Magnetic reconnection and physical processes

[Michael Mozina]

Nope the ruse again simply remains yours.

Nope, it's yours. You are intentionally and willfully butchering science. The force you're describing already has a proper scientific term. It's called "magnetic attraction/repulsion". Period. Any attempt on your part to relabel "magnetic attraction" to some other term, in this case "reconnection" is simply bizarre. There is no "reconnection" taking place, just simple "magnetic attraction" between two fields. There is nothing new going on in your example that warrants a relabeling of known force of nature. Magnetic attraction and magnetic repulsion already have proper scientific terms. Intentionally calling it something else is nothing but a ruse.

 

[Michael Mozina]

That is not quite right.
We all (except you) agree that magnetic reconnection exists as a change in magnetic field topology as in Ziggurat' year old post (based on an even older post).

We all agree that "magnetic ropes' change their topology (and evidently "current flow") pattern in that same "topology change".

We all agree that there is one paper that explains 2 solar flares as magnetic reconnection between 2 twisted magnetic ropes.

We all agree that two magnetic ropes "reconnect". You however seem to have your own personal definition of a 'magnetic rope" since Alfven described a magnetic rope as a current carrying filament of plasma.

We all (except you) agree that there is a model of solar flares that has magnetic reconnection happening in loops of magnetic flux (coronal loops).

You're completely ignoring that fact that those same flares can be described in terms of macroscopic circuits. You're in pure denial of that first paper not to mention Alfven's life's work, all of Bruces work, and even Birkeland's empirical experiments with "electricity".

There is no disagreement on what to call this process - it is called magnetic reconnection.

Alfven called that term "pseudoscience".

Whatever the process that you have made up and called "circuit reconnection" is, it is not magnetic reconection.

Boloney. They are exactly the same physical process. It's just that you insist on calling a topology change between two "current flows" a "magnetic reconnection" event. It's like calling a short circuit a "magnetic reconnection" event. That's exactly what's going on too, a short circuit in the plasma, followed by a topology change between the two filaments as the electrons running through the filaments seek a path of less resistance through the other magnetic rope. None of you even seem to be aware of the "current flow" of electrons that generates the field around the rope.

 

[The Man]

MM you might be having a hard time visualizing the type of refrigerator magnet I am talking about and how the reconfiguring of the fields shifts the positions of the magnets. Very simply put you can consider the north south stripes (magnetic domains) on the magnets (in cross section) as a series of bar magnets placed north end to south end as shown below (of course there are more than just four domains)


:N S:N S:N S:N S:


So the original configuration of the two refrigerator magnets might be..

:S N:S N:S N:S N:
:N S:N S:N S:N S:



And they would always return to that position without a reconnection between the domains.



After reconnection however the positioning can change to perhaps.

:n::::S N:S N:S N:S N:
:N S:N S:N S:N S:

 

[Michael Mozina]

Oh yeah, again that nonsens part on the wiki page. I don't understand that, could you please explain to me what "The resulting cross-section pattern indicates a hollow beam of electron in the form of a circle of vortices, a formation called the diocotron instability" and then especially the "hollow beam part" means.

It means that the filament is acting as a "conductor" or "wire" as in that quote from Alfven. The plasma that makes up the tube is also conducting current flow in the form of electrons.

 

[Michael Mozina]

MM you might be having a hard time visualizing the type of refrigerator magnet I am talking about

You're attempting to complicate the example to make it "seem" like it's different than a simple example of magnetic attraction, but it's not. You've essentially described a binary series of N/S magnets, all experiencing "charge attraction", and/or "charge repulsion". Nothing is "reconnecting". You're still just talking about magnetic attraction and magnetic repulsion between two (or more) magnetic fields. The fields are not actually "reconnecting" to the other field, they are either repulsing or attracting the magnetic field of the other magnet.

 

[The Man]

Nope, it's yours. You are intentionally and willfully butchering science. The force you're describing already has a proper scientific term. It's called "magnetic attraction/repulsion". Period. Any attempt on your part to relabel "magnetic attraction" to some other term, in this case "reconnection" is simply bizarre. There is no "reconnection" taking place, just simple "magnetic attraction" between two fields.

Nope you are simply ignoring the changes in the magnetic fields and desperately trying to label it as anything else, even "magnet reconnection" that somehow is not magnetic.

There is nothing new going on in your example that warrants a relabeling of known force of nature.

No one has claimed anything new and certainly no one has claimed anything “warrants a relabeling of known force of nature”. That you simply do not understand magnetic fields is certainly nothing new to anyone here and you are the only one I see desperately trying to relabel magnetic reconnection and magnetic fields as anything but magnetic.

Magnetic attraction and magnetic repulsion already have proper scientific terms. Intentionally calling it something else is nothing but a ruse.

So do induction and EMF, so try taking your own advice.

 

[The Man]

You're attempting to complicate the example to make it "seem" like it's different than a simple example of magnetic attraction, but it's not. You've essentially described a binary series of N/S magnets, all experiencing "charge attraction", and/or "charge repulsion". Nothing is "reconnecting". You're still just talking about magnetic attraction and magnetic repulsion between two (or more) magnetic fields. The fields are not actually "reconnecting" to the other field, they are either repulsing or attracting the magnetic field of the other magnet.

Sorry, but that is the example that was given (even simplified to some degree), if that seems complicated to you then you really must not understand the example. Again “"charge attraction", and/or "charge repulsion"” alone can not explain the change in the connections between the magnetic domains of the two refrigerator magnets, but you’re more than welcome to give that explanation a try.

 

[sol invictus]

I'm saying that in TM's example it is "magnetic repulsion" and "magnetic attraction" at work, and *THAT* behavior is *NOT* "magnetic reconnection". I'll have to look at your math and links now that you've provided some background.

For the third (?) time: do you or do you not agree that the B field lines are reconnecting in these examples? If you do not agree, how do you reconcile that with the movie (which shows it completely plainly) and the explicit solution above?

Keep in mind that we all seem to agree that two "magnetic ropes" can and do in fact "reconnect", or more specifically a topology change occurs between the ropes.

"Magnetic rope" is not a physics term I'm familiar with. Is it synonymous with "magnetic field line"?

 

[Reality Check]

Outstanding question for Michael Mozina

We all agree that "magnetic ropes' change their topology (and evidently "current flow") pattern in that same "topology change".

No.
We agree that all magenetic fileds can change their topology and that a certain change in toppology is called magnetic reconnection.

Magnetic ropes is actually the wrong term to use (sorry for repeating your misuse of the term). A "magnetic rope" is actually a Birkeland curent.

The correct term to use is magnetic flux or magnetic flux tube.
An example of magnetic reconnection is the model of solar flares where a magnetic flux experiences magnetic reconnection.

We all agree that two magnetic ropes "reconnect". You however seem to have your own personal definition of a 'magnetic rope" since Alfven described a magnetic rope as a current carrying filament of plasma.

We all agree that two magnetic fields reconnect.
Two magnetic ropes (as in Birkeland currents) could connect together. Thta is not reconnection unless the magnetic ropes split previously.

We all agree that there is one paper that explains 2 solar flares as magnetic reconnection between 2 twisted "magnetic ropes" (actually magnetic fluxes).

You're completely ignoring that fact that those same flares can be described in terms of macroscopic circuits. You're in pure denial of that first paper not to mention Alfven's life's work, all of Bruces work, and even Birkeland's empirical experiments with "electricity".

We all (except you) agree that there is a model of solar flares that has magnetic reconnection happening in loops of magnetic flux (coronal loops). That model works.

The energy in solar flares can be calculated in terms of electrical circuits. That does not mean that they are physically electrical wires or currents. Observations show that in a typical solar flare there are magnetic fluxes that exist containg energy before the flare and that they do not exist (or are smaller) after the flare. The energy released in the flare is of the same magnitude as the energy that was contained in the magnetic flux.

It is possible (as in the paper you cited) that some solar flares are powered differently, e.g. by currents flowing in the photosphere. This of cource has no impact on the observation that many solar flares are driven by magnetic reconnection.

I am not in denial of Alfven's life's work. He did good work in establishing the basics of MHD.

I am not in denial of Bruce's really bad science in thinking that dust particle can exist in the solar photosphere (a temperature of ~6000K!)

You are in denial (or more probably ignorant of) of the decades pf progress that have been made in MHD and solar physics since that paper and book of Alfven's that you are obsessed with.

Alfven called that term "pseudoscience".

There you go with your deifying of Alfven again.

Priest & Forbes call it science (and there are 2 of them Alfven must be wrong !).

Boloney. They are exactly the same physical process.

Boloney.
Magnetic reconnection is an established area of physics with 100's (1000's?) of papers written on it, many textbooks, 100's of observations and many experiments.


So far "circuit reconnection" is a figment of your imagination.

• Michael Mozina: What is "circuit reconnection"
  First asked 30 January 2010.
  Specifically: Point us to the textbook definition that you are using.

 

[Michael Mozina]

For the third (?) time: do you or do you not agree that the B field lines are reconnecting in these examples?

Which examples, yours or TM's? I need more background on your movie to actually comment. As far as I can tell, that too could be a form of magnetic repulsion. Is there a paper that goes along with that movie?

"Magnetic rope" is not a physics term I'm familiar with. Is it synonymous with "magnetic field line"?

Not exactly. A "magnetic rope" is "bunched" or "twisted" by the current flow inside the magnetic rope. Here's how Alfven described a rope. It's essentially an ordinary current carrying filament, a scaled up cousin to the filaments inside an ordinary plasma ball. The "magnetic lines" are not straight, but form a spiral, just like an ordinary Birkeland current.

From Cosmic Plasma:

"However, in cosmic plasmas the perhaps most important constriction mechanism is the electromagnetic attraction between parallel currents . A manifestation of this mechanism is the pinch effect, which was studied by Bennett long ago (1934), and has received much attention in connection with thermonuclear research . As we shall see, phenomena of this general type also exist on a cosmic scale, and lead to a bunching of currents and magnetic fields to filaments or `magnetic ropes' . This bunching is usually accompanied by an accumulation of matter, and it may explain the observational fact that cosmic matter exhibits an abundance of filamentary structures (II .4 .1) . This same mechanism may also evacuate the regions near the rope and produce regions of exceptionally low densities."

The primary "difference" between a "magnetic line" and a "magnetic rope" is the fact that the currents inside the rope cause the magnetic lines to "twist" the plasma into a tube, and of course the magnetic field gets twisted in that same process. It's a current carrying filament.

 

[sol invictus]

Which examples, yours or TM's?

There are now three examples. TM's, the explicit solution I quoted, and the solution shown in that movie.

I need more background on your movie to actually comment. As far as I can tell, that too could be a form of magnetic repulsion. Is there a paper that goes along with that movie?

I already gave you the only background you need to answer my question, which is that those white lines are magnetic field lines. The fact that you will not agree that those lines are reconnecting when you can see it right in front of your eyes is.... well, it indicates that there is no point in further communication with you on this issue.

Not exactly. A "magnetic rope" is "bunched" or "twisted" by the current flow inside the magnetic rope.

Then that's something else entirely. There is no current along the reconnecting lines in any of these three examples.

 

[Michael Mozina]

There are now three examples. TM's,

Without any doubt that is an example of 'magnetic attraction/repulsion".

the explicit solution I quoted,

Unless I missed it, you never explained "PHYSICALLY" which particles are transferring energy and which ones receive that energy.

and the solution shown in that movie.

I don't know what that movie is showing me because I don't have a clue how it was developed or what it's supposed to represent. What are the arrows, field orientations?

I already gave you the only background you need to answer my question,

I already gave you my answer in regard to TM's claim. I need more information to respond the other two examples.

Then that's something else entirely. There is no current along the reconnecting lines in any of these three examples.

Ok. Do you have a link to a paper that the movie relates to?

 

[Michael Mozina]

No.
We agree that all magenetic fileds can change their topology and that a certain change in toppology is called magnetic reconnection.

Does it have to a "certain" change in topology or *ANY* change in topology? If the former is true, what is specifically unique about the change in topology required to be called "magnetic reconnection"?

 

[Michael Mozina]

No.
We agree that all magenetic fileds can change their topology and that a certain change in toppology is called magnetic reconnection.

Magnetic ropes is actually the wrong term to use (sorry for repeating your misuse of the term). A "magnetic rope" is actually a Birkeland curent.

The correct term to use is magnetic flux or magnetic flux tube.

It would not be a "tube" at all without "current flow"!

 

[Reality Check]

It would not be a "tube" at all without "current flow"!

Yes it will be a magnetc flux tube without current flow in the magnetic flux!

 

[Reality Check]

Does it have to a "certain" change in topology or *ANY* change in topology? If the former is true, what is specifically unique about the change in topology required to be called "magnetic reconnection"?

It is any change in magnetic field topology that reconnects field lines - thus the reconnection part of magnetic reconnection.
That is really simple, Michael Mozina.

 

[Reality Check]

I will have a go at asnwering a couple of questions:

I don't know what that movie is showing me because I don't have a clue how it was developed or what it's supposed to represent. What are the arrows, field orientations?

The movie was developed using PIC (Particle-in-cell) to solve equations for a plasma contaning a magnetic field.
ETA
These are relativistic MHD equatrions with resistive effects added (i.e. definitely not the ideal MHD theory developed by Alfven). This is an example of how science has progressed in the decades since Alfven first set out ideal MHD theory.

The arrows look like the direction in which the field is changing, i.e. increasing in the direction of the arrows. This has nothing to do with the fact that the field lines (shown in white) are reconnecting.

Ok. Do you have a link to a paper that the movie relates to?

The movie may not be related to any one paper. It looks like a standard application of PIC to solve magnetic reconnection. But it may be cited in one of S Zenitani's papers.

ETA
sol invictus probably pointed you to this movie as one of the many of depictions of magnetic reconnection that are available in the scientific literature.
You may be tempted to think that this has something to do with solar flares. However the author's research area is relativistic magnetic reconnection. That is applicable to high-energy astrophysical events (solar flares are actually quite average in astrophysical terms!) such as soft gamma repeaters.

 

[Michael Mozina]

Yes it will be a magnetc flux tube without current flow in the magnetic flux!

No. The "current flow" is what creates your "tube" in the first place. Without the current flow your "magnetic line" would not form into a "tube". The tubular shape is directly related to the current flow inside that tube. The "flux" of the magnetic field is directly related to "current flow" inside the tube.

 

[tusenfem]

Oh yeah, again that nonsens part on the wiki page. I don't understand that, could you please explain to me what "The resulting cross-section pattern indicates a hollow beam of electron in the form of a circle of vortices, a formation called the diocotron instability" and then especially the "hollow beam part" means.

It means that the filament is acting as a "conductor" or "wire" as in that quote from Alfven. The plasma that makes up the tube is also conducting current flow in the form of electrons.

That is not what I asked, Michael. You are a real gem at answering questions that are not asked and not answering questions that are asked.

That current can flow along field lines should be obvious from the papers I have written about that, which you know, so I am hardly asking about that.

First of all on the wiki page, "multi-terawatt pulsed power generators" can generate "birkeland currents", well I call them field aligned currents (as you can read on the top of the page). However, I created field aligned currents in a plasma in the laboratory (creating double layers) with a voltage of 200 V and I did not need any "multi-terawatt blahbalh". (here is the paper in case you are interested).

What I wanted to know from you was what these "hollow beam electrons" are, and why you are specifically referring to them. Also, I want you (or actually brantc, but he seems incapable of answering) how these electrons create the field they are flowing along. Seems not too difficult a question, now does it? And this time please give a real answer, thank you very much.

 

[Michael Mozina]

What I wanted to know from you was what these "hollow beam electrons" are,

They are electrons that are flowing through the plasma tube!

and why you are specifically referring to them.

I am referring to them because they are a part of those macroscopic circuits you keep ignoring! The electrons flowing through the tube generate the field, not just the current flow of the tube itself as your question seemed to imply.

Also, I want you (or actually brantc, but he seems incapable of answering) how these electrons create the field they are flowing along.

Did you even read that first paper on macroscopic currents or did you just skim it?