It's all Greek to me

Science went back to its roots this week. Results just reported in the science journal Nature (DOI: 10.1038/nature05357) have focused the spotlight on several chunks of green and white metal that were found in the eastern Mediterranean in 1900.  It might not sound much to get excited about but the century-old find is forcing a drastic reassessment of ancient technology.

Next to the island of Antikythera, roughly half way between Crete and the mainland of Greece, sponge divers found a Roman ship that had been transporting Greek cargo. In amongst the recovered objects were 82 fragments of bronze.  Over the years, different people have had a bash at looking at the bits and pieces but the remains continued to puzzle scientists. The British researcher De Solla Price spent much of his career from the 1950s to the 1970s trying to understand them.  He argued they were the part of a sophisticated device capable of astronomical calculations.  Not everyone was convinced. The find became known as the Antikythera Mechanism.

The Antikythera Mechanism
The fragments of the bronze mechanism have just been re-analyzed and the results are stunning.  The research team from Britain, Greece and the USA threw a plethora of new scientific methods at the lumps of metal.  They were literally able to look inside the alloy mass without damaging the remains.  Once the team were able to make out the shape and size of the surviving pieces they set about working out how they all fitted together.

This amazing device seems to have been made up by a series of gears and pointers.  Probably housed in a wooden-framed case measuring somewhere between 32 x 19 x 10 cm, it had doors front and back.  By setting and turning the dials by hand, this bit of wizardry was able predict eclipses, and track the movement of the Moon and Sun across the constellations.  It looks like it was even able to work out the paths of the five planets known at the time.

But when was it made?  Well, coins discovered on board the wreck seemed to show the ship went down sometime between 80 and 60 BC.  But this was not when the device was built.  The science in the mechanism helps give us an upper limit.  One of the dials at the back allows the machine to calculate the relatively erratic movement of the Moon, an idea originally developed on the island of Rhodes by the Greek astronomer Hipparchos sometime between 146 and 128 BC.  This is supported by the style of the Greek lettering on the dials and casing that suggests the device was made between 150 and 100 BC. The ship was thought to have been sailing from Rhodes when it sank.  Perhaps the great astronomer himself played a part in its construction.  


Regardless of who made it, nothing like it was seen again for another thousand years.  It makes you wonder what else the Greeks were making.

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