[APG Public List] Regarding GPS

linda at fpr.com linda at fpr.com
Mon Nov 1 20:03:22 MDT 2010


Thanks, John.

I appreciate your clarifying what what you meant by "it" in the
statement you wrote.

Linda
____________
Linda Gardner
Massachusetts

> -------- Original Message --------
> Subject: Re: [APG Public List] Regarding GPS
> From: John Yates <john at jytangledweb.org>
> Date: Mon, November 01, 2010 8:24 pm
> To: apgpubliclist at apgen.org
> 
> 
> On 11/1/2010 2:39 PM, linda at fpr.com wrote:
> > Jay replied to a question I had asked John about one of his (John's)
> > posts:
> >
> >>
> >> A few items were mentioned in the last several postings regarding GPS.
> >>
> > [Linda asked John]
> >>> How exactly would one associate a GPS coordinate set with a place name,
> >>> so that it complies with your [John's] statement that while "the name of the
> >>> place is changed by changing, evolving, or revisionist history, the GPS
> >>> coordinates of it will never change."   When you [John] wrote "the GPS
> >>> coordinates of it will never change,"  what is the "it" ?
> >>
> > [Jay answered]
> >> "It" would be the point on the earth of  particular coordinates.
> 
> Correct.
> 
> >>
> >
> > Jay, when I read John's statement I thought he meant the "it" referred
> > to "place."   Restated in my own words, I read his statement to mean
> > that while the place names might change [for a variety of reasons] the
> > coordinates [for a place] wouldn't, ever.
> >
> > This does not make any sense to me.  So I asked John questions so that I
> > might improve my understanding of what he wrote, including different
> > scenarios of name changes, boundary changes, and overlapping boundaries.
> >
> >
> > Your reading of "it" is clearly different than mine.   Only John can
> > give further explanation of what he meant when he wrote his statement.
> 
> See above.
> 
> In a chosen coordinate system, the coordinates of a precise place won't
> change. If they do, it exposes a flaw in defining the coordinate system.
> Are there flaws in latitude longitude? Yes. One is continental drift.
> Sizable over millennia. Not so much in a lifetime. Catastrophic events
> like bomb blasts, earthquakes, etc. Possible, but rare.
> 
> If we change coordinate systems, there will be a one time, one to one
> mapping of the old coordinate pairs to the new coordinates. The place
> hasn't moved, just how we describe it.
> 
> I pretty much depend on the fact that my house will be at the same
> digital location when I come home again. And if I invite someone over
> for dinner, all I need to give them is a day, a time, and a pair of
> numbers. No other information is required. No city, state, continent,
> etc. And yet anyone in the world could find my door. Elegant!
> 
> John
> 
> > Linda
> > ____________
> > Linda Gardner
> > Massachusetts
> >
> >



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