Problems With Magnetic Reconnection

[michaelsuede]

The OP did not say "reconnection can't occur because there's a double layer, and a current sheet, and there's infinity, and also 3D, and plasma". It said:



Funny how quickly that morphs into a totally different argument about how magnetic reconnection doesn't work in some specific plasma context.

By default, the standard model of reconnection would be invalidated by the existence of a double layer.

I assumed you could figure that part out on your own.

Just answer the question and I'll shut up about EU forever.

Does a double layer exist at the boundary of two differing plasma regions or not?

You can completely rid me of all my EU beliefs if you can demonstrate that there is no such thing as a double layer.

Double layers create current sheets.

 

[ben m]

By default, the standard model of reconnection would be invalidated by the existence of a double layer.

Does a double layer exist at the boundary of two differing plasma regions or not?

Double layers create current sheets.

That's funny, I could have sworn you said:

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.

 

[michaelsuede]

Oh by the way guys, I'm still a little fuzzy where the standard theory of reconnection gets it's current sheet from.

I've tried to find a paper where they apply their theory to a real resistive plasma and derive a current sheet from MHD theory, but I didn't manage to find one.

So I am still a little unclear how the existence of this current sheet is justified and how it was predicted by MHD models.

I'm assuming that if MHD was actually valid it should have predicted the existence of the neutral sheet - right?

 

[Ziggurat]

By default, the standard model of reconnection would be invalidated by the existence of a double layer.

I assumed you could figure that part out on your own.

Nobody here knows what the hell you mean by that, so no, we can't figure it out on your own. It also doesn't appear to resemble your earlier claim regarding the impossibility of magnetic reconnection, a claim which has been disproven but which you will neither admit was nonsense nor defend by actually doing the math.

Just answer the question and I'll shut up about EU forever.

Just prove that you can do the math and I'll shut up about your total inability to understand electrodynamics at all.

Double layers create current sheets.

That's nice. It's also irrelevant. Magnetic reconnection theory doesn't require that double layers or current sheets don't exist.

 

[ben m]

I've tried to find a paper where they apply their theory to a real resistive plasma and derive a current sheet from MHD theory, but I didn't manage to find one.

If only there was a way to find papers on particular science topics!

http://lmgtfy.com/?q=resistive+reconnection

 

[Ziggurat]

Oh by the way guys, I'm still a little fuzzy where the standard theory of reconnection gets it's current sheet from.

You're fuzzy on a lot of things, including basic electrodynamics. Which is why you still haven't done those basic calculations: you don't know how to.

But you can't bring yourself to admit that you can't.

 

[Tubbythin]

I thought I just did.

With a peer reviewed paper no less.

Well i suppose you did respond. Just not in any meaningful or particularly coherent manner.

 

[Reality Check]

Does the double layer exist or does one not exist.

That's all I'm asking for.

It looks like we have another plasma cosmology proponent who does not know the basics of plasma physics or electromagnetism.
Ziggurat has given you a defintion of a magnetic vector field. That magnetic vector field undergoes magnetic reconnection as it changes configuration with time.

The answer to your question is trivial: Double layers exist.
They are nothing to do with the theory of magnetic reconnection.

 

[dafydd]

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?

Not another one! Haven't these mathproof geniuses got anything better to do?

 

[dafydd]

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

Any electrical engineer reading the article will find it quite compelling.hilarious

ftfy

 

[Reality Check]

LOL

Great scientific response.

LOL - you are supposed to be the person who claims that magnetic reconnection is impossible despite the fact that Maxwell's equations say that it is possible.

You have a claim. You need to produce the evidence for the claim. That is science.

 

[dafydd]

Oh by the way guys, I'm still a little fuzzy where the standard theory of reconnection gets it's current sheet from.

I've tried to find a paper where they apply their theory to a real resistive plasma and derive a current sheet from MHD theory, but I didn't manage to find one.

So I am still a little unclear how the existence of this current sheet is justified and how it was predicted by MHD models.

I'm assuming that if MHD was actually valid it should have predicted the existence of the neutral sheet - right?

Can you do the math or not? Then the thread can proceed.

 

[dafydd]

LOL - you are supposed to be the person who claims that magnetic reconnection is impossible despite the fact that Maxwell's equations say that it is possible.

You have a claim. You need to produce the evidence for the claim. That is science.

These people do not do science.

 

[tusenfem]

I wonder where exactly this double layer is supposed to be located. The easiest way of measuring the topology of reconnection is in the Earth's magnetotail. There are very good observations presented in a paper by Runov et al. (2003) (I am co-author on that paper) where the structure of the magnetic field is clearly shown to be in agreement with Hall reconnection. However, there is no such thing as a double layer.

Now, why is there no double layer? michaelsuede is claiming that there are regions of differing plasmas. Indeed, a double layer can be created on the boundary of two different plasmas (e.g. of different temperature, or composition). But in reconnection this is not the case, there is, e.g. in the tail, two regions of oppositely directed magnetic field. However, in the simplest case the magnetic field is a Harris current sheet, where there is only a field in the X-direction which is a function of z and given by B(z) = B0 * tanh(z/L). Note that at z=0 there is NO magnetic field, which is to be expected at the center of a current sheet which separates these two regions. So, the only thing that is changing is the magnetic field strength, and that is gradually. Although there is a small region where the ions and the electrons get demagnetized in the centre, there is no reason there for a double layer (probably with the E-field in the z direction, but none of this anti-reconnection group of people have ever said how this DL should be situated).

Now, indeed the magnetic field is a vector field and at every point (x,y,z) with all three of them elements of R, and thus at any value the field is determined. And doing reconnection research, naturally the magnetic field is a vector field. However, to visualize some steps, to get an idea of how the topology of the field looks like, one can draw field lines. This is just a tool, but an important tool, as e.g. it will show how there is curvature in the magnetic field, that there is tension in the magnetic field etc. etc.

For the rest we can just copy/paste all the post that were made in MM's numerous threads talking about MRx, there is nothing new about all these comments, and most of them don't even make sense and some are blatently false (the magnetic field of a charged ball? No 3D zero magnetic field, one should look at the magnetometer calibration lab at my insitute).

So, first question, please draw a picture of how exactly we should visualize this double layer.

 

[dafydd]

I wonder where exactly this double layer is supposed to be located. The easiest way of measuring the topology of reconnection is in the Earth's magnetotail. There are very good observations presented in a paper by Runov et al. (2003) (I am co-author on that paper) where the structure of the magnetic field is clearly shown to be in agreement with Hall reconnection. However, there is no such thing as a double layer.

Now, why is there no double layer? michaelsuede is claiming that there are regions of differing plasmas. Indeed, a double layer can be created on the boundary of two different plasmas (e.g. of different temperature, or composition). But in reconnection this is not the case, there is, e.g. in the tail, two regions of oppositely directed magnetic field. However, in the simplest case the magnetic field is a Harris current sheet, where there is only a field in the X-direction which is a function of z and given by B(z) = B0 * tanh(z/L). Note that at z=0 there is NO magnetic field, which is to be expected at the center of a current sheet which separates these two regions. So, the only thing that is changing is the magnetic field strength, and that is gradually. Although there is a small region where the ions and the electrons get demagnetized in the centre, there is no reason there for a double layer (probably with the E-field in the z direction, but none of this anti-reconnection group of people have ever said how this DL should be situated).

Now, indeed the magnetic field is a vector field and at every point (x,y,z) with all three of them elements of R, and thus at any value the field is determined. And doing reconnection research, naturally the magnetic field is a vector field. However, to visualize some steps, to get an idea of how the topology of the field looks like, one can draw field lines. This is just a tool, but an important tool, as e.g. it will show how there is curvature in the magnetic field, that there is tension in the magnetic field etc. etc.

For the rest we can just copy/paste all the post that were made in MM's numerous threads talking about MRx, there is nothing new about all these comments, and most of them don't even make sense and some are blatently false (the magnetic field of a charged ball? No 3D zero magnetic field, one should look at the magnetometer calibration lab at my insitute).

So, first question, please draw a picture of how exactly we should visualize this double layer.

Do the two Michaels know each other?

 

[W.D.Clinger]

Why can't you answer this question, Michael? Could it be you don't understand basic electrodynamics?

The question doesn't even require any knowledge of electromagnetism. It's a question about vector fields, which are allegedly the basis of his argument.

His web site's 10 links for "Anti-Fascist Science" include a link to Pilots for 9/11 Truth. If he's impressed by their math, he must have trouble with basic calculus.

LOL

Great scientific response.

I hope you aren't teaching any students.

You are supposed to be far smarter than me, it isn't fair to make the dumb kid go first.

Your mathematical arguments (in posts #14, #23, #28, #30, and #35) made no sense at all. Given a chance to prove yourself by answering a freshman-level problem in vector calculus, you hit the "LOL" key, threw more , and asked us to take pity on a "dumb kid".

When I was in college, I was lucky enough to take courses from some of the world's best teachers. Some were famous, some were practically unknown, but I knew I'd be stupid not to learn everything I could learn from them. Here in this subforum, I've learned quite a bit from sol invictus, ben m, Ziggurat, and tusenfem, who have already taken the time to respond to you in this thread. You're lucky they're talking to you at all. I'm not so patient.

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

Any electrical engineer reading the article will find it quite compelling.

There's no need to insult EEs. I've worked with a lot of them over the years, and most have known how to calculate the divergence and curl of a simple vector field. I think most of them would recognize the vacuity of your argument.

 

[Reality Check]

Any electrical engineer reading the article will find it quite compelling.

Any electrical engineer reading the article will find it full of mistakes, e.g.

1. All Some plasmas require a constant source of electrical input to sustain them.
   Others just need heat to disassociate neutral atoms , e.g. just about every astronomical plasma.
2. All Laboratory plasmas have electrical currents flowing through them at all times.
   Plasmas in general have no electrical currents flowing through them. What they have is moving electrons and ions. These give currents at lengths comparable to the Debye length.
3. All Some magnetic fields in a plasma are caused by the electrical currents that are flowing through them.
   There are also external magnetic fields. And once again the magnetic fields caused by the moving electrons and ions are small scale.
4. "All plasmas must obey Kirchoff’s circuit laws" on scales of the Debye length, e.g. about a 10 meters for the solar wind.
5. The Sweet-Parker model of magnetic reconnection does not mention a double layer because there is none. It is a model where plasmas with opposite magnetic fields are pushed together.
   There is no current imposed on the plasma so this is a current-free plasma. To get a current-free double layer you need plasma with different properties such as electron temperature, composition or density.

 

[dafydd]

Any electrical engineer reading the article will find it full of mistakes, e.g.

1. All Some plasmas require a constant source of electrical input to sustain them.
   Others just need heat to disassociate neutral atoms , e.g. just about every astronomical plasma.
2. All Laboratory plasmas have electrical currents flowing through them at all times.
   Plasmas in general have no electrical currents flowing through them. What they have is moving electrons and ions. These give currents at lengths comparable to the Debye length.
3. All Some magnetic fields in a plasma are caused by the electrical currents that are flowing through them.
   There are also external magnetic fields. And once again the magnetic fields caused by the moving electrons and ions are small scale.
4. "All plasmas must obey Kirchoff’s circuit laws" on scales of the Debye length, e.g. about a 10 meters for the solar wind.
5. The Sweet-Parker model of magnetic reconnection does not mention a double layer because there is none. It is a model where plasmas with opposite magnetic fields are pushed together.
   There is no current imposed on the plasma so this is a current-free plasma. To get a current-free double layer you need plasma with different properties such as electron temperature, composition or density.

There you are Mikey boy,even a dumbo like me can understand that.

 

[michaelsuede]

So, first question, please draw a picture of how exactly we should visualize this double layer.

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

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

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

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

 

[dafydd]

Research by wikipedia. Got any real sources?