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    Re: Refraction
    From: Marcel Tschudin
    Date: 2005 Aug 6, 22:23 +0300

    George wrote:
    
    >>R(-2?)  =  R(0?)  +  (  R(0?) - R(+2?)  )
    
    > To me, that argument doesn't hold water. If Marcel wishes to maintain it,
    > I
    > would like to see a more detailed justification. Agreed, in the case of
    > negative altitudes, there's a curved light path on both sides of the
    > tangent point. The curvature of this second light path is in the same
    > direction as the first, so their refractions add. But how does his
    > conclusion follow?
    
    The proposed formula is the outcome of a purely a heuristic approach, based
    on the thoughts already mentioned. The equal sign seems really to be wrong.
    However, it seems to me that this formula may possibly be used for
    estimating an upper limit, i.e. is really
    
    R(-2?)  <  R(0?)  +  (  R(0?) - R(+2?)  )    ???
    
    Even if this would be correct, it would unfortunately not answer my initial
    question.
    
    Marcel
    
    
    

       
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