Google Doodle: The fantastic Antikythera Mechanism

May 17, 2017 • 8:30 am

Today’s Google Doodle in most of the world portrays the Antikythera Mechanism, as today is the 115th anniversary of its discovery, at least according to Google.  Wikipedia, however, says it was recovered on August 4, 1901, so figure it out yourself. It wasn’t even studied until 1951, as other artifacts from the wreck were deemed more important:

Whatever the date, this is one of the most splendid devices known from ancient times. Recovered in a wooden box in a sunken Roman shipwreck off Greece, it was in 82 fragments. These reside at the National Archaeological Museum in Athens:

Wikipedia describes its use:

Using modern computer x-raytomography and high resolution surface scanning, a team led by Mike Edmunds and Tony Freeth at Cardiff University peered inside fragments of the crust-encased mechanism and read the faintest inscriptions that once covered the outer casing of the machine. Detailed imaging of the mechanism suggests it dates back to 150-100 BC and had 37 gear wheels enabling it to follow the movements of the moon and the sun through the zodiac, predict eclipses and even recreate the irregular orbit of the moon. The motion, known as the first lunar anomaly, was developed by the astronomer Hipparchus of Rhodes in the 2nd century BC, and he may have been consulted in the machine’s construction, the scientists speculate. Its remains were found as one lump later separated in three main fragments, which are now divided into 82 separate fragments after conservation works. Four of these fragments contain gears, while inscriptions are found on many others. The largest gear is approximately 140 millimetres (5.5 in) in diameter and originally had 224 teeth.

After this was made, we have no record of such complex technology until over 1300 years later–in the astronomical clocks of medieval Europe!

Here’s “Fragment A“, front and back, the most complex piece (captions from Wikipedia):

The main fragment and contains the majority of the known mechanism. Clearly visible on the front is the large b1 gear, and under closer inspection further gears behind said gear (parts of the l, m, c, and d trains are clearly visible as gears to the naked eye). The crank mechanism socket and the side-mounted gear that meshes with b1 is on Fragment A. The back of the fragment contains the rearmost e and k gears for synthesis of the moon anomaly, noticeable also is the pin and slot mechanism of the k train. It is noticed from detailed scans of the fragment that all gears are very closely packed and have sustained damage and displacement due to their years in the sea. The fragment is approximately 30 mm thick at its thickest point.


Fragment A also contains divisions of the upper left quarter of the Saros spiral and 14 inscriptions from said spiral. The fragment also contains inscriptions for the Exeligmos dial and visible on the back surface the remnants of the dial face. Finally, this fragment contains some back door inscriptions.

Here are speculative reconstructions, first the front and then the computer-reconstructed back:

The reconstructed front in the Archaeological Museum in Athens:

The back (computer reconstructed):

Here’s an explanatory video featuring Michael Wright who made the replica:


And here is the gear scheme as reconstructed by scientists:

Finally, two (of 15) fun facts about the device from Mental Floss (quoted verbatim):

  • Since long before the invention of the digital computer you are undoubtedly reading this on, there have been analog computers. These types of computers range from mechanical aids like a slide rule to a device that can predict the tides. The Antikythera mechanism, which was designed to calculate dates and predict astronomical phenomena, has therefore been called the earliest analog computer.


  • Jones and colleagues’ new interpretation of the mechanism is based on the extant 3400 Greek characters on the device, although thousands more characters are likely missing due to the incomplete nature of the artifact. Most notably, in their thorough linguistic analysis, these scholars discovered that the mechanism refers to eclipses’ color, size, and associated winds. The Greeks believed that characteristics of an eclipse were related to good and bad omens. Because of this belief, by building in predictive eclipse technology, the creator of the mechanism was letting the user divine the future.


30 thoughts on “Google Doodle: The fantastic Antikythera Mechanism

  1. Nova did a documentary on the Scientist who did the research on this about 3 or 4 years ago. I watched it on PBS. It can still be seen on You Tube. Just google Nova- Official Website.

  2. Damned nice of the aliens to make this device using only the tech available to the Greeks at the time, why its almost authentic!/

  3. extraordinary and mind-boggling though it is, it isn’t helpful, pace “Mental Floss”, to think of the Antikythera mechanism as a computer without mispresenting the way that word is used today. Once manufactured, its inputs couldn’t change, leading to new or different outputs. More fundamentally, it was not programmable, i.e. it didn’t have a generalized capability. It was capable of doing the one thing for which it was made, i.e. showing the passage of time and the position of celestial bodies.

        1. And I have no problem with that.

          Does an old Co-co II not count as a computer anymore because it had only 4 K and was extremely limited compared to today’s smart phones?

          1. How about a waffle iron then? It successfully does the one thing it was made to do. Does that make it a computer?

            As Jonathan says, computers are understood to be programmable, multi-purpose devices. Your CoCo 2 meets that criterion. The Mickey Mouse watch and the Antikythera Mechanism don’t.

            1. No, waffle irons don’t compute anything.

              So do calculators count? No pun intended.

              They compute but they are (generally) programable.

            2. Computers don’t have to be “multi-purpose”. As for “programmable” putting in new starting information may satisfy that requirement. Just like an adding machine can be called a computer (since it computes).

              You’re getting confused by the word “programmable” and needlessly adding in “multi-purpose”.

              1. I think I’m pretty clear on the difference between computation and mere calculation. This distinction was articulated by Turing in the 1930s and is at the very foundation of modern computer science, in which computers are viewed as Universal Turing Machines capable (in principle) of computing any computable function (i.e. both programmable and multi-purpose). The Antikythera Mechanism is clearly not in that category.

  4. Hi Jerry. This may seem like a silly question, but do you think the human brain had, at one point, evolved to design complex structures and then changed again at a later time. It seems that for a long period of time humans were capable of building pyramids, walls, and this mechanism, as well as manifold other structures (chariots, Machu Picchu, etc.) that we, today, say, how did they do that?

    1. Perhaps I’m misunderstanding your question, but it sounds like you think we’re somehow incapable of building pyramids, walls, or chariots today.

    2. @Mark Cagnetta

      We do indeed wonder how ‘the ancients’ accomplished some of their building works, but that is not evidence of a superior ancient cognition back then – merely that some skills/techniques have been lost. You are using a ‘god of the gaps’ style argument to propose a superior human intellect back then because we don’t have a 100% understanding of how it was done.

      We DID have a similar problem relating to the construction of medieval cathedrals, but many of those lost skills have recently being rediscovered due to scholarship & the resurgence in cathedral builind & repair.

      Taking Machu Picchu as an example, you should ask critical questions such as…

      [1] Is it REALLY that great an achievement compared with say European cathedral architecture which is from the same era or older? Answer: No

      [2] The Incas never used the arch, the vault & the dome – even in areas of their empire not prone to seismic activity. Why, given that the idea was known & used for 3,500 years on the other side of the world? Answer: If it occurred to them they didn’t bother. Probably because [my theory] it was a hierarchical, rigid society where fresh ideas had no currency & could get you killed..

      [3] The Incas never used the wheel + axle [it seems] for transport or building – only for toys. Why not even though they did have flat areas where wheeled axels would have been highly practical even if only human powered? Answer: As for [2] probably

      You are probably getting your false ideas about the past from all those rubbish, conspiracy/aliens sites that leave out the inconvenient facts! Facts such as…

      ** We know today from the nearby quarries containing partly cut stones AND tools exactly how the cutting was performed.

      ** By looking at the finished structures we can see how the stones were so closely fitted [“so that a knife blade can’t be inserted” to quote the many rubbish online sites promoting aliens etc.] by looking at the marks near the joints where tools were used to refine the seam between blocks. One must realise that this ‘seamless’ joining of blocks is only ‘seamless’ at the visible surface. Behind the surface the blocks have large bevels which are infilled with adobe & rubble

      Don’t get me started on the pyramids!

  5. Holy pareidolia, Batman! Does anyone else see the face of a cat in the center of Fragment A in the first picture?

  6. Looking at the coloured diagram, what staggers me most about the Mechanism is, how did they make those concentric shafts (spindles?).

    Not so much the design, or even the gears (clockmakers a few hundred years ago were capable of making precise gears with what we would regard as very primitive machinery). But how on earth did they fabricate those tubes to be sufficiently precise that they would rotate freely inside each other yet not so loose that the cumulative ‘slop’ of seven tubes would let the gear wheel on the innermost spindle jump out of mesh?

    I seem to recall reading that Babbage’s Difference Engine demanded, and was the driving force behind, major advances in precision engineering (the Moon shot of its day). Looking at the complexity and precision required for the Antikythera mechanism just to be constructed and function (without jamming up or falling to pieces) I would guess it must have been the Greek equivalent – both in technology and costs.

    Are there any references to it in ancient literature? One would think there really should be, for such a marvellous mechanism. One might almost suspect that it might be a recent piece of machinery, misidentified, but I assume its provenance and the studies that have been conducted authenticate it properly.


    1. @infiniteimprobabilit

      I think that Wiki coloured diagram is absurd speculation – note that the cross-hatched parts [which includes the central spindle with seven concentric ‘Russian doll’ sleeves] are proposals not grounded in actual physical evidence.

      The Wiki mentions that the reconstructed mechanisms is not particular true to life [how the heavens behaved from an Earth POV] & that it gets worse with some of the imagined gearing to such an extent that the ‘noise’ of imprecise engineering would overwhelm the output that was being modelled.

      Here is a link to a more realistic model which has a lunar central spindle [with black/white moon globe] & a sleeve driving the sun – that’s all – just one sleeve:

      1. Gods, there are dozens of videos on the subject! Obviously a source of fascination for many people.

        I think your comment is credible – all those spindles are what struck me as the most unlikely / difficult to fabricate. Amongst other issues, how to fix the relevant gear wheels securely and rigidly onto the end of each successive spindle.

        I don’t wish to denigrate the skill of the makers of the mechanism – I think even a two-shaft version would be a credit to the skill of any ancient craftsman.


    1. Wikipedia says there are bronze gears.

      I’ve got to think about the history here. Interesting.

  7. Inscriptions? No doubt they say “Your device has stopped unexpectedly. You may need to restart your gears. If this problem persists, please consult you wheel administrator”

  8. It is said that many developments of the ancient world, both technological and philosophical and political, (see also the library of Alexandria), suggest that if European culture had not been hijacked by religious sentiments, it might have created what we consider the modern world at a much earlier time. The thinking that went into such a complex mechanism as this, hints at intriguing potential paths of history. Of course the actual course of history was determined and there is no free will, but…

Leave a Reply