This webpage belongs to www.janzuidhoek.com, which is a website promoting [Jan Zuidhoek (2019) Reconstructing Metonic 19-year Lunar Cycles (on the basis of NASA’s Six Millennium Catalog of Phases of the Moon): Zwolle], and shows an open letter from its author Jan Zuidhoek to his colleagues in the field of computus Paul Butzer, Sandor Chardonnens, Lisa Lynn Chen, Georges Declercq, Bruce Eastwood, Brigitte Englisch, Menso Folkerts, Leofranc Holford-Strevens, Pavel Kuzenkov, Máirin Maccarron, Stephen McCluskey, Philipp Nothaft, Masako Ohashi, James Palmer, Marina Smyth, Kerstin Springsfeld, Sacha Stern, Peter Verbist, and Faith Wallis (who could not be reached by email), in order to acquaint them with the existence of this pioneering book on early Alexandrian computus, which is available via this website.
Open Letter to
Colleagues in the Field of Computus
Dear colleagues,
My contribution to the Third International
Conference on the Science of Computus in Ireland and Europe in Galway in 2010,
which resulted rather recently (2017) in the publication of my article entitled
“The initial year of De ratione paschali
and the relevance of its paschal dates” as a part of the conference proceedings
entitled “Late Antique Calendrical Thought and its Reception in the Early
Middle Ages” and edited by Immo Warntjes & Dáibhí Ó Cróinín, was a rather
modest one, because, at least in 2010, as a retired teacher of mathematics (at
the Gymnasium Celeanum in Zwolle), I was a relative outsider in the field of
computus. So I finished that article by expressing my rather ambitious
intention to, in due course, supplement my qualitative account for the 2-day
gap established therein between the so called proto-Alexandrian and the
classical Alexandrian 19‑year lunar cycle with “a quantitative one by
performing a complete reconstruction of the classical Alexandrian cycle”.
Well, that originally intended quantitative
account would ultimately run into a both qualitative and quantitative account
for a similar 2‑day gap between two crucial lost ante-Nicene Alexandrian
Metonic 19‑year lunar cycles. This resulted from my recent (2018)
analysis by reconstructing both the Alexandrian Metonic 19‑year lunar
cycles which must have been actively constructed already before the first
council of Nicaea, namely Anatolius’ 19‑year lunar cycle (second half of
the third century) and the (first quarter of the fourth century) common
archetype of the three well‑known post‑Nicene Alexandrian Metonic
19‑year lunar cycles.
I am happy to report that the aforesaid
(2018) analysis has been realized in the recent (2019) publication of my book
entitled “Reconstructing Metonic 19-year lunar cycles (on the basis of NASA’s
Six Millennium Catalog of Phases of the Moon)”, thus reducing the aforesaid
(2017) article to a preparatory study for this book. If you would like to
receive a complimentary copy of this pioneering book, which has been dedicated
to Daniel P. Mc Carthy, please email your postal address to me at janzuidhoek@gmail.com. If you would
also like to receive (also for free) a copy of it intended for the library of
your university, please do not hesitate to mention this.
Sincerely,
Jan Zuidhoek
© Jan Zuidhoek 2019-2021