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upriver
2007-May-21, 03:27 AM
Orginally posted by tusenfem
You may think what you want, Upriver, care to enlighten us how the Io plasma torus creates the enormous Jovian magnetic field?


No, not the Io plasma torus, the Jupiter plasma torus, also known as a ring current.



I think you also wanted the radiation belts of the Earth to create the Earth's magnetic fields,


Yes, the inner belt, also known as the ring current.

Radiation Belt Storm Probes.
http://geospace.jhuapl.edu/spacecraft/overview.php

"Initial Simulation Results of Storm-Time Ring
Current in a Self-Consistent Magnetic Field Model"
http://www.atmos.ucla.edu/~larry/2005SelfConsistRingCurrent.pdf

That would make it a solenoid with its attendant magnetic field.



even though Gauss has already proven that the Earth's magnetic field is internally generated. The same applies Jupiter.


No, Gauss just proved that the densest part of the magnetic field is inside the Earth.
Here is a google image search on solenoid.
http://images.google.com/images?um=1&tab=wi&channel=s&client=firefox-a&hl=en&hs=qkx&rls=org.mozilla:en-US:official&q=solenoid+magnetic+field

Notice how the densest part of the field is inside.



If you would be only a little bit of an electric engineer as you claim, you would be informed about such effects.


What, geodynamo simulations?
Ring currents?
Solenoids?



And if you do not believe me, you may want to read up on the papers from the distinguished Prof. Neubauer from Cologne university, that I mentioned above.


Point me to a paper of his that I dont have to pay for, please.




And it does not create a current flow in the form of a flux tube. It creates a current because of the v-cross-B electric field and the current flows along the magnetic field (field aligned currents, Birkeland currents!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!) The "flux tube" that "connects" Io (or Europa or Ganymede or Callisto or Titan or Enceladus or or or or ) is just a mathematical concept, which can be used in steady state. In real life there is not one flux tube, the magnetic field is constantly moving past the moon, and thus (do I dare use the word, because it will be used against me in another thread) thus is "recreated constantly". It is all in the theory of Alfven Wings.


I'm not sure what you meant by all that, but these mathematical concepts leave footprints.
http://www.jupiterradio.com/images/jupiter-aurora.jpg
http://www.jupiterradio.com/jove-emission.php

Are you saying that these footprints are quantized in motion from location to location?



This is such a stupid pointless discussion. The ATM people (even if they do not want to be called that) are just here to nerve the mainstreamers with dumb and ambiguous statements and answers.



Here is something. These simulations are claiming that there is a coherent magnetic field produced by semi-chaotic motion in the liquid center of the earth.
Here is a picture.
http://www.psc.edu/science/Glatzmaier/field_big.gif
Researchers: Gary Glatzmaier, Los Alamos National Laboratory.
http://www.psc.edu/science/glatzmaier.html

Just by looking at this picture, you can see its fantasy land if you have any engineering training at all.

Since when does a magnetic fields have line of force? And how about a whole bunch of them converging and turning a corner, and popping out of the surface of the earth? Where's the accompanying charge current?

Van Rijn
2007-May-21, 03:47 AM
Just by looking at this picture, you can see its fantasy land if you have any engineering training at all.


:)

(emphasis added) Just had to quote that line.

Anyway, upriver, could you please state what your specific ATM proposal is for this thread? Is it "Jupiter's magnetic field is created externally"? Or something else?

The Backroad Astronomer
2007-May-21, 04:10 AM
What trap the particles in Van Allen belts in the first place?

The Backroad Astronomer
2007-May-21, 04:12 AM
Just by looking at this picture
:wall:

cjl
2007-May-21, 04:40 AM
Just by looking at this picture, you can see its fantasy land if you have any engineering training at all.
And THIS is always a wonderful sign of an impending coherent, well thought out, and thoroughly reasoned argument...

:wall:

tusenfem
2007-May-21, 07:20 AM
No, not the Io plasma torus, the Jupiter plasma torus, also known as a ring current.

Yes, the inner belt, also known as the ring current.

Radiation Belt Storm Probes.
http://geospace.jhuapl.edu/spacecraft/overview.php
"Initial Simulation Results of Storm-Time Ring
Current in a Self-Consistent Magnetic Field Model"
http://www.atmos.ucla.edu/~larry/2005SelfConsistRingCurrent.pdf

That would make it a solenoid with its attendant magnetic field.

No, Gauss just proved that the densest part of the magnetic field is inside the Earth.
Here is a google image search on solenoid.
http://images.google.com/images?um=1&tab=wi&channel=s&client=firefox-a&hl=en&hs=qkx&rls=org.mozilla:en-US:official&q=solenoid+magnetic+field

Notice how the densest part of the field is inside.

What, geodynamo simulations?
Ring currents?
Solenoids?

Point me to a paper of his that I dont have to pay for, please.

I'm not sure what you meant by all that, but these mathematical concepts leave footprints.
http://www.jupiterradio.com/images/jupiter-aurora.jpg
http://www.jupiterradio.com/jove-emission.php

Are you saying that these footprints are quantized in motion from location to location?

Here is something. These simulations are claiming that there is a coherent magnetic field produced by semi-chaotic motion in the liquid center of the earth.
Here is a picture.
http://www.psc.edu/science/Glatzmaier/field_big.gif
Researchers: Gary Glatzmaier, Los Alamos National Laboratory.
http://www.psc.edu/science/glatzmaier.html

Just by looking at this picture, you can see its fantasy land if you have any engineering training at all.

Since when does a magnetic fields have line of force? And how about a whole bunch of them converging and turning a corner, and popping out of the surface of the earth? Where's the accompanying charge current?

If we talk about the plasma torus, in the context of Jupiter, it is always the Io plasma torus. But, anywhooo, the ring current is supposed to make the dipolar magnetic field. Please show us that this is possible. As an engineer you will be able to calculate this, and then please show us that the total current is reasonable for Jupiter or the Earth.
And with the second link, the preprint of the paper by Lui et al. you shoot yourself in the foot, because it shows that at the center of the Earth the magnetic deviation caused by the ring current is only 20 nT.

I will have to look it up about Gauss, but yes I know what a solenoidal field looks like.

"such effects" did not refer to geodynamo or stuff like that, it referred to that a moving magnetic field will create an electric field for a stationary observer. I cannot send you the first papers by Neubauer, because there are no pdfs I can send you my paper on Europa, which uses the same equations as Neubauer did, and give a small introduction to this work. Otherwise you can have a look at "Jupiter, the planet, satellites and magnetosphere" by Bagenal et al. (great book) and look up Alfven wings.

There is nothing quantized or something. The magnetic field is passing by the moon at the corotional velocity minus the orbital velocity. In steady state (which it basically is) you can describe the interaction with a picture in which the field lines "stand still" and then you find the link from the moon to the ionosphere of Jupiter, and you find the footpoint in the aurora, created by the strong currents that are flowing in the flux tube connecting them.

Then the simulations by Glazmeier. The first pic you link to is exactly what one would expect from an alpha-omega dynamo. A very twisted magnetic field in the center and as soon as it leaves the conducting center of the Earth, the field becomes dipolar.

The currents are not plotted in the picture, naturally there are currents flowing, otherwise there would be no magnetic field, let alone bend magnetic field lines. I fail to find magnetic lines of force, but magnetic field lines are sometimes also called magnetic force lines.

Once again, you are doing "look at the picture" without even understanding what is presented in the picture. Come with some real ideas apart from complaining about "anyone can see that" and "I claim that". The latter you can do, but back up your claim.

korjik
2007-May-21, 03:19 PM
I want to amplify what Tusenfem was saying in his last post.

I will restrict to Earth as a test bed for the proposition that the ring current generates the Earth's field.

Upriver, What is the ring current, or ring current density needed to create the Earth's dipole field?

Upriver, What is the ring current in both a)quiescent non-substorm times, and b) during a substorm. Please cite what paper and instrument are giving the readings.

Upriver, why can we see that the form of the Earth's dipole is dipolar at the surface, if we are far inside the generating current? Why dosent the field at the surface look solenoidal?

I will expect at least an attempt to give real anwers. If you ignore my questions again, I will report it.

hhEb09'1
2007-May-21, 04:01 PM
No, Gauss just proved that the densest part of the magnetic field is inside the Earth.No, that's not it.

From this link (http://www.higp.hawaii.edu/~mfuller/rosetta_stone/ZApp.02.EarthsMa15B65D.doc.pdf) (I did a quick google) "Although Gauss showed that to the accuracy of his observations the earth’s field was of internal origin, there is also an external field."

An external field exists, but the geomagnetic field that we talk about today is of internal origin.

upriver
2007-May-24, 09:40 PM
No, that's not it.

From this link (http://www.higp.hawaii.edu/~mfuller/rosetta_stone/ZApp.02.EarthsMa15B65D.doc.pdf) (I did a quick google) "Although Gauss showed that to the accuracy of his observations the earth’s field was of internal origin, there is also an external field."

An external field exists, but the geomagnetic field that we talk about today is of internal origin.

They are using a lodestone as the reference model. Different magnetic field than a solenoid.

Carl Gauss- (30 April 1777 – 23 February 1855)

When was the solenoid invented?(along with electricity?)

Tesla- (10 July 1856 - 7 January 1943)


Their model is outdated.

tusenfem
2007-May-25, 08:32 AM
They are using a lodestone as the reference model. Different magnetic field than a solenoid.

Carl Gauss- (30 April 1777 – 23 February 1855)

When was the solenoid invented?(along with electricity?)

Tesla- (10 July 1856 - 7 January 1943)


Their model is outdated.

Then show us wrong, Upriver, show us that the magnetic field of the Earth is created by a solenoid, created by the ring current. And please show that the observations show that the ringcurrent is indeed as strong as you claim.

The Earth's magnetic field strength is 30,000 nT (give or take a few), so that means double at the poles (why you need this at the poles I leave as a homework assignment).

The magnetic field of a long solenoid is, well look in Jackson, Classical electrodynamics, it is too bothersome to write equations here, you can find it in chapter 5. Now, Jackson is rather difficult sometimes, therefore you might also want to look at Lorrain & Corson, Electromagnetic fields and waves, page 317, where there is an example of "The short solenoid".

I am looking forward to your answer.

papageno
2007-May-25, 08:36 PM
When was the solenoid invented?(along with electricity?)

Tesla- (10 July 1856 - 7 January 1943)


I hope you are not suggesting that Tesla invented the solenoid or electricity.

Why do you think the names Coulomb, Ampere, Faraday, Ohm and of many others come up in textbooks about electromagnetism?
What do you think Faraday was using in the experiments that lead to discovery of induction?

(Not to mention that you cannot invent electricity, but only discover it.)

upriver
2007-May-25, 08:49 PM
I hope you are not suggesting that Tesla invented the solenoid or electricity.

Why do you think the names Coulomb, Ampere, Faraday, Ohm and of many others come up in textbooks about electromagnetism?
What do you think Faraday was using in the experiments that lead to discovery of induction?

(Not to mention that you cannot invent electricity, but only discover it.)

Yes, you are correct. Tesla discovered AC and electric motors. Plus numerous high voltage phenomena.
Coulomb, Ampere, Faraday, Ohm were DC guys. Right?

Faraday in 1831, he began his great series of experiments in which he discovered electromagnetic induction.

papageno
2007-May-25, 08:58 PM
Yes, you are correct. Tesla discovered AC and electric motors. Plus numerous high voltage phenomena.
Coulomb, Ampere, Faraday, Ohm were DC guys. Right?


Since when do you get induction with fields that do not change in time?

Or did you miss all those terms in Maxwell's equations with the time-derivatives?

upriver
2007-May-25, 09:39 PM
Since when do you get induction with fields that do not change in time?

Or did you miss all those terms in Maxwell's equations with the time-derivatives?

You can experiment in induction without "AC". When I said DC guys, I meant they used batteries and DC pulsed generators. I said nothing about their use of Maxwell's equations.

The point I was making is that Gauss was more likely using the lodestone model because of his placement in time vs using a solenoid induction model.

publius
2007-May-25, 09:44 PM
I sort of dropped out of following ATM (it will drive you nuts if you let it :) ), but now I had to start looking at some of this electric you-know-what stuff. I may go crazy again.

What Tesla invented was the AC polyphase induction motor, a very clever trick, of getting two magnetic fields, one induced by the other via transformer effect to chase each other around in a circle. Induction motors make the world go 'round, really. Induction motors avoid the need for a connection between rotor and stator, avoiding the need for and brushes/slip rings. "The workhorse of industry" they can be called.

Induction motors are absolutely fascinating. Though they are fairly simple physically, the are the most complex to describe mathematically. Some very interesting and even counterintuitive things come out. Of course, to understand that, you need to know EM theory. *sigh*.

Anyway, you can divide rotating machines into two broad classes, "AC" and "DC", although considering how a series field "DC" motor will run on AC, and so is sometimes called a universal motor (that's what powers most hand-held power tools; power/torque to weight ratio is fairly high which makes it ideal for this. Efficiency however, is not so good compared to other designs), this doesn't exactly mean that.

A "DC" machine is a commutator machine. The function of that is usually thought of in a generating sense as a rectifier device, but if you look at what it does to the fields, you'll see something. The commutator keeps the armature(rotor) field at 90 degrees to the main stator field. The armature field ("reaction" field, it's generally called) is trying to align, but as it turns a bit, the commutator switches the current flow to kick it back to 90 degrees.

That is angle is known as the torque angle (or power angle). The toque between two magnets goes as the sine of this angle. 90 degrees thus maximizes the torque. So the main characteristic of a DC machine is the fields are fixed and held at the maximum torque angle.

AC machines are a bit more complex than that, and I'll simply refer anyone interested to the literature. The main characteristic of AC machines is a rotating field. Imagine a bar magnet rotating around a perpendicular axis through the center. That's what goes on inside AC machines, both synchronous and induction. The torque angle is variable.

The rotor field lags behind the stator field by this torque angle as both rotate around at synchronous speed (determined by the frequency). When a synchronous machine is motoring, the stator field is pulling the rotor around. When it's generating, the rotor leads the stator, and the rotor can be seen as pulling the stator field around.

And this is the main difference between AC and DC machines. In the latter, the fields are fixed by the commutator, which keeps switching the current around as the rotor turns. In AC machines, the fields themselves rotate, dragging the load around with them.

Tesla's genius insight was in realizing how to use transformer effect to induce that rotating field in the rotor. Polyphase AC is inherently "rotational" (well, when thought of in this way).

-Richard

upriver
2007-May-25, 09:47 PM
Then show us wrong, Upriver, show us that the magnetic field of the Earth is created by a solenoid, created by the ring current. And please show that the observations show that the ringcurrent is indeed as strong as you claim.

The Earth's magnetic field strength is 30,000 nT (give or take a few), so that means double at the poles (why you need this at the poles I leave as a homework assignment).

The magnetic field of a long solenoid is, well look in Jackson, Classical electrodynamics, it is too bothersome to write equations here, you can find it in chapter 5. Now, Jackson is rather difficult sometimes, therefore you might also want to look at Lorrain & Corson, Electromagnetic fields and waves, page 317, where there is an example of "The short solenoid".

I am looking forward to your answer.

Yes, so am I.

I have been working on this for a few days now.

I think this is an application of Amperes Law.
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/solenoid.html#c2

Then we use the case of the iron core because we think there is some amount of iron in the earth that is not molten.

"The ferromagnetic property of the iron core causes the internal magnetic domains of the iron to line up with the smaller driving magnetic field produced by the current in the solenoid. The effect is the multiplication of the magnetic field by factors of tens to even thousands. "

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/elemag.html#c4

Here is an applet.
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/solenoid.html#c3


For a solenoid of length L = 10000 m with N = 1 turns,

the turn density is n=N/L = 0.0001 turns/m.

If the current in the solenoid is I = 10000 amperes

and the relative permeability of the core is k = 200,

then the magnetic field at the center of the solenoid is

B = 0.00025132 Tesla 2.51327412 = gauss.

The Earth's magnetic field is about half a gauss.

The relative permeability of magnetic iron is around 200.


If I have more accurate measurements of the ring current then I can get closer. These are all best guesses.

"WHAT IS THE DST INDEX?

The Dst is a geomagnetic index which monitors the world wide magnetic storm level. It is constructed by averaging the horizontal component of the geomagnetic field from mid-latitude and equatorial magnetograms from all over the world. Negative Dst values indicate a magnetic storm is in progress, the more negative Dst is the more intense the magnetic storm. The negative deflections in the Dst index are caused by the storm time ring current which flows around the Earth from east to west in the equatorial plane. The ring current results from the differential gradient and curvature drifts of electrons and protons in the near Earth region and its strength is coupled to the solar wind conditions. Only when there is an eastward electric field in the solar wind which corresponds to a southward interplanetary magnetic field (IMF) is there any significant ring current injection resulting in a negative change to the Dst index. Thus, by knowing the solar wind conditions and the form of the coupling function between solar wind and ring current, an estimate of the Dst index can be made. "

publius
2007-May-25, 09:53 PM
Since when do you get induction with fields that do not change in time?


That reminds me of something. "Induction" generally means time-varying magnetic fields inducing electric fields, or voltages produced by time-varying currents in circuit theory.

However, there is another purely electric use of that term. I don't like it because of the confusion. Take a power line example. Run a floating wire parallel to an energized for a long length, and capacitive (or electric field) effects "induce" a voltage to ground on the floating wire. With typical 7200V to ground power lines running for miles, a "dead" phase/wire will easily have enough voltage on it to drop you dead if you don't ground it out.

And, alas, that effect is called "induction", but it has nothing to do with magnetic induction.

There is complex general formula for calculating the capacitance between a general system of conductors. It leads to a matrix type expression that is fairly complex.

The diagonal terms are called the "coefficients of capacity" ("self capacitance" sometimes) and the cross terms are called "coefficients of induction".

-Richard

upriver
2007-May-26, 05:06 AM
That reminds me of something. "Induction" generally means time-varying magnetic fields inducing electric fields, or voltages produced by time-varying currents in circuit theory.

However, there is another purely electric use of that term. I don't like it because of the confusion. Take a power line example. Run a floating wire parallel to an energized for a long length, and capacitive (or electric field) effects "induce" a voltage to ground on the floating wire. With typical 7200V to ground power lines running for miles, a "dead" phase/wire will easily have enough voltage on it to drop you dead if you don't ground it out.

And, alas, that effect is called "induction", but it has nothing to do with magnetic induction.

There is complex general formula for calculating the capacitance between a general system of conductors. It leads to a matrix type expression that is fairly complex.

The diagonal terms are called the "coefficients of capacity" ("self capacitance" sometimes) and the cross terms are called "coefficients of induction".

-Richard



Would that also be known as transmission line theory?

upriver
2007-May-26, 06:19 AM
"The trapping regions of high-energy charged particles surrounding the Earth are called radiation (or van Allen) belts (Van Allen et al., 1958; Van Allen and Frank, 1959). The inner one, located between about X = 1.1 - 3.3 Re (Earth radii, geocentric) in the equatorial plane, contains primarily protons with energies exceeding 10 MeV. Flux maximum is at about X = 2 Re. (Distances given here are approximate, since the location of particles is energy dependent.) This is a fairly stable population but it is subject to occasional perturbations due to geomagnetic storms, and it varies with 11-year solar cycle. The source of protons in this region is the decay of cosmic ray induced albedo from the atmosphere."

"The outer belt contains mainly electrons with energies up to 10 MeV. It is produced by injection and energization events following geomagnetic storms, which makes it much more dynamic than the inner belt (it is also subject to day-night variations). It has an equatorial distance of about 3 - 9 Re, with maximum for electrons above 1 MeV occurring at about X = 4 Re. 'Horns' of the outer belt dip sharply in towards the polar caps."

"Recently a new belt has been found within the inner belt. It contains heavy nuclei (mainly oxygen, but also nitrogen and helium, and very little carbon) with energies below 50 MeV/nuc. The source of these particles are the so called "anomalous cosmic rays" of interstellar origin."
http://www.oulu.fi/~spaceweb/textbook/radbelts.html


Partial mapping of the ring current.
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=37597&secured=-1

Cluster says;
55 nA/m2


Earth radius 6,356km times 8(total ring size) = 50848 km ring diameter.

8122408265.216 square km * 1000 for meters = 8,122,408,265,216 meters^2

8122408265216 * 55 nA = 446732454586880 nA over the total area of the ring current. The area of greatest density is about 2 eR. This is taken at about 4 eR.

446732454586880 / 1000000 (nanoampere to amp) = 446,732,454.58688 amps over the area of the ring current.

Probably not 446,732,454.58688 amps, but well within that required for solenoid generation of the earths magnetic field by an order of magnitude or 2.

upriver
2007-May-26, 06:32 AM
So plugging in my new numbers from Cluster into the applet and reducing the amperage in the ring current to a value that matches Io's observed approximately 10 million amps.


For a solenoid of length L = 50848000 m with N = 1 turns,

the turn density is n=N/L= 1.9666456891126493e-8 turns/m.

If the current in the solenoid is I = 10,000,000 amperes

and the relative permeability of the core is k = 200,

then the magnetic field at the center of the solenoid is

B = 0.00004942719719304268 Tesla = 0.49427197 gauss.


The Earth's magnetic field is about half a gauss in the center.

hhEb09'1
2007-May-26, 08:33 AM
Probably not 446,732,454.58688 amps, but well within that required for solenoid generation of the earths magnetic field by an order of magnitude or 2.And, the earth's magnetic field (the geomagnetic field) rotates with the earth.

papageno
2007-May-26, 08:58 AM
The point I was making is that Gauss was more likely using the lodestone model because of his placement in time vs using a solenoid induction model.


Or maybe because modelling the Earth as a lodestone seemed to be more accurate than as a solenoid.

Gauss's placement in time overlaps with Faraday's, so there is no reason that Gauss would not know about solenoids.




However, there is another purely electric use of that term.


Yes, of course. I usually refer to it as "electrostatic induction".
But in the context it was clear that we were talking about the dynamic stuff.

Gillianren
2007-May-26, 07:15 PM
Hey, upriver, Gods know I'm not qualified to say if your math is right or not. However, let me applaud your use of it.

upriver
2007-May-26, 09:15 PM
Hey, upriver, Gods know I'm not qualified to say if your math is right or not. However, let me applaud your use of it.

Thank You. I'm trying.

I'm sure there is an error somewhere, but if I keep working at it, they will go away.

upriver
2007-May-26, 09:38 PM
Or maybe because modelling the Earth as a lodestone seemed to be more accurate than as a solenoid.

Gauss's placement in time overlaps with Faraday's, so there is no reason that Gauss would not know about solenoids.



Yes, I believe you are correct. It seems that they all knew each other, Ampere, Weber and Gauss.

It doesnt say it directly but Weber was doing work with solenoids and about that time he and Gauss started to work together.

This is an interesting article about the The Inverse Square Law that contains some history.
http://american_almanac.tripod.com/inverse.htm

Gillianren
2007-May-27, 01:13 AM
Thank You. I'm trying.

I'm sure there is an error somewhere, but if I keep working at it, they will go away.

That's science in a nutshell.

korjik
2007-May-27, 04:12 AM
"The trapping regions of high-energy charged particles surrounding the Earth are called radiation (or van Allen) belts (Van Allen et al., 1958; Van Allen and Frank, 1959). The inner one, located between about X = 1.1 - 3.3 Re (Earth radii, geocentric) in the equatorial plane, contains primarily protons with energies exceeding 10 MeV. Flux maximum is at about X = 2 Re. (Distances given here are approximate, since the location of particles is energy dependent.) This is a fairly stable population but it is subject to occasional perturbations due to geomagnetic storms, and it varies with 11-year solar cycle. The source of protons in this region is the decay of cosmic ray induced albedo from the atmosphere."

"The outer belt contains mainly electrons with energies up to 10 MeV. It is produced by injection and energization events following geomagnetic storms, which makes it much more dynamic than the inner belt (it is also subject to day-night variations). It has an equatorial distance of about 3 - 9 Re, with maximum for electrons above 1 MeV occurring at about X = 4 Re. 'Horns' of the outer belt dip sharply in towards the polar caps."

"Recently a new belt has been found within the inner belt. It contains heavy nuclei (mainly oxygen, but also nitrogen and helium, and very little carbon) with energies below 50 MeV/nuc. The source of these particles are the so called "anomalous cosmic rays" of interstellar origin."
http://www.oulu.fi/~spaceweb/textbook/radbelts.html


Partial mapping of the ring current.
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=37597&secured=-1

Cluster says;
55 nA/m2


Earth radius 6,356km times 8(total ring size) = 50848 km ring diameter.

8122408265.216 square km * 1000 for meters = 8,122,408,265,216 meters^2

8122408265216 * 55 nA = 446732454586880 nA over the total area of the ring current. The area of greatest density is about 2 eR. This is taken at about 4 eR.

446732454586880 / 1000000 (nanoampere to amp) = 446,732,454.58688 amps over the area of the ring current.

Probably not 446,732,454.58688 amps, but well within that required for solenoid generation of the earths magnetic field by an order of magnitude or 2.

diameter should be Re*(2.2+1)*2=6.4 Re not 8

you should be using the average not the max, cause it will give you anomalously high values.

nanogauss to gauss is 1,000,000,000 not 1,000,000

Good work otherwise.

Now, how do the fluctuations in Dst change the field strength you should measure on the surface, and are these fields detected?

I am not trying to harass you, but just to point out a flaw in you supposition.

tusenfem
2007-May-27, 10:41 AM
Chapeau! Upriver.

I got a different number, though.

I assumed that the ringcurrent is located at 4Re and that the cluster value of 55 nA/m2 is applicable.
The ring current is a torus (doughnut) around the Earth with a cross section scaled by the Earth's cross section, i.e. A*pi*Re2. So, now we can get the total current in the ringcurrent I = 55 A pi Re2 nA = 55 A pi Re2 10-9 Amps
Now, we have to get a value for L the central length of the solenoid where the calculation is valid. Let's scale that too to the Earth radius, say L = l Re
Taking the solenoid approximation for the field as given in the link that you provided one has:

B = mu0 N I / L

for which we have all values now and mu0 = 4 PI 10-7, we take N=1 (basically we are calculating the current of a ring then) and we get

B = mu0 1 55 A pi Re2 10-9 / l Re =
13 10-7 T = 1300 A/l nT

But basically, the solenoid calculation is flawed here, and one can, as I said, better transform it to the field of a current loop (now this is flawed too! naturally one has to solve jus the basic Biot-Savart law, but we let that be, too complicated)

In that case with the same scalings it is found that the field is about 200 A nT at the pole of the Earth, whereas one should find 60000 nT. However, this kind of perturbance is basically what is found on the ground for storm times, basically up to say max -1000 nT

Here (http://farside.ph.utexas.edu/teaching/plasma/lectures/node23.html) is a link to a description of the ring current and how the particles behave. And there is one thing that has not been considered and that is that the ring current reduces the field at Earth when it increases:



It is clear that, in addition to their gyromotion and periodic bouncing motion along field-lines, charged particles trapped in the magnetosphere also slowly precess around the Earth. The ions drift westwards and the electrons drift eastwards, giving rise to a net westward current circulating around the Earth. This current is known as the ring current.

skip

Although the perturbations to the Earth's magnetic field induced by the ring current are small, they are still detectable. In fact, the ring current causes a slight reduction in the Earth's magnetic field in equatorial regions. The size of this reduction is a good measure of the number of charged particles contained in the Van Allen belts. During the development of so-called geomagnetic storms, charged particles are injected into the Van Allen belts from the outer magnetosphere, giving rise to a sharp increase in the ring current, and a corresponding decrease in the Earth's equatorial magnetic field.


I guess this was not totally fair of me, but this does show how not taking everything into account "thaumaturgy" can lead to very wrong results.

But still, I admire Upriver's efforts to show himself right. He has done more than many a EU proponent until now.

tusenfem
2007-May-27, 10:46 AM
Chapeau! Upriver.

I got a different number, though.

I assumed that the ringcurrent is located at 4Re and that the cluster value of 55 nA/m2 is applicable.
The ring current is a torus (doughnut) around the Earth with a cross section scaled by the Earth's cross section, i.e. A*pi*Re2. So, now we can get the total current in the ringcurrent I = 55 A pi Re2 nA = 55 A pi Re2 10-9 Amps
Now, we have to get a value for L the central length of the solenoid where the calculation is valid. Let's scale that too to the Earth radius, say L = l Re
Taking the solenoid approximation for the field as given in the link that you provided one has:

B = mu0 N I / L

for which we have all values now and mu0 = 4 PI 10-7, we take N=1 (basically we are calculating the current of a ring then) and we get

B = mu0 1 55 A pi Re2 10-9 / l Re =
13 10-7 T = 1300 A/l nT

But basically, the solenoid calculation is flawed here, and one can, as I said, better transform it to the field of a current loop (now this is flawed too! naturally one has to solve jus the basic Biot-Savart law, but we let that be, too complicated)

In that case with the same scalings it is found that the field is about 200 A nT at the pole of the Earth, whereas one should find 60000 nT. However, this kind of perturbance is basically what is found on the ground for storm times, basically up to say max -1000 nT

Here (http://farside.ph.utexas.edu/teaching/plasma/lectures/node23.html) is a link to a description of the ring current and how the particles behave. And there is one thing that has not been considered and that is that the ring current reduces the field at Earth when it increases:



It is clear that, in addition to their gyromotion and periodic bouncing motion along field-lines, charged particles trapped in the magnetosphere also slowly precess around the Earth. The ions drift westwards and the electrons drift eastwards, giving rise to a net westward current circulating around the Earth. This current is known as the ring current.

skip

Although the perturbations to the Earth's magnetic field induced by the ring current are small, they are still detectable. In fact, the ring current causes a slight reduction in the Earth's magnetic field in equatorial regions. The size of this reduction is a good measure of the number of charged particles contained in the Van Allen belts. During the development of so-called geomagnetic storms, charged particles are injected into the Van Allen belts from the outer magnetosphere, giving rise to a sharp increase in the ring current, and a corresponding decrease in the Earth's equatorial magnetic field.


I guess this was not totally fair of me, but this does show how not taking everything into account "thaumaturgy" can lead to very wrong results.

But still, I admire Upriver's efforts to show himself right. He has done more than many a EU proponent until now.

upriver
2007-May-28, 01:29 AM
Chapeau! Upriver.

I got a different number, though.

I assumed that the ringcurrent is located at 4Re and that the cluster value of 55 nA/m2 is applicable.
The ring current is a torus (doughnut) around the Earth with a cross section scaled by the Earth's cross section, i.e. A*pi*Re2. So, now we can get the total current in the ringcurrent I = 55 A pi Re2 nA = 55 A pi Re2 10-9 Amps
Now, we have to get a value for L the central length of the solenoid where the calculation is valid. Let's scale that too to the Earth radius, say L = l Re
Taking the solenoid approximation for the field as given in the link that you provided one has:

B = mu0 N I / L

for which we have all values now and mu0 = 4 PI 10-7, we take N=1 (basically we are calculating the current of a ring then) and we get

B = mu0 1 55 A pi Re2 10-9 / l Re =
13 10-7 T = 1300 A/l nT

But basically, the solenoid calculation is flawed here, and one can, as I said, better transform it to the field of a current loop (now this is flawed too! naturally one has to solve jus the basic Biot-Savart law, but we let that be, too complicated)

In that case with the same scalings it is found that the field is about 200 A nT at the pole of the Earth, whereas one should find 60000 nT. However, this kind of perturbance is basically what is found on the ground for storm times, basically up to say max -1000 nT

Here (http://farside.ph.utexas.edu/teaching/plasma/lectures/node23.html) is a link to a description of the ring current and how the particles behave. And there is one thing that has not been considered and that is that the ring current reduces the field at Earth when it increases:



I guess this was not totally fair of me, but this does show how not taking everything into account "thaumaturgy" can lead to very wrong results.

But still, I admire Upriver's efforts to show himself right. He has done more than many a EU proponent until now.

After I posted those calculations I decided to do some more reading on the Van Allen belts as I felt I was missing something. It turns out there are different papers depending on the search term you use(duh!).

Well I thought the inner Van Allen belt was the ring current or part of the ring current, which is not the case.

I have found out that the ring current(outer belt) is part of the DST index and is outside the plasma sphere, where as the inner belt is extremely stable and is inside the plasma sphere.

The boundary between the ring current and the inner plasma sphere does not change although the ring current may compress up against this boundary, indicating that the inner belt is very strong.

The area between the inner boundary and the outer van allen belt/ring current is called the slot.

So from what I can see, it is the inner van allen belt that I have been talking about but calling the ring current.

"The inner one, located between about X = 1.1 - 3.3 Re (Earth radii, geocentric) in the equatorial plane, contains primarily protons with energies exceeding 10 MeV."

"The outer belt contains mainly electrons with energies up to 10 MeV. It is produced by injection and energization events following geomagnetic storms, which makes it much more dynamic than the inner belt (it is also subject to day-night variations). It has an equatorial distance of about 3 - 9 Re, with maximum for electrons above 1 MeV occurring at about X = 4 Re."

And as you can see, it may have up to 10 times the energy as the outer belt.

Although it shows the inner plasma sphere shrinking, according to other observations that I have read, the inner plasma sphere does not change shape. This must be because of the strength of the inner belt current.
http://enarc.space.swri.edu/PAPERS/PUBs/nature03116.pdf

Now since the outer belt is composed primarily of electrons, I would expect it to modulate the field strength of the inner one, composed of protons.

The important thing is that the inner one is very stable, which is the first requirement to be considered for the earths magnetic field.

So what powers that inner belt?

Now if I can get some B measurements for that inner belt, which I expect to be many times stronger, I would be on the right track.

The Backroad Astronomer
2007-May-28, 01:48 AM
To hold the charge particles in belts in space around our planet wouldn't there have to be magnetic field to hold them there.

ToSeek
2007-May-28, 03:46 AM
Post to force showing page 2 of thread.

The Backroad Astronomer
2007-May-28, 03:49 AM
thanks ToSeek

upriver
2007-May-28, 06:59 AM
Energetic neutral atom imaging of space plasmas

Mike Gruntman

Abstract

Experimental techniques and instrumentation for space plasma imaging in fluxes of energetic neutral atoms (ENAs) are reviewed. ENAs are born in charge exchange collisions between space plasma energetic ions and background neutral gas. ENAs are ubiquitous in the space environment and their energies are in the range from a few eV up to >100 keV. Contrary to charged particles, ENAs can travel large distances through space with minimal disturbance, and by recording ENA fluxes as a function of observational direction, one can reconstruct a global image of a planetary magnetosphere or the heliosphere. Plasma ion energy distribution and ion composition can be remotely established by measuring ENA energies and masses. ENA imaging opens a new window on various phenomena in space plasmas with a promise to qualitatively improve our understanding of global magnetospheric and heliospheric processes. At first we review ENA fluxes in space and their properties, and present a brief history of ENA experimental studies and the evolution of experimental approaches. The concepts of ENA imaging and particle identification are considered and followed by comparison with corpuscular diagnostics of fusion plasmas. Basic ENA techniques and instrument components are then described in detail and critically evaluated; performance characteristics, limitations, and requirements to key instrumental elements are discussed. And finally, representative ENA instruments are shown, and promising instrumental approaches are identified.

http://astronauticsnow.com/ENA/ena_rsi_1997.html

tusenfem
2007-May-28, 08:58 AM
Now if I can get some B measurements for that inner belt, which I expect to be many times stronger, I would be on the right track.

All well and good, but the current goes the wrong way for them to create the Earth's magnetic field. The motion of the charged particles in the inner or outer radiation belt or ring currents are governed by gradient drift and curvature drift. (See e.g. Kivelson and Russell, Introduction to space physics, pages 309- 312). These two drifts make positive particle to move westward and negative particles to move eastward, thereby decreasing the Earth's magnetic field when the current is increasing. So, sorry but no cigar, the ring currents, or Van Allen radiation belts cannot create the Earth's magnetic field.

Apart from that, there is also the comment by hhEb09'1 stating that the magnetic field rotates with the Earth, which would not be in agreement with an external source.

So, no need to search further.

Michael Noonan
2007-May-28, 11:11 AM
I sort of dropped out of following ATM (it will drive you nuts if you let it :) ), but now I had to start looking at some of this electric you-know-what stuff. I may go crazy again.

What Tesla invented was the AC polyphase induction motor, a very clever trick, of getting two magnetic fields, one induced by the other via transformer effect to chase each other around in a circle. Induction motors make the world go 'round, really. Induction motors avoid the need for a connection between rotor and stator, avoiding the need for and brushes/slip rings. "The workhorse of industry" they can be called.

Induction motors are absolutely fascinating. Though they are fairly simple physically, the are the most complex to describe mathematically. Some very interesting and even counterintuitive things come out. Of course, to understand that, you need to know EM theory. *sigh*.

Anyway, you can divide rotating machines into two broad classes, "AC" and "DC", although considering how a series field "DC" motor will run on AC, and so is sometimes called a universal motor (that's what powers most hand-held power tools; power/torque to weight ratio is fairly high which makes it ideal for this. Efficiency however, is not so good compared to other designs), this doesn't exactly mean that.

A "DC" machine is a commutator machine. The function of that is usually thought of in a generating sense as a rectifier device, but if you look at what it does to the fields, you'll see something. The commutator keeps the armature(rotor) field at 90 degrees to the main stator field. The armature field ("reaction" field, it's generally called) is trying to align, but as it turns a bit, the commutator switches the current flow to kick it back to 90 degrees.

That is angle is known as the torque angle (or power angle). The toque between two magnets goes as the sine of this angle. 90 degrees thus maximizes the torque. So the main characteristic of a DC machine is the fields are fixed and held at the maximum torque angle.

AC machines are a bit more complex than that, and I'll simply refer anyone interested to the literature. The main characteristic of AC machines is a rotating field. Imagine a bar magnet rotating around a perpendicular axis through the center. That's what goes on inside AC machines, both synchronous and induction. The torque angle is variable.

The rotor field lags behind the stator field by this torque angle as both rotate around at synchronous speed (determined by the frequency). When a synchronous machine is motoring, the stator field is pulling the rotor around. When it's generating, the rotor leads the stator, and the rotor can be seen as pulling the stator field around.

And this is the main difference between AC and DC machines. In the latter, the fields are fixed by the commutator, which keeps switching the current around as the rotor turns. In AC machines, the fields themselves rotate, dragging the load around with them.

Tesla's genius insight was in realizing how to use transformer effect to induce that rotating field in the rotor. Polyphase AC is inherently "rotational" (well, when thought of in this way).

-Richard

I find your insights extemely interesting.
Thanks to you publius I have found an interest in a new music form.

Back to this idea, the induction motor has one of its components as a static vehicle. Has there been any experimentation where both rotor and casing counter rotate.

I was thinking if the right shape of windings and the use of different materials could do more than provide work as a generator or motor.

Certainly all effects are cancelled as the fields are circular (most basic shape) and effects therefore cancel out.

If however the windings had an alternate shape and materials with opposite properties were used on each side of the windings new effects could be found.

I was thinking that iron or ferrous materials are highly magnetic where bezium has almost totally anti magnetic properties. Given that the three components are electricity magnetism and push, could that combination be manipulated to form a push effect of the entire motor in one direction predominantly more than the others.

A word of caution is that gravito magnetic effects are in the order of 10 thousand billion times greater than predictions gave credit to a very low power experiment may be in order.

Just a second caution would be a thing of best fit. If fields had an effect on components such as heating or even size variance it may be adviseable to use slip fitting to allow for expansion etc.

Cheers Mike :)

upriver
2007-May-28, 08:57 PM
All well and good, but the current goes the wrong way for them to create the Earth's magnetic field. The motion of the charged particles in the inner or outer radiation belt or ring currents are governed by gradient drift and curvature drift. (See e.g. Kivelson and Russell, Introduction to space physics, pages 309- 312). These two drifts make positive particle to move westward and negative particles to move eastward, thereby decreasing the Earth's magnetic field when the current is increasing. So, sorry but no cigar, the ring currents, or Van Allen radiation belts cannot create the Earth's magnetic field.

Apart from that, there is also the comment by hhEb09'1 stating that the magnetic field rotates with the Earth, which would not be in agreement with an external source.

So, no need to search further.

If your happy with the geodynamo model. I'm not.

The more I read about it, the more I see its not tenable.

If we distill this down to its basic features, we need either a circulating ring current just under or just above the earths crust, or a bar magnet in the very center.

The geodynamo does not provide those features. I dont think there is a bar magnet suspended in the middle of the earth.

Maybe the earth is hollow? With a electric magnetic plasma ball in the middle!!! ;)


I dont know what this means.
"Recently a new belt has been found within the inner belt. It contains heavy nuclei (mainly oxygen, but also nitrogen and helium, and very little carbon) with energies below 50 MeV/nuc. The source of these particles are the so called "anomalous cosmic rays" of interstellar origin."

I would venture to say that these particles are the result of reconnection(pinch) acceleration.

Anyways, this is by no means done. I wonder if the Birkeland current sheets are somehow connected.

This is definitely a dynamic current issue.

hhEb09'1
2007-May-28, 09:42 PM
If we distill this down to its basic features, we need either a circulating ring current just under or just above the earths crust, or a bar magnet in the very center.Why in the world would you say that? :)

tusenfem
2007-May-29, 07:45 AM
If your happy with the geodynamo model. I'm not.
The more I read about it, the more I see its not tenable.


I am very happy with it, it describes the field well, and modern models even show that the pole reversals are a "natural" phenomenon of the dynamo



If we distill this down to its basic features, we need either a circulating ring current just under or just above the earths crust, or a bar magnet in the very center.


No, we do not need a circulating ring current. That is just the thing of the dynamo, it works through dynamo action (oof, not a good sentence) driven by differential rotation and convection etc. creating a bending and folding of the field lines (of if you like creating a chaging current pattern), that comes out of the molten core as mainly a dipolar field (because the higher order fields drop off more quickly with distance). And a bar magnet does not work, because the core is well above the Curie temperature.



The geodynamo does not provide those features. I dont think there is a bar magnet suspended in the middle of the earth.
Maybe the earth is hollow? With a electric magnetic plasma ball in the middle!!!


Maybe the moon is made of green cheese.



I dont know what this means.
"Recently a new belt has been found within the inner belt. It contains heavy nuclei (mainly oxygen, but also nitrogen and helium, and very little carbon) with energies below 50 MeV/nuc. The source of these particles are the so called "anomalous cosmic rays" of interstellar origin."

I would venture to say that these particles are the result of reconnection(pinch) acceleration.


These particles are coming into the inner magnetosphere from the magnetotail during (sub)storm times. And when in the correct region they start to drift. I am not sure about the "anomalous cosmic rays" comment. But I don't know where your quote comes from.



Anyways, this is by no means done. I wonder if the Birkeland current sheets are somehow connected. This is definitely a dynamic current issue.


I have no idea what you mean with the Birkeland current sheets being connected. You mean the different sheets at "either side of the Earth"? These are connected, yes, through the westward electrojet. I am just writing a paper about that, actually.
Or do you mean the Birkeland currents connected to the ring currents?
And yes, there are a lot of currents on which I am currently working (ooooh bad pun).

Gillianren
2007-May-29, 08:33 AM
(oof, not a good sentence)

Since you bring it up . . . .

I know, it's a terribly ominous beginning. However, I just want to point out that I often forget that you're not a native speaker. When I don't understand what you're saying, it has nothing to do with your word choices!

korjik
2007-May-29, 03:27 PM
Since you bring it up . . . .

I know, it's a terribly ominous beginning. However, I just want to point out that I often forget that you're not a native speaker. When I don't understand what you're saying, it has nothing to do with your word choices!

As a counterpoint, I would probably have said the same thing the same way. :)

Then again, I only speak two languages, english and bad english, and i am far more fluent in bad english.