Article #259
Subject: Subject: How to validate data on Egyptian lunar dates around the time of the first coming of Christ compared to Jewish Christian dates?
Author: Andrew W. Harrell
Posted: 7/20/2015 05:26:24 PM

Subject: How to validate data on Egyptian lunar dates around the time of the
first coming of Christ compared to Jewish Christian dates?
Author: Andrew W. Harrell
Posted: 7/17/2015 01:06:14 PM
The question is from friends in MS. In the annex
to the draft of my book "Early Explorations in the Southern US" I have some
mathematical calculations of how Andrew Ellicott used the moons of Jupiter
and star positions to compute land navigation longitudes similar to the way
mariners compute positions at sea from just stars.
As I understand it, your husband has a paper on Egpytian lunar calendar dates
relative to Hebrew dates he wants to find out where to get data of the moons
positions around this time and how to use mathematical formulas to validate
his calculations with the nominal values astronomers use for the time and
dates of the moon's position then.

I said, that the US Government's Nautical Almanac
(http://aa.usno.navy.mil/publications/docs/na.php) is the standard reference
for this. But, it is somewhat hard to use.
You might want to study the book "Celestial Navigation Made Easy Using a
Pocket Calculator by Francois Meyer for an easier introduction to this.

The excellent book by Nachum Dershowitz and Edward Reingold "Calendrical
Calculations, 3rd edition available on Amazon has all the formulas you need
to understand how Jewish and Christian and Egyptian Religious calendars are
calculated.

Then you could compare and validate their data with yours using an free Excel
Spreadsheet add-on software package that does linear and non-linear
statistical regression calculations.
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Article #257
Subject: Reply
Author: Andrew W. Harrell
Posted: 7/17/2015 01:07:02 PM
Hi Andrew
I found the book on Amazon and will order it today. Can't believe we have not
run across it in bibliographies before.
I think I made a mistake in using the term "validation." Thanks for taking
the time to explain how difficult and complicated that would be. Perhaps we
can do some "comparisons" between Starry Night and NASA reconstructions of
lunar events in the second millennium BC.

Article #260
Subject: Comparison of Starry Night and NASA lunar eclipse data
Author: Amos
Posted: 7/21/2015 09:25:04 PM

Starry Night® 7 Enthusiast astronomy software was used in this study for
determinations of lunar crescent visibility and to assess possibilities of
Sothic risings on particular dates. Starry Night is commercially available
software that utilizes NASA’s delta-T values and calculations:
http://eclipse.gsfc.nasa.gov/SEhelp/deltatpoly2004.html (accessed June 11,
2015); https://support.simulationcurriculum.com/entries/20723932-
Archeoastronomy-Mathematical-Accuracy-Starry-Night (accessed June 11,
2015).
The following table is a comparison of NASA and Starry Night® 7 Enthusiast
data for eclipses demonstrating Starry Night's ability to accurately
reconstruct lunar events and achieve the same outcome as NASA. NASA
publishes a five millennium calendar of solar eclipses:
http://eclipse.gsfc.nasa.gov/SEcat5/SEcatalog.html , accessed July 20,
2015, from which the NASA data was drawn.
TABLE 8.3 Comparison of NASA lunar data with results from Starry Night® 7
Enthusiast.
Eclipse of March 31, 1429 BC. (NASA date is -1428.) Circumstances at
greatest eclipse, provided by NASA: 7:2:33 UT, Latitude 31.9 N, Longitude
64.3 E
Program Altitude-Sun Azimuth-Sun Altitude-Moon Azimuth-Moon
NASA 55.2 158.5
Starry Night 55.5 157.4 55.5 157.4

Eclipse of March 13, 1335 BC. (NASA date is -1334.) Circumstances at
greatest eclipse, provided by NASA: 10.15.25 UT, Latitude 26.7 N,
Longitude 18.9 E
Program Altitude-Sun Azimuth-Sun Altitude-Moon Azimuth-Moon
NASA 54.0 161.3
Starry Night 54.19 159.5 54.19 159.5

Eclipse of June 15, 763 BC. (NASA date is -762.) Circumstances at greatest
eclipse, provided by NASA: 8.14.01 UT, Latitude 38.9 N, Longitude 54.3 E
NASA 64.5 4.9 NASA 64.5
NASA 74.0 178.9
Starry Night 74.4 177.5 74.4 177.5

Eclipse of June 25, 204 BC. (NASA date is -203.) Circumstances at greatest
eclipse, provided by NASA: 14.0.7 UT, Latitude 1.7 S, Longitude 33.1 W
Program Altitude-Sun Azimuth-Sun Altitude-Moon Azimuth-Moon
NASA 64.5 4.9
Starry Night 65.4 4.5 65.5 4.5

Also confirmed with Starry Night were two total eclipses (Jan 8, 1340 BC
1339, and Mar 13, 1335 BC) in Hattusa (Turkey) that were highlighted by
Peter Huber in “The Astronomical Basis of Egyptian Chronology of the
Second Millennium BC,” JEH 4 (2011): 200.