Delaware Valley Amateur Astronomers
Speaker: John Symborski
Title: The Antikythera Mechanism Fully Explained
John's original presentation on the The Antikythera Device and its Place in Historical Astronomy 2009 concluded that the possible planetary display could not be proven, only that it could have existed - as demonstrated 'in principle' by a working model by Michael Wright using gearing similar to that surviving in the original device.
New detailed CAT scans prove that there was an extensive upper assembly - apparently sheared away at some point after the shipwreck, but before the bronze was transformed into fragile oxides by centuries under ocean water. A logical model of the display (much simpler than the Wright model) has been proposed by the Antikythera Research group, yet it does not explain a mysterious cross-drilled lug on one arm of the main solar gear. Nor does the model reasonably allow for the eclipse node (dragon) point to be displayed on the model with correct precession.
A competing group discovered that the date and degree markings have distinctly different centers, (a fact ignored by others) and proposed a simpler way of modeling the solar anomaly. The work of both research groups can by 'synthesized' into an elegant solution that uses all of surviving architecture to display not only the 5 planets know to the ancients, but the solar and eclipse node precessions as well! While researchers argue about who 'discovered' what, a combination of the best ideas of put forth thus far point to the most likely answer - as put forth in John's presentation.