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Old 7th March 2012, 07:45 PM   #6687
Tim Thompson
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Lightbulb Magnetic Reconnection: In Plasma and In Vacuo

Originally Posted by Michael Mozina View Post
And for two years now you've utterly ignored that paper by Mann and Onel that disprove your claim. Why is that?

See my post Onel & Mann, Circuits, and Real Plasma Physics, dated 9 Aprl 2011, where I cleverly ignore the Onel & Mann paper by examining it in detail, including a comparison with Alfven's boundary conditions, discussing the physics of the paper and the value of the circuit paradigm. So much for me "ignoring" the Onel & Mann paper.


Originally Posted by Michael Mozina View Post
But you're simply mislabeling several *DIFFERENT* things "magnetic reconnection", and failing to support your claim with *PUBLISHED* material that plasma is OPTIONAL Tim! How can I deal with that "scientifically"?

I have in fact supported my claim with several published references to magnetic reconnection in a vacuum. Here is a list of my posts on the topic, which the industrious reader may wish to peruse for the various references therein.

Of course, Mozina has vociferously insisted that all of the references I have provided are MHD based. All of his claims amount to wishful thinking and sub standard reading skills, and are all without a doubt quite false. In each and every case, without exception, the reconnection of magnetic fields is presented in a true vacuum, no MHD, no plasma, none whatsoever.

And I am certainly not by any means "mislabeling several *DIFFERENT* things" as magnetic reconnection. I am in fact consistent and present one and only one definition of magnetic reconnection; see my post Magnetic Reconnection defined and Described. All of my sources present the same definition of magnetic reconnection, albeit in different words, and it is the one and only definition I have used, which I will present here in my own words of the moment: A change in the topology of the magnetic field, changing the connectivity of the lines of force of the magnetic field. There is an important distinction to make here:


Originally Posted by Michael Mozina View Post
First you seem to be relabeling "magnetic flux change/time in a vacuum" = "magnetic reconnection". Then you're relabeling an INDUCEMENT OF CURRENT IN A PLASMA that results in an "electrical discharge" the EXACT SAME TERM! See a problem there Tim?

No, I don't see any problem. Mozina is the one who is confused, thinking that the presence of plasma & current are a requirement of magnetic reconnection.

Originally Posted by Michael Mozina View Post
I'm still waiting for a ligitimate PUBLISHED reference for 'reconnection' that generates any energy that isn't based upon MHD theory. It's never going to happen either. Without plasma, as Sweet points out, no currents are INDUCED in the plasma. It's just a flux change that has no real effect on any real particles because no real particles are present. MHD theory doesn't even apply! No ENERGY EXCHANGE can occur. No CHARGED PARTICLE ACCELERATION can occur. No currents can be generated, and no DISCHARGE occurs. You can't take plasma out and still call it 'reconnection'. It's just "flux changes" that induce no current. No magnetic energy can be converted to charged particle kinetic energy.

There is no such reference. Then again, why should it be a relevant point? Nobody is making the absurd claim that magnetic reconnection produces current in a vacuum! Look at the definition I gave in my own words above, confirmed by the sources in my post: A change in the topology of the magnetic field, changing the connectivity of the lines of force of the magnetic field. This process almost always results in the magnetic field transitioning from a higher to a lower energy state (there my be exceptional cases where the energy of the field does not change, but they are surely very strange and not important for this discussion). If that happens in a vacuum, there will be no current induced, no electricity, no "discharge", none of that. How could there be? It's a vacuum! Nobody ever made such a claim that I am aware of, and I most certainly never have. However, if that process happens in a plasma environment, then instead of the excess energy simply radiating away unnoticed to the vacuum, it goes into the plasma when the post reconnection magnetic field relaxes from higher to lower energy. Only then do we get currents and all of the nifty plasma physics that comes out of magnetic reconnection. Nobody writes papers about the magnetic field reconnecting & relaxing in a vacuum because it's a really boring thing that does nothing worth writing about. On the other hand, everybody wants to write papers about the reconnection of magnetic fields in a plasma because lots of really fascinating stuff happens in that case.

Let me be clear about this: Magnetic reconnection is a process whereby the topology of the magnetic field changes. That's its raw definition. I have never defined the post reconnection plasma physics as magnetic reconnection and nobody should; although it might appear to be so in colloquial usage between experts who know what they are talking about, it is certainly not a proper or formal definition.


Originally Posted by Michael Mozina View Post
Originally Posted by tusenfem View Post
Let's see the fallacy is yours, then, because you equate a change of flux with magnetic reconnection.
Boloney. Tim did that. He essentially claimed that any FLUX CHANGE = "magnetic reconnection" and the NULL isn't "special" at all.

I did associate a change in flux with magnetic reconnection, but I certainly did not claim that "any flux change = magnetic reconnection". Go back and look what I actually did say:

Originally Posted by Tim Thompson View Post
Any change in the topology of the magnetic flux is magnetic reconnection by definition. See my earlier post Magnetic Reconnection Defined and Described (24 January 2012). The terms "magnetic flux" and "magnetic field" are related to each other as shown by the passages below ...

Any old change won't do, only a change in the topology. In that post I also show the definition of magnetic flux as the surface integral of the magnetic field. In associating the magnetic flux with magnetic reconnection, I imagine a small unit area, a nearly infinitesimal circle perhaps, over which the flux is integrated. If the volume of magnetic field is sufficiently sampled by the unit area integral, you will have a volume representation of the flux. The flux at each area element will be a vector parallel to the normal vector to the surface, if the sampling surface is small enough. That volume representation of the flux should have a topology related to the topology of the field, and if the field topology changes, then so must the topology of the volume representation of the flux. I was trying to use flux in a manner akin to Mozina's without being technically incorrect and thought I had succeeded.

But in any case, it has to be stressed that in the end there is one and only one correct definition of magnetic reconnection and that is the change in topology of the magnetic field, which will of course produce plasma phenomena only in the presence of a plasma and never in a vacuum.
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