Problems With Magnetic Reconnection

[michaelsuede]

Research by wikipedia. Got any real sources?

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870013880_1987013880.pdf

 

[dafydd]

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870013880_1987013880.pdf

I'm the same as you mate,the math is beyond me,I'll leave it to the experts to answer you.

 

[Reality Check]

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870013880_1987013880.pdf

This is the 1986 "Double Layers in Astrophysics" conference proceedings that plasma cosmology proponents ignorantly tout because Alfven gave the keynote speech.

Nothing to do with any scientific evidence that magnetic reconnection does not exist.

 

[ben m]

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870013880_1987013880.pdf

Let me repeat what I said to your last link:

This does not argue any of your points, which were "field lines are ill defined" (wrong) and "field lines mathematically cannot cross" (wrong). It is, however, a pretty good argument in favor of my point: You, personally, don't know enough plasma physics to conduct a coherent discussion of it. All you have is a pile of Alfven-ite literature that you don't quite understand; you're going to shovel it out randomly and declare intellectual victory after each shovelful.

In this new shovel-load, where will I find a mathematical statement that {Bx,By} = {ay, bx} is not a realistic magnetic field configuration? Or that it doesn't contain crossing field lines?

 

[Aitch]

Michael, are you this Michael Suede?

 

[tusenfem]

Alfven explains where the DL is located in the criticism section at the bottom.

http://en.wikipedia.org/w/index.php?title=Magnetic_reconnection&oldid=419551364

No Alfvén lets a double layer explode in a circuit, e.g. in the magnetic loop of a solar prominence. This mechanism is not the same as what happens in magnetic reconnection.

So, once more, take the data from the Runov et al. (2003) paper and show us exactly where this double layer is supposed to be.

Don't come with statements like "there has to be a double layer" because "there are different plasmas" and then quote Alfvén, who is clearly taking about a double layer created in a current carrying plasma. The two kinds of double layers are not the same. Maybe you should read the double layer wiki page, which is for the biggest part the introduction chapter of my PhD thesis.

http://en.wikipedia.org/wiki/File:Figure11.JPG

MHD doesn't explain why your current sheet should exist.

That is just silly, even MHD uses Maxwell's equations. If you have two regions of oppositely directed magnetic field in a plasma then a current sheet has to exist. It is just a consequence of curl(B) = μ J. Alfvén turns around in his grave when his so-called defenders make claims like this.

The figure by Rolf Boström is nice, to see a substorm in a circuit representation. But as I have told MM before, and I probably need to tell you too, circuit representation of plasma physical processes is the long wavelength approximation of the plasma physics equations, not unlike Alfvén when developing MDH (and why in MDH you often find circuit representations), therefore, per definition, a circuit representation cannot describe the process of magnetic reconnection. It can only indicate that something happens and estimates can be made about the power that may or may not be released, however the small scale physics can never be described, let alone the reconfiguration of the magnetic field around the X-point/line.

Modeling a current sheet is not the same as explaining why it is there in the first place.

If you would know plasma physics, or even know a little bit about Maxwell's equations, you would understand why a current sheet needs to be there, and is actually measured and it can be modeled, and the Harris model seems most often to be very appropriate.

 

[tusenfem]

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870013880_1987013880.pdf

The only time that magnetic reconnection is mentioned in these proceedings is in Alfvén's keynote address, where he discusses magnetic merging. Basically, he is claiming there that reconnection cannot happen in ideal MHD, something any plasma physicist know by now, and e.g. the reason why numerical modeling of MRx can only be done in resistive-MHD, however, some of the times you may see that an MDH code is used, but because of the numerical errors in the programming (due to rounding errors) there is a numerical diffusion, which represents the resistivity of the plasma.

Especially the last comment by Alfvén is very strange: "anyone believing in magnetic merging does not believe that double layers exist", or that "whenever a double layer is found it is another nail to the coffin of magnetic merging." Although a keynote address is supposed to be challenging and thought provoking, the latter comment for example makes no sense at all, because double layers are found above the auroral regions, where the electrons are accelerated Earthward, and nobody would ever suggest that in that region magnetic merging would be a feasable process to occur.

So michaelsuede, please explain the observations by Runov et al. (2003) with a double layer, I am very interested how you are going to explain all the magnetic signatures.

 

[sol invictus]

It is just a consequence of curl(B) = μ J.

As we've already verified, Michael has no idea what that equation means.

This thread is analogous to someone saying "pneumonia can never be caused by bacteria, that's nonsense!" and then turning out not to know that bacteria are small organisms with DNA that can be grown in petri dishes.

 

[dafydd]

As we've already verified, Michael has no idea what that equation means.

This thread is analogous to someone saying "pneumonia can never be caused by bacteria, that's nonsense!" and then turning out not to know that bacteria are small organisms with DNA that can be grown in petri dishes.

A very good analogy. "A little knowledge is a dangerous thing."-Alexander Pope.

 

[michaelsuede]

The only time that magnetic reconnection is mentioned in these proceedings is in Alfvén's keynote address, where he discusses magnetic merging. Basically, he is claiming there that reconnection cannot happen in ideal MHD, something any plasma physicist know by now, and e.g. the reason why numerical modeling of MRx can only be done in resistive-MHD, however, some of the times you may see that an MDH code is used, but because of the numerical errors in the programming (due to rounding errors) there is a numerical diffusion, which represents the resistivity of the plasma.

Especially the last comment by Alfvén is very strange: "anyone believing in magnetic merging does not believe that double layers exist", or that "whenever a double layer is found it is another nail to the coffin of magnetic merging." Although a keynote address is supposed to be challenging and thought provoking, the latter comment for example makes no sense at all, because double layers are found above the auroral regions, where the electrons are accelerated Earthward, and nobody would ever suggest that in that region magnetic merging would be a feasable process to occur.

So michaelsuede, please explain the observations by Runov et al. (2003) with a double layer, I am very interested how you are going to explain all the magnetic signatures.

The Cluster signatures are inconsequential as to the issue of reconnection when taken from Alfven's point of view.

Alfven is contending that the onset of a substorm is caused by the creation of a DL which redirects the tail current into ionosphere.

Alfven gives a crude picture of how and why the neutral sheet is formed in this paper:

http://articles.adsabs.harvard.edu/...GH&whole_paper=YES&type=PRINTER&filetype=.pdf

And explains the substorms generally here:

Figure 11. Bostrom(1974) has given a summary of his theory of magnetic substorms in the form of a circuit. Solar wind energy produces a cross-tail current in the neutral sheet. The arrow indicates that this current can give rise to a very large voltage. (In our terminology, it should be replaced by the DL symbol.) This causes the circuit energy to be discharged over the ionosphere, where it is observed as a magnetic substorm. At substorm onset, the resistance of the neutral sheet increases because a DL is produced and the tail current is redirected to the ionosphere.

 

[ben m]

The Cluster signatures are inconsequential as to the issue of reconnection when taken from Alfven's point of view.

"I have built a vacuum-tube that emits x-rays. Therefore I understand neutron star binaries from my own point of view. Don't bother showing me Chandra telescope data, they're inconsequential."

ETA: either the data agree with your model and/or a competing model; or the data do not agree with your model and/or a competing model. There is no such thing as inconsequential data. Unless you actually have no idea what's going on, and are making excuses for why you won't discuss anything except what's pre-loaded onto your shovel.

 

[michaelsuede]

"I have built a vacuum-tube that emits x-rays. Therefore I understand neutron star binaries from my own point of view. Don't bother showing me Chandra telescope data, they're inconsequential."

Alfven gives a treatment of why neutral point reconnection is wrong in his book "Cosmic Plasma" from a theory point of view.

Until it can be demonstrated that there is no DL formation/explosion at substorm onset, there is no reason to conclude that 'magnetic reconnection' is a function of novel plasma properties.

 

[ben m]

Alfven gives a treatment of why neutral point reconnection is wrong in his book "Cosmic Plasma" from a theory point of view.

Until it can be demonstrated that there is no DL formation/explosion at substorm onset, there is no reason to conclude that 'magnetic reconnection' is a function of novel plasma properties.

First: No one is asking whether Alfven had a theory. We knew that. Many people have theories. Many of them are wrong. This is a discussion of the real world, as measured by the Cluster spacecraft (whose data look like reconnection) and as governed by Maxwell's Equations (whose allowable B fields allow for reconnection.)

Do you even remember posting the following?

Since a magnetic field is an infinite continuum, there can be no splitting and reconnecting of field lines. In order for a field line (which is a mathematical construct used to describe the location of a magnetic field) to “reconnect” it would first have to be spliced in half.

 

[catsmate]

Is this going to be another one of those "I'm going to overturn a large segment of known physics with this idea I have and random documents I link to but refuse to math" threads?

Yes it would appear so, the poster is involved with the thunderbolts crack-pottery forum.

 

[catsmate]

Because I didn't write that article for astrophysicists, I wrote it for average joe electrical engineers who understand circuit theory.

So you deliberately write for people who don't understand the field in question? This really reminds me about a thread here on crackpot physics and why there is so much of it; engineers are so commonly involved in it

[With apologies to then sane majority of engineers, I live with two of them.]

 

[temporalillusion]

It's not just moving the goalposts. The goalposts have been removed and replaced with a panel of figure-skating judges.

I demand this be added to all lists of logical fallacies.

 

[tusenfem]

The Cluster signatures are inconsequential as to the issue of reconnection when taken from Alfven's point of view.

Alfven is contending that the onset of a substorm is caused by the creation of a DL which redirects the tail current into ionosphere.

And what current would that be exactly? The same current as the substorm current wedge? From the THEMIS results it has been found that the creation of the substorm current wedge is not the onset of the substorm.

Also, how is the double layer producing the fast plasma flows (both electrons and ions) towards the Earth, including the flux transport of magnetic field?

Also, the Cluster observations are very consequential, as they show that all signatures that are associated with magnetic reconnection are actually there in the Earth's magnetotail. Just dismissing data because they do not fit your preconceptions is hardly scientific.

Alfven gives a crude picture of how and why the neutral sheet is formed in this paper:

http://articles.adsabs.harvard.edu/...GH&whole_paper=YES&type=PRINTER&filetype=.pdf

Alfvén has cut open the magnetotail here. And he shows how the currents are closed, this is a rather crude superposition model of a dipole and a background field and some varying field, but then, it is a paper from 1981. Note the neutral line that is in the model, just for that you should dismiss this model immediately, because there cannot be a B=0 point in a 3D magnetic field according to you.

And explains the substorms generally here:

[qimg]http://upload.wikimedia.org/wikipedia/en/0/0b/Figure11.JPG[/qimg]

Figure 11. Bostrom(1974) has given a summary of his theory of magnetic substorms in the form of a circuit. Solar wind energy produces a cross-tail current in the neutral sheet. The arrow indicates that this current can give rise to a very large voltage. (In our terminology, it should be replaced by the DL symbol.) This causes the circuit energy to be discharged over the ionosphere, where it is observed as a magnetic substorm. At substorm onset, the resistance of the neutral sheet increases because a DL is produced and the tail current is redirected to the ionosphere.

No, this is not an explanation of a substorm, this is a circuit model of a substorm, there is quite a difference. For one, you don't see any real physics in that circuit model, everything is just averaged and put into large scale properties as one resistivity or one capacitance etc. etc. All the details that are taking place in the Earth's magnetotail disappear in this kind of description.

No large scale double layer has been measured in the tail at the creation of the substorm current wedge. There are a lot of instabilities measured there, but from none of them arises a double layer. Basically the region where this starts shows ballooning instability, and drives a possible current disruption (which is NOT an exploding double layer).

Keeping haning on to old papers is not going to bring anything when you subsequently dismiss the best measurements of the tail ever by Cluster and THEMIS.

 

[tusenfem]

Unfortunately, the EU/ES/EC/PU/PC proponents have switched off physics after Alfvén wrote Cosmic Plasma. Next to that most of them have not got the foggiest about real plasma physics or even simple electrodynamics.

In this case here michaelsuede just has a certain group of links and prepared answers and comments that will be repeated ad infinitum, and any observations, measurements or theoretical developments after ~1981 will be discarded as non-consequential. We know this e.g. from the other michael on this forum, who stems from the same group.

Basically, this discussion here is totally useless because MS just like MM is not going to listen to any modern day explanations.

 

[Ziggurat]

Alfven gives a treatment of why neutral point reconnection is wrong in his book "Cosmic Plasma" from a theory point of view.

And how can you claim to be in any position to evaluate what he said if you can't do even the most basic electrodynamic calculations?

 

[fuelair]

Throwing out a list of random stuff that has nothing to do with the topic does nothing to diminish the points made in my article.

1. MHD can not describe the double layer condition, which we know must exist between two differing plasma fields.

2. Magnetic reconnection theory does not incorporate a double layer, which we know must exist between two differing plasma fields.

3. Magnetic null points are an artifact of how MHD treats the plasma. As was stated, this treatment is wrong on several levels. Given that an intense electric field is generated along the boundary of two differing plasmas, there is no way that a magnetic null point can form.

There are 2 or 3 people here I am pretty sure can argue/discuss this with you meaningfully. None of us AFAIK can make you any money or make you famous. So, why are you trying to convince us. Publish in Nature or other juried journal. That is what will accomplish something