This is a fully working model of the Antikythera mechanism (AM), constructed using modern materials (perspex panels, brass shafts, screws and nylon gears) with extremely careful attention to design and performance, after careful development and testing, by John Lancashire (UK). The design consists of two gear trains joined by a single (B3) shaft - the first being the calendar mechanism leading to the dials believed to lie on the back panel of the AM and an orrery mechanism and pointers representing the sun, moon and planets (together with moon phase read-out) on the front panel. The mechanism reflects current understanding that the optimum mechanical point to drive the mechanism is through the B3 shaft (in this case driven by a key connected to it from the back panel).
The device can be purchased either in kit form (leading to an interesting couple of days of assembly) or as an assembled device. The result is a smoothly working device capable of showing the positions of planets, sun, moon at any date, as well as eclipses, and major significant Ancient Greek games (including the Olympic games), fully demonstrating all hypothesised outputs of the original AM.
Despite the important work done by the Antikythera Research Project (ARP - whose outputs were reported in a seminal article in Nature, there remains strong reasons to doubt the full details of their conclusion. In particular their decision to allocate a port on the side of the AM to a drive shaft, delivering power to the instrument through the large crown gear is mechanically unfavourable, and the proposition that there was a fully working orrery at the front of the machine (as indeed instantiated in Lancashire’s model, seems increasingly unlikely. Reasoning for this is provided by Voulgaris et al. In particular to do so would have required the ancient greeks to have fabricated a shaft of 8 concentric tubes each connecting to a different planetary pointer and rotated by a complex epicyclic gearbox of which there is no surviving trace. As Voulgaris et all show, the surviving “user’s manual” script from the AM is ambiguous -and can be read either as an indication that there was a planetary model, or of how the other outputs relate to the motions of the planets. Voulgaris et al argue that the information provided was not through an orrery but rather through a Dragonic dial output through the shaft allocated by the ARP as the drive shaft for the mechanism. From this point of view the orrery provided at the front of this model may be a modern artifact rather than a true representation of the original AM.
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