# The Antikythera Mechanism

**URL:** <https://boards.straightdope.com/t/the-antikythera-mechanism/383780>\
**Category:** Factual Questions\
**Created:** [December 12, 2006, 3:24am UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780 "2006-12-12T03:24:03Z")\
**Posts on this page:** 12\
**Page:** 1

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**Author:** ![njcultist](https://avatars.discourse-cdn.com/v4/letter/n/3d9bf3/32.png) [@njcultist](https://boards.straightdope.com/u/njcultist)\
**Post date:** [December 12, 2006, 3:24am UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/1 "2006-12-12T03:24:03Z")

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Per this article:  
[http://www.washingtonpost.com/wp-dyn/content/article/2006/12/10/AR2006121000628.html](http://www.washingtonpost.com/wp-dyn/content/article/2006/12/10/AR2006121000628.html)

> [@](#):
>
> Given that astronomers of the time already knew how to calculate the positions of the sun and the moon and to predict eclipses without the device, it would have been the equivalent of a device built for a planetarium today

So I did a brief Google search to see how they did this and got lots of links to software that will calculate various celestial events.

Would anyone point me in the direction or show me how the ancient Greeks did this?

Also where can I buy a replica or build an Antikythera Mechanism???

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**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\
**Post date:** [December 12, 2006, 3:39am UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/2 "2006-12-12T03:39:43Z")

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[Wikiedia has a decent article on it](http://en.wikipedia.org/wiki/Antikythera_Mechanism), but as of a few months ago, we still do not know exactly what it does or how. So a full recreation is out of the question, but [build](http://www.donrogerson.com/bricks/orrery.html) an [orrery](http://en.wikipedia.org/wiki/Orrery) with 37 gears and you will be close.  
[Non-Lego Plans](http://www.ncsu.edu/project/agronauts/TeacherResources/teachernotes.htm)

Jim

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**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\
**Post date:** [December 12, 2006, 4:31am UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/3 "2006-12-12T04:31:59Z")

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Are you asking how they designed or made the antikythera, or how they did the astronomical calculations without one?

If the latter, look up Ptolemy’s Almagest. Animated versions of some of the geometrical models (theoretical models, not physical devices) are [here](http://www.csit.fsu.edu/~dduke/models).

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**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\
**Post date:** [December 12, 2006, 4:34am UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/4 "2006-12-12T04:34:56Z")

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[New Scientist](http://www.newscientist.com/channel/being-human/mg19225805.500-enigmatic-relic-was-eclipse-calculator.html) had an update on this just a couple of weeks ago:

> [@](#):
>
> a team led by Mike Edmunds at Cardiff University in Wales has shown that the Antikythera mechanism was designed to predict eclipses from the relative positions of the Earth, moon and sun. Edmunds’s team used a CT scanner to map out the gear trains within the mineral-encrusted fragments and to determine how they fit together. The team also found fragments of previously hidden text.
> 
> “The real significance of this is just how sophisticated the device was - much more complex than a modern wristwatch,” says Edmunds. “It is beautifully designed.”
> 
> The team is constructing a virtual model of the mechanism, which they hope to have complete within a few months (Nature, DOI: 10.1038/nature05357)

So you may be able to see exactly how it works, online at least.

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**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\
**Post date:** [December 12, 2006, 6:05am UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/5 "2006-12-12T06:05:48Z")

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This paper from [Tufts](http://www.perseus.tufts.edu/GreekScience/Students/Jesse/CLOCK1A.html) describes some of the ways that they approached building models. It includes [this link to this diagram](http://www.perseus.tufts.edu/GreekScience/Students/Jesse/antik.gif) of the gearing for the Antikythera Mechanism.

And [this site notes](http://www.grand-illusions.com/antikyth.htm) that John Gleave, who makes orreries, built his own replica.

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**Author:** ![Kythereia](https://avatars.discourse-cdn.com/v4/letter/k/e8c25b/32.png) [@Kythereia](https://boards.straightdope.com/u/Kythereia)\
**Post date:** [December 12, 2006, 6:11am UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/6 "2006-12-12T06:11:39Z")

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DON’T ask me about it, OKAY?!?

([Here](http://content.techrepublic.com.com/2346-10877_11-38336-1.html) are some more pretty cool photos, if you’re interested.

Out of curiosity, why do you want a replica?)

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**Author:** ![T\_SQUARE](https://avatars.discourse-cdn.com/v4/letter/t/9de053/32.png) [@T\_SQUARE](https://boards.straightdope.com/u/T_SQUARE)\
**Post date:** [December 12, 2006, 12:27pm UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/7 "2006-12-12T12:27:50Z")

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[QUOTE=njcultist]  
Also where can I buy a replica or build an Antikythera Mechanism???  
[/QUOTE]

I want one too! I got Antikythera fever a few weeks ago and wanted to buy [this](http://rens.cgsociety.org/gallery/247258/). Turns out it’s just a computer animation. Damn.

I bet there would be a demand if some craftsman could turn out a replica and offered it for sale.

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**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\
**Post date:** [December 12, 2006, 5:21pm UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/8 "2006-12-12T17:21:00Z")

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Question: has anyone analyzed the isoptic composition of the bronze or brass gear wheels? i’m wondering if the place of production of the machine could be pinned down.  
Second; why was there only one machine? One would think that every temple would want sucha useful mechanism. have any ancient greek water clocks survived?

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**Author:** ![dropzone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dropzone/32/7515_2.png) [@dropzone](https://boards.straightdope.com/u/dropzone)\
**Post date:** [December 12, 2006, 7:07pm UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/9 "2006-12-12T19:07:00Z")

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[QUOTE=Kythereia]  
DON’T ask me about it, OKAY?!?  
[/QUOTE]  
We wouldn’t because we like you and this mechanism is _anti_ **Kythereia**

> [@](#):
>
> Out of curiosity, why do you want a replica?

(blinking in confusion) Uh, because it’s COOL?

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**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\
**Post date:** [December 12, 2006, 7:35pm UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/10 "2006-12-12T19:35:30Z")

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[Nature](http://www.nature.com/news/2006/061127/full/444534a.html) has a good summary article on it, plus the actual paper from the researchers (which requires a subscription to view).

The hypothesis for why it’s the only surviving mechanism is that the metal they are composed of is more valuable than the functional device. So the others have all been melted down. Apparently all surviving Greek bronze statues were also recovered from shipwrecks; all others were destroyed.

It was found with ceramics were made in Rhodes, so it seems the ship had been there. It’s possible the mechanism was produced there as well.

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**Author:** ![Alive\_At\_Both\_Ends](https://avatars.discourse-cdn.com/v4/letter/a/73ab20/32.png) [@Alive\_At\_Both\_Ends](https://boards.straightdope.com/u/Alive_At_Both_Ends)\
**Post date:** [December 12, 2006, 8:38pm UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/11 "2006-12-12T20:38:44Z")

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[QUOTE=ralph124c]  
why was there only one machine? One would think that every temple would want sucha useful mechanism.  
[/QUOTE]  
What makes you think there was only ever one? There may have been lots of them, but only one has survived.

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**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\
**Post date:** [December 12, 2006, 9:01pm UTC](https://boards.straightdope.com/t/the-antikythera-mechanism/383780/12 "2006-12-12T21:01:02Z")

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AFAIK, such elaborate orrery-type devices were never common in antiquity (although the surviving example probably wasn’t literally unique). They would have been more on the order of fancy luxury toys than routine scientific tools. If all you want is to calculate planetary positions or eclipses, it would be a lot less expense and trouble just to get a copy of Ptolemy’s [Handy Tables](http://www.hps.cam.ac.uk/starry/ptoltables.html) and do the computations yourself
