What produce the earth magnetic fields ?

[ngkamsengpeter]

I am wonder what produce the Earth's magnetic field .Can anyone tell me . Besides , I am doing a experiment to measure the horizontal component of Earth's magnetic field . I am using a copper (about 16 mm in length) and a power supply of two volt . I use the copper to create the solonoid but suprisingly the ammeter show that there is no current flow in the circuit . That means that the copper cannot conduct electricity . How it can be the copper cannot conduct eletricity since the wire is made of copper .

 

[marlon]

I am wonder what produce the Earth's magnetic field .Can anyone tell me .

The Earth's magnetic field is caused by electric curents in the Earth's core region. This core is metallic in nature.

Check this out


marlon

 

[Gokul43201]

I am wonder what produce the Earth's magnetic field .Can anyone tell me .

The current state of understanding of this matter is very poor. The dynamo effect is the best guess, but still does not answer many questions (like the cause of the pole flips).

As for your field measurement circuit...we can not tell you what is wrong unless you show a diagram/schematic of the circuit (in the advanced post page, there is an option to attach files) or give us a complete description.

What principle are you using to measure the field ?

 

[vanesch]

I use the copper to create the solonoid but suprisingly the ammeter show that there is no current flow in the circuit . That means that the copper cannot conduct electricity . How it can be the copper cannot conduct eletricity since the wire is made of copper .

Naive question of course, but your solenoid is moving/rotating, right ?
If it is static of course you won't see anything...

 

[ngkamsengpeter]

Naive question of course, but your solenoid is moving/rotating, right ?
If it is static of course you won't see anything...

I use the battery to connect to the solenoid so that it become a magnet ,not se the solenoid to generate electricity . But there is no current flow .I waonder why

 

[ZapperZ]

I use the battery to connect to the solenoid so that it become a magnet ,not se the solenoid to generate electricity . But there is no current flow .I waonder why

I thought you said that you used a "...power supply of two volt ..."?

As Gokul said, without a complete description, who knows what is going on.

Zz.

 

[vanesch]

I use the battery to connect to the solenoid so that it become a magnet ,not se the solenoid to generate electricity . But there is no current flow .I waonder why

In other words, you shorted the battery, and now it is empty ?

 

[Gokul43201]

In other words, you shorted the battery, and now it is empty ?

Sounds like it.

peter : But that's only a guess. Unless you describe the circuit, no one will really know what happened.

Use a voltmeter and check that your battery is still okay. Next time, use a series resistor of at least 20 ohms (for a 0.25W resistor). If you don't do this, you will draw a very large current from the battery. Most household batteries are not rated to deliver more than 1A.

In any case, by making an electromagnet, how do you achieve the objective of measuring the horizontal component of the Earth's field ? Tell us the principle you are using to perform this measurement. Then tell use how you are building a device that uses this principle.

Of course, if you feel lost, ask for help.

 

[Ukitake Jyuushirou]

wat i remember about Earth sciences back in high school is that the Earth's mantle or core is made up of molten iron and other magnetic material and becoz they are rotating around inside the earth, they generate a magnetic field

correct me if I am wrong...

 

[Mk]

wat i remember about Earth sciences back in high school is that the Earth's mantle or core is made up of molten iron and other magnetic material and becoz they are rotating around inside the earth, they generate a magnetic field

correct me if I am wrong...

I think it is the other way around, the magnetic field is making the core spin.

 

[PaulD]

wat i remember about Earth sciences back in high school is that the Earth's mantle or core is made up of molten iron and other magnetic material and becoz they are rotating around inside the earth, they generate a magnetic field

correct me if I am wrong...

I just happen to have a copy of the Scientific American to hand, just as well because this isn't my field at all! "Probing the Geodynamo". It would appear that the mantle revolves faster than the inner and outer core. The upwelling of hot buoyant parcels of liquid iron towards the mantle combined with the Coriolis effect give a rotational speed differential between the core and the mantle and hence the dynamo effect.
Regards
Paul D

 

[Danger]

Thanks for that, Paul. Weird... I buy every issue of SA, and I don't remember seeing that.
Ngk (no way am I going to type out your whole damn name); this might seem idiotically simplistic, but are you sure that there's no break in the continuity of your circuit? Could there perhaps be a defect in the connection into your VOM? That's happened to me a couple of times. If a meter gets beaten around a bit, the plug-ins sometimes don't conduct properly. I learned that the hard way after carrying mine around in the same tool pouch with a few sets of Vise-Grips and a dozen screwdrivers.

 

[Paula]

That is really on my mind too.
It seems like the most easy suspect is different rotation speeds, since that is what you find on the sun.
But as far as I can see, many, not all planets, and some moons, have magnetic fields.
http://gsc.nrcan.gc.ca/geomag/index_e.php

Still, layman to layman, it seems like you really have to have a magnet present to get the magnetic field from the rotation of the ores.

 

[Mk]

That's why the magnetic field is making the core turn, and not the other way around. Am I right?

 

[Paula]

"The theory of the process is very mathematical and intricate, because to produce the currents, you need not only a flow of liquid iron, you also need a magnetic field, and this field is none other, but the one created by the currents themselves!"
http://www.phy6.org/earthmag/NSTA1C.htm

Also, I think there are some problems with the aging of a magnetic field. Hope you got your experiment going again.

 

[LURCH]

Considered by many to be the leader in the field;
http://complex.umd.edu/
Still no diffinitive answer, but they are producing real datya in a laboratory model.

 

[Paula]

Oh my gosh! It's a good thing they can do this experiment with those tubes and copper and sodium and refrigerator size magnets! That is better than crashing all those LARGE computers on the complexity of the problem! After all, this is taxpayer funded, via the NSF $6billion per year.

 

[Integral]

All you need to generate a magnetic field is a flow of current. Relative motion of the various depths will represent charge in relative motion, this is a current. Thus a electro-magnetic field will be generated.

Mk,
For the magnetic field to drive the core you must have a source of energy. The core is quite massive it would take tremendous forces to drive this mass of metal. What is your source of energy to do this?

 

[pallidin]

Relative motion differentiation, in itself, causes electron current flow? Since when?

Show me an experiment that molten metal, spun at "layerd" differential speeds(such as in a blender-type apparatus) has produced a magnetic field.

 

[Integral]

That sounds like a challening experiment on any scale, and I doubt that it has been done on a large scale. It is concievable that small scale would give different results from large scale as it could be a matter of measurability.

(Perhaps I need to spend some time looking at the above links.)

 

[Voodoo Conductor]

It seems like the most easy suspect is different rotation speeds, since that is what you find on the sun.QUOTE]

Unfortunately the sun is a poor comparison as its dynamo is thought to be driven by its fluid nature. The equator has a shorter rotation period than that of higher latitudes; about 25 days at the equator vs about 27 days at 40 deg latitude. Planetary crust doesn't quite have that degree of freedom.

 

[Steve Miller]

Hello!

Seriously, you should move closer to one, North or South Pole.

Steve

 

[tehno]

I am wonder what produce the Earth's magnetic field .Can anyone tell me . Besides , I am doing a experiment to measure the horizontal component of Earth's magnetic field .

I really don't know for sure.
But I would think that magma movements inside the core of the planet has something to do with it.
It definitely contains permeable elements like Iron and Nickel.
IIRC,the most interesting enigma about it is a decrease of Earth magnetic field measured over centuries.
I also remember reading somewhere they established that every 1000- 2000 centuries or so in history,poles of the "earth magnet" exchange their polarity (reverse signs).
Also unknown why!

 

[Paula]

techno--

The polar reversals are recorded on the ocean floor and all rocks that acquire the direction of the poles at the time they were formed. Paleomagnetic dating looks super fascinating and it would be fun to have a SQUID! Anyway, 1000-2000 centuries is not quite correct. What the scientists say is that they happen very sporadically, from several thousand to several million years between events. Then they say each reversal takes 5000 years. The poles wander quite a bit also.

I personally struggle with the estimation that it happens so irregularly. If you look at the stripes on the ocean floor, they are pretty even. I need to find some pictures of the magnetec anomalies that are a lot further away from the mid-ocean ridges, just to be sure. Also, the sun reverses polarity every 11 years. I wish I could find more about reversals on other planets, and moons--maybe someone has more info.

Also, you mentioned that the magnetic field has weakened, and it has over the last century, by as much as 10% some studies say. I try to use reputable sites for my info. The weakening may very well mean we are due for a polar reversal.

 

[tehno]

100,000-200,000 years were figures from my memory Paula.
Maybe that's was an estimated mean of the average period of the reversals?I don't know becouse it was long ago I heard/read about it..

Yup,we are likely to be close to yet another reversal I agree.
The "end" of World is coming !

 

[LURCH]

I've e-mailed Dr Lathrop in the past to ask about the possible role radiative decay in the core might play in generating the field. I asked him if they ever ran computer models that include this variable, but he seemed to missunderstand my meaning. He replied that conducting the lab experiment with radioactive materials would be far too dangerous (and I heartily agree).

Also, I wonder if Solar Max (inversion of the Sun's poles) might triger the inversion of our planetary poles, once they are destabalised enough. But if thwe revbersal hapens gradually over a 5,000-yr period, then this seems unlikely.

 

[Paula]

Maybe it is not known what is in the earth. We should scrap tradition: look, if the sun is so large, and is not an iron core prototype, and magnetic fields are common enough in our solar system, we need to put everything back on the table for some answers. Don't gas giants also have poles?!

 

[Paula]

And is there anything in the works to get more evidence? The only reason I said Voodoo, that different rotating speeds of molten core is the likely suspect is that is the current fashionable explanation. We do know that the sun rotates slowly at the equator. fine. But it also has a lot of wacky currents and storms, climaxing in solar maximum, and then a flip. Our Earth has some turbulence too. And flips. So let's not be dogmatic about some old musty college explanations. I say iron-- is it out?

 

[Paula]

Lookit, What is the source of magnetism we are talking about here?

"Lookit," are you out there?

 

[Paula]

"The composition of Jupiter's atmosphere is similar to that of the Sun - mostly hydrogen and helium. Deep in the atmosphere, the pressure and temperature increase, compressing the hydrogen gas into a liquid. At depths about a third of the way down, the hydrogen becomes metallic and electrically conducting. In this metallic layer, Jupiter's powerful magnetic field is generated by electrical currents driven by Jupiter's fast rotation. At the center, the immense pressure may support a solid core of ice-rock about the size of Earth.

Jupiter's enormous magnetic field is nearly 20,000 times as powerful as Earth's. Trapped within Jupiter's magnetosphere (the area in which magnetic field lines encircle the planet from pole to pole) are swarms of charged particles. Jupiter's rings and moons are embedded in an intense radiation belt of electrons and ions trapped in the magnetic field. The jovian magnetosphere, comprising these particles and fields, balloons 1 to 3 million kilometers (600,000 to 2 million miles) toward the Sun and tapers into a windsock-shaped tail extending more than 1 billion kilometers (600 million miles) behind Jupiter as far as Saturn's orbit."

http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=OverviewLong

Now suppose, for the sake of the unindoctrinated, that you need Hydrogen to generate a truly powerful and enormous, and lasting magnetic field. The astronomers, without knowing, continue to insert an iron rotating core at the middle, wherever they can. (How can you drop a probe onto Jupiter, when you have trouble deploying a parachute at times?!) (I am so sorry I said that, I love you NASA!)

Is there any, any possible scenario, in which planets are lighter and gaseous and hydrogen based on the inside?

(The wild eddies in the magnetosphere would seem to point to iron, but perhaps not.)

And can Hydrogen spontaneously jump into "a metallic layer," as they seem to suggest in this article? And even in this case, would this create a magnetic force, rather than respond to one and perpetuate it?