Decoding 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.
