The Antikythera mechanism is a 2,100-year-old computer

The Antikythera mechanism is a 2,100-year-old computer:

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116 years ago (1902), divers found a chunk of bronze off a Greek island. It has radically changed our understanding of human history.

One hundred sixteen years ago, an archaeologist was sifting through objects found in the wreck of a 2,000-year-old vessel off the Greek island Antikythera. Among the wreck’s treasures, fine vases and pots, jewellery and, fittingly enough, a bronze statue of an ancient philosopher, he found a peculiar contraption, consisting of a series of brass gears and dials mounted in a case the size of a mantel clock. Archaeologists dubbed the instrument the Antikythera mechanism. The genius — and mystery — of this piece of ancient Greek technology is that arguably it is the world’s first computer. If we gaze inside the machine, we find clear evidence of at least two dozen gears, laid neatly on top of one another, calibrated with the precision of a master-crafted Swiss watch. This was a level of technology that archaeologists would usually date to the sixteenth century AD. But a mystery remained: What was this contraption used for? 

To archaeologists, it was immediately apparent that the mechanism was some sort of clock, calendar or calculating device. But they had no idea what it was for. For decades, they debated. Was the Antikythera a toy model of the planets or was it a kind of early astrolabe, a device which calculates latitude?

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At long last, in 1959, Princeton science historian Derek J. de Solla Price provided the most convincing scientific analysis of this amazing device to date. After a meticulous study of the gears, he deduced that the mechanism was used to predict the position of the planets and stars in the sky depending on the calendar month. The single primary gear would move to represent the calendar year, and would, in turn, activate many separate smaller gears to represent the motions of the planets, sun and moon. So you could set the main gear to the calendar date and get close approximations for where those celestial objects in the sky on that date. And Price declared in the pages of Scientific American that it was a computer: “The mechanism is like a great astronomical clock ... or like a modern analogue computer which uses mechanical parts to save tedious calculation.”
 



It was a computer in the sense that you, as a user, could input a few simple variables and it would yield a flurry of complicated mathematical calculations. Today the programming of computers is written in digital code, a series of ones and zeros. This ancient analog clock had its code written into the mathematical ratios of its gears. All the user had to do was enter the main date on one gear, and through a series of subsequent gear revolutions, the mechanism could calculate variables such as the angle of the sun crossing the sky. As a point of referencdee, mechanical calculators using gear ratios to add and subtract, didn’t surface in Europe until the 1600s. 

Since Price’s assessment, modern X-ray and 3D mapping technology have allowed scientists to peer deeper into the remains of the mechanism to learn even more of its secrets. In the early 2000s, researchers discovered text in the guise of an instruction manual that had never been seen before, inscribed on parts of the mechanism. The text, written in tiny typeface but legible ancient Greek, helped them bring closure to complete the puzzle of what the machine did and how it was operated.
 
The mechanism had several dials and clock faces, each which served a different function for measuring movements of the sun, moon, stars, and planets, but they were all operated by just one main crank. Small stone or glass orbs moved across the machine’s face to show the motion of Mercury, Venus, Mars, Saturn, and Jupiter in the night sky and the position of the sun and moon relative to the 12 constellations of the zodiac. Another dial would forecast solar and lunar eclipses and even, amazingly enough, predictions about their colour. Today, researchers surmise that different coloured eclipses were considered omens of the future. After all, the ancient Greeks, like all ancients, were a little superstitious. 

The mechanism consisted of:
- a solar calendar, charting the 365 days of the year 
- a lunar calendar, counting a 19 year lunar cycle 
- a tiny pearl-size ball that rotated to illustrate the phase of the moon, and another dial that counted down the days to regularly scheduled sporting events around the Greek isles, like the Olympics.  The mechanics of this device are absurdly complicated. A 2006, in the journal Nature, a paper plotted out a highly complex schematic of the mechanics that connect all the gears. 

Researchers are still not sure who exactly used it. Did philosophers, scientists and even mariners build it to assist them in their calculations? Or was it a type of a teaching tool, to show students the math that held the cosmos together? Was it unique? Or are there more similar devices yet to be discovered? To date, none others have been found.

Its assembly remains another mystery. How the ancient Greeks accomplished this astonishing feat is unknown to this day. Whatever it was used for and however it was built, we know this: its discovery has forever changed our understanding of human history, and reminds us that flashes of genius are possible in every human era. Nothing like this instrument is preserved elsewhere. Nothing comparable to it is known from any ancient scientific text or literary allusion,” Price wrote in 1959. “It is a bit frightening, to know that just before the fall of their great civilization the ancient Greeks had come so close to our age, not only in their thought, but also in their scientific technology.”

There are amazing fully operational modern versions of the Antikythera Mechanism, such as these:

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