So, I have questions.
About what? Well, by now you’ve heard about this wonderful machine that was found 100 years or so ago, which after a lot of research, has been found to be a remarkably sophisticated mechanical computer designed and built in ancient Greece about 2,100 years ago. There’s a nice LA Times story on it by Thomas H. Maugh II here, and a New York Times story* by John Noble Wilford here and a Reuters article by Patricia Reaney here. (The image to the right (click for larger) is from the University of Cardiff.)
From the articles you can learn that the machine was able to perform computational tasks 1400 years or so before the time when machines of this sort (but less sophisticated) were thought to have appeared. What sort of tasks? Well, using 37 gears or so it can do subtractions, multiplications and divisions to show the cycles of the moon, predict eclipses, etc. From the LA times article:
The complicated meshing of the gears is a physical representation of the so-called Callippic and saros astronomical cycles. In the Callippic cycle, for example, the sun, moon and Earth return to the same relative orientations four times in 76 years minus one day.
The saros cycle predicts that, following a solar or lunar eclipse, a similar eclipse will occur 223 lunar months later.
By turning the gears with a hand crank, the user could select a specific day in the past or future and observe the positions of the heavenly objects on that day.
It is called the Antikythera mechanism, after the Greek island near which it was found in a wreck of a Roman ship in 1901, on a major ancient trade route between Rhodes and Rome. Mike G. Edmunds and Tony Freeth of Cardiff University in Wales led the team that did the recent X-ray tomography work on the artifact to indentify and analyze its innards.
Such a sophisticated Astronomical computer is not really supposed to have existed so early, and so this is rather exciting. Nobody knows who made it, but it is supposed that it is by the Greek astronomer Hipparchus or a follower of Hipparchus, perhaps the philosopher Posidonius. The LA Times article quotes the Roman Cicero who
later wrote that Posidonius had made an instrument “which at each revolution reproduces the same motions of the sun, the moon and the five planets that take place in the heavens every day and night.”
and speculates that perhaps these words, thought to be somewhat fanciful, were indeed true, and this is the device of which he spoke. Very exciting indeed.
So my questions. Well, the obvious one is whether this device was unique… but some of the follow up questions are – Why was it on a ship between Rome and Rhodes? Was it a gift? A prize? A working tool or a curiosity? Perhaps it was not unique and there were several others, and so it was not a big deal for it to be being transported away from one place to another.
Either way, it does make one wonder if the technology had been used in other ways, and we just have not found more examples yet.