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    Re: Leap seconds
    From: Greg R_
    Date: 2009 Jan 11, 11:33 -0800

    No need for George to get snippy either, though he has a history of doing that 
    and then complaining whenever someone calls him on it.
    
    --
    GregR
    
    
    --- On Sun, 1/11/09, Fred Hebard  wrote:
    
    > From: Fred Hebard 
    > Subject: [NavList 6981] Re: Leap seconds
    > To: NavList@fer3.com
    > Date: Sunday, January 11, 2009, 10:02 AM
    > No need for this Greg.
    >
    > On Jan 11, 2009, at 12:23 PM, Greg R. wrote:
    >
    > >
    > > Ignoring his usual pomposity (not to mention the
    > unnecessary
    > > verbosity and prolixity in this post), I take it that
    > George agrees
    > > substantially with what I originally posted (at least
    > in principle,
    > > if not necessarily with my particular choice of
    > words).
    > >
    > > So thanks for finally agreeing with me, George - if
    > only in your
    > > usual oblique (and occasionally obtuse) manner. That
    > wasn't so
    > > hard, was it?
    > >
    > > --
    > > GregR
    > >
    > >
    > >
    > > --- On Sat, 1/10/09, George Huxtable
    >  wrote:
    > >
    > >> From: George Huxtable 
    > >> Subject: [NavList 6976] Re: Leap seconds
    > >> To: NavList@fer3.com
    > >> Date: Saturday, January 10, 2009, 3:52 PM
    > >> Referring, apparently,  to posting [6933] (with
    > which I have
    > >> no
    > >> disagreement) from Gary LaPook, GregR has written-
    > >>
    > >>
    > >> "George:
    > >>
    > >> Are you reading this? Because this is EXACTLY what
    > I was
    > >> referring to
    > >> earlier (i.e. that whatever time scale we use as
    > navigators
    > >> is totally
    > >> irrelevant - as long as we can correlate it to the
    > time in
    > >> an almanac, or
    > >> whatever is used to obtain the date/time for a
    > celestial
    > >> event).
    > >>
    > >> I still don't know if you were being troll-ish
    > earlier
    > >> or honestly trying to
    > >> contribute to the discussion, but at least I'm
    > not the
    > >> only one who
    > >> understands the concept - however abstract it
    > might be for
    > >> some on the list
    > >> to comprehend."
    > >>
    > >> =============================
    > >>
    > >> Coming from anyone else on this list, I would
    > simply laugh
    > >> off the personal
    > >> comments in that posting, but GregR has a track
    > record of
    > >> repeated and
    > >> unwarranted personal unpleasantness in some of his
    > earlier
    > >> contributions, so
    > >> I am disinclined to treat such matters lightly,
    > from him.
    > >>
    > >> If he can avoid getting overheated, and deal with
    > any
    > >> question on a straight
    > >> factual basis, as I will do, we may be able to
    > manage
    > >> fruitful discussion
    > >> between us. Otherwise, not.
    > >>
    > >> ============================
    > >>
    > >> To be honest, I'm not really sure what Greg is
    > arguing
    > >> about. He contends
    > >> "that whatever time scale we use as
    > navigators is
    > >> totally irrelevant - as
    > >> long as we can correlate it to the time in an
    > almanac, or
    > >> whatever is used
    > >> to obtain the date/time for a celestial
    > event"
    > >>
    > >> I might well agree, depending on what meaning we
    > agree on
    > >> for "correlate".
    > >> If that includes adjusting for the number of leap
    > seconds
    > >> that would have
    > >> occurred since the almanac was produced, which is
    > what
    > >> would need to happen
    > >> if we adopted Atomic Time for our clocks, then
    > GregR and I
    > >> do not differ.
    > >>
    > >> I don't know how long in advance almanacs are
    > >> calculated and printed, but
    > >> let's say, for the purpose of argument, five
    > years. So
    > >> that means that the
    > >> almanacs that we use today were produced in 2004.
    > There was
    > >> no way the
    > >> compilers could predict, then, just how much the
    > Earth
    > >> would slow in the
    > >> next 5 years. If we were to switch to Atomic Time,
    > it would
    > >> mean that before
    > >> we could use any of the data in an almanac, we
    > would need
    > >> to discover how
    > >> much the Earth's spin had diverged from its
    > nominal
    > >> rate in that interval,
    > >> and allow for it by adjusting the reading of an
    > accurate
    > >> clock. That applies
    > >> to predictions, not just of the Sun, but of any
    > planet, and
    > >> via GHA Aries,
    > >> any star. Each one of us, individually, would have
    > to work
    > >> out our own
    > >> correction, depending on the date of our almanac
    > and the
    > >> (unpredictable)
    > >> adjustment that's called for. Instead of what
    > happens
    > >> now, when it's done
    > >> automatically (within less than a second of error,
    > anyway)
    > >> for us all, by
    > >> applying leap-seconds to everyone's clock.
    > >>
    > >> It's a matter of discussion whether Atomic
    > Time or the
    > >> present compromise of
    > >> Leap-second-adjusted time is the most convenient
    > way to
    > >> work our clocks in
    > >> the future. My personal opinion is that neither
    > is, but a
    > >> smoothly adjusted
    > >> clock-rate, that corresponds as well as possible
    > to the
    > >> observed rotation of
    > >> the Earth, would be more viable over the long run.
    > But that
    > >> isn't relevant
    > >> to our present discussion.
    > >>
    > >> Let's take the chance, now, to clear up some
    > loose ends
    > >> from GregR's initial
    > >> posting, [6805]. He had written "Besides, the
    > almanacs
    > >> have been on UT since
    > >> when - mid 70s? (and thus pretty much
    > >> "disconnected" from "sun
    > time")."
    > >> On
    > >> the contrary, we have seen that almanacs are,
    > indeed,
    > >> closely connected with
    > >> Sun Time, because UT is, within less than a
    > second, by the
    > >> operation of leap
    > >> seconds. And I have asked him what it is that he
    > reckons
    > >> occurred in the
    > >> mid-70s to change that situation, to which there
    > has been
    > >> no reply.
    > >>
    > >> George.
    > >>
    > >> contact George Huxtable, at  george{at}hux.me.uk
    > >> or at +44 1865 820222 (from UK, 01865 820222)
    > >> or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13
    > 5HX, UK.
    > >>
    > >>
    > >>
    > >>
    > >>
    > >>
    > >
    > > >
    > >
    >
    >
    >
    
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