Subject: Re: How far is it?
Date: Mar 11, 2004 @ 16:14
Author: acroorca2002 ("acroorca2002" <orc@...>)
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> greatthemselves
> thanx
> i get it
>
> so we should drop the circumferential pursuit
> because even if we could determine the exact longitudes of the
> longest meridional circuit
> which we cant
> no single pair of points on that circuit would present
> as being any farther apart along the earths surface than any&
> other pair
>
> & this regardless of whether they were actually antipodal or not
> hahaha
>
> & therefore we can cut back to the only chase that we still have
> left to us
> by examining & comparing topographical maps of the sumatra
> ecuador neighborhoodsMcManus"
> so as to try to find the pair of antipodes thereabouts with the
> greatest combined elevation above sea level
>
> to be continued no doubt
>
>
> --- In BoundaryPoint@yahoogroups.com, "Lowell G. McManus"
> <mcmanus71496@m...> wrote:
> > Insertions below between lines marked thus: +++++++++
> >
> >
> >
> > ----- Original Message -----
> > From: "m06079" <barbaria_longa@h...>
> > To: <BoundaryPoint@yahoogroups.com>
> > Sent: Wednesday, March 10, 2004 8:00 PM
> > Subject: [BoundaryPoint] Re: How far is it?
> >
> >
> > --- In BoundaryPoint@yahoogroups.com, "Lowell G.
> > <mcmanus71496@m...> wrote:pertaining
> > > I seem to have misconstrued the original quest as
> > to tripoints.&
> > >
> > > If it pertained to [just] points, then I think that the two points
> > farthest
> > > apart diametetrically would be the two equatorial or very
> nearly
> > equatorial
> > > antipodes with the greatest combined elevation above sea
> > level. The bulging
> > > equatorial diameter would easily overcome any elevational
> > advantages of
> > > non-equatorial points. I would nominate some Ecuadorian
> > peak and its Sumatran
> > > antipode.
> >
> > good thinking
> >
> > i also realized the diametric maximum would fall within the
> > famous equatorial bulge
> > just as the diametric minimum would fall within the equally
> > famous area of polar compression
> > but have no idea how broad or how locally steep this bulge &
> this
> > compression are
> >
> > like
> > are they very nearly as linear & perpendicular as the equator
> > axis themselves arearc
> > being confined to say only a very few degrees of spheroidal
> > ormuch
> > do they perhaps spread out much more broadly & blend
> > more gradually with their surrounding regions until finallyup
> > disappearing somewhere around the 45th parallel
> >
> > ++++++++++++++++
> > If the solid structure of the earth were a perfect sphere,
> centrifugal force
> > from the diurnal rotation would cause our fluid seas to pile
> 27 miles deep atpolar
> > the Equator, swamping everything there while leaving the
> regions high andSince
> > dry. Centrifugal force being what it is, the seas do pile up 27
> miles deep
> > there anyway, but the sea floors and the dry lands of the
> equatorial regions
> > providently bulge upward to precisely match their swell!
> solid structureand
> > and centrifugal effects on fluid must be in perfect agreement,
> the equatorial
> > bulge and the polar flats must necessarily spread broadly
> blend gradually.would
> > I doubt that the rate of bulging is constant throughout. I
> expect theforce
> > rate to be greatest near the equator where the centrifugal
> is greatest.an
> > If it were constant, though, that rate would be 477 meters per
> degree of
> > latitude. If so, then just a few degrees of latitude from the
> equator would
> > negate the effects of some fairly pronounced differences in
> relief.
> > ++++++++++++++++
> >
> > if the former
> > then you must be right on with ecuador & sumatra
> > & we might proceed to narrow the possibilities further
> >
> > & if the latter
> > then we might have to consider peaks of the entire equatorial
> > region
> > conceivably even as far afield as the tropics
> >
> > ++++++++++++++++
> > It wouldn't be nearly that far.
> > ++++++++++++++++
> >
> > still guessing wildly here of course
> >
> > in other words
> > i do realize lowness of latitude will generally trump height of
> > altitude
> > but dont know yet at what latitude this advantage begins to
> taper
> > off
> >
> > so can you think of any way to evaluate these parameters
> > or to at least bridge the apparent data gap
> > because i think this additional understanding could be
> essential
> > before proceeding further
> >
> > more below
> >
> >
> >
> > > The two most circumferentially distant antipodes present
> > entirely differentthrough
> > > question. The polar flattening causes the shortest
> > circumferential routes
> > > between any two antipodes to be along a great circle
> > the poles.between
> >
> > ok but thats the shortest & we want the longest
> >
> > ++++++++++++++++
> > Yes, but what we want to find is the longest of the shortest
> (most direct
> > possible) circumferential routes--as opposed to those that
> take unnecessarily
> > long and scenic paths just to make themselves longer.
> Imagine two equatorial
> > antipodes and the question of the circumferential distance
> between them. They
> > could be joined by an equatorial route, a polar route, or
> anything in between.
> > The equatorial route would be unnecessarily long because it
> runs the bulge all
> > the way around. The polar route would clearly be shortest
> (most direct), and
> > thus the truest answer to the question of the distance
> any pair ofthan
> > antipodes.
> > ++++++++++++++++
> >
> > & does your next statement follow from this
> >
> > you seem to follow now by saying there are none shorter
> > any otherscertainly
> > which seems a contradiction of the above
> >
> > ++++++++++++++++
> > What I say is that none of the most direct (polar) routes would
> differ in length
> > from each other on an earth without relief. They would
> differ fromany
> > unnecessarily longer indirect (non-polar) routes.
> > ++++++++++++++++
> >
> > or do both of these propositions make sense independently
> >
> > On a
> > > smooth oblate spheroid (an earth without relief), any pair of
> > antipodes would be
> > > equally interdistant one from the other. This is because
> > imaginable greatonly
> > > circle connecting them would make two crossings of the
> > bulging equatorial region
> > > and two of the flattened polar regions. On the real world,
> > the matter ofchoose
> > > elevational relief crossed in the process would differentiate
> the
> > distances
> > > between any pair of antipodes. You would want to pick the
> > diametrically
> > > opposite pair of west and east longitudes that cross the
> > maximum amount of
> > > continental relief during their circuit of the earth, then
> > any twoand
> > > antipodes on that circuit--perhaps something like 70° W
> > 110° E.possible
> >
> > interesting too
> > tho i am not sure i understand
> >
> > are you saying here that all circumferential differences are
> > levelled except for those presented by relief
> >
> > ++++++++++++++++
> > Unfortunately, yes. I am saying that all direct polar routes
> between any two
> > true antipodes should be equal except for the effects of
> intervening relief.
> > ++++++++++++++++
> >
> > but in that case it seems to me we face the difficulty of having
> to
> > measure in detail the actual terrain crossed by every
> > great circle in the world&
> >
> > or rather not just the difficulty but the ultimate imponderability
> > practical impossibility of itactually
> >
> > so maybe the supposed answerability of this question
> > evaporates under the heat of scrutinylength
> >
> > ++++++++++++++++
> > Yes, it does! Of course, there would be no way to effectively
> measure such
> > relief. One could only generalize that a route running the
> of the Andessmooth
> > would be considerably longer than one skimming the
> waters of the Pacific,relief
> > etc. That is why we would probably do best to disregard
> as a factor andour
> > simply bask in the sheer wonder of this proposition: The
> equality of
> > circumferential distance between any two antipodes
> (something that we would
> > expect to find on a perfect sphere) obtains nevertheless on
> oblatelyto
> > spheroidal earth! End of my insertions.
> > ++++++++++++++++
> >
> > but i am sure i dont fully understand this yet
> > so please clarify further if you can
> >
> > thanx
> >
> > end insertions
> >
> > >
> > > Lowell G. McManus
> > > Leesville, Louisiana, USA
> > >
> > >
> > > ----- Original Message -----
> > > From: "acroorca2002" <orc@o...>
> > > To: <BoundaryPoint@yahoogroups.com>
> > > Sent: Wednesday, March 10, 2004 12:41 PM
> > > Subject: [BoundaryPoint] Re: How far is it?
> > >
> > >
> > > > in bp terms
> > > > you have improved as well as redeemed what was only a
> try
> > > > pointing quest by turning it into an actual tripointing quest
> > > >
> > > > moreover your upgraded version is interesting in its own
> right
> > > >
> > > > & it holds forth some promise of being ultimately
> answerable
> > too
> > > >
> > > >
> > > > so have a leading pair of candidates suggested
> themselves
> > yet
> > > >
> > > >
> > > >
> > > > & having tried a few things too
> > > > i can report that the original quest
> > > > namely
> > > > which points on earth are farthest apart
> > > > & exactly how far apart are they
> > > > remains as hard to make any real headway with as it is
> hard
> > to
> > > > improve upon in curiosity value & elegance
> > > >
> > > >
> > > > --- In BoundaryPoint@yahoogroups.com, "Lowell G.
> > McManus"
> > > > <mcmanus71496@m...> wrote:
> > > > > 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
> > > > Equator is typicallymost
> > > > > stated in the range of 40 to 43 km. The supposedly
> > > > precise model pegs theOn
> > > > > figure at 42,952 meters, which is less than 27 miles.
> > top ofpair
> > > > this distance,
> > > > > elevation could add a few more miles if one found a
> ofyet
> > > > 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
> > > > anothervarious
> > > > > 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
> > > > mathematical modelsthrough
> > > > > of the shape of the earth, from perfectly spherical
> acurrently
> > > > number of
> > > > > spheroidal models. Among these last, the one
> > > > accepted isthese
> > > > > WGS84/NAD83/GRS80.
> > > > >
> > > > > Lowell G. McManus
> > > > > Leesville, Louisiana, USA
> > > > >
> > > > >
> > > > >
> > > > > ----- Original Message -----
> > > > > From: "acroorca2002" <orc@o...>
> > > > > 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
> > > > endssome
> > > > > > 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
> > > > degreetwo
> > > > > > 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
> > > > selected
> > > > > > points:
> > > > > > >
> > > > > > > www.indo.com/distance/
> > > > > > >
> > > > > > > LN
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > Yahoo! Groups Links
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > >
> > > >
> > > >
> > > >
> > > > Yahoo! Groups Links
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links