Reconstruction Synthesis of the Calendrical Subsystem of Antikythera Mechanism

Abstract

The damaged excavation of the Antikythera mechanism presents the oldest astronomical analog computer in ancient Greece. Its interior mechanism is a complicated gear train with many subsystems in which some are unclear, such as the calendrical subsystem. This work focuses on the reconstruction synthesis of the calendrical subsystem and provides a systematic approach to generate all feasible designs. Based on the studies of historical literatures and existing designs, the required design constraints are concluded. Then, according to the concepts of generalization and specialization of mechanisms, two feasible designs and 14 results of teeth counting, including the existing one by Freeth et al. (2002, “The Antikythera Mechanism: 1. Challenging the Classic Research,” Mediterranean Archaeology & Archaeometry, 2, pp. 21–35; 2002, “The Antikythera Mechanism: 2. Is It Posidonius Orrery?,” Mediterranean Archaeology & Archaeometry, 2, pp. 45–58; 2006, “Decoding the Ancient Greek Astronomical Calculator Known as the Antikythera Mechanism,” Nature (London), 444, pp. 587–591; 2008, “Calendars With Olympiad Display and Eclipse Prediction on the Antikythera Mechanism,” Nature (London), 454, pp. 614–617; 2009, “Decoding an Ancient Computer,” Sci. Am., 301(6), pp. 76–83), which are in consistent with the science theories and techniques of the subject’s time period, are synthesized.