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Path: utzoo!linus!philabs!seismo!hao!hplabs!hp-pcd!hpfcla!ajs
From: ajs@hpfcla.UUCP
Newsgroups: net.astro
Subject: Re: Solstice =/= Earliest Sunset? - (nf)
Message-ID: <3540@hp-pcd.UUCP>
Date: Fri, 30-Dec-83 03:45:24 EST
Article-I.D.: hp-pcd.3540
Posted: Fri Dec 30 03:45:24 1983
Date-Received: Sun, 1-Jan-84 02:20:40 EST
Sender: notes_gateway@hp-pcd.UUCP
Organization: Hewlett-Packard, Fort Collins, CO
Lines: 19

#R:decwrl:-469600:hpfcla:37600001:000:830
hpfcla!ajs    Dec 25 17:10:00 1983

Length of day is  dependent  on the angle of the Earth's  axis away from
the Sun.  The minimum occurs when the Earth passes  through the point in
its orbit  where the North Pole is furthest  "out".  However,  the small
ellipticity  of the Earth's  orbit  causes it to be a little  "ahead" or
"behind" of where a circular orbit would put it at certain  times.  This
is expressed in the "equation of time", which gives the deviation (up to
14 minutes, if I recall  correctly).  So, it's possible that the sunrise
time could get a little  earlier for a time near the  Solstice,  even as
the days got shorter.

So much for my layman's  explanation;  let's see how the experts correct
me.

Alan Silverstein, Hewlett-Packard Fort Collins Systems Division, Colorado
ucbvax!hplabs!hpfcla!ajs, 303-226-3800 x3053, N 40 31'31" W 105 00'43"