The Antikythera Clock Mechanism (pronounced an-ti-ki-theer-uh)

Antikythera Movement

Often, as I work with the intricate and delicate mechanisms inside antique clocks, I cannot help but wonder at the inventiveness and engineering abilities of those craftsmen of yesterday.  However the genius that created the Antikythera Mechanism takes me to a whole different level of awe.  If we didn't have the physical evidence of this mechanism, anyone postulating that the ancients could have conceived of such a device (never mind build one) would be in danger of being decried as a charlatan and buffoon.  So join me on a brief journey back 2,000 years to look at this incredible device and its creators.

"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. It dates from around the 1st century B.C. 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."

From The Antikythera Mechanism Research Project (AMRP), http://www.antikythera-mechanism.gr/

The following is an abbreviated account of the amazing functionality of the mechanism from Wikipedia:

Antikythera Movement

The mechanism has three main dials, one on the front, and two on the back.  The front dial has two concentric scales. The outer ring is marked off with the days of the 365-day Egyptian calendar.  Inside this, there is a second dial marked with the Greek signs of the Zodiac and divided into degrees.  The calendar dial can be moved to adjust, to compensate for the effect of the extra quarter day in the year (there are almost 365.25 days per year) by turning the scale backwards one day every four years.  Note that the Julian calendar, the first calendar of the region to contain leap years, was not introduced until about 46 BC, up to a century after the device was said to have been built (and the leap year was implemented with errors until the early first century).

"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 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.

There is reference in the inscriptions for the planets Mars and Venus, and it would have certainly been within the capabilities of the maker of this mechanism to include gearing to show their positions. There is some speculation that the mechanism may have had indicators for all the five planets known to the Greeks.  None of the gearing, except for one unaccounted gear, for such planetary mechanisms survives.

"Finally, the front dial includes a parapegma, a precursor to the modern day Almanac, which was 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."

From Wikipedia http://en.wikipedia.org/wiki/Antikythera_mechanism

As if that wasn't enough

Antikythera Movement

"Two dials on the front show the zodiac and a calendar of the days of the year that can be adjusted for leap years.  Metal pointers show the positions in the zodiac of the sun, moon and five planets known in antiquity.  Two spiral dials on the back show the cycles of the moon and predict eclipses.

Using more powerful computers to analyze the CT data, researchers were able to decipher the names of all 12 months, as well as names identifying several Greek games.  The key to the Olympiad Dial was the discovery of the words "NEMEA," "ISTHMIA," "PYTHIA" and "OLYMPIA."  The first reference is to the Nemean Games, one of the events that were part of the four-year cycles that climaxed with the Olympics. Isthmia represented the games at Corinth, Pythia those at Delphi and Olympia the Olympics themselves."

From  the Mercury News, 07/31/2008 http://www.mercurynews.com/news/ci_10052792

I'd encourage all of you to follow the links here as there is a wealth more information available on this incredible device.  As for me, I will continue to be awe-struck by the craftsmen that fashioned the beautiful clocks I prepare for you but part of me will be looking over their shoulders, back 2,000 years further to the great minds that developed this marvel of the Ancient World.