More than a hundred years ago an extraordinary mechanism was found by sponge divers at the bottom of the sea near the island of Antikythera. It astonished the whole international community of experts on the ancient world. Was it an astrolabe? Was it an orrery or an astronomical clock? Or something else?
For decades, scientific investigation failed to yield much light and relied more on imagination than the facts. However research over the last half century has begun to reveal its secrets. The machine dates from around the end of the 2nd century . and is the most sophisticated mechanism known from the ancient world. Nothing as complex is known for the next thousand years. The Antikythera Mechanism is now understood to be dedicated to astronomical phenomena and operates as a complex mechanical "computer" which tracks the cycles of the Solar System .
The animations were produced using Microsoft's Visual J++ . In my opinion, J++ at is still very much a beta (or should I say my beta noire). It's reintroduced what I call "elevator shaft programming," when an innocent or stupid mistake seizes the system up, the debugger won't load, and the power switch is the only way out. A lot like assembly language programming without an assembler. Real "elevator shaft programming" is writing programs in machine language to control machines or industrial processes. At least with J++, nobody gets killed.
On the front face of the mechanism (see reproduction here:  ) there is a fixed ring dial representing the ecliptic , the twelve zodiacal signs marked off with equal 30 degree sectors. This matched with the Babylonian custom of assigning one twelfth of the ecliptic to each zodiac sign equally, even though the constellation boundaries were variable. Outside of that dial is another ring which is rotatable, marked off with the months and days of the Sothic Egyptian calendar , twelve months of 30 days plus five intercalary days . The months are marked with the Egyptian names for the months transcribed into the Greek alphabet. The first task, then, is to rotate the Egyptian calendar ring to match the current zodiac points. The Egyptian calendar ignored leap days, so it advanced through a full zodiac sign in about 120 years.