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    Re: December Solstice
    From: Frank Reed CT
    Date: 2003 Dec 19, 02:04 EST
    Pierre Boucher wrote:
    "Please comment on the facts that:
    Starting on Dec 13 (9 days before DSO) Sunset time is later day after day
    and It is only from Jan 9 (18 days after DSO) that Sunrise time stars to be earlier day after day"

    Right. The earliest sunset occurs BEFORE the solstice, and the latest sunrise occurs AFTER the solstice. This is a little difficult to explain without pictures, but there a couple of things you should consider. First, on the solstice, the day is shortest. That much is guaranteed. The time from sunrise to sunset is least. If you take the actual clock times of sunrise and sunset and find the time halfway between those, you will discover that it's not noon --not 12:00:00. That's really why the times of earliest sunset and latest sunrise are off --the time of local apparent noon is sliding about as the year passes. Local *apparent* noon is not the same as the noon we measure on our clocks because the Sun in the sky is not a perfect clock. It runs fast during certain parts of the year, slow during other parts. As I say, it helps a lot if you can see this with pictures, so I would direct you to a web site: www.analemma.com . It has lots of great information relevant to this issue. If you still have questions after reading there, I would be glad to talk more, and I am sure other people on the list would help, too.

    Frank E. Reed
    [X] Mystic, Connecticut
    [ ] Chicago, Illinois
       
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