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    Re: Green Flash and Longitude
    From: Frank Reed CT
    Date: 2006 Jan 5, 17:50 EST

    Bruce Stark, you wrote:
    "To my knowledge, no  history of navigation has yet been written by anyone
    who's at ease in that way  of thinking. I hope you'll consider writing such a
    history yourself.  "
    Consider it? Yes. Even wrote quite a bit. Finish it?? Well, that  depends on
    whether I can think of a way to make it profitable --in a broad sense  of the
    "Anyone hard wired in the twentieth century way of  thinking will immediately
    see that by noting the time of a Green Flash (should  you be so lucky as to
    see one) you'd have the makings of a longitude LOP. How  accurate it would be
    is another question."
    Clearly it would not be  particularly accurate --no more so than any other
    sunset/sunrise LOP which means  +/-5 or 10 minutes of arc error in the resulting
    line of position.
    Could  I ask you to clarify something for me: have you yourself heard of this
    before?  Have you heard or read that the green flash can be used to determine
    longitude  (or at least a more or less north-south LOP)? Do you remember the
    context of the  discussion? Finally, do you recall any reason why someone
    would have suggested  using the green flash specifically, which is quite rare,
    instead of timing an  ordinary sunset?
    42.0N 87.7W, or 41.4N  72.1W.

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