A scientific detective story about the world's first computer


BOOK OF THE DAY: Decoding the Heavens: solving the mystery of the world's first computer. By Jo Marchant. Heinemann. 328pp; £12.99

THE INGENUITY is breathtaking. Arguably one of the greatest mechanical inventions, and the most important scientific artefact from classical Greek times, the Antikythera mechanism is over 2,000 years old, has some three-dozen intricate gear wheels, and its sophistication was not matched until the 18th century. Erich von Däniken saw it as proof that alien civilisations had visited Earth thousands of years ago.

For the last century, scientists, historians, archaeologists and technologists have investigated what is clearly a computer of some kind, trying to understand its structure and purpose, and how something so ancient could be so elaborate.

And yet it almost went unnoticed. The bronze and wood device was part of a treasure trove discovered by sponge divers in 1900, off the small Greek island of Antikythera. Amidst a haul of bronze and marble statues, shields and weapons, vessels and amphoras, lamps and kettles, even bedsteads and thrones, was a corroded lump of bronze that was initially ignored. Not until the timber started drying out and the formless lump cracked open to reveal traces of gear wheels and ancient inscriptions did anyone take notice.

Then, one by one, people fell under its spell, and joined the race to be the first to explain the mechanism. This is the fascinating story that Jo Marchant tells so well - starting with the first-ever discovery of an ancient shipwreck, the challenges of early marine archaeology and underwater excavations, and even the limitations of primitive diving equipment. Experts in ancient manuscripts find clues in the inscriptions - some of which include actual operating instructions. Archaeologists versed in the nuances of amphora design help pinpoint the date of the shipwreck to approximately 70-60 BC, and its port of origin as Pergamon in modern-day Turkey.

But it is the investigation of the mechanism that takes centre stage. Marchant presents pen-pictures of the many people involved, not all of whom engaged in fair play. There is drama and rivalry here. Michael Wright, a former curator in London's Science Museum, comes across especially well: smitten by the mechanism when he read about it first, aged 26, he devotes his life savings to decoding the mystery and building working replicas. Wright, who arrives in Athens for the first time to discover that modern Greek is unlike the classical Greek he learned at school, presents his conclusions at a conference in Athens in 2003, thinking he has solved the puzzle, only to hear that a substantial new fragment has just been found.

The analysis continues today, although we now know the Antikythera mechanism had at least three-dozen gear wheels, with drive wheels, and differential and epicyclic gearing, and that it was a computer.

The operator inputted information, turned a handle and got an answer, certainly for calendars and predicting eclipses, and possibly more.

Could Archimedes have designed this? And why? And why is there no trace in the records of other, simpler geared mechanisms that must surely have been made before this one could even have been conceived? What else has been lost in the mists of time?

If you are interested in ancient Greece, in the history of clocks and calendars, in astronomy and archaeology, and especially in the history of science and instrumentation, but above all in a few enjoyable stories, then this book will delight you.

And if you are ever in the Athens National Archaeological Museum, make sure to check out this fascinating mechanism, which is s surely the oldest known computer.

Mary Mulvihill is a science writer and broadcaster. Her book Drive like a Woman, Shop like a Manwill be published by New Island in the New Year