StanfordMLOctave/machine-learning-ex6/ex6/easy_ham/2193.8220cdccae38ad8e498499...

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From rssfeeds@jmason.org Tue Oct 1 10:36:26 2002
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From: boingboing <rssfeeds@example.com>
Subject: 2000+ year old Greek computer reinterpreted
Date: Tue, 01 Oct 2002 08:00:32 -0000
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URL: http://boingboing.net/#85507259
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The Antikythera mechanism, recovered off a sunken ship in Greece in 1900, is
thought to be a clockwork device to calculate the orbits of the celestial
bodies. New analysis of the remaining fragments shows that it was wicked-cool:
The Greeks believed in an earth-centric universe and accounted for
celestial bodies' motions using elaborate models based on epicycles, in
which each body describes a circle (the epicycle) around a point that
itself moves in a circle around the earth. Mr Wright found evidence that
the Antikythera mechanism would have been able to reproduce the motions of
the sun and moon accurately, using an epicyclic model devised by
Hipparchus, and of the planets Mercury and Venus, using an epicyclic model
derived by Apollonius of Perga. (These models, which predate the mechanism,
were subsequently incorporated into the work of Claudius Ptolemy in the
second century AD.)
A device that just modelled the motions of the sun, moon, Mercury and Venus
does not make much sense. But if an upper layer of mechanism had been
built, and lost, these extra gears could have modelled the motions of the
three other planets known at the time<6D>Mars, Jupiter and Saturn. In other
words, the device may have been able to predict the positions of the known
celestial bodies for any given date with a respectable degree of accuracy,
using bronze pointers on a circular dial with the constellations of the
zodiac running round its edge.
Link[1] Discuss[2] (_Thanks, Mark!_)
[1] http://www.economist.com/displaystory.cfm?story_id=1337165
[2] http://www.quicktopic.com/boing/H/UKW9AAQCsFibH