The Back Plate Inscription and eclipse scheme of the Antikythera Mechanism revisited

Abstract

This paper presents a new edition of the Back Plate Inscription (BPI) of the Antikythera Mechanism, a series of descriptions of circumstances associated with eclipses indicated cyclically by the inscriptions of the Mechanism's Saros Dial Scale. Our edition features several significant new readings as well as the confirmation of a disputed reading pertaining to one of the index letters by which the BPI's paragraphs are linked to the specific eclipse glyphs of the Saros Dial. On the basis of the new text, we deduce a revision of the established models for determining which lunar months of the Saros cycle had solar and lunar eclipse possibilities (EPs) and for assigning the solar EPs to paragraphs of the BPI. We further confirm that the entire extant part of the BPI comprises consecutive paragraphs concerning the solar EPs, all inscribed along the right side of the Mechanism's Back Plate, and we revisit the questions of what the BPI's predictions mean and how they relate to the model for the solar EPs. Abbreviations IG Inscriptiones Graecae IGUR Inscriptiones Graecae Urbis Romae PLond Greek Papyri in the British Museum POxy. astr. Jones 1999 Communicated by Jed Buchwald. Iversen is primarily responsible for Sects. 2 and 3, and Jones for Sect. 4, though both authors have made contributions to each other's sections.

Renumbering of the Antikythera Mechanism Saros Cells, Resulting From the Saros Spiral Mechanical Apokatastasis

“…The results of the measurements for the secret pin(s) positions match very well to the theoretical results based on the AM symmetrical design. The present work observations and calculations lead to a correction on the initial numbering of the Saros cells, published by Freeth et al, 2008;Carman and Evans, 2014;Anastasiou et al, 2016;Iversen and Jones, 2019;Freeth, 2019;Jones, 2020.…”

“…21, No 2, (2021), pp. 107-128 Freeth et al, 2008;Carman and Evans, 2014;Anastasiou et al, 2016;Freeth, 2019;Iversen and Jones, 2019;Jones, 2020). (2)…”

“…This hole, will additionally downgrade the poor mechanical stability of the spiral turns and this unstable behavior having an impact on the axis-e in stabilization. Moreover, on the cell-166 has been predicted a solar eclipse event (index event Ξ̅ /symbol, see Table 4.6-Revised glyph sequence in Anastasiou et al, 2016, also Freeth, 2019Iversen and Jones, 2019) and if there was a hole, the event engraving is impossible (Fig. 9E).…”

“…The observations and the results of Chapter 4, alter the initial Saros cell-numbering and the eclipse information scheme, presented elsewhere (Freeth et al, 2008;Freeth, 2014;Anastasiou et al, 2016b;Freeth, 2019;Iversen andJones, 2019 andJones, 2020). The new cell numbering of the Saros events, Fig.…”

“…The axisg (and its gears) in which the (lost) Saros pointer was adapted, is also preserved on Fragment A (Anastasiou et al, 2014). Today, 22 eclipse information events are preserved on the Saros cells (Freeth et al, 2008;Anastasiou et al, 2016;Freeth, 2019;Iversen and Jones, 2019;Jones, 2020).…”