Re: Magnetic Polarity Re: Magnetic quenching.

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "teri mckenney" <mck-at-ezy-dot-net> 

Hello All,
This is getting off topic but what I find interesting is that scientist have
discovered by studying old lava flows that the polarity of the earth flip
flops every so often.Something going on in the core of the earth? This would
support an earlier post that said north and south were arbitrary.There are
two polarity's which trade places every so often thus keeping each other
even.
Bill Mck.
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, April 28, 2004 2:08 PM
Subject: Re: Magnetic Polarity Re: Magnetic quenching.


 > Original poster: davep-at-quik-dot-com
 >
 >  > Original poster: Ed Phillips <evp-at-pacbell-dot-net>
 >  >
 >  > Tesla list wrote:
 >  >  >
 >  >  > Original poster: "Daniel Ullfig" <DUllfig-at-sbcglobal-dot-net>
 >  >  >
 >  >  >  >     The definition of North Magnetic Pole is That Which Points
 >  > Geographic North.  Period.
 >  >  >  >
 >  >  >  >     THIS means that the Earth's Geographic North Pole is
 >  > associated with a SOUTH magnetic polarity there (actually:
 >  > Northern Canada, or the nearby ice pack...  8)>>)
 >  >  >  >
 >  >  >  >     yes: it is counterintuitive and mind bending.  Also true..
Had
 >  > it cross checked by a physicist once.  For experimental
 >  > verification:
 >  >  >  >     Wind a solenoid, observing 'left hand' rule for winding
 >  > direction, connect DC PSU in Specified Polarity and check
 >  > compass...
 >  >  >
 >  >  > The concept of north and south poles is completely arbitrary;
 >  > Physicists could have started by saying "the earth is a giant magnet,
 >  > and the north pole coincides with the magnetic north pole". then we
 >  > would have decided that the south pole of a magnet is that which
 >  > points to the north; finaly, when we discovered that electricity
 >  > produces a magnetic field, we would have discovered the "right hand
 >  > rule" instead of the "left hand rule", and it would all have worked
 >  > out anyways. In physics, some rules are just arbitrary, and everyone
 >  > agrees to them.
 >
 >  > It was common in the older books to refer to the "north-seeking >pole"
 > of a compass needle, which is not ambiguous.
 >      Agreed.
 >
 >  >  Of course, this is the south pole of the needle.
 >      Is it?
 >      Have you tested?
 >      My understanding and testing and reading indicate that the
 >      'n' end of a compass needle is defined as the North Seeking
 >      End, shortened to 'noth pole' which makes geographic
 >      NORTH a Magnetic SOUTH pole.  Counterintuitive.
 >
 >  >  I wonder if the original designation of north
 >  > came about because most navigation was done in the northern hemisphere
 >  > where Polaris was commonly observed to indicate north?
 >      Likely.  At least nitially.  At least for Europeans.
 >
 >