Imbeded comments:

"Richard Harrison" wrote in message
...
Dave Shrader wrote: (amoung other things...)
...
Earth`s magnetic field produces an electron and ion flow which protects
Earth from the solar wind, turns aside charged cosmic rays, and causes
auroras. A magnetosphere turns with the rotation of the planet.

I do not believe Earth`s magnetic field "produces" any electrons or ions.
It deflects them coming from the sun because of the effect a magnetic field
has on electrical charges - the charges tend to move alonf the lines of
force and, therefore, the stuff gets routed to the poles or around the
planet.
I'm also not so sure that a magnetic field "turns" when the magnet
rotates about an axis through the poles. I think the lines going around one
of Earth's hemispheres (east-west speaking) are indestinguishable from those
of another hemisphere. Something in the field will not be dragged around
with the rotation of the planet.

every 100,000 years the Earth`s magnetic field reverses, interchanging
north and south magnetic poles.

The NOVA the other evening said it is something like 200 to 700 million
years, I believe. (May have the multiplier wrong, but the significant digit
is what they said)

So, if the earth keeps on turning as it always has, the magnetic
polarities will continue their reversals as throughout history when man
did not exist or was too primative to record such events.
Best regards, Richard Harrison, KB5WZI

The NOVA was not too clear about how a rotating molten conductor
creates a field, but once you get one, I can understand how the field and
current in the core can cross couple and keep each other going.

Regards, Steve k.9,d;c/i