Subject: Re: [BoundaryPoint] Re: How far is it?
Date: Mar 10, 2004 @ 19:46
Author: Jesper Nielsen ("Jesper Nielsen" <jesniel@...>)
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I know which two tps are the closest (not counting the bwnazazw mess)

Jesper
----- Original Message -----
From: "Lowell G. McManus" <mcmanus71496@...>
To: "Boundary Point" <boundarypoint@yahoogroups.com>
Sent: Wednesday, March 10, 2004 5:49 PM
Subject: Re: [BoundaryPoint] Re: How far is it?


> If one wanted to determine the two tripoints that are farthest apart, one
should
> first determine which few pairs are the most likely candidates based on
their
> relative antipodality from each other. This would take some trial and
error.
> However, since the antipodes of most continents are oceanic, there
shouldn't be
> an abundance of likely candidates.
>
> Next, the few candidates might have to be evaluated for the effects of the
> spheroidicity of the earth and for elevation. The earth is an oblate
spheroid,
> bulging at the Equator and flattened at the poles. However, the
difference
> between sea level diameters pole-to-pole and Equator to Equator is
typically
> stated in the range of 40 to 43 km. The supposedly most precise model
pegs the
> figure at 42,952 meters, which is less than 27 miles. On top of this
distance,
> elevation could add a few more miles if one found a pair of relatively
antipodal
> tripoints both in high mountains. Elevation would most affect diametric
> distance and would be much less significant circumferentially.
>
> Considering the relative paucity of land-land antipodes and the relative
paucity
> of tripoints near the poles, the variations due to spheriodicity and
elevation
> above sea level would probably be inconsequential in determining the two
most
> interdistant tripoints.
>
> At http://williams.best.vwh.net/gccalc.htm , you will find yet another
> great-circle distance calculator into which one can enter the coordinates
of any
> two points and get their circumferential distance apart. This calculator
> differs from the others in that you can chose from various mathematical
models
> of the shape of the earth, from perfectly spherical through a number of
> spheroidal models. Among these last, the one currently accepted is
> WGS84/NAD83/GRS80.
>
> Lowell G. McManus
> Leesville, Louisiana, USA
>
>
>
> ----- Original Message -----
> From: "acroorca2002" <orc@...>
> To: <BoundaryPoint@yahoogroups.com>
> Sent: Wednesday, March 10, 2004 8:31 AM
> Subject: [BoundaryPoint] Re: How far is it?
>
>
> > really
> > i dont remember that
> >
> > & it is an interesting question
> > as well as a challenging try pointing quest
> >
> > perhaps even 2 of each
> > since the farthest pair of points measured circumferentially
> > might not be the same points as the diametrically farthest pair
> >
> >
> > yet exactly how to solve for either set
> >
> >
> >
> > alternatively
> > someone may already have solved & posted answers for them
> >
> > so perhaps a prior question is
> > exactly how to search for any such ready made answers
> >
> >
> > &or
> > failing that
> > there must be some data on the geoid already developed &
> > available somewhere that might be useful toward these ends
> > if we knew what to look for
> >
> > like
> > greatest circumference & diameter figures might be a good
> > place to start
> > since these are likely to have been worked out to some degree
> > of specificity & accuracy
> >
> > but where & how to find them
> >
> > & could we in fact approach the correct answers via these data
> >
> > & if so
> > by exactly what means could we get there from here
> >
> >
> >
> > but can anyone solve or advance this
> >
> > or even clearly see the right way to go
> >
> >
> > --- In BoundaryPoint@yahoogroups.com, "L. A. Nadybal"
> > <lnadybal@c...> wrote:
> > > We discussed some time back the maximum distance that any
> > two places
> > > on earth could be from one another.
> > >
> > > This site claims to deliver the distances between two selected
> > points:
> > >
> > > www.indo.com/distance/
> > >
> > > LN
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>
>
>
> Yahoo! Groups Links
>
>
>
>
>