Magnetic Quality of Ferrous Materials on Earth

That picture looks like someone got sloshed and their wineglass fell over.

How certain are you about the core not being solid?

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Doesn't iron lose its strong ferromagnetic properties when it is heated above the curie temp? Isn't the curie temp far below the melting point?

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I suspect that if 'magnetism' was different around planets of different composition that we would have indication of such by now.... for example, it probably would have been noticed as Voyager 1 or 2 passed the gas giants or the ice giants.

Doesn't iron lose its strong ferromagnetic properties when it is heated above the curie temp
Around 1400 degrees F.

Yeah! That's a good point. Doesn't iron lose strong ferromagnetic properties at the curie point...and isn't the curie point below the melting point?

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How about that apple?

Yeah - but - copper is NOT ferromagnetic but sure does a great job of creating a magnetic field when current flows through it. That's the point of this exercise. Molten metal churns and creates a current which in turn creates a magnetic field. Doesn't matter which metal it is. Could be liquid sodium and you'd still get the magnetic field. So - molten gold - churns - currents flow - magnetic field is created. So now, is gold at surface temperatures magnetic. Probably not.

<< Break >> "...is gold at surface temperatures magnetic. Probably not." "CORRECT"

Gold is among those metals that exhibit diamagnetism.

The OP has my mind in a tizzy, gandering-over the replies here. He seems to be proposing / suggesting that (exaggeration here) IF the earth's core were composed of liquid sodium, then, perhaps sodium would be "the magnetically reactive material" on this planet...(?)

He asked-&-stated : "If there was a planet out there with a golden core, would the magnetically reactive material on that planet be gold as well?" and
"The Biot-Savat (sic) law shows the realtion (sic) between the magnetic field (B) and induced current (I). Would an alternator made of gold work and that with iron not work in such a planet?"

Ferromagnetism is an inherent property of numerous materials including iron ore (magnetite / lodestone), gadolinium, dysprosium, and numerous alloys such as nickel-cobalt, Alnico (aluminium, nickel and cobalt with iron and small amounts of other elements), Samarium-Cobalt and Neodymium-Iron-Boron (NIB).

I for one would not buy-into a theory that these "inherent qualities" (with respect to magnetizability) would change simply due to their location , be it on mercury, earth, venus, pluto, or Krypton.

Just my 2¢

Flowing liquid metal should be a good conductor, right?

If it is a good conductor, what else is acting to create a separation of charge?

If there is no separation of charge, then flowing liquid metal will have a tough time generating a magnetic field, since there won't be a net flow of charge created by the conductors motion....

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The model you have details would seem to suggest that a magnetic field would be developed merely by spinning a block of copper. How would spinning a block of copper create a current? How is a spinning blob of molten iron different than a spinning block of copper as to allow the generation of current and magnetic fields?

Can't explain the physics at this time, as I haven't dug into it that deep but in the early part of the last decade a German-Lativian collaboration were able to generate a magnetic field from (the reason I mentioned it) rapidly stirred liquid sodium. In 2007 a similar experiment had similar results in France. The purpose of these experiments was to validate the belief that molten iron swirling in the Earth's core creates our magnetic field.

I've heard the swirling liquid iron explanation before. I'd say it is probably the most popular explanation

I haven't yet come across a good explanation describing how the swirling liquid iron generates magnetic fields. I haven't heard anyone who espouses this belief provide a plausible explanation of the mechanism or a model demonstrating the effect.....but I did miss the swirling sodium experiments.....

Perhaps someone has a link, or understands the theory sufficiently well to explain the mechanism in general terms?

Maybe the core is golden...?

http://gizmodo.com/5839001/ancient-earth-got-a-galactic-golden-shower

Or maybe it is chocolate and we are living on a great big M&M.

Two things: according to the best geo-physical measurements, the density, volume, and mass of Earth is a known. If the core of Earth were composed of gold, the planet would have a considerably higher mass, or the core would have to be considerably smaller than indicated by measurements. To consider how an element (on an atomic level) will interact with a magnetic field, or how conductive the material is, one usually considers the electron configuration of the element. Iron is certainly a great conductor of electric current in the molten state. Iron can be melted by induction heating, as I recall. The larger question which came first, the magnetic field, or the current in the iron?

One would tend to think that since gold is conductive but non magnetic it would not create a magnetic field- this could also apply to others in the rare earth group- but in our lifetime these esoteric ideas are playthings only

Is it a mere coincidence that the core and the magnetically active material are both made of Iron?
Yes. As others have stated, iron is not magnetic at those temperatures.

If there was a planet out there with a golden core, would the magnetically reactive material on that planet be gold as well?
No. Ferromagnetism has nothing to do with what's inside the planet. It is due to the unpaired electrons in the iron atom. Iron atoms anywhere in the universe are identical, as far as we know, as are gold atoms.
There are other planets in our solar system that have a magnetosphere (Jupiter, Saturn, Uranus, and Neptune) and a molten core, but there is no indication of how the material make-up of the core co-relates (or doesn't) with the magnetically reactive material on that planet.
As stated before, it has nothing to do with iron. It's the same effect as a self excited generator (dynamo).

I like it!

So the translation for my cheap seat is that in a spinning liquid metal conductor there is always electron flow, and therefore a field will be established because the electron configuration is never completed throughout the metal?

<*post-enlightenment*>

There is no co-relation between the type molten metal at the core and the magnetically reactive metals on the surface. The latter possess these qualities and will react as such, anyway, to the magnetic field induced via the Geo-dynamo effect.

Consequently, there will neither be an effect on electromagnetism.

I found a comprehensive report of the Sodium experiment that showed that a dipole could indeed be created in a similar fashion as in nature. Also, here's a video.

Electro-magnetic induction requires three components - a conductor, (it matters not whether the conductor is ferromagnetic), an EXCITATION FIELD, and the Rate of Change.

GA from me. Much appreciated.

I also appreciate the humour in the face of such an odd/ridiculous question. Hey, at least its not as ridiculous as a planet 8 times the size of Earth made of diamond! Imagine if such a planet was inhabited by "beings" who would save up to buy expensive copper rings for their spouses becasuse it is a rare element in that planet