Book Review — Marchant, Decoding the Heavens

Marchant, Jo, Decoding the Heavens: A 2,000-Year-Old Computer–and the Century-Long Search to Discover Its Secrets, Da Capo Press, 2009, 328 pp.

Defining the Word “Anachronism”

In the latter half of the nineteenth century, the sponge divers of Greece lived through a technical revolution … the appearance of the diving helmet. After many centuries of free diving to harvest local sponges, the new equipment suddenly allowed access to much more of the Mediterranean sea floor and previously unexploited sponge beds. The industry boomed. Inadvertently, the diving helmet also led to the discovery of a shipwreck off the coast of the small island of Antikythera. Amidst the spectacular bronze and marble statues at the wreck site was a strange lunch box-sized lump, covered in a limestone coating from centuries of immersion and distorted by the effects of decomposition and corrosion. Here and there were visible bits of wood and corroded bronze, faint inscriptions of ancient Greek and what appeared to be thin loops or gears.

Compared to the glamorous artworks it was found with, the “lump” was rather unprepossessing and, indeed, it spent most of the 20th century in obscurity. Not knowing what it was, the curators made little effort to preserve the object, and increasingly, it broke into a more and more fragments in the storage rooms of the Athens’ National Archaeological Museum. The early 20th century descriptions made their way into the hands of a physicist and historian of science named Derek De Solla Price. In the 1950s, he made serious efforts to fully explain what it was, culminating in a 1974 book Gears From the Greeks. And it was partly through his efforts that people as diverse as Arthur C. Clarke, Jacques Cousteau, and Richard Feynman took an interest in the enigmatic archaeological find.

Now, after a century of scholarship and scientific investigation, the humble lump of metal and stone known as the Antikythera mechanism is finally getting its due and we think we know what it is … a geared device, powered by hand, that allowed the successful prediction of solar, lunar, planetary, and eclipse cycles across many decades. It was meant for an educated amateur and came with extensive inscribed instructions on its metal parts. It is the ancient ancestor (in a sense) of the elaborate clocks that were to sweep through western Europe in the 14th and 15th centuries. Except that it was likely built around 100 BC, after what was clearly a long period of earlier experimentation and technical wizardry. What was it doing there? And why does it stand alone amidst classical history without predecessors, companions or contemporary explanation? The mechanism is so unlikely that for many decades it was assumed that it simply could not be from a period in antiquity … or, according to Erich von Daniken, it was left on Earth by aliens. The Antikythera is the ultimate “anachronism” … something that doesn’t seem to belong to its time.

Science writer Jo Marchant provides the first comprehensive book on the device in the last 35 years, a substantial expansion of her 2006 summary article in Nature (In search of lost time, Nature 444, 534-538 (30 November 2006) | doi:10.1038/444534a) which includes the dramatic new discoveries about the mechanism published in 2008. Decoding the Heavens recounts how each generation of archaeologists examined the mechanism and made judgments about what it was and what it did. The story of the men and women who devoted years trying to discover the nature and purpose of the object binds the scientific tale together, often in tragic ways. Science can be a blood sport and the Antikythera brought out the best and worst in many of its students. Our most recent understanding of the mechanism dramatically changes our beliefs about the role of Greek technology in subsequent Muslim and Christian mechanical devices. Hundreds or perhaps thousands of similar devices were subject to damage, loss, and the re-melting of their brass components. The Antikythera mechanism is one-of-a-kind and that, in itself, is a sobering piece of information about the implosion of culture and technology in late antiquity.

In the end, it was the development of non-destructive testing methods (photography, linear X-ray tomography, microfocus computer tomography, polynomial texture mapping ) that finally allowed the most recent generation of scholars and enthusiasts to precisely determine how the device was assembled and operated without irreversibly damaging the fragile remains. Such space-age technology provided an exact means to measure the components, the associated gear teeth and read the faint inscriptions on metal surfaces, even when the metal parts were buried in limestone and largely corroded away. And it was the assembly of an interdisciplinary team of archaeologists, astronomers, artisans, and historians of science that permits some level of confidence in the latest conclusions.

At the margins, the final few details of the operation and function will remain under debate. Did the Antikythera draw upon centuries-long records of Babylonian star-gazing? Was the Antikythera device an astrological tool for elite Greeks and Romans? Was it a functional demonstration of the philosophical orderliness of the universe (especially that of eclipses)? Was this the grand achievement of the final generations of hyper-literate Greek Stoics before Rome dominated the eastern Mediterranean? Where was it made and what relationship did it have to the devices we know were created by Archimedes in Syracuse [Sicily]? Cicero described one as “a sphere that showed the motions of the Sun, Moon and planets around the Earth.” Knowing *what* the device did promises to open up new questions of why elite Greeks wanted to make it.

What is certain is that modern Greeks are immensely proud of the significance of the new discoveries. The Antikythera is slated for its own museum, pulled out of the national museum’s storehouses and given pride of place amongst the gorgeous sculptures and ceramics that typify our idea of ancient Greek culture. It’s clear that the “clockwork” inheritance of Western Europe (so ably outlined in Crosby’s The Measure of Reality — Quantification and Western Society 1250-1600, cb review here) had its roots in the devices first created and elaborated in ancient Greece. And it’s a further sobering addendum to the recent work on Roman archaeology (Ward-Perkins’s The Fall of Rome and the End of Civilization, cb review here) which highlights just how much was lost of the literature, technology, and artisanship of the ancient world. Europe was to wait a thousand years for a reappearance of good roads, effective ceramics and glass, and high levels of literacy. Re-establishing Greek rationality was a halting and initially unsuccessful venture (cf. Tina Stiefel’s The Intellectual Revolution in Twelfth Century Europe, 1985). Devices such as the Antikythera mechanism suggest that even the Roman imperium was a step back, in some areas, from the philosophical and mathematical purposes of the Greeks.

Decoding the Heavens is a straight-forward and well-written account of the history and personalities associated with the examination of the Antikythera mechanism. The author adds atmosphere to the people and places without pitching over into melodrama. One would expect no less from a news editor of Nature. For those with an interest in astronomy, the history of science, or Greek archaeology … this would make an excellent gift, or a fascinating read over several evenings.

One caveat. One personal regret. The story of the discovery and examination of the Antikythera mechanism is so amazing … and it’s significance for ancient history so far-reaching … that we might consider Decoding the Heavens a wonderful foundation for a “teachable moment” in either high schools or universities. A fascinating syllabus or educational module could be created in ancient history, physics or science built around this book and the mechanism itself. The Internet (as evidenced by the Wikipedia article on the device) is awash with enthusiasts and commentators. There are some excellent simulated Antikythera models available in “virtual reality” which really help understand how the moving parts related to each other. It hard to imagine that students wouldn’t warm to the subject with the right introduction.

It’s regrettable that the edition of the book I read is virtually devoid of effective maps and diagrams. Reading the author’s written descriptions of Aegean voyages, astrolabes, astronomical cycles, polynomial texture mapping, pin-and-slot/differential gears, and scholarly dead-ends seemed needlessly challenging. The author is an excellent writer but not all readers start with the same technical background. The set of photographs in the book were welcome but couldn’t replace a more generous graphics budget. A few simple illustrations would make all the difference for a general reader following the failures and successes of the scholars and scientists who examined the mechanism. It’s very unfortunate that the first drawing of the mechanism appears on page 247! A map of Aegean place names mentioned in the book doesn’t seem like a publishing luxury. With Google Maps, I was able to screen capture a workable map while reading but it would have been nice to have one included in the book. Thankfully the end matter … Sources and Further Reading/Index … is very well-done and would support further study if the reader desires. For some reason, the companion website (, which offers a great deal more information of interest, receives little prominence in the book. As mentioned, this is a topic (and book) that begs for interactivity and a substantial role in science education.

The 2006 Antikythera Nature articles were far more fully illustrated and I feel that Decoding the Heavens deserved a bit better in this regard. It’s to be fervently hoped that this gap is corrected in the paperback edition. With better illustrations, spaced strategically throughout the book, this title could be widely recommended for the budding teenage scientist in any house or for the general reader who’s not mechanically or scientifically inclined. This book clearly received a lot of care and attention in the writing. It could be greatly strengthened with equal attention to illustrations and online resources (especially new discoveries in coming years).

Left as is, its natural audience will inevitably be far narrower. Those mechanically or astronomically inclined will find it easy going. All else will struggle at times, and be left to ponder instead the internecine battles between scholars who put forward their own theories on what the Antikythera mechanism was … and what it meant.

Decoding the Heavens is inspiring, thought-provoking, and well done. Those with an interest in ancient history and technology will enjoy it very much.

12 thoughts on “Book Review — Marchant, Decoding the Heavens”

  1. James, is there any sense of how widespread this technology was? I recall reading years ago L. Sprague DeCamp’s book The Ancient Engineers — his assessment was that the ancient Mediterranean world failed to have a technological breakthrough because it did not have — wait for it! — patent law. Interesting. To this day, in Italy, where businesses are often very sophisticated, medium-sized, and experts at pricey, custom goods they rely on trade secrets and do not trust anything to the legal system. So, was this machine the possession of some small community of people who kept it a secret among themselves? If so, the fall of ancient civilization may not have been from a “peak” represented by this machine, where this machine and its owners and users were a tiny minority who could not and would not have expanded the technology to widespread use.

    Technology without a legal and institutional framework and a high radius of trust in commercial dealings ends up as small islands of cleverness or genius, but the ripples cannot spread far. Early modern Europe, especially England, had the framework in place. The ancients, the Chinese, the Muslims … all had moments of brilliance but could not get self-sustaining science and technology going.

    Of course, it may be the case that there was a lot more of this stuff, but it has all been lost … .

  2. Yes — the Roman world had much of the technology that was regained by Renaissance times, but the didn’t seem to have the political or financial mechanisms in place that drove the expansion of Europeans into the wider world. If they could make an astronomical calculator like this they probably could have made a mechanical desktop adding machine such as were common in offices before the advent of the electronic computer. But their financial mechanisms were so primitive that they wouldn’t have gotten much benefit from them.

  3. Technological secrecy was the bane of the classical world. With no means of protecting intellectual property, people kept anything they discovered close to their vest. Anyone who publicized an innovation lost it for ever.

    One striking thing one notices about the experiments done at the dawn of the scientific era was how trivial they were. Galileo’s experiments on motion required no technology more sophisticated a wood ramp and ball.

    The classical world could not exploit its technological innovations because they didn’t have the attitude or belief that knowledge could be created. They had no conception that experiments proved anything.

  4. Shepherd’s Historical Atlas is a good source for the location of ancient place names, kingdoms, queendoms, dukedoms, et al. I use the 1964 edition. Amazon has the 1980 editon.


  5. Equally important to protection of intellectual property is the ability to tell some one who can understand what you have discovered. Beginning in medieval times, the establishment of universities and postal systems enabled scholars to share ideas and help each other discover new things. The fact that they had Latin as a common language made sharing ideas possible. The printing press broadcast new ideas (ometimes in Latin, sometimes in vulgar languages) and this stimulated science.

    We live in a modern age of global commication and it is easy to forget how a separation of a 100 miles can be an insurmountable barrier to sharing seemingly useless thoughts.

  6. Sol – “We live in a modern age of global commication and it is easy to forget how a separation of a 100 miles can be an insurmountable barrier to sharing seemingly useless thoughts.” Looks like that barrier’s gone, heh.

    James, or anybody else who wants to chime in: I am tremendously intrigued by the suggestion that “[a] fascinating syllabus or educational module” be created from Decoding the Heavens. I frequently give presentations on current astronomical topics at Powell Observatory. Based on your impression of the book, could its essence be distilled to a PowerPoint deck of 50 slides or less and imparted to a general audience? If this seems even remotely possible, I’m going to buy it and see what I can do.

  7. Lexington Green says:

    >>Technology without a legal and institutional framework and a high radius of trust in commercial dealings ends up as small islands of cleverness or genius, but the ripples cannot spread far.

    Could Lex or anyone else recommend to this reader (who is a non-specialist in everything discussed here) a book or two, or an essay or two, on the importance of trust in contexts like this one? I have come to increasingly appreciate its role in organizations (by observing what happens when trust collapses), and would like to dip into the literature on the subject.

    Many thanks. (And yes, the Antikythera mechanism is unbelievably cool.)

  8. Lex: re: dispersion of Antikythera mechanisms. Marchant’s book suggests that there were likely hundreds of such devices (in various levels of sophistication) because the mechanism was so clearly evolved from simpler versions. Now the race is on between academics to identify whether the elite demand for such items was driven by a new interest in astrology or a new interest in rationalism. There are tantalizing snippets from Roman literature that the Romans took items from Syracuse/Archimedes (a colony of Corinth) which were still shown off in elite collections in Rome, 4 centuries later. Islamic automated sundials/astrolabes from eight-nine centuries later appear to be descendants of Byzantine iterations.

    Like ancient Roman/Greek bronze statuary (of which there were thousands, if not hundreds of thousands made), the bronze Antikythera device may have only survived when submerged in the ocean. Vast quantities of metal were re-melted in antiquity and late antiquity/early medieval periods because of their value. If
    the role of the Antikythera device became obscure, a household might sell it as scrap in later generations. Clearly the Romans admired Greek ingenuity but turned their attention more to monumental and civil engineering. It’s worth nothing that the equipment they used for such huge projects is also largely gone!

    And examples like Vindolanda []
    show how much mundane and elite literature must have been lost … which might have explained why the Romans did not maintain (in public record at least) the geared technology (and analog computation) of the Antikythera device. The Romans had a love/hate relationship with Greeks and Greek culture that continued to the very end.

    Passing Reader:

    By great good fortune, I’ve reviewed two books on CB which go directly to your question. The first shows how the social milieu in north-west Europe supported dynamic co-operation between artisans and theoreticians. Mokyr Gifts of Athena

    The second tells a wonderful historical tale of the counterintuitive way in which Newton’s Principia received strong British and European elite support … and then how very ordinary blue-collar folk ran with the implications of his work. Jacob & Stewart Practical Matter

    Best to all, J.

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