But Mr Wright is convinced that his epicyclic interpretation is correct, and that the original device modelled the entire known solar system.The Greeks had a word for itThat tallies with ancient sources that refer to such devices.
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.
The unparalleled numerical accuracy achieved by the theory of epicyclic motions for planetary motions lent great empirical validity to the Ptolemaic system.
The topics include definitions of various units of time, eccentric and epicyclic models of planetary motion (see Hipparchus for earlier Greek models), planetary longitude corrections for different terrestrial locations, and a theory of "lords of the hours and days" (an astrological concept used for determining propitious times for action).
In order to explain the motion of the planets, Ptolemy combined eccentricity with an epicyclic model.
By carefully coordinating these two cycles, the epicyclic model explained the observed phenomenon of planets retrograding when at perigee.
The drive train for the lunar position is extremely sophisticated, involving epicyclic gearing and a slot-and-pin mechanism to mimic subtle variations (known as the "first anomaly") in the Moon's motion across the sky.
Apollonius introduced an alternative "epicyclic" model, in which the planet turns about a point that itself orbits in a circle (the "deferent") centred at or near the Earth.
They developed an epicyclic model that would reproduce the observed planetary motions with quite astonishing accuracy.
It's a clever beast with a petrol engine and not one but two electric motors, plus something called an "epicyclic" hybrid system and four-wheel drive.
As Apollonius knew, his epicyclic model is geometrically equivalent to an eccentric.
