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    Re: Lewis and Clark lunars: more 1803 Almanac data
    From: Fred Hebard
    Date: 2004 Apr 18, 23:26 -0400

    Just to ride this hobby horse a bit farther, I don't see why street
    lights can't be capped with reflectors so that the light goes down, but
    not up, and also doesn't go sideways very far.  It would save quite a
    bit of electricity, due to doubling of the light output on the target
    from the reflector, and reduce light pollution.  It wouldn't be that
    difficult to implement, and would be reasonably cost free.
    
    Fred
    
    On Apr 18, 2004, at 5:14 PM, Gordon Talge wrote:
    
    > Just a personal note of modern life in the big city.
    >
    >
    >
    > A few years ago, my family and  I took a trip to Death Valley
    > out in the desert here in California. I was astonished at the
    > stars visible on a clear night without the interference of the
    > lights of Los Angeles. At the Grand Canyon in Arizona a few years
    > later it was the same.
    >
    > This is what it must have been like for the people observing
    > before the "let's light everything up" syndrome took hold.
    >
    > Has anyone seen the picture of Europe and North/South America from
    > space taken at night? You can see the outline of the continents
    > from space like a map just from the lights of cities and towns!
    >
    > I can certainly see how some star that "cannot" be seen now with
    > the light pollution, could very well have been seen without difficulty
    > in the past.
    >
    > -- Gordon
    >
    >
    >
    >
    >>
    >> I am no expert on maritime celestial navigation but have read widely
    >> on 17th and 18th century terrestrial celestial navigation and the
    >> stars used. Delambre, Mason and Dixon, Gregory, Thompson, Everest-
    >> they knew a stack of stars and used ones for zenith transits that
    >> today I can barely see. I am continually astonished how they got such
    >> good results from what are in some instances low magnitude relatively
    >> obscure stars.
    >>
    >> As an example of the variety consider a few of the stars used by Mason
    >> and Dixon viz Hamal, Vega, Deneb, delta and gamma Cygni, eta Pleiades,
    >> Aldebaran. And for Gregory beta Centauri, alpha Cor. Borealis, Tri
    >> Aust, Vega, beta Cygni, alpha Aquilae (Altair) and what about epsilon
    >> Pegasi and zeta Aquilae. Today I wouldn't be able to find these last
    >> two in the night sky let alone get them into an artificial horizon.
    >>
    >>  I repeat my contention that it is dangerous to suggest that stars
    >> weren't being used just because sailors weren't using them.
    >>
    >> Kieran Kelly
    >>
    >> 
    >>
    >>
    >
    > --
    >                               ,,,
    >                              (. .)
    > +-------------------------ooO-(_)-Ooo------------------------+
    > | Gordon Talge WB6YKK           e-mail: gtalge AT pe DOT net |
    > | Department of Mathematics      http://www.nlmusd.k12.ca.us |
    > | Norwalk High School                   Norwalk, CA          |
    > | (o-    Debian / GNU / Linux                                |
    > | //\    The Choice of the GNU Generation                    |
    > | v_/_                  .oooO                                |
    > |    - E Aho Laula -     (  )   Oooo. - Wider is Better -    |
    > +-------------------------\ (---(  )-------------------------+
    >                            \_)  ) /
    >                                (_/
    >
    
    
    

       
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