December 3, 2006
Reversing Gears
Freeth et al. have uncovered additional inscriptions and evidence of gears in an intricate early computing device, the Antikythera Mechanism. In the abstract to a recent Nature article, they write:
The mechanism predicted lunar and solar eclipses on the basis of Babylonian arithmetic-progression cycles. The inscriptions support suggestions of mechanical display of planetary positions, now lost. In the second century BC, Hipparchos developed a theory to explain the irregularities of the Moon’s motion across the sky caused by its elliptic orbit. We find a mechanical realization of this theory in the gearing of the mechanism …
Nature also has a news feature about the famous machine. Christos H. Papadimitriou’s novel Turing posited an alternate theory of how a fictionalized analogue of the Antikythera Mechanism – the discovery of this theory is one of the main plots. Archeologists have had different ideas, too, which we can learn about in the free encyclopedia that anyone can edit.
Scientists had to travel to Greece and construct an X-ray tomography system in the National Archaeological Museum of Athens in order to analyze the device. The DMCA makes reverse engineering illegal in the United States, after all…