Re: Magnetic Polarity Re: Magnetic quenching.

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

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.