Earth's Magnetic Field

Tonight's "NOVA" is an examination of whether Earth's magnetic field could
reverse or disappear -- should be pretty interesting.

http://www.pbs.org/wgbh/nova/magnetic/

-- Stinger

Hi Stinger They did not mention that there was "solid" iron at the
core,and liquid iron surrounding this solid iron. With white hot liquid
iron what theory do they use to overcome that iron that hot losses its
mangnetisim. Madam Curie told us this 100 years ago. Hard to create a
dynamo with no magnetism. I have not tested this but a bar magnet should
lose its magnetisim when it gets hot enough to radiate photons of
light,and heat. Bert

It was an interesting show, though. They at least made a good case as to
why we should want the magnetic field to remain stable and where it is. I
hope this sort of research contiues to get funding.

-- Stinger

"G=EMC^2 Glazier" wrote in message
...
Hi Stinger They did not mention that there was "solid" iron at the
core,and liquid iron surrounding this solid iron. With white hot liquid
iron what theory do they use to overcome that iron that hot losses its
mangnetisim. Madam Curie told us this 100 years ago. Hard to create a
dynamo with no magnetism. I have not tested this but a bar magnet should
lose its magnetisim when it gets hot enough to radiate photons of
light,and heat. Bert

(G=EMC^2 Glazier) wrote in news:14009-3FBB6C0D-10
@storefull-2355.public.lawson.webtv.net:

Hi Stinger They did not mention that there was "solid" iron at the
core,and liquid iron surrounding this solid iron. With white hot liquid
iron what theory do they use to overcome that iron that hot losses its
mangnetisim. Madam Curie told us this 100 years ago. Hard to create a
dynamo with no magnetism. I have not tested this but a bar magnet should
lose its magnetisim when it gets hot enough to radiate photons of
light,and heat. Bert


Howdy Bert,

Watched the show. Very interesting. I think (if I am remembering
correctly) that the point was the earths core is a molten metal that acts
like a superconducter. This in turn generates the magnetic field
surrounding the earth. As opposed to it actually being a giant magnet. In
the physics lab-experiment they were using liquid sodium to generate a
magnetic field around their model of earth.

Jed

"G=EMC^2 Glazier" wrote in message
...
Hi Stinger They did not mention that there was "solid" iron at the
core,and liquid iron surrounding this solid iron. With white hot liquid
iron what theory do they use to overcome that iron that hot losses its
mangnetisim. Madam Curie told us this 100 years ago. Hard to create a
dynamo with no magnetism. I have not tested this but a bar magnet should
lose its magnetisim when it gets hot enough to radiate photons of
light,and heat. Bert


Hi Bert,
To be very simplistic, there are two sources of magnetism. Those inherent to
the atoms. In ferromagnetism, the fields is created by when the magnetic
moments of the atoms tend to align in a preferred direction. As the
temperature increases, the alignments become more random, decreasing the
magnetic field.
The other source is electric currents. As long as current flows, these are
not affected by temperature.

DaveL

Hi DaveL That is what is called the Curie effect. Random motion means
there is no magnetism. You mentioned electric current as another way to
create a magnetic field,but what is the source of this current? I have
read of a theory that radio active material can create an electrical
current,and that there is such a material at the Earth's core. That
could be the answer to over come the Curie effect(random motion created
by heat) Well I did post still another way in my "What If" post
yesterday. Bert