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KF5JRV > TECH 15.11.16 14:24l 64 Lines 3262 Bytes #999 (0) @ WW
BID : 5393_KF5JRV
Read: GUEST
Subj: Antikythera Mechanism
Path: IZ3LSV<F1OYP<F4DUR<CX2SA<N9PMO<NS2B<KF5JRV
Sent: 161115/1315Z 5393@KF5JRV.#NWAR.AR.USA.NA BPQK6.0.13
Scientists have examined hitherto-obscure inscriptions on the Antikythera
Mechanism, a first century BC apparatus comprised of interlocking gears, and
now believe the device could predict eclipses and the motion of the planets.
The Antikythera Mechanism is a scientific and archaeological marvel, because
nothing else like it has ever been found. A few classical sources mention
geared devices, but the Mechanism is the only one to survive from antiquity.
“Surviveö may be too strong a word: the device was found on the sea bed near
the Greek island of Antikythera after spending almost two millennia under
water before its re-discovery in the year 1900. The machine has become
crushed, its gears mashed together and some parts are missing.
In 1900 archaeologists saw the gears and obvious inscriptions and guessed the
device was a mechanical calendar of some sorts. In recent years non-invasive
imaging techniques have made it possible to peer inside the bronze artefact's
innards, resulting in reconstructions that hinted the device was also a
navigational tool.
Now boffins have given the device the most comprehensive going-over ever,
imaging its surface and interior inscriptions with computed tomography
(aka CT scans) and polynomial textual mapping (a technique HP Inc uses to peer
inside objects).
The journal Almagest has now published an issue reporting those analyses.
Among their findings is an interpretation of the text found on the Mechanism's
cover, which is now felt to be “a systematic description of the dials,
pointers, and other external features of the Mechanism, beginning with the
front face and continuing with the rear face.ö
“The best preserved passages include descriptions of features on lost parts of
the Mechanism: a display of pointers bearing small spheres representing the
Sun and planets on the front dial, and a dial on the upper back face
representing a 76-year 'Kallippic' calendrical cycle.
In other words, a user manual.
Other findings include:
Text called “the Parapegma Inscriptionö recorded “an alphabetically
indexed list of annually repeating astronomical events relating to the Sun
and to fixed stars;ö
The Mechanism included several calendars, to calculate the time until the
next occurrence of sacred games and other festivals;
The Mechanism could predict solar and lunar eclipses and attendant
inscriptions “may imply a meteorological aspect by referring to
predictions of winds attending the eclipses;ö
The device's front cover is now felt to record “data on synodic cycles for
the five planetsö and “strongly support the idea that planetary motions
were displayed on the front face of the Mechanism using simple epicyclic
or eccentric models. Previously unattested long and accurate period
relations are given for Venus and Saturn, which are favourable for geared
representation and probably of Greek, rather than Babylonian, origin.
The Mechanism's examiners are also now more confident that the device was
built in Greece, rather than imported from Babylon, as analysis of the newly
revealed texts suggests the machine's creators were familiar with Greek
astronomy.
73 Scott KF5JRV
KF5JRV.#NWAR.AR.USA.NA
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