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    Re: Sun squash- was Green Flash and Longitude
    From: Glenn Geers
    Date: 2006 Jan 16, 12:41 +1100

    Ken Gebhart wrote:
    > On 1/14/06 9:24 PM, "Fred Hebard"  wrote:
    >> Great post Ken.  I can imagine it would be a lot of fun, or
    >> something, to try to work out a sight by hand while steering with
    >> one's knees!
    >> How would you measure squash?  The altitude of the two limbs and
    >> assuming the SD for the width or the semi-diameter both ways?  I
    >> don't know how to do semi-diameter with an aircraft sextant (or
    >> anything else with an aircraft sextant!).
    >> Fred
    > Thanks Fred,
    > The idea is just a visual observation without a sextant.  The ellipse
    > templates as mentioned, could be used to compare with the squashed sun to
    > get a good value.  The entire squash phenomenon takes place during a 15 to
    > 20 minute period.  The first discernable squash is at about 2%, and can best
    > be seen with the head tilted 90 deg to the side. For some reason we humans
    > can detect a slight ellipse with the major axis vertical rather than
    > horizontal.
    > Ken
    I would suspect that preference for ellipses with a vertical major axis
    comes about from our innate ability
    to visually locate faces in all sorts of whacky backgrounds and
    environments. Ain't evolution grand.
    I know it's off topic.

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