url URL date not supplied the antikythera mechanism recovered off a sunken ship in greece in NUMBER 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 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 NUMBER discuss NUMBER _thanks mark _ NUMBER URL NUMBER URL 