Mainstream astronomy continues to ignore magnatism

[Dancing David]

As if!
http://antwrp.gsfc.nasa.gov/apod/ap090721.html

[Darth Rotor]

As if!
http://antwrp.gsfc.nasa.gov/apod/ap090721.html
Hmm, do they have a shot of the horse's arse nebula as well? Oh, wait, here is one (http://www.gabbyattic3.com/truepix/tim%20robbins.jpg).

OBTW, thanks for the link to a great shot.

[Sol88]

Ok DD I'll bite

Streams of gas leaving the nebula are funneled by a strong magnetic field. Bright spots in the Horsehead Nebula's base are young stars just in the process of forming.

Where is the mention of the electric current that sustains the strong magnetic field DD?

Yeah thought so :rolleyes:

[Zeuzzz]

hmmmm. Question asked. No answer given.

BUMP.

[Zeuzzz]

*magnetism, btw. ;)

Though my english isn't exactly beyond reproach. So take this as more a meagre (rather pedantic) observation, rather than a cheap shot. :)

[Dancing David]

:) , why should they mention it, I am just pointing out that much maligned M, in EM fields did get a mention. I also recently posted a link to a book about cosmic plasma, i suppose that was all imagination as well?

Where were you when i did that Sol88 or Zuezzz, where were you when the supposedly not studied or considered plasma was found to have a huge source text in mainstrem physics?

[Dancing David]

Hmm, where were you two?

http://books.google.com/books?id=KfIr-f1YbdIC&pg=PA120&lpg=PA120&dq=damping+landau+resonances&source=bl&ots=4d9xEF-CYR&sig=rTWn60cRnFiMWLvjBPpcV248Ygk&hl=en&ei=cShmSs3GN42QMYn13J8B&sa=X&oi=book_result&ct=result&resnum=4

[Zeuzzz]

Where were you when i did that Sol88 or Zuezzz, where were you when the supposedly not studied or considered plasma was found to have a huge source text in mainstrem physics?


I was at home.

And I care not for pseudoplasma (http://www.plasma-universe.com/index.php/Pseudo-plasma), or Big Bang (http://www.plasma-universe.com/index.php/Plasma_Universe_/_Big_Bang_comparison) predicated models.

Is there anywhere in that article where they mention the Pds or currents that sustain the magnetic fields?

[Zeuzzz]

Hmm, where were you two?

http://books.google.com/books?id=KfIr-f1YbdIC&pg=PA120&lpg=PA120&dq=damping+landau+resonances&source=bl&ots=4d9xEF-CYR&sig=rTWn60cRnFiMWLvjBPpcV248Ygk&hl=en&ei=cShmSs3GN42QMYn13J8B&sa=X&oi=book_result&ct=result&resnum=4


Here: http://catalogue.nla.gov.au/Record/3020361/Details?&
Here: http://www.plasma-universe.com/index.php/Physics_of_the_Plasma_Universe_(Book)
And more generally, here: http://www.plasma-universe.com/index.php/Special:Allpages

[Reality Check]

Ok DD I'll bite

Where is the mention of the electric current that sustains the strong magnetic field DD?

Yeah thought so :rolleyes:
I will make a guess:
There is no "electric current that sustains the strong magnetic field"?

This is in the same sense as there is no "electric current" that sustains the Sun's magnetic field (http://www.cora.nwra.com/~werne/eos/text/dynamo.html).

I do not know the origin of the magnetic fields that causes the "streamers" that are seen in the image. Perhaps an interaction between the magnetic fields of the stars in the nebula and the galactic magnetic field?

[Wangler]

This is in the same sense as there is no "electric current" that sustains the Sun's magnetic field (http://www.cora.nwra.com/~werne/eos/text/dynamo.html).

RC, can you help me? I am having trouble understanding your comment in relation to some text from your link:

"In order to understand how the Sun generates magnetic fields you have basically only need to remember two facts. Firstly, the convection zone consists of a plasma, i.e. a gas that contains electrically charged particles. Secondly, the plasma in the convection zone is continuously moving around. Since the plasma is moving, the charged particles are moving and we obtain electrical currents."

Is the current they mention virtual, or something like that?

[Eggs Ackley]

RC, can you help me? I am having trouble understanding your comment in relation to some text from your link:

"In order to understand how the Sun generates magnetic fields you have basically only need to remember two facts. Firstly, the convection zone consists of a plasma, i.e. a gas that contains electrically charged particles. Secondly, the plasma in the convection zone is continuously moving around. Since the plasma is moving, the charged particles are moving and we obtain electrical currents."

Is the current they mention virtual, or something like that?

Those two facts are not sufficient to understand how the sun generates a magnetic field. The definition of a plasma is that at least some of the electrons of the atoms of a gas are dissociated. This does not in itself imply that the plasma has a net charge and so moving a plasma around does not ensure a magnetic field is generated. Either, the plasma has to be non-neutral, or something has to be happening so that the positive part is not moving exactly oppositely to the negative part.

It seems plausible to me that inside the sun the plasma is not locally neutral everywhere, so I am not arguing that there can be no field, I am only saying that the explanation in the quote is not correct or sufficient.

[tusenfem]

Here: http://www.plasma-universe.com/index.php/Physics_of_the_Plasma_Universe_(Book)


Wow, I am really impressed by this page about the book, explains it all!

[Reality Check]

Those two facts are not sufficient to understand how the sun generates a magnetic field. The definition of a plasma is that at least some of the electrons of the atoms of a gas are dissociated. This does not in itself imply that the plasma has a net charge and so moving a plasma around does not ensure a magnetic field is generated. Either, the plasma has to be non-neutral, or something has to be happening so that the positive part is not moving exactly oppositely to the negative part.

It seems plausible to me that inside the sun the plasma is not locally neutral everywhere, so I am not arguing that there can be no field, I am only saying that the explanation in the quote is not correct or sufficient.
That is right. The web page is making it simple by saying "electric current" but this implies an electric current as in a wire. What it really is (AFAIK) is the plasma becoming non-neutral because it is flowing turbulently in three dimensions and helically (as stated a little further down).

An analogy would be the magnetic field generated by a a rod with an electrostatic charge. If the rod moves then there are moving charges and a magnetic field. But there is no actual electric current - just moving charges.

[Wangler]

Thanks, RC and EA!

No question, you gotta love the sun. Just amazing.

RC, your last bit: "..there is no electric current, just moving charges." is kind of funny, even to a physics neopyte like myself.

[Sol88]

Thanks, RC and EA!

No question, you gotta love the sun. Just amazing.

RC, your last bit: "..there is no electric current, just moving charges." is kind of funny, even to a physics neopyte like myself.

Yeah! He's like that :rolleyes:

[Sol88]

, why should they mention it, I am just pointing out that much maligned M, in EM fields did get a mention. I also recently posted a link to a book about cosmic plasma, i suppose that was all imagination as well?

No you are wrong MAGNETISM is mainstream eg tangled magnetic fields, magnetic reconnection et cetera!

But where is the mention of the electric current that MUST sustain the magnetic field???

Dancing David? Reality check?

Mainstream ASSUMES all cosmic plasma's MUST be quasi neutral, hence no "electric current"

[Reality Check]

Thanks, RC and EA!

No question, you gotta love the sun. Just amazing.

RC, your last bit: "..there is no electric current, just moving charges." is kind of funny, even to a physics neopyte like myself.
What I meant is that the electrons move and the ions move. This is not an electric current where the electrons move and the ions stay still (e.g. electrons moving in a wire).

[Reality Check]

No you are wrong MAGNETISM is mainstream eg tangled magnetic fields, magnetic reconnection et cetera!

But where is the mention of the electric current that MUST sustain the magnetic field???

There is no "electric current that sustains the strong magnetic field"
This is in the same sense as there is no "electric current" that sustains the Sun's magnetic field (http://www.cora.nwra.com/~werne/eos/text/dynamo.html).

I do not know the origin of the magnetic fields that causes the "streamers" that are seen in the image. Perhaps an interaction between the magnetic fields of the stars in the nebula and the galactic magnetic field?

Mainstream ASSUMES all cosmic plasma's MUST be quasi neutral, hence no "electric current"
Actual science calculates that plasma (http://en.wikipedia.org/wiki/Plasma_(physics)#Non-neutral_plasma) must be normally quasi neutral. Of course there are non-neutral plasmas:
The strength and range of the electric force and the good conductivity of plasmas usually ensure that the density of positive and negative charges in any sizeable region are equal ("quasineutrality"). A plasma which has a significant excess of charge density or which is, in the extreme case, composed of only a single species, is called a non-neutral plasma. In such a plasma, electric fields play a dominant role. Examples are charged particle beams (http://forums.randi.org/wiki/Particle_beam), an electron cloud in a Penning trap (http://forums.randi.org/wiki/Penning_trap), and positron plasmas.[24] (http://forums.randi.org/newreply.php?do=newreply&p=4932141#cite_note-23)
And also:

Since plasmas are very good conductors, electric potentials play an important role. The potential as it exists on average in the space between charged particles, independent of the question of how it can be measured, is called the "plasma potential" or the "space potential". If an electrode is inserted into a plasma, its potential will generally lie considerably below the plasma potential due to what is termed a Debye sheath (http://forums.randi.org/wiki/Debye_sheath). The good electrical conductivity of plasmas causes their electric fields to be very small. This results in the important concept of "quasineutrality", which says the density of negative charges is approximately equal to the density of positive charges over large volumes of the plasma (http://upload.wikimedia.org/math/0/e/9/0e95e37c4a9cd4d6c103ea29fe705e6d.png), but on the scale of the Debye length there can be charge imbalance. In the special case that double layers (http://forums.randi.org/wiki/Double_layer_(plasma)) are formed, the charge separation can extend some tens of Debye lengths.

And you know what the Debye length (http://en.wikipedia.org/wiki/Debye_length) is.

[tusenfem]

No you are wrong MAGNETISM is mainstream eg tangled magnetic fields, magnetic reconnection et cetera!

But where is the mention of the electric current that MUST sustain the magnetic field???

Dancing David? Reality check?

Mainstream ASSUMES all cosmic plasma's MUST be quasi neutral, hence no "electric current"

As already has been mentioned to you a bezillion times: quasi-neutrality and electric currents are NOT related. A plasma can be quasi neutral (usually is) and carry or not carry a current.


Quasi-neutral: Σi ni qi = 0 (with i running over electrons and all ion species) over volumes greater than the Debye sphere, with the exception of e.g. double layers
(No) Current: Σi ni qi vi (with i running over electrons and all ion species) which can be zero or non zero.
Substituting the first into the second gives, in the simple case of only electrons and protons nel qel(vel - vpr), so if the electron and proton have the same velocity, then no current, if they have different velocity, then current.



ETA: ah!!!!! beaten by RC!!

In the solar dynamo you can actually get the currents, though it is a big mess. The process is most easily explained in magnetic loops being stretched and twisted and folded and so on (and then you can calculate the currents that are needed from Maxwell's equations, messy messy).

[Sol88]

As already has been mentioned to you a bezillion times: quasi-neutrality and electric currents are NOT related. A plasma can be quasi neutral (usually is) and carry or not carry a current.



Ahhh so a current can flow thru a QN plasma? like 'em Birkeland currents from the sun or a comets tail?

Why does it not, the current, not just equalize with the surrounding QN plasma? eh?

[Aepervius]

I do too ignore Magna. I never was in Uath. I do not have a car either, so much for magna steyr.

I also tend to ignore people which want to discuss deep physic and cannot even get the term correctly in a thread title.

[Wangler]

What I meant is that the electrons move and the ions move. This is not an electric current where the electrons move and the ions stay still (e.g. electrons moving in a wire).

RC, thank you. It sounds like it is random/chaotic movement as well.

If electrons in a wire were moving in a chaotic fashion, not one direction, there wouldn't be a current either, right?

[Dancing David]

I do too ignore Magna. I never was in Uath. I do not have a car either, so much for magna steyr.

I also tend to ignore people which want to discuss deep physic and cannot even get the term correctly in a thread title.


Great goats batman, what an insightful comment.

Sorry you spelling freak, I made a mistake.

Your lack of tolerance is most likely not matched by your intelligence.

[tusenfem]

Ahhh so a current can flow thru a QN plasma? like 'em Birkeland currents from the sun or a comets tail?


Like Birkeland currents yes. Nobody ever claimed that no currents can flow throug a quasi-neutral plasma as I showed above.


Why does it not, the current, not just equalize with the surrounding QN plasma? eh?

Maybe because these currents are not driven by a charge difference, but by an EMF. You know, just like when you ride your bike (if you have already learned how to do that) turn on the dynamo and currents start to flow. Why does that not stop, equalizing?

But then the whole expression "equalize with the surrounding QN" does not really make any sense. But we don't expect anything else from you.

[Zeuzzz]

I also tend to ignore people which want to discuss deep physic and cannot even get the term correctly in a thread title.


Do you mean deep physics? Because that sentence doesn't make much sense otherwise, gramatically or logically.

I smell a Spelling Nazi

[Reality Check]

RC, thank you. It sounds like it is random/chaotic movement as well.

If electrons in a wire were moving in a chaotic fashion, not one direction, there wouldn't be a current either, right?
If electrons in a wire were moving in random directions then there would not be a current.

[Zeuzzz]

There is no "electric current that sustains the strong magnetic field"
This is in the same sense as there is no "electric current" that sustains the Sun's magnetic field (http://www.cora.nwra.com/~werne/eos/text/dynamo.html).


While that page is largely respectable, I have to point out that tis not gospel, or as definitive as it seems.

To quote a few:

The Dynamo in the Sun.

Where is the solar dynamo located?

Today, most solar physicists believe that the solar dynamo is located either at the bottom of the convection zone or in a thin region called the overshoot zone.The overshoot zone is located between the convection zone and the radiative zone.


At least they said most solar physicists, because thinking that this is known beyond repute is ridiculous.

One, out of many, many completely different models for example:

Overshoot at the Base of the Solar Convection Zone: A Semianalytical Approach (http://adsabs.harvard.edu/abs/2004ApJ...607.1046R) The Astrophysical Journal, Volume 607, Issue 2, pp. 1046-1064.
Despite the importance of overshoot at the base of the solar convection zone for the storage of strong toroidal magnetic field produced there by the solar dynamo, uncertainties concerning the depth and mean subadiabatic stratification remain large. Overshoot models based on the nonlocal mixing-length theory generally produce a shallow, weakly subadiabatic region with a sharp transition to the radiative interior, whereas several numerical simulations lead to significantly subadiabatic overshoot with penetration depth of more than a pressure scale height. We present a semianalytical convection zone/overshoot region model based on the assumption that the convective energy flux is governed by coherent downflow structures starting at the top of the domain and continuing all the way down into the overshoot region, which allows for modeling both the parameter regime addressed by nonlocal mixing-length approach and the regime addressed by numerical simulations. [....]


All the models are based on a heap of assumptions, the main one being that their convective based models produce laminar flows. Donald Scott for example states (as pointed out well many years ago by juergens first),

http://www.electric-cosmos.org/Rejoinder.pdf
In the hypothesized 'convection zone,' the question is not whether convection or conduction occurs. The question is: Since the Reynolds number is so large (remember that how it is numerically evaluated is based on many assumptions about a region we cannot observe), any convection must be turbulent, not laminar, flow. But the photospheric 'tufts‘ that we do observe are claimed to be the tops of laminar columns that reach from the Sun‘s radiative zone all the way up to the photosphere. How these stable columns can exist in the highly turbulent convection zone is what is being questioned. Dr. Eugene N. Parker, perhaps the most eminent solar astronomer, worried in print[1] that, "the Reynolds number [in the convection zone] is on the order of 1012 and, perhaps worse, the convective zone is vertically stratified." [....]

Classic astronomy (and its offshoots: helioseismology, astrophysics, cosmology, etc.) have never made any real predictions that turned out to be true – although they are past-masters at inventing 'dynamos' and invisible entities to explain things retroactively. After-the-fact explanations are easy, especially if you can get away with saying ―The hidden 'dynamo' did it. Before they were forced into it, classical astronomers were wrong about how the auroras are powered, about the temperature of Venus, about the rocky nature of comets, about x-rays coming from comets and other objects, about the existence of natural radio emissions from the planets. And I claim they are wrong about many things they are now saying about the Sun.

* The Physics of the Sun and the Gateway to the Stars, Eugene N. Parker, Physics Today, June 2000, p. 26-31.


I like the fact that they have a detailed page on how it all works, then when we get onto the section that says "Advanced Research Topics Related to the Solar Dynamo" to get down to the real bulk material underlying their webpage, it rather bluntly states the truth:

Many aspects concerning the solar dynamo are not well understood even today. Here are just a few problems that scientists are working on at the moment:

1. It is still not totally clear where the solar dynamo is located. is it sitting in the convection zone or in the overshoot zone?
2. Does the alpha-effect work or does it not work. This is a very hotly debated question.
3. What causes the differential rotation of the Sun?


So a few other models to consider:

Double radio sources and the new approach to cosmical plasma physics (http://www.springerlink.com/content/t12874633l884606/) Astrophysics and Space Science Volume 54, Number 2 / April, 1978
Abstract The methodology of cosmic plasma physics is discussed. It is very hazardous to try to describe plasma phenomena by theories which have not been carefully tested experimentally. One present approach is to rely on laboratory measurements andin situ measurements in the magnetosphere and heliosphere, and to approach galactic phenomena by scaling up the wellknown phenomena to galactic dimensions. A summary is given of laboratory investigations of electric double layers, a phenomenon which is known to be very important in laboratory discharges. A summary is
also given of thein situ measurements in the magnetosphere by which the importance of electric double layers in the Earth's surrounding is established. The scaling laws between laboratory and magnetospheric double layers are studied. The successful scaling between laboratory and magnetospheric phenomena encourages an extrapolation to heliospheric phenomena. A further extrapolation to galactic phenomena leads to a theory of double radio sources.
In analogy with the Sun which, acting as a homopolar inductor, energizes the heliospheric current system, a rotating magnetized galaxy should produce a similar current system. From analogy with laboratory and magnetospheric current systems it is argued that the galactic current might produce double layers where a large energy dissipation takes place. This leads to a theory of the double radio sources which, within the necessary wide limits of uncertainty, is quantitatively reconcilable with observations.


http://www.plasma-universe.com/index.php/Heliospheric_current_circuit
http://www.plasma-universe.com/index.php/Sun_and_stars#Unipolar_generator

http://arxiv.org/ftp/arxiv/papers/0902/0902.0181.pdf
HELIOSHEATH SYNCHROTRON RADIATION AS A POSSIBLE SOURCE FOR THE ARCADE 2 CMB DISTORTIONS
H.N. Sharpe

ABSTRACT
This brief note speculates that the recently reported residual CMB signal [Seiffert et al 2009] may originate within the Sun’s heliosheath. A temperature spectrum function is derived that has the same power law form as the fitted function in Seiffert et al. In particular a spectral index of +2 is implied. An optically thin radiating shell of thickness ~ 1AU could match the required 1K deg power law amplitude. A possible mechanism for the heliosheath magnetic fields is discussed based on Alfven’s heliospheric current model with embedded double layers as the energy source for the relativistic electrons.

http://arxiv.org/ftp/arxiv/papers/0906/0906.2739.pdf
A non-cosmological origin for the CMB low-order multipoles and associated anomalies is suggested in this paper. We discuss the possibility that these features of the power spectrum originate in the termination shock (TS) region of the heliosheath that surrounds the solar system. If the intrinsic CMB spectrum is assumed to be a pure monopole (2.73K) then thermal processes occurring within an ellipsoidal shaped plasma region of the TS region could imprint the observed low-order multipoles and their alignment (so-called ‘axis of exil”) onto this background CMB. A key requirement of the model is that the TS plasma be characterized as an optically thin graybody with non-LTE perturbations to explain both the blackbody and non-blackbody anomalies. Nonthermal TS processes are also discussed. TS synchrotron radiation is shown as a possible cause for the reported ARCADE 2 CMB distortion. Magnetoacoustic oscillations and heliosheath turbulence are suggested as possible sources for the higher-order multipole moments of the CMB. [.....]

Next we consider the nature of the heliosheath magnetic fields and the energetic electrons. Alfven [14] developed a heliospheric current model along the lines of the observed terrestrial magnetospheric current system. Briefly, the Sun acts as a unipolar inductor that generates an emf which drives two polar current systems. These currents spread out, possibly to the heliosheath, and return to the Sun near the equatorial plane thereby completing the “circuit”. It is not known if the polar currents spread out to form current sheets or if they concentrate into filaments. It is likely that they break up into cylindrical filaments and pinch down in a Bennett-type pinch effect. But whereas the Bennett pinch represents a balance between the plasma pressure and a compressing electromagnetic force, a low density plasma like that in the heliosheath cannot generate an internal plasma pressure. The result is a force-free magnetic field in a reference frame which moves with the current because the electric and magnetic fields are aligned in this frame. To an outside observer the magnetic field would appear as a twisted magnetic “rope” [15]. Force-free fields represent the lowest state of magnetic energy that a closed system may attain [16]. Hence an initial current sheet should break into Birkeland (magnetic field aligned) vortex tubes having a characteristic distribution function. Recent Voyager data suggest the presence of magnetic rope structures in the heliosheath [17].

Relativistic electrons in the heliosheath could be produced in a system of double layers distributed along the field-aligned current systems. The double layer is an electrostatic structure a few Debye lengths wide which may appear in a current carrying plasma. It can sustain a high net potential difference which could accelerate electrons traversing it. It may then provide a mechanism for transforming stored magnetic energy into the directed kinetic energy of the accelerated particles. Alfven [18] discusses the production of relativistic electrons in double layers associated with a heliospheric current system similar to the mechanism he proposed for the Earth’s magnetosphere. Intense localized plasma-wave electric fields recently observed at the TS [8] could accelerate electrons to these relativistic energies.

[8] D.A. Gurnett and W.S. Kurth. Intense Plasma Waves at and near the Solar Wind Termination
Shock, Nature V.454 Issue 7200 2008.
[14] Alfven, H. Cosmic Plasma. D. Reidel 1981.
[15] Alfven, H. and C-G Falthammar. Cosmical Electrodynamics 2nd Edition Oxford 1963.
[16] Peratt, A.L. Physics of the Plasma Universe. Springer-Verlag 1992.
[17] Burlaga, L.F. Ness, N.F. and M.H. Acuria. Multiscale Structure of Magnetic Fields in the Heliosheath.
J. Geophys. Res. V.111, Issue A9 2006.
[18] Alfven, H. Double Layers and Circuits in Astrophysics. IEEE Trans. Plasma Physics. V. PS-14. No.6
1986.


I highly recommend citations 14-18.

[Zeuzzz]

The title of the OP i disagree with; if anything mainstream astronomy continues to use magnetism too much, when they should be focussing on the plasma physics, currents and potentials that create them.

If the title was "Mainstream astronomy continues to plasma physics and electric circuits" I would tend to agree.