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    Re: ? ? ? Re: Dip uncertainty
    From: Alexandre Eremenko
    Date: 2004 Dec 6, 12:54 -0500

    I find George's argument more convincing.
    Let me try to rephrase it in a short and
    more abstract form.
    Consider two observers, one of height h (small)
    another of height H (large).
    Let L be the line from the eye of H,
    tangent to the sphere, that is the line from her
    eye to her horizon.
    Now we can place the shorter observer h so
    that his line from his eye to his horizon is
    a PART of the line L.
    Then whatever uncertainty in the dip h experiences
    will also affect the H's sight PLUS H will have additional uncertainty
    which comes from the additional segment of L from h's eye to H's eye.
    I like this argument very much because of its very
    general character. (No particular low of refraction is
    assumed here).
    On Mon, 6 Dec 2004, Bruce Stark wrote:
    > Thanks, Alex,
    > I hope people will continue to look for more information. The crux of my
    > argument, which I don't think has been addressed yet, was in the last paragraph:
    > "Set a prism between you and a line on the wall. Put the prism near the wall
    > and look at the line from across the room. You'll see the line not far from
    > its true position. Bring the prism close to your eye and you'll see the line a
    > considerable distance out of place."
    > Bruce

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