"Driven by a storm from their usual area of work,
a crew of Greek sponge divers found themselves off
the Aegean island of Antikythera. There, in 200 feet
of water, they discovered the remains of a shipwreck
from classical times. This ship, it was later surmised,
was a Roman galley laden with Greek statues and other
treasure: booty being taken back to the imperial capitol.
Among the relics brought up from this shipwreck and
taken to the Greek National Archeological Museum was
a coral encrusted bronze mechanism." |
"The device is on display
in the National Archaeological Museum in Athens.
There is a one line explanation saying something
like "computer from Anti-Kythera". A huge
understatement if you ask me."
Article:
June 1959 Scientific American p.60-7
incl page images and text
Other Antikythera Mechanism Links
E. Christopher
Zeeman's (K.B., F.R.S.) lecture
website and lecture Gears
from the Greeks
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This is a gamma radiograph of one of
the fragments ("A") of the mechanism. The
gears can be matched with their positions in the gearplan.
The three concentric bands at the lower left are part
of the display dials on the back of the mechanism,
whose function is not completely understood.
A Reconstruction of the Antikythera
Mechanism few years ago, John
Gleave, an orrery maker based in the United Kingdom,
decided to construct a working replica of the original
mechanism. |
The Antikythera Mechanism
It was not clear initially what the
device was, except that it was clearly a sophisticated
mechanism. X-ray analysis was subsequently used to
probe the inner structure of the device, the details
of the gears. Finally in 1974, a full analysis was
published by Professor D. De Solla Price. While some
of the original gearing was missing, there was enough
to work out that the device was intended to show the
motion of the Moon, Sun, and most likely the Planets
through the years, when the handle was turned.
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The sun gear has 64 teeth.
It meshes with the smaller of a 38,48 gear pair.
The 48 meshes with the smaller of a 24,127 gear
pair. The 127 meshes with the 32 teeth of the
moon gear. The ratio of angular speeds can then
be calculated as
| 64 |
|
48 |
|
127 |
|
254 |
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|
x |
|
x |
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= |
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|
| 38 |
|
24 |
|
32 |
|
19 |
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| |
|
|
= |
13.36842.. |
which is an excellent approximation
of the astronomical ratio 13.368267..
see also
Fractions,
Cycles, and Time
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This
image(right) can be java-animated.
It shows the operation of the Sun-Moon assembly, with
a somewhat fanciful simulation of the display. In the
actual device, the zodiac constellations were represented
by their Greek names ("Libra" and the end
of "Virgo" are decipherable in the relic).
The constellation-schemata used here are imitations
of the more accurate versions in Find the Constellations
by H. A. Rey, Houghton-Mifflin Co., Boston, 1988.
Java animation: GO
(by Bill Casselman, University of British Columbia).
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