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From: crs@lanl.ARPA
Newsgroups: net.astro
Subject: Re: StarDate: April 5 Spring Tides
Message-ID: <24204@lanl.ARPA>
Date: Mon, 8-Apr-85 09:31:22 EST
Article-I.D.: lanl.24204
Posted: Mon Apr  8 09:31:22 1985
Date-Received: Tue, 9-Apr-85 03:49:30 EST
References: <43@utastro.UUCP>
Sender: newsreader@lanl.ARPA
Organization: Los Alamos National Laboratory
Lines: 27

> 
> It so happens that the moon is at perigee today -- and that fact
> contributes to today's high spring tides.  But there's something else
> causing the high tides -- the fact that the moon also reaches the crest
> of its full phase today.  You may have noticed a very full looking moon
> in the sky last night.  It'll be there again when the sun goes down
> Friday evening.
> 
> A full moon at perigee is a prescription for very high spring tides --
> because
>
> a full moon is *opposite* the sun in space -- or lined up in
> space with the Earth and sun.
>
> During such a time, the gravity of the
> sun comes into play, too -- causing tides that are higher than usual --
> which some of you who live near the ocean may notice.
> 
Am I missing something?  If, as described above, the earth, moon and
sun are in a line with earth in the middle, won't the gravitational
fields of moon and sun subtract rather than add?

No flames, please.  I'm not an astronomer, just interested.

Charlie Sorsby
...!{cmcl2,ihnp4,...}!lanl!crs
crs@lanl.arpa