“Decoding the Heavens” by Jo Marchant

Decoding the Heavens by Jo MarchantDecoding the Heavens: A 2,000-Year-Old Computer—And the Century-Long Search to Discover its Secrets (phew! long title!) is a very well-written and well-researched account of the discovery and study of the Antikythera Mechanism. The Antikythera Mechanism (which I’ve posted about before) is a complex geared device made in Greece in the second century B.C. and recovered from an ancient shipwreck off the Greek island of Antikythera in 1901. Put simply, it displays the positions of heavenly bodies over time. By turning a knob on the side, pointers on three dials mark the passage of time on various scales—solar months, lunar months, Olympiads, etc.—and predicts the positions of the sun, moon (with its phases), important zodiacal stars and possibly the known planets as well. It represents not only the state of the art of astronomy at the time, but also the most advanced mechanical engineering known from the ancient world. However it was probably not a scientific instrument. Why turn a knob around and around when you can easily look things up in a table or do a quick calculation? It is thought that this was actually a luxury item, a personal planetarium for some rich and powerful individual who wanted to have the universe at his fingertips.

We know all this now, but it took a long time and a tremendous amount of painstaking work to get to this point. The mechanism itself is in pieces and badly corroded by sea water. Early archaeologists paid little attention to it. Attempts were made to study it visually, but it was not until it was x-rayed that it started to reveal its true functions. Jo Marchant tells the story of the individuals who caught the Antikythera bug and studied it obsessively for years, sometimes at great personal risk and cost, sometimes without giving due credit to their predecessors and colleagues. They all wanted to be known as the one who discovered what the Antikythera Mechanism did.

This made me think about how science works. The macro view is that knowledge is built up, brick by brick, on the foundation of those that came before—a sort of grand collaboration over time. But the micro view is individuals striving to make major discoveries all by themselves and not being too particular about how they cut out the competition. Would cooperation achieve greater results, or does the lure of glory accelerate scientific progress?

In any case, the lure of glory has led us to understand the Antikythera Mechanism, though some details remain murky. It is likely that it showed the position of the 5 planets then known to the Greeks but those parts of the mechanism are missing except for one gear. Some of the inscriptions on the faces of the device—instructions for its use—have also been lost to corrosion. We still don’t know for sure who made it, where it was made, or who it was made for. But I think what we do know about it is more important that what we don’t. It tells us that the ancient Greeks were far more sophisticated engineers than we though, and more importantly, it tells us to be more careful about making assumptions about the past. So many artefacts have been lost to time and accident, and genius can be so fleeting, that we shouldn’t assume we’ve already seen it all. Though it is possible to trace some legacy of this technology through time to modern clock-builders, the Antikythera Mechanism really represents a geographically-isolated tradition that was snuffed out by the Roman conquest of Greece. There are contemporary accounts of similar geared instruments but, in the absence of hard evidence, scholars dismissed them as fables. If it were not for the accidental discovery of the shipwreck of the island of Antikythera, we would, in our hubris, have continued to underestimate ancient Greek technology. Two thousand years later and the Greeks still have much to teach us.


4 comments on ““Decoding the Heavens” by Jo Marchant

  1. wil says:

    “There are contemporary accounts of similar geared instruments but, in the absence of hard evidence, scholars dismissed them as fables.” — Nice example of what I see as a weakness of the “Western, scientific” mind. The lack of ready evidence didn't lead to a neutral, perhaps skeptical, position, but a complete dismissal of the idea!

  2. Sylvia says:

    Indeed. Absence of evidence is not evidence of absence. But then that's what the UFO people say… 😉

  3. Sandra says:

    I have far too much to say about this book because I was friends with Allan Bromley – the Australian academic – for 20 years. I don't even recognise the person in this book; I can't imagine liking him. Since reading it I've helped go through correspondence from the time (which the author didn't try to see) and we think it shows that the book's account is wrong in several significant ways.

    Which leads to some unsettling thoughts. Because I knew Allan and knew beyond question that one part of the book was not to be trusted, I read the rest of it far more closely than I would have done otherwise. I found lots of other problems with it, which I think I would not have noticed if I'd come to the book with no background information. That upsets me because I like pop science books and I tend to regard them as reliable. The biggest lesson for me is that I need to read these books more critically than I've usually done.

    One more comment, on wil's comment above. In this case I don't think the “Western, scientific” mind was (is) responsible for the dismissal of the idea. Most scientists and technologists didn't know anything about it, though at the popular level I think technologists have been the most intrigued. Classical scholars weren't particularly interested, partly by temperament and training, and partly because the literary accounts are so few and not easy to interpret.

  4. Sylvia says:

    Thanks for that, Sandra. I guess it's easy to give scientists and scholars a rough ride after the fact. It took a lot of disciplines working together to find out what the Antikythera mechanism was, so perhaps it's no wonder it took so long. Still, even solitary literary accounts should perhaps be taken more seriously now that we know they can turn out to be true. Maybe scholars should make a bit more use of imagination in their work (or have I been reading too much Anne of Green Gables? ;).

    For those who haven't read the book, Allan Bromley is one of the researchers described in the book, and the portrayal is less than flattering. He died before the book was written and so never got a chance to tell his side of the story.

    Yes, I'm afraid we are at the mercy of the writers when it comes to pop science (or any nonfiction). I guess it's probably a good idea not to rely on just one source for important information.

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