The Antikythera mechanism
Computers have become part of our lives. We tend to think that it is a prerogative of modern man, as it happened rather recently. But it is not quite true. Let me introduce you an ancient analog computer – the Antikythera mechanism. However you won’t find a close resemblance between the modern and the ancient computer.
So, how it all began. In 1901, the remains of the ancient ship were found near the Greek island of Antikythera. Many artifacts have been raised from the bottom. Several bronze gears were found among them. Due to the remains of wooden hull, they turned into a monolith. Until 1951, the artifact remained unexplored. Artifact remained unexplored for a long time. But in 1951 the British historian Derek de Solla Price became interested in it. He was the first who determined that the remains of a strange mechanism were unique computing device.
This device dates back to 150-100 BC. The mechanism includes special details and structure; scientific-savvy Chinese began to use similar technology only 1,000 years later. And this artifact belonged to the ancient Greeks!
Mr. Price made X-ray research of the mechanism, and realized its reconstruction a few years later by making a life-size model. In 1959, the scientists published a detailed description of the device in the journal “Scientific American”. The full diagram of the device was introduced only in 1971. The researches continued. Later emerged that the artifact contained 37 gears, only 30 of them survived.
The research lasted for 20 years. The scientists, headed by Derek de Solla Price, came to the conclusion that the artifact was a mechanical astronomical appliance. Presumably, it served for modeling of movement of five planets – Sun, Moon, Mars, Jupiter and Saturn. They argued that the principle of differential gear formed the basis of the mechanism. Previously it was believed that it was invented not earlier than in the XVI century.
Forty years later the research was resumed. Michael Wright, a specialist in mechanical devices from the London Science Museum, decided to try his hand. After its own calculations, the scientist denied the differential gear. But the main conclusions were the same. In addition, he added a list of the aforementioned planets by such as Mercury and Venus. Further study revealed more new possibilities of the device. So, it turned out, the tool had the possibility of addition and subtraction, division, and also to take into account the ellipticity motion orbit of the moon.
The device was bilateral. The front side contained a dial, the back – two. Both dials on the back panel had additional small dials on the center circles. The rotary wheel on the right side wall of the mechanism set them in motion. The front dial indicated the days of the year and the signs of the zodiac – it was divided according to the system of the Egyptian calendar of 12 months and 365 days. The device could be also customized to the leap years. Thus, the dial served as a kind of stellar calendar.
One of the back dials had 235 divisions which reflected months of the so-called 19-year Metonic cycle. It showed the duration of the lunar month and the solar year in the lunar-solar calendar. This is the cycle that was created by the Greek astronomer Meton of Athens in 433 BC and formed the basis of the Greek calendar.
The second disc had 223 divisions and displayed the Saros cycle of eclipses, or the Draconian period. It consisted of 223 synodic months, after which an eclipse of the Moon and the Sun approximately repeated in the same order.
Many additional disks gave the opportunity for the mechanism to point out other interesting astronomical information. The mechanism has also preserved remains of inscriptions – about 2000 of Greek characters. Greek researchers have shown that they were fragments of a technical device manual.
Thus, the Antikythera mechanism was a complex astronomical device, a kind of ancient mechanical computer. Such a device made it possible not only to conduct accurate astronomical calculation, but also to predict certain celestial events. Such a high level of art of ancient mariners navigating amazes a modern man! Scientists say that the technology of the mechanism is comparable to the technology of mechanical watches of the XIV century.