Re: [Phys-l] Is something wrong here?????

["Quist, Oren" <Oren.Quist@SDSTATE.EDU>]

My original question has been answered.  Thank You.  It just bugs me to see such blatant errors in public print that I could not let it lie (the mistake was also in the news release that one of the posts sent me to).  Perhaps a majority of people have heard of the polar bear or similar jokes and they laugh at them.  But no one it seems able to pick out real mistakes in the media.  If it is in print, it must be true -- don't even think about it.  And, this is an election year.  God help us!

Oren

________________________________________
From: phys-l-bounces@carnot.physics.buffalo.edu [phys-l-bounces@carnot.physics.buffalo.edu] on behalf of John Denker [jsd@av8n.com]
Sent: Tuesday, February 14, 2012 3:26 PM
To: Forum for Physics Educators
Subject: Re: [Phys-l] Is something wrong here?????

On 02/14/2012 11:33 AM, Quist, Oren wrote:

> It was announced a few days ago (in our local newspaper) that the
> Russians had drilled down and discovered a freshwater lake deep below
> the ice surface.  The location is approximately 80 miles (or was it
> km ??) southeast of the South Pole.
>
> Am I missing something here??

This is about what I expect from the local newspaper, i.e. arrant
nonsense.

1) The Russians did not recently "discover" the lake.  It (and others
like it) have been known for at least 50 years.
  http://en.wikipedia.org/wiki/Lake_Vostok
They only recently got around to drilling down into it.

2) According to Wikipedia, Lake Vostok is about degrees from the south
 pole, which corresponds to about 720 nautical miles.  You can do
 that conversion in your head, since one degree of latitude is 60 nm.
 It is not a coincidence that this is a round number.

 Wikipedia is not infallible, but the coordinates of Vostok Station
 i.e. -78.464422, 106.837328 are confirmed by satellite imagery.
 I calculate that point is 1288.280 km north of the south pole.
 My calculation takes into account the ellipsoidal shape of the geoid.
 I happen to have a good tool for that sort of calculation lying around.

3) Like *everything* else, it is north of the south pole.  It is not
 south, east, northwest, northeast, or anything else.  Just north.


On 02/14/2012 12:54 PM, Strickert, Rick wrote:
> > > If one is on the point pole and moves in the direction of S.
> > > America
> > > > that is certainly W. of moving towards Eurasia.  S. America is W.
> > > > of the prime meridian, and Eurasia is E.  No?
> > Indeed, one can use the definitions of Western and Eastern
> > Hemispheres and the Prime Meridian and Antimeridian.
> >
> > If, at the North/South Pole, one moves south/north in a direction
> > between the lines of 0 to +180 deg longitude one is travelling
> > (south/north) west, and if one moves in a direction between the lines
> > of +180 to +360 (0) deg longitude, one is travelling (south/north)
> > east.

Nonsense!

Suppose you are initially near the south pole and flying directly toward
it.  Your true heading will be 180.  As you pass over the pole, your
true heading will snap to 360.  There is no ambiguity about this whatsoever.
Longitude has got nothing to do with it.

If you are at the south pole and wish to fly toward a particular point,
you cannot specify it in terms of heading.  You can specify it in terms
of longitude, but that is not the same thing.

There is a singularity in the coordinate system at the pole.  Wishful
thinking will not make the singularity go away.

Strictly speaking, the singularity only occupies a set of measure zero,
so the singularity itself is not the main thing worth worrying about.
Instead, the interesting physics has to do with the bad behavior of the
coordinate system in the /vicinity/ of the pole.  Among other things,
the vector basis system _induced_ by the coordinate system is badly
behaved.  Great-circle routes are not lines of constant heading.  This
causes huge, dramatic problems near the poles (not just "at" the poles)
... and indeed the effect is noticeable even at temperate latitudes, for
any not-very-short flight.  Great-circle routes are not lines of constant
heading.

This has little to do with the intrinsic curvature of the earth.  It has
much more directly to do with the weirdness of the coordinate system.   You
can see this from the following:
 -- Intrinsic curvature affects the physics of /geodesic deviation/ i.e.
  the deviation of one geodesic relative to another
 -- If you see something funny happening along a /single/ geodesic, it
  can't be fundamental physics.  It must be associated with superficial
  weirdness in the coordinate system (or the vector basis system induced
  by the coordinate system).
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