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 3rd March 2012, 11:49 PM #6632 Tim Thompson Muse     Join Date: Dec 2008 Posts: 969 Magnetic Reconnection and the Mozina Fallacy Originally Posted by Michael Mozina Originally Posted by Tim Thompson Any change in the topology of the magnetic flux is magnetic reconnection by definition. So your ENTIRE argument is one giant equivocation fallacy? Certainly not. The equivocation fallacy is "the misleading use of a term with more than one meaning or sense (by glossing over which meaning is intended at a particular time)". In this case, the word "flux" is not at all ambiguous to anyone who actually knows what they are talking about ... Originally Posted by Tim Thompson Originally Posted by Lorrain & Corson, 1970, chapter 7 The next three chapters will deal with various aspects of magnetic fields. We shall start by studying in some detail the properties of two vector quantities, namely, the magnetic induction B and the vector potential A, which are used to describe magnetic fields. { ... } As in electrostatics, where we used lines of force to describe an electric field, we can describe a magnetic field by drawing lines of B that are everywhere tangent to the direction of B. Similarly, it is convenient to use the concept of flux, the flux of the magnetic induction B through a surface S being defined as the normal component of B integrated over S: $\phi = \int_s \bold B \cdot \bold {da}$ Originally Posted by tusenfem Originally Posted by Michael Mozina Let me rephrase that. Two magnets and magnetic *FIELDS* experience magnetic flux when brought together or pulled apart in a vacuum or non-conductive medium. No current is induced as Sweet states, and no "electrical discharge" could occur as Dungey describes. Sheesh! magnets and fields are experiencing magnetic flux?????????? Magnetic flux is, to use words, the number of field lines that cross through a unit surface, it is a value, it cannot do anything, whatsoever. In math, if you can understand it, magnetic flux is: $ \Phi = \int \int {\bf B} \cdot d{\bf S}$ Flux can increase, or decrease, but it is just a number, nothing more nothing less. If you want to have a real scientific discussion, then get your terms correct. Originally Posted by tusenfem If you really don't know what the difference is between magnetic flux and magnetic reconnection you really are a lost cause, and apparently never ever read a book on plasma physics. The fallacy of equivocation rests entirely with you & you alone. You are the one who is guilty of the misleading use of the term "flux". As for my definition of magnetic reconnection, there is neither equivocation nor ambiguity, and I once again refer the reader to my post from 24 January, Magnetic Reconnection Defined and Described as an objective substantiation of my assertion. Originally Posted by Michael Mozina Originally Posted by Tim Thompson The plasma processes associated with magnetic reconnection happen because first the topology of the magnetic field changes to that of a lower energy state and then the energy is transferred to the plasma which reacts accordingly. It's called "induction". It most certainly is not. And to the surprise of no one, we have already been down this road. The key to understanding why it cannot be induction is that induction can change only the geometry of a magnetic field, but can never change its topology. From 24 December 2009, over two years ago ... Originally Posted by Tim Thompson Originally Posted by Michael Mozina Yet you won't personally explain what's unique about magnetic reconnection, so what can I say Tim? That's not true, and you know it. It's no wonder that people keep calling you a liar. Are you trying to add me to the list? I have already done that many times. I said it was a change in the topology of the magnetic field, and that certainly is not induction by any stretch of the imagination. Besides, induction is strictly limited by the diffusion timescale of the plasma, whereas reconnection is impulsive. The two processes are distinctly different both in theory and in practice. Impulsive energy release, such as a solar flare, is quite impossible for any induction process. Had you bothered to read any of the source material you have been directed to (for instance the book Magnetic Reconnection by Priest & Forbes) you would already know this, since it is spelled out in detail (I would be more specific but I am 1000 miles from home and the book at the moment). That's why I say I don't believe you when you say you are really interested in learning. Anyone truly interested in learning would naturally consult the books & papers they are referred to. I see no indication that you do that. As it stands, you appear to implicitly assert that you know more about physics than everyone else, and simply ignore everything else. It should come as no great surprise that few people have confidence in your alleged expertise in this field. From 30 December 2009 ... Originally Posted by Tim Thompson Reference the book Magnetic Reconnection: MHD Theory and Applications by Eric Priest & Terry Forbes, Cambridge University Press, 2000. Magnetic reconnection is not induction. Here is the induction equation in a plasma as given in Priest & Forbes, page 5: $(1) \partial \boldsymbol B / \partial t = \nabla \times (\boldsymbol v \times \boldsymbol B) - \nabla \times (\eta \nabla \times \boldsymbol B)$ Here $\eta$ is the magnetic diffusivity. If $\eta$ is uniform then the induction equation reduces to ... $(2) \partial \boldsymbol B / \partial t = \nabla \times (\boldsymbol v \times \boldsymbol B) + \eta \nabla^2 \boldsymbol B$ { ... } The conversion of magnetic energy into a current always operates on a time-scale characteristic of the system, and that time scale is controlled by the ability of the magnetic field to move through the conductor, in order to create a dB/dt term from which the current is generated. That time-scale in a plasma is rather different than it is for a fixed conductor. Here we find the real deal once again in Priest & Forbes: "In space physics the distinction between ideal and non-ideal processes is important because simple estimates imply that magnetic dissipation acts on a time-scale which is many orders of magnitude slower than the observed time-scale of dynamic phenomena. For example, solar flares release stored magnetic energy in the corona within a period of 100 s. By comparison, the time-scale for magnetic dissipation based on a global scale length of 105 km is of the order of 106 yrs." Priest & Forbes, page 6 Induction is a motion of the magnetic field relative to the plasma as illustrated by the induction equation given above, which depends on the magnetic diffusivity of the plasma and is therefore limited to the diffusion timescale, and which cannot change the topology of the field. Magnetic reconnection is a change in the topology of the field and therefore cannot be induction in any way. And all of this was hashed out over two years ago, and here we are, right back to where we were then. I am right and you are dead wrong, just as wrong now as you were two years ago. Originally Posted by Michael Mozina Because it's NOT the "root cause" Tim. You're fundamentally relabeling an INDUCTION process 'reconnection". A simple coil in a car does the same thing Tim. It changes the field topology over time in the presence of a "conductor". Is that "magnetic reconnection" as well? To begin with, no the simple coil in a car does not change the topology of the magnetic field, it changes only the geometry, and it is therefore magnetic induction and certainly not magnetic reconnection. You could not tell the difference between a coil of wire and a plasma two years ago, and you still can't tell the difference ... Originally Posted by Tim Thompson Evidently, Mozina has never realized that a magnetized plasma and a coil of wire are not the same thing. So I will respond to Mozina's incredible ignorance of physics by quoting once again from Priest & Forbes, only this time with real physics, rather than the strange imitation of physics being promoted elsewhere. Given the equation I have labeled (2) above, we find ... "This is the basic equation of magnetic behavior in MHD, and it determines B once v is known. In the electromagnetic theory of fixed conductors, the electric field and electric current are primary variables with the current driven by electric fields. in such a fixed system the magnetic field is a secondary variable derived from the currents. However, in MHD the basic physics is quite different, since the plasma velocity (v) and magnetic field (B) are the primary variables, determined by the induction equation and the equation of motion, while the resulting current density (j) and electric field (E) are secondary and may be deduced from equations (1.8) and (1.10a) if required (Parker, 1996)." Priest & Forbes, page 14. So we come full circle? Two years ago you were ignorant about plasma physics. Today you are still ignorant of plasma physics. You can't use the basic words correctly, you have no clue to the basic physics, and cannot even tell the difference between a plasma and a coil of wire. So in conclusion, again from two years ago, ... Originally Posted by Tim Thompson This entire thread is just one constant repetition of the same tired old arguments: real physics vs. the pure prejudice of Mozina. It will never change because Mozina will never learn. So get used to zillions of pages to come with no change & no progress & no real physics ever from Mozina. That you can count on. And so my prophecy has come to pass. Zillions of pages and two years later we are right back where we started; no change, no progress, no real physics from Mozina, and Mozina, as predicted, never learned a thing. __________________ The point of philosophy is to start with something so simple as not to seem worth stating, and to end with something so paradoxical that no one will believe it. -- Bertrand Russell