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    Re: The Star of Bethlehem and Navigation
    From: Bill B
    Date: 2009 Jan 04, 08:14 -0500

    FER wrote
    > While we worry about leap seconds once every year or two, if you want to work
    > the same problem 2,000 years backward in time, you need something like three
    > hours worth of leap seconds, give or take 500. In other words, we can specify
    > atomic time or ephemeris time without much ambiguity and calculate most
    > phenomena in the heavens, like occultations and eclipses, with great accuracy.
    > Their relative timings will be accurate. But we don't know the exact local
    > time when those events occurred as seen from the Earth since we don't know
    > exactly how much mean time differed from "true" time back then. Was it 4:30 or
    > 4:35 local apparent time? Right now, there's no way to know.
    Thank you for accurate observation, also IMHO relative to the (too)
    long-running thread on leap seconds and cel nav ("time" vs. body GP).
    Bill B.
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