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Re: south in the north




At 7:19 PM +0200 5/5/98, Miguel A. Santos wrote:
I would say this is the second time
this topic is discussed in this list...and I thought this
was an already closed question. How naive I was.
Indeed, after reading and re-reading the contributions
of this second attempt, I am no longer sure if my
picture of magnet-earth pair is right.

That's how I fitted these things together:
-for the origin of earth's B field, I imagine, f.i.
a solenoide, located at the earth's center, the current
circulating from London to South Africa.
-The bar magnet has magnetic dipole pointing from its
white end (south) to its red end (north) (suppose no one
has inverted its magnetization, so that red is actually
its north)
-A magnetic moment will always aling (same direction
and orientation) with the B field wherein the former lies.
-The compass we have in our hands lies always outside the
solenoid wich models the Earth's B field.

I see the current loop (solenoid) with its axis parallel to the rotational
axis of the earth (almost). The loop lies under the equator (how deep?).

For conventional (positive) current, the motion of the positive charges is
from East to West. For electron flow the direction would be from West to
East.

This geometry creates a field INSIDE the loop that points toward the
penguins and a field OUTSIDE the earth that points toward Santa Claus. (and
Polaris the North Star)

Once the Earth's field reverses, will we rename the continents of North and
South America?????

-. .-. .-. .-. .-. .-. .-. .-. .-. .-
\ / \ / \ 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


I don't worry about the origin of the Earth's magnetic field. I just
accept there is one, with its B vector pointing north-south. As it
has no sources, their lines make loops. At the Earth surface we
would see these lines turning back. Hence the compass needle
has a reversed orientation with respect to the B inside.

Why does this picture fails?

M.A.Santos
msantos@etse.urv.es