declination when the moon is full and equal when the moon is new.
This can't be right.
You're right; it isn't. The *longitude* of the moon is equal and
opposite ... equal, respectively: that's the definition of a full and
a new moon; but the *declination* is an independent variable, and in
fact the Sun has no declination at all, or rather a constant
declination of 0, since the definition of the celestial equator is
the path of the Sun. When both longitude and declination are equal
(i.e., when the Moon's declination is 0), you have a solar eclipse;
when the declination is equal and the longitude is opposite, you have
a lunar eclipse. It makes no sense to say "the declination of the
moon is opposite that of the sun", by the way. I haven't been
following the thread carefully, but the original writer may merely
have meant "longitude" instead of "declination".
--
Bill Thayer
41N53 87W38
col cuore a
42N59.5 12E42.4 alt.313m
E Buon Natale a tutti!
http://www.ukans.edu/history/index/europe/ancient_rome/I/home.html
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