Sunday, August 1, 2010

Intricate Devices of Antiquity

ANTIKYTHERA MECHANISM


















Used to calculate motions of astronomical bodies. It's almost exactly precise, and it was created about 2,100 years ago by the Greeks (not to be confused with geeks)!!! The device's workings are based on the geocentric model of astronomy. Found in 1901 as part of a shipwreck in the town which shares the same name as the device, the original is on display at the National Archaeological Museum in Athens (http://www.namuseum.gr/wellcome-en.html). Devices of similar complexity to this appear to have been lost for some time and only recreated around the 1300's.

Check out wikipedia for a much better description:
http://en.wikipedia.org/wiki/Antikythera_mechanism

Michael Wright's Model:



Here's a simulation of the internal gear workings:


ASTROLABE




















It's another astronomical calculator (less intricate) developed in 150 BC. This primative version isn't quite as impressive as the 13th-century one shown in the next video.

Again, check wikipedia; it's much better:
http://en.wikipedia.org/wiki/Astrolabe

Tom Wujec demos the 13th-century Astrolabe:


Here's a spherical astrolabe, like those of the middle ages:














BAGHDAD BATTERY

These are most likely from the early centuries AD. There are a couple theories as to the use of these devices. Some suggest they weren't actually electrochemical cells at all, but that they were for storing scrolls, which decayed and then left acidic traces within. This theory is largely based on the lack of voltage which can be generated by a battery, but it's not completely unrealistic to assume that multiple batteries were connected by wires to achieve more usable voltages. I don't ascribe to this theory. I personally think they were used for electroplating (coating silver with gold in this case via a redox reaction) based on the different theories I've read. Other ideas are that they were used for electrical acupuncture or even a religious experience (shock). When Mythbusters tested 3 of these theories (electroplating, acupuncture, religious experience) by stringing a couple of the batteries together in series, all 3 were found to be plausible. Note that if these were indeed used as electrochemical cells, they precede the invention of batteries by over 1,000 years.

Wikipedia: http://en.wikipedia.org/wiki/Baghdad_Battery



No comments:

Post a Comment