The Gentile Times Reconsidered Chronology Christ

334 THE GENTILE TIMES RECONSIDERED
sunset, duration of partial and total phases, sometimes also
magnitude and position relative to stars or constellations, the
identification of the eclipses described in such texts usually creates
no problems, provided that the texts are well preserved.
The Watchtower of March 15, 1969, pages 184 onward, refers to
another factor, which, it is held, makes it difficult to identify
ancient eclipses. It is pointed out that astronomers for a long time
(for centuries, actually) have been aware of the fact that the tides
produced by the moon and the sun in the oceans and body of the
earth create a retardation of the earth’s rotation, causing a gradual
lengthening of the day. This, it is said in the article, affects the
ancient records.
However, when it comes to identifying ancient lunar eclipses
from the eighth century B.C.E. onward, this is not a major problem
today. The great number of observations recorded on cuneiform
tablets have, in fact, enabled modern astronomers to measure the
exact rate of this change of the earth’s rotation. It is known today
that the length of the day increases at a rate of 1.7 milliseconds per
century. The day in Late Babylonian time was thus about 43–44
milliseconds shorter than present. 54
Today astronomers, of course, make allowance for the variation
in the earth’s rotation in their calculations of the dates of ancient
eclipses. The Watchtower article discussed solar eclipses only. But as
very few reliable observations of solar eclipses are preserved from
ancient times, and as none of them are connected with the
chronology of the Neo-Babylonian period, they are irrelevant to
our discussion.
As I wanted to know how ancient records of lunar eclipses are
affected by this increasing of the solar day, I wrote to Professor
Robert R. Newton, who at that time (in 1981) was a leading
authority on this problem. 55 I wanted to know how much the
lengthening of the solar day has affected ancient records of lunar
eclipses and if we can still rely upon the older tables of calculations
of lunar eclipses published by Oppolzer in 1887 and Ginzel in
1899.
54 This most recent value is the result of the very careful research performed by
Richard Stephenson of the University of Durham and Leslie Morrison, formerly of
the Royal Greenwich Observatory in Cambridge.—See New Scientist, January 30,
1999, pp. 30–33.
55 Newton’s research in this area has since been improved upon by other scholars.
See, now, the exhaustive discussion by F. Richard Stephenson in Historical
Eclipses and Earth’s Rotation (Cambridge: Cambridge University Press, 1997).