Wednesday, April 18, 2007

μέγασ ελληνικόσ !

Today at the U one of the Archaeology undergrads is giving a symposium on the O μηχανισμός των Αντικυθήρων (the Antikythera Mechanism), which was more or less the world's first computer, though it was analogue instead of digital. Basically it's an astrological calculator, but the amazing thing is how advanced the mechanisms were. It's comparable to 18th century clock-making. A sponge diver found it off the Greek island Antikythera, and Jacques Cousteau was one of the divers who helped recover it. It was on a Roman cargo ship, so there's lots of debate as to what they were doing with it. The best guess is that it was being brought to Rome for one of Julius Caesar's triuphal processions, having been made at Rhodes (another Greek island), which was a center for engineering and mechanics, as there was an academy there founded by the Stoic philosopher Posidonius. The craziest part is that the principles behind it's function are based on heliocentrism, rather than geocentrism, which was Aristotle's deal. Heliocentrism was not popular.

I can't explain how it works, so here's what Wiki says:

The mechanism has 3 main dials, one on the front, and two on the back.
The front dial is marked with the divisions of the Egyptian calendar, or the Sothic year, based on the Sothic cycle. Inside this there is a second dial marked with the Greek signs of the Zodiac. This second dial can be moved to adjust, with respect to the Sothic dial, to compensate for leap years.
The front dial probably carried at least three hands, one showing the date, and two others showing the positions of the Sun and the Moon. The Moon indicator is ingeniously adjusted to show the first anomaly of the Moon's orbit. It is reasonable to suppose the Sun indicator had a similar adjustment, but any gearing for this mechanism (if it existed) has been lost. The front dial also includes a second mechanism with a spherical model of the Moon that displays the Lunar phase.
Finally, the front dial includes a parapegma (a precursor to the modern day Almanac) used to mark the rising and setting of specific stars. Each star is thought to be identified by Greek characters which cross reference details inscribed on the mechanism.
The upper back dial, is in the form of a spiral, with 47 divisions per turn, displaying the 235 months of the 19 year Metonic cycle. This dial contains a smaller subsidiary dial which displays the 76 year Callippic cycle. (There are 4 Metonic cycles within 1 Callippic cycle.) Both of these cycles are important in fixing calendars.
The lower back dial is also in the form of a spiral, with 223 divisions showing the Saros cycle. It also has a smaller subsidiary dial which displays the 54 year Exeligmos cycle. (There are 3 Saros cycles within 1 Exeligmos cycle.)

HOLY SHIT!
All this in a 33x17x9cm bronze case. It was tiny for what it did, and the time it was made.
BEHOLD THE GREEK BRAIN POWERS.

1 comment:

Anonymous said...

like, woah. holy balls. i want in on that dig.