Re: Earth's Magnetic Field

[Chuck Britton <britton@ODIE.NCSSM.EDU>]

> At 02:36 PM 5/10/99 -0600, Larry Smith wrote:
> >I don't care which way we decide to do
> >it, as long as we can all agree together.  What is the vote on this list
> >for the convention?
>
> There's not much to vote on.  The conventions have been standard worldwide
> and unchanged for at least 400 years
>  http://es.rice.edu/ES/humsoc/Galileo/People/gilbert.html
> and probably much longer.
>
> 1) Compasses are marked so that their "N" poles point toward Canada.
>
> 2) Other bar magnets are marked the same way as compass needles.
>
> 3) Other magnets are marked the same way as bar magnets.
>
> --------
>
> Now for some pedagogic tools:
>
> a) The following statement seems to work:
>  The earth and its magnetic field can be modelled by taking a sphere and
>  skewering it with a bar magnet.  The "S" pole of the bar magnet is in
>  northern Canada and the "N" pole is in Antarctica.
>
> b) I recommend avoiding the term "geomagnetic north pole" because it is a
> notorious source of confusion.  Note that the recommended statement uses
> Canada as a circumlocution for geographic north, and uses "N" and "S" (not
> "North" and "South") to denote the markings on a bar magnet.


Hear, hear, 'nuf said (so I'll say a BIT more ;-)

A compass needle *IS* a bar magnet and a bar magnet *IS* a compass
when hung in the classroom. Do it, and leave it for kids to
'assimilate'.

Do away with the 'seeking' word unless you are JUST going for historic stuff.

Bar magnets and compass needles are labeled the SAME!

(Just wait another several thousand years and the penguins will be at
the South Magnetic as well as the South Geographic 'Pole'.

Actually, I'm trying to lessen the importance of the word 'Pole'
until the monopole is again experimentally seen.

And it is a surprisingly SHORT 'bar' magnet that models the shape of
the earth's field.

  -.     .-.     .-.     .-.     .-.     .-.     .-.     .-.     .-.     .-
    \   /   \   /   \ N /   \ C /   \ S /   \ S /   \ M /   \   /   \   /
     `-'     `-'     `-'     `-'     `-'     `-'     `-'     `-'     `-'
Chuck Britton                                   Education is what is left when
britton@odie.ncssm.edu                          you have forgotten everything
North Carolina School of Science & Math         you learned in school.
(919) 286-3366  x224                            Albert Einstein,        1936