whatisitcomputer

A group of scientists from the U.K. and Greece led by Mike Edmunds, an
astronomer from the University of Cardiff, has unlocked a code more ancient
and mysterious than those found in Foucault's Pendulum or The Da Vinci Code.
The team has deciphered the Antikythera Mechanism, an ancient computer
named for the Greek island where it was discovered.

The Antikythera Mechanism was found by divers in 1901 off the coast of
Antikythera, a Greek island 18 miles north of Crete. A rough replica of the
device was eventually constructed and archeologists guessed that it was an
astronomical calculator. But the inner workings and the device's true nature
went unknown for 100 years. Now, several physical factors and the device's
reference to Hipparchos, place the mechanism between 140-200 B.C., and a
complete computer model of the device (shown here) has been constructed,
according to the group's findings published in the November 30, 2006, issue of
Nature.

High-tech x-rays and imaging methods have shed new light on the mystery
object, enabling scientists to reconstruct the device's internal components with
computer generated imagery. They were also able to read its "instruction
manual." The findings are being discussed at the "Decoding the Antikythera
Mechanism--Science and Technology in Ancient Greece" conference in Athens,
Greece.

By using tomography developed by British x-ray tech company X-Tek on the
Antikythera Mechanism's remaining fragments, scientists were able to
determine the placement of the inner gears.

The Antikythera could be considered the first analog computer. The team of
experts from the U.K. and Greece discovered that its system of dials and more
than 30 gears is more complex than those found in medieval clocks, according
to the Nature article. It suggests that the Hellenic people were much further
along technologically than scientists, historians and archeologists had assumed.
The device, in other words, is at least 1,000 years ahead of its time.
So with one mystery solved, another one has presented itself. How is it that
such an invention had no historical effect? What stopped the technology from
being spread and perpetuated throughout the rest of the world?

While parts of the Antikythera Mechanism inscription had been deciphered,
many parts remained unreadable. A Polynomia Texture Maps (PTM) machine,
constructed specifically for the Antikythera Mechanism, was developed by
Hewlett-Packard Laboratories and brought on location to Greece. PTM are
made from a series of reflected light images under varying lighting conditions.
This allows multiple views of a textured surface to be seen.
The scientific team used the "PTM Dome" to more clearly "see" the device's
surfaces, which included minute inscriptions.

The inscriptions on the Antikythera Mechanism have been deciphered to reveal
theories for ancient planetary positions. The mechanism was used to predict
and calculate lunar and solar eclipses on the basis of Babylonian
arithmetic-progression cycles, according to the team's report. The mechanism
also calculates lunar positions based on theories by the famous Greek
astronomer Hipparchos for deciphering the Moon's elliptical orbit. The
machine's ability to calculate sophisticated astronomical knowledge of the
Moon's unusual orbit surprised the scientists.