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    Re: Standing over Giants' shoulders (Was Exercise Lunar Distance with Mercury)
    From: Antoine Cou�tte
    Date: 2009 Sep 24, 03:18 -0700

    Dear George,
    
    
    
    You wrote in [NavList 9880] :
    
    ... " sextant's lighter-toned shades " ...
    
    that is the expression I was looking for. Everybody has to use such "shading 
    glasses", at least for the Sun, in order not to get blinded by its light. So, 
    thank you very much for your help here.
    
    ******
    
    You also wrote in [NavList 9880] :
    
    " But really, is it possible, with the sort of scope to be found on a 
    sextant, to discern Mercury as any more than a point of light, anyway? To do 
    better must call for remarkably acute vision. But, assuming that it's 
    possible, is the use of a shade going to reduce it from a finite size to a 
    point-source? I would have doubts about that. "
    
    
    I would suggest that if it maybe very true that even a "low shade" might make 
    Mercury difficult to see through, the observer should first swing-kiss and 
    adjust the sextant without such "shade", and only use the shade just after 
    that first sextant presetting. The planet will not be far away from the limb 
    as it moves a at speed roughly equal to 0.1 arc minute in 10 to 15 seconds of 
    time. What would regularly trained Lunar Observers think about this method 
    (Frank and Jeremy ?)
    
    *******
    
    
    And you also wrote in [NavList 9880] :
    
    " Antoine seems to have the advantage of direct contact with the originators 
    of the Paris predictions who, to me, are no more than revered names in 
    Meeus. "
    
    
    
    AS REGARDS SOLAR SYSTEM PLANETARY THEORIES
    
    I had the extreme good luck of being Friend with Dr Pierre Bretagnon, who 
    unfortunately for the Astronomical Community passed away almost 7 years ago 
    now.
    
    
    He was a "Giant" who stood upon the shoulders of many Giants before him, 
    coming from all countries over the centuries, to name some of them :
    
    Hipparcos from Ancient Greece,
    
    Galileo Galilei from Italy,
    
    Tycho Brahe from Denmark,
    
    Copernicus from Poland,
    
    Kepler from Germany (your country Peter ?)
    
    the GREAT NEWTON from your own Country George,
    
    Urbain Le Verrier from France who was the First to publish a theory covering 
    all 8 Planets from our Solar System,
    
    the Great Simon Newcomb for the USA, who was the second to undertake the same 
    task, and with significantly more accurate results for the inner planets,
    
    Albert Einstein, from Germany before he was hosted by the USA,
    
    and the J.P.L. Planetary team (your country again Frank) !
    
    Dr Pierre Bretagnon was the third one after Urbain Le Verrier and Simon 
    Newcomb to publish an 8 Planet Theory (VSOP 82) further refined into VSOP87, 
    leading the way to the new Theories from Bureau des Longitudes even much more 
    accurate. It is astounding that now for planetary Positions (almost) only 
    remain now the J.P.L. with Numerical Integration Methods and the French 
    Bureau des Longitudes with Analytical Theories. Both are (almost) equally 
    accurate (true that the BDL Theories "line up" on sample positions from JPL) 
    and they are complementary in many respects. As an example only Analytical 
    Theories can give super-accurate long term trends (Precession values). When 
    Pierre disappeared he had started an incredibly accurate new Nutation Theory 
    and he led the way here again to further developments in this field.   
    
    ... AND AS REGARDS THE MOON THEORIES
    
    Dr Jean and Mrs Michelle Chapront also stand on the shoulders of Former Giants, such as 
    
    Tobias Mayer,from Germany too,
    
    Hansen from Germany, again
    
    Delaunay from France,
    
    Airy from the UK,
    
    Brown from the UK, so much celebrated and revered by Eckert who was astounded 
    by his incredible computational power (not a single error in many thousands 
    terms computed !!! )
    
    and the current J.P.L. Planetary and Lunar Team (your country again Frank !).
    
    Dr Jean Chapront and his wife Dr Michelle Chapront-Touze are (almost) the only 
    ones who entirely succeeded in completing a full semi-analytical Moon theory 
    deadly accurate (within just a few centimeters for Erath-Moon Distance when 
    compared to the current best JPL's numerical integration). And again, like 
    for the Planetary Theories, only remain both the J.P.L. and the French Bureau 
    des Longitudes when it comes to computing the Moon position.
    
    
    So many efforts over so many centuries, all around the world - and let all the 
    Giants I forgot naming here for lack of space forgive me ! - for results 
    which can be now almost in everybody's computer, calculator or the like, with 
    such incredible computing power with virtually error free results (as long as 
    programming has been correctly done, because nothing is ever more stupid than 
    a Computer or Calculator, but this is another story ... ).
    
    
    To summarize, I thank you George for your remark on the "revered names" 
    because it gave me the opportunity of writing here how wonderful it can be 
    nowadays to have instant access to such beauties !!! An other example 
    permitted by to-day technology : the entire Music written by the GREAT Johann 
    Sebastian Bach himslef can be carried out in just 2 DVD's !!!!
    
    
    Best Regards to you all, and thank you again
    
    
    Antoine
    
    
    Antoine M. "Kermit" Couette
    
    
    
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