Planet Earth Magnetic Field

[tpetar]

I have one question, its not in semiconductors/conductors area, I apology for that, but its interesting.

What make Magnetic Field of Planet Earth ?


We dont know how Earth is maked and other planets to, we only make assumption and speculation about that through science.
Yes, yes, yes, I know science is there that we dont have assumptions and speculations, and that we have exact values and confirmations, but is there some situation in science when scientist say, "We dont know how this works, but we will work on that?". Just look thesis about Quasars and black holes.

How we can explain situation about Planet Earth Magnetic Field is it natural magnet or artificial ?

If we know that permanent magnet CANT exist on higher temperatures. Curie temperature of iron is around 770C. The Earth's core is hotter than that and therefore not magnetic. So how did the Earth get its magnetic field? By contrast of that artificial magnetic field can exist on higher temperature. Then geomagnetic rocks.... but we know that magnetic field comes from centre, and not from surface of cold rocks.

Although the details of the dynamo effect are not known in detail, the rotation of the Earth plays a part in generating the currents which are presumed to be the source of the magnetic field. Mariner 2 found that Venus does not have such a magnetic field although its core iron content must be similar to that of the Earth. Venus's rotation period of 243 Earth days is just too slow to produce the dynamo effect.
It does seem clear that the generation of the magnetic field is linked to the rotation of the earth, since Venus with a similar iron-core composition but a 243 Earth-day rotation period does not have a measurable magnetic field.

They say fluid metallic iron which makes up a large portion of the interior, and the rotating conductor model leads to the term "dynamo effect" or "geodynamo", evoking the image of an electric generator. Melting of iron is on high temp 1200C and up, but we know that we lose magnet around 770C.



Dont understand me wrong, I just want to see different thinking about this.


**broken link removed**

 

[BradtheRad]

I once asked an engineer buddy the same question, seeing that iron loses its magnetic properties at high temperatures.

He said 'eddy currents'.

That is the answer. Thus it's possible for the magnetic field to be linked to earth's rotation. Thus it's possible for the North and South magnetic poles to reverse every so often.

 

[tpetar]

I found this thread in some forum its interesting, yes they also say Eddy currents :

https://www.physicsforums.com/showthread.php?p=2830537




But what if Sun solar wind get stronger and stronger ? Maybe that process is right now?

 

[BradtheRad]

I don't know much about the process of eddy currents within the earth, or how much the sun influences them.

Just as a matter of interest, I once saw an article speculating that a sufficiently strong solar wind could conceivably distort the earth's magnetic field, pushing it forcibly enough toward the unilluminated side, so as to expose an area of our planet's surface close to the sun. This could be lethal for life in that region, unprotected from the sun's radiation, because it is earth's magnetic field which protects us and all other life on the planet.

 

[jasonc2]

Well I found this: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magearth.html but judging by your post you already found that too (and probably everything else in the first google page for "earth's magnetic field" :lol.

This is an interesting article that also touches on the subject of dynamo theory: http://en.wikipedia.org/wiki/Geomagnetic_reversal

 

[tpetar]

Yes, my friend, I think this is interesting question.

I read many theories about that mistery but I must say I didnt convinced in this stories. I think they give some solutions like we must have any solutions, true or false, but we must have solution. Maybe we cant have it for now, because we must learn more or something else.

Also there is mistery about grannite, but this story is much acceptable.

 

[jeffrey samuel]

one great possibility is due to the variation in the force of gravity on the lower hemisphere in the summer by the cumulative effect of the gravitational powers of both the sun and jupiter coming in a same line