Thanks go to Charles Jones at Ancient World Online for posting this “pre-print” article, “The Cosmos in the Antikythera Mechanism” (due to the size, it is best to right-click and “Save File As”; you will also have to re-size the file in Adobe Reader, since the images do not scale with the font size). It is far and away the most detailed report on the Antikythera Mechanism I’ve seen.  It is basically a full analysis of the mechanism, and ancient celestial calculator, that I’ve seen. It has many X-Ray photos and graphical reconstruction images. If you’re interested in this amazing piece of ancient HUMAN technology, this is a must-read.

Since the link for the article is not permanent, I have converted the page to PDF. But be advised, all the images in it make the file large (30 MB), so give it time to download.  The permanent URL for online access to this paper is not active yet, but will be:

And for those who will insist the mechanism is another example of alien technology, either given to humans or “reverse engineered” by the ancient Greeks, think again. As amazing as the mechanism is, it didn’t work that well. From section 3.10 of the report:

We compare the positions of Mars, as reconstructed by NASA with the Mechanism’s predictions over the middle seven retrogrades of Mars in the 1st Century BC—a period of about 13 years.(86) Serious error spikes can be seen, amounting to nearly 38°—more than a zodiac sign—at the retrogrades. The deferent and epicycle theories, on which the mechanisms depended, might be regarded as an adequate first-order approximation but were completely inadequate for accurate prediction at the retrogrades, particularly for Mars. More accuracy would have to wait for more sophisticated theories such as those employed by Ptolemy in the second century AD. Added to these inherent theoretical errors were significant mechanical inaccuracies because of the way that the rotations were transmitted through the gear trains.(87)

In short, the Antikythera Mechanism was a machine designed to predict celestial phenomena according to the sophisticated astronomical theories current in its day, the the sole witness to a lost history of brilliant engineering, a conception of pure genius, one of the great wonders of the ancient world—but it didn’t really work very well!