dial.

      More importantly, we can only speculate about features that have been lost to history. Estimates of the gear count range from 30 to 70. No one today known for sure.

      Still, it is an impressive bit of lego work!

      • by mikael (484)

        HP Labs managed to recover the instruction manual that was written on the side of the machine, so the archaeologists are more or
        less certain they know the purpose of each internal gear, as well as the dials and indicators.

        High resolution image [hp.com]

        Fascinating to know that someone was designing interactive user interface 2000 years ago...

        • See the most recent Antikythera mechanism paper [Nature V468 P496, 25 Nov 2010] for proof that our knowledge of the mechanism is incomplete. For example: "Evans’s hypothesis forces a rethink of other parts of the mechanism, too. Previously, scholars assumed that the positions of the Sun, Moon and planets were all displayed around the same zodiac scale. But if the zodiac scale had been tweaked to accommodate the varying speed of the Sun, it would no longer be accurate for showing the positions of the
        • by loshwomp (468955)

          HP Labs managed to recover the instruction manual that was written on the side of the machine

          I didn't see a translation anywhere, but I'm pretty sure it says "replace toner cartridge now".

  • ...is there anything you can't build?
  • So what's this "kythera" that they were so afraid of? Is it coming?

  • It's really an accomplishment to have been able to piece out the internal structure of the badly corroded artifact and deduce its function and how it worked. It's also remarkable to have built one out of Legos. What a coincidence that the dimensions of the Lego parts were very close to the same dimensions of the parts in the artifact; if not the Lego machine would be a working model, not a replica.

  • A quick blurb says it uses twice as many gears as the original, perhaps because they had to use off-the-shelf teeth counts. I'd like to see a reconstruction of the original, not a reconstruction of the function.

  • Arthur C. Clarke on the TV show "Mysterious World" said if the Antikythera Mechanism had not been lost, we might have populated all the stars visible to the naked eye. What he meant was that the lost of the Antikythera Mechanism set back computing by 2000 years. He reasoned that if it had not been lost, that we might have been 2000 years farther along in computing. It really does boggle my mind to think what could have been if this had become widely known and used, would we have really gone to the stars

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