Decoding the Heavens: A 2,000-year-old Computer--and the Century-long Search to Discover Its Secrets [Paperback]

The "Antikythera Mechanism" has baffled archeologists and scientists for more than a century. Discovered in an ancient Greek shipwreck in 1901 near the Greek island of Antikythera, between Kythera and Crete, it is the first known mechanical computer in human history. It is rumored to have been used to calculate astronomical positions, and probably dates to the first century before the Common Era (BCE).

The "Antikythera Mechanism" was remarkable in that its many gears betray a complexity not found elsewhere in the ancient Mediterranean world. Not until the high Medieval era would technological artifacts of similar complexity be found. With more than 30 gears, there is some difference of opinion on the number, it had the potential to enter a date and the mechanism could calculate the position of the Sun, Moon, or the other planets. It also had the capability to predict lunar and solar eclipses.

Jo Marchant, a well-known journalist and the editor of "New Scientist," has written a fascinating account of the discovery of this remarkable relic, its reconstruction, and the process of discovery of scientists gradually coming to understand its use. Made of bronze and found in pieces on the sea floor, it took considerable time to put it back together and to get it to work.

Hundreds of scholars have investigated the "Antikythera Mechanism," and employed high-technology analysis to understand the artifact. Even so, it took a century to unlock its secrets. Michael Wright, curator at the Science Museum in London, worked for more than two decades to build a working model of the artifact, using only tools and methods known to have been available in ancient Greece. Roger Hadland, an engineering entrepreneur, invested heavily to develop high-technology instruments, including a special X-ray machine, to image the object. These and others contributed to a long-term effort to learn the nature of this remarkable ancient machine.

Part detective story as well as a record of remarkable and diligent scientific investigation, "Decoding the Heavens" is a wonderfully researched and written exploration of efforts in the modern era to learn more about activities of the ancient world.

In 1900 an ancient shipwreck was discovered off the coast of the Greek island of Antikythera. Divers quickly brought up statues and other readily recognizable pieces, along with, almost as an afterthought, a strange lump of something metallic which at first seemed worthless. Then startled archaeologists and scientists noticed gears and cogs and realized that something far more interesting than any statue had been uncovered. The Antikythera mechanism was to perplex and intrigue investigators throughout the twentieth century and into the twenty-first.

Jo Marchant, a science writer for Nature and other scientific journals, has the gift of writing clearly and excitingly about subjects which might seem impenetrably obscure to laymen. Decoding the Heavens is her account of the long process of determining what the Antikythera Mechanism was designed to do, how it actually functioned, and who might have been its original designer. She is able to give life to the succession of highly intelligent and sometimes irascible and eccentric investigators who spent much of their lives on the Antikythera Mechanism. She is also able to explain the complexities of modern technological developments which enabled the investigators to finally unravel the secrets of the Mechanism.

I really enjoyed Decoding the Heavens, particularly the parts in which Marchant speculates on who might have been the Mechanism's original designer. While I wish a map of the eastern Mediterranean had been included to help pinpoint Antikythera, Rhodes, Corinth, Syracuse, and the many other places mentioned in the book, I have no hesitation in recommending this book to anyone interested in the Greek and Roman world or in ancient and modern technology.

Below is a different review of the same book, which I wrote for 'Antiquarian Horology':

JO MARCHANT,Decoding the Heavens :

A 2,000-Year-Old Computer and the Century-Long Search to Discover Its Secrets, published by Da Capo Press, Cambridge MA, 2009, hardcover. Also available in a UK edition as Decoding the Heavens: Solving the Mystery of the World's First Computer. Or borrow from the NAWCC Library in Columbia (Members only)

Most students of the history of timekeeping machinery will have come across various pieces of information on the Antikythera mechanism in their reading and recall the outline account of its discovery. In the fall of the year 1900, the Greek Captain Dimitros Kontos and his crew of sponge divers stumbled upon a shipwreck from antiquity off the island of Antikythera, and thereby started the science of underwater archeology. In addition to a large number of statues and other artifacts, one recovered item was completely different. It consisted of several fragments of a very complex, geared, bronze mechanism with mysterious inscriptions. Whatever that object was, it was destined to substantially rewrite the history of technology.

The book under review is an up-to-date, detailed retelling of the story of this mechanism, its discovery, its interpretation and the search for its function. The author incorporates the discoveries and new theories that have been developed about the Antikythera mechanism during the last several years.

Michael Wright, formerly of the London Science Museum, has constructed a new replica and published his findings in this magazine and elsewhere. Regular readers of Antiquarian Horology are probably familiar with his three major articles on the subject in 2003 (Vol. 27, pp. 270-279), 2005 (Vol.29, pp. 51-63) and 2006 (Vol.29, pp. 319-329), titled `Epicyclic gearing and the Antikythera Mechanism, Part I & II' and `The Antikythera Mechanism and the Early History of the Moon-Phase Display'. Completely independently, British scholars Mike Edmunds and Tony Freeth have also become obsessed with decoding the mechanism, just like Derek de Solla Price of Princeton University did half a century earlier. And -most importantly- a Greek based multidisciplinary research team agreed to analyze the object in detail using newly developed, state-of-the art American high energy X-ray technology, which allowed for the first time to examine the inside of the object in amazing detail, yielding new teeth counts and additional ancient inscriptions. Much of this research is ongoing, and every few months additional inscriptions are deciphered, new papers are published, and new physical models are built or existing ones are modified.

This book is not a scholarly treatment of the subject matter. The author is not a scientist publishing new scholarly insights, but a journalist telling a compelling story. In many ways this book reminded this reviewer of Dava Sobel's bestseller Longitude; there, as well, the focus was not primarily on the technical specifics of the physical artifact, but on the `human interest story' behind the object, the story of the struggles of Harrison and Gould. Here, too, the author writes an eminently readable account of the numerous twists and dead ends which various scientists have encountered in researching the functionality of the mechanism. She focuses on the passions and personalities of the scholars, as much as she does on the intricacies of the mechanism, which - as it turns out- is not a `timekeeper' in the narrower sense of the word, but a sophisticated `time calculator', specifically a planetary calculator. `Planets' is here used in Ptolemy's sense, i.e. including sun and moon, and the machine apparently uses epicyclic gearing, the 19 year metonic cycle, and a spiral display.

The main characters in the book are scholars like De Solla Price, Bromley, Wright, Edmunds and Freeth, and a large supporting cast of Greek museum officials, archeologists, philologists and "cryptographers". These people all become alive in the book, as a captivating story of discovery is told, with side plots involving rivalries, egos and national pride. This is a book about both the 'process' of decoding the mechanism and the egos of the key players, rather than a detailed account of the mechanism itself. This reviewer found the book fascinating and informative, mainly due to the fact that virtually everything else that has been published on the history of technology typically covers the objects themselves, and ignores the process of scholarship and the personalities involved.

The book has triggered a wave of criticism from various scholars involved in the recent discoveries. A recent Greek translation of the book contains 84 corrective footnotes; for a list see the Research Project's webpage [...] where a pdf can be downloaded regarding so-called `errors' in Merchant's text. Many of these seem to concern different interpretation of data, or points of Greek national pride. To this reviewer this latest controversy just reinforces one of the key themes of the book: there is hardly a historic object in the history of technology which has triggered as many passions as the Antikythera mechanism.
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