Posted on 12/18/2020 10:36:13 AM PST by SunkenCiv
New finding from Antikythera MechanismBased onstatistical analysis of micro CT imaging of the more than 2,000-year-old Antikythera Mechanism, we show unexpected evidence establishing a lunar calendar with Egyptian civil-calendar month-names circa 100 B.C. This finding displaces a century-long presumption of a 365-day solar calendar on the Antikythera Mechanism with a 354-day lunar calendar and may inform a fundamental question of the number and type of calendars used in Ancient Egypt.
(Excerpt) Read more at osf.io ...
All of the ancient Greek city-states had lunar calendars. Meton of Athens in the fifth century BC discovered the Metonic cycle which could have been used to add intercalary months from time to time accurately (to keep the year approximately in line with the solar year) but the Athenian officials do not appear to have used it.
The period of the moon’s “elliptical” orbit is the anomalistic month, which is different, also. The anomalistic month determines the moon’s variation in angular diameter over the course of a month. The moon’s orbit changes shape, or eccentricity and the perigee moves slightly. I am not sure what 26.5 represents.
https://en.wikipedia.org/wiki/Lunar_month#Types
Month type Length in days (in year 2000)
draconitic 27.212220815
tropical 27.321582252
sidereal 27.321661554
anomalistic 27.554549886
synodic 29.530588861
Here’s one in Legos: https://www.youtube.com/watch?v=RLPVCJjTNgk
“Get the new NileWatch! Accurate to within 4 weeks per century! So compact it will fit on back of your camel! GPS feature will follow any moving star to within 10 meters of any stable in Bethlehem!”
Yup, lucky it had valves, because it wound up spending a couple thousand years underwater. ;^)
A crank.
HACKER’S DISCOVERY CHANGES UNDERSTANDING OF THE ANTIKYTHERA MECHANISM
41 Comments
by: Dan Maloney
December 12, 2020
https://hackaday.com/2020/12/12/hackers-discovery-changes-understanding-of-the-antikythera-mechanism/
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