Talk:Magnetic reconnection/Archive 1

2D versus 3D Reconnection

I'd just like to make a comment. This article does a fine job describing reconnection in 2D. The 3D generalization is not trivial though. In 3D sweet-parker or petcheck reconnection effectively becomes 3D null-point reconnection (without getting into quai-separatrix layers versus true separatricies). In addition, the application to the Magnetosphere is very different than the application to the solar corona, in that magnetospheric reconnection topologically requires a 4-flux system, whereas the solar corona requires only a 2-flux system.

Okay, I didn't realize how technical this article was going to be until I started writing it. I'll make an effort to fill in some of the empty links, provide a diagram or three, and place links to this article on the relevant pages.

I'm currently conducting an experiment to study magnetic reconnection - if you have questions, post them here or on my talk page... but be warned, I'll be at a conference for the next week, so my response may be slow.SMesser 00:51, 14 Nov 2004 (UTC)

I removed an anonymous edit that claimed magnetic reconnection occurs when the magnetic pressure exceeds the plasma pressure (ie when the plasma $\beta$ parameter is less than unity). This is not the case! Magnetic reconnection (or the lack thereof) is related to the line-tying effect of high electrical conductivity, not to the magnetic pressure. zowie 22:41, 29 December 2005 (UTC)

Zowie. While you are correct that reconnection occurs in both high and low beta plasmas, the process is local and does not depend on whether the system is line tied or not. Formally, magnetic reconnection is the tearing mode, of resistive MHD instability theory (see Furth, H.P., Killeen, J., and Rosenbluth, M. N., 1963, Phys. of Fluids, 6, 459). Several researches have shown line-tying the system simply slows the (linear) tearing mode growth rate (see Velli, M. and Hood, A. W., 1989, Sol Phys 119, 107; Velli, M., Einaudi, G., and Hood, A. W., 1990, ApJ, 350, 419). —Preceding unsigned comment added by 137.79.89.69 (talk) 22:15, 2 August 2010 (UTC)

Topology rather than current sheets

I took the liberty of reducing the discussion of current sheets, which are not directly related to reconnection (they are in some sense a symptom of lack of magnetic reconnection!) and instead introduced separatrix surfaces and separators, the topological terms describing the domain boundaries. (Note that separatrices, and magnetic reconnection, can exist in a vacuum, while current sheets cannot).

The discussion still needs considerable work, some work on the X-point figure (it would be nice to have the seapratrices and separator marked), an perhaps a 3-D figure to visualize domain topology -- but I'm out of borrowed time for today.

Happy new year! zowie 19:02, 1 January 2006 (UTC)

While it is true that topological separatricies exist independent of the plasma, reconnection cannot occur in vacuum. Reconnection absolutely requires a plasma, because it's the plasma that supports the dissipative current sheets that form along these separatricies.

Dissent about "Magnetic Reconnection?"

Should notable peer-reviewed papers dissenting with the theory of magnetic reconnection be included in the article?

If so, Nobel prize winning plasma physicist Hannes Alfvén (the so-called "Father of MHD") has dissented in several articles (Double Layers and Circuits in Astrophysics, On frozen-in field lines and field-line reconnection), calling "magnetic merging" ("reconnection") a pseudo-science. More recently, electrical engineer Don Scott has also published a dissenting paper (Real Properties of Electromagnetic Fields and Plasma in the Cosmos). Mgmirkin (talk) 17:43, 11 June 2008 (UTC)

Of course not. That would be scientific heresy. This is about proping up failed theories and supporting misguided research.

To quote Alfvén: The conecepts 'frozen-in magnetic field lines' and 'field-line reconnection' play a certain role in discussions of the theory of the magnetosphere. The use of these concepts has been criticized and we shall here demonstrate that both concepts are unnecessary and often misleading.

Oh btw, you forgot another paper showing the whole thing is a bunch of nonsense.

On the Concept of Moving Magnetic Field Lines Eos, Vol. 88, No. 15, 10 April 2007 http://plasma.colorado.edu/phys7810/articles/Falthammar_MovingFieldLines_2007.pdf

--75.84.109.235 (talk) 01:48, 4 March 2009 (UTC)

This IEEE paper above, "Real Properties of Electromagnetic Fields and Plasma in the Cosmos" by Donald Scott "refuting" reconnection and other astrophysical analyses has been shown to be nothing more than Donald Scott refuting his own misconception/misunderstanding of the framework in which astrophysicists work. Dr. Scott does not understand the conversation.

First, all solar astrophysics researchers know that field lines are not substantial quantities. Magnetic lines of force are a graphic and useful concept invented by Michael Faraday in the nineteenth century for representing the configuration of the magnetic field. In this case, they are a useful construction to describe the very very real phenomenon that is the rapid conversion of magnetic energy to bulk plasma kinetic energy, and particle acceleration.

Second, Dr. Scott has clearly missed the qualifier known by all astrophysicists when talking about "open" field lines, or field line foot points anchored in the photosphere; that is that the field lines are not actually open in the sense that they have an end point. The label "open field lines" always comes with the qualifier. In coronal astrophysics, we talk about open field with the caveat that the field lines that pass from the solar interior, and pass through the low-beta coronal environment into the solar wind, and closing back to the solar interior hundreds of AU away, or connecting to the interstellar, or even the intergalactic magnetic field. Dr. Scott also questions what happens to field lines as they pass into the solar interior; clearly it has not occurred to him that those field lines do not terminate either, but rather they connect through the interior in very complex ways. A major point here that Dr. Scott apparently doesn't know about, is that the thermal energy density of the solar interior is eight orders of magnitude greater than the magnetic energy density, meaning the intertia of the gas completely dominates the electrodynamics in the convection envelope below the photosphere - so it doesn't matter at all where the magnetic field in the solar interior connects to, since it is begin driven around by the motions of the gas.

Third, the framework used by astrophysicists to describe the behavior of magnetic field absolutely includes all associated currents. Dr. Scott seems to have forgotten that all the relevant behavior of currents outside the domain of interest are accounted for by the boundary conditions. In addition, inside the domain of interest, since magnetic fields and currents are related through the Ampere-Maxwell relation (in non-relativistic situations the displacement current is negligible, of order v/c, so that J ~ curl B), one may be eliminated in favor of the other in the equations of hydromagentics. The momentum equation may be written (modulo the constants appropriate to the unit system employed),

rho DV/Dt = J x B - grad P = (curl B) x B - grad P = (B.del) B - grad( P + B^2/2 )

This equation contains all the information of the currents. Usually, astrophysicists prefer to work in the B-V paradigm, rather than the E-J paradigm, though, both frameworks have been shown to be perfectly equivalent ways of describing the same phenomenon.

Fourth, OF COURSE no real plasma is perfectly conductive. This is an approximation that is made to simplify the analysis of a given system. For systems with exceedingly high Lunquist numbers, resistive effects are negligible - it would be like analyzing the trajectory of a ballistic missile using the general theory of relativity; unnecessary!

Fifth, the phenomenon of magnetic reconnection requires resistive dissipation. In highly conductive plasma systems, such as the solar corona, for the most part resistive effects are completely negligible. But, near places where the magnetic field strength goes to zero, the finite resistivity effects can become very important, even dominant, no matter how small the resistivity is. Dr. Scott's assertion that no energy is stored at a magnetic null point, and therefore cannot be dissipated, has nothing to do with the resistive dissipation (i.e., eta j^2 term) that happens there due to the magnetic field geometry in the vicinity. This is analogous to saying that the derivative of a function is not zero at a point where the value of the function itself is zero.

Sixth, Dr. Scott quotes the MHD equilibrium equation (equation 4) as the governing equation for reconnection. This is just wrong. Magnetic reconnection is a dynamic phenomenon, and therefore by definition is not described by,

rho DV/Dt = 0, or as in equation 4 of Dr Scott's paper, grad( P + B^2/2) - (B.del) B = 0

All in all, it is clear that Dr. Scott does not correctly understand the conversation, and has refuted his own misunderstandings.

Finally, to the point of why reconnection is called reconnection. In any dynamic system, if you freeze the time and integrate the field lines, you will always find the solenoidal condition is satisfied; the field lines are always continuous, and either closed, or exiting the system by crossing the domain boundary (or, equivalently, extend to infinity). If at a later time, you freeze the system, and integrate to find the same field lines, from known positions of the initial points of integration, you will find that the ones that passed through the resistive region have changed their topology mapping ... hence the *qualitative* description "reconnection". We do not actually know what happens inside the dissipation region. We do, however, know it is definitely not the double layer instability because the required geometry is inconsistent with "reconnection" systems. —Preceding unsigned comment added by 137.79.89.69 (talk) 22:59, 4 March 2011 (UTC)

No, you do not "know it is definitely not the double layer instability because the required geometry is inconsistent with "reconnection" systems." In fact I doubt you personally even know what a double layer explosion is; because if you did, you wouldn't utter such nonsense. They mirror what is observed in so-called "reconnection" events precisely, right down to the drift. By the way, your explanation of why the plasma suddenly decides to become resistive is hilarious. Thanks for that at least.

Also, Fälthammar responds to this:

" If at a later time, you freeze the system, and integrate to find the same field lines, from known positions of the initial points of integration, you will find that the ones that passed through the resistive region have changed their topology mapping ... hence the *qualitative* description "reconnection"."

With this:

"The basic reason for these difficulties with ‘moving’ magnetic field lines is, of course, that motion of magnetic field lines is inherently meaningless. The magnetic field B is a vector field defined as a function of space coordinates and time. At a fixed time, one may trace a field line from any given point in space. But that field line has no identity, and in a time-dependent magnetic field it cannot be identified with any field line at a different time, except by one convention or another. As we have seen, such conventions are fraught with pitfalls and should only be used with utmost care lest they lead to erroneous conclusions. To paraphrase Ralph Nader, moving magnetic field lines are 'unsafe at any speed.'"

--158.61.151.200 (talk) 23:33, 4 March 2011 (UTC)

The electric fields consistent with double-layers are perpendicular to the electric fields consistent with reconnection systems.

Nobody said anything about "the plasma suddenly decides to become resistive". The physics of the process under consideration is fairly simple. Singular lines (such as X-lines) in the plasma may exist, depending on the geometry, where the electric field is not equal to zero in the plasma reference frame. The electric current density at these lines is so great that dissipation becomes significant no matter how small the plasma electric resistivity is.

Nobody disagrees with your field line assessment - hence, the very first point made above that "field lines are not substantial quantities. Magnetic lines of force are a graphic and useful concept ... for representing the configuration of the magnetic field." At a fixed time you can integrate all the field lines you like. The system dynamics are always calculated with the hydromagentic equations, and say nothing of field lines. The only way to be sure that you are discussing the same field line is to initiate the field line integration from the same plasma parcel at both times, for which you know the fluid trajectory passed no where near a singular line, and you know that the resistive slip of the field through the plasma parcel is negligibly small - hence the very high conductivity caveat. If you look at the system's field line mapping at time t0, and compare it with the system's field line mapping at a later time t1 (t1 > t0), making sure your initial integration point at both times is the same highly conductive parcel of plasma, you can say that the magnetic field was dragged with that particular parcel of plasma, no matter the particular dynamics, between time t0 and time t1. And if the field line mapping at time t1, does not match the mapping at time t0, then "reconnection" has gone on somewhere within the plasma. —Preceding unsigned comment added by 137.79.89.69 (talk) 22:59, 4 March 2011 (UTC)

You are by-passing my entire argument. MHD theory treats the plasma as a perfectly conductive magnetic fluid. This is entirely WRONG since, as you acknowledge, a real plasma is never perfectly conductive! Which relates directly to why you are wrong about the field lines being dragged with the plasma. B × curl [B(E•B/B2)] = 0 is not satisfied.

Fälthammar explains:

The second concern is that the construct of moving field lines is sometimes confused with the concept of moving flux tubes. A flux tube can be thought of as an ensemble of field lines that are identified by their low energy plasma, which moves at the E×B/B2 velocity. Some researchers have asserted that as the plasma moves from region A to region B at this velocity, the field lines that were at A are later at B, so the magnetic field lines moved together with the plasma. This conclusion is wrong for two reasons. First, it is meaningless to assert that a field line that was at A is now at B, because there is no way to identify or distinguish one magnetic field line from another. Second, the concept of moving magnetic field lines is reasonable if it is used only for visualizing the temporal evolution of the magnetic field, and then, only if equation (2) is satisfied. This point is emphasized by the fact that there are an infinite number of field line velocities that produce the correct temporal evolution of the field when equation (2) is satisfied [Vasyliunas, 1972].

--158.61.151.200 (talk) 01:01, 5 March 2011 (UTC)

I see where you are getting confused. "MHD theory treats the plasma as a perfectly conductive magnetic fluid." MHD does not imply ideal evolution. MHD is the continuum approximation; valid when dealing with systems with characteristic length scales much much greater than the particle mean free path in collisional plasmas, or Larmor radius in collisionless magnetized plasmas, and timescales much much longer than the inverse of the collision frequency (in collisional plasmas), or 1/gyrofrequency (in collisionless plasmas). The MHD induction equation describing the evolution of the magnetic field may absolutely include resistive effects. The derivation of the resistive MHD Induction equation (i.e., the equation of magnetic field evolution) combines the Faraday and Ampere-Maxwell laws relating E, B, and dBdt, with an Ohm's law constituative relation relating E and J. (Modulo constants appropriate to the unit system being employed, {c, 4pi, mu0, etc}).

Starting with Faraday,

dBdt + curl E = 0

In the plasma rest frame, Ohm's law is,

J = sigma E'

Where sigma is the electrical conductivity, or equivalently the electrical resistivity eta = 1/sigma. Transforming to a "lab" frame, E' = E + V x B, where V is the fluid motion of the plasma.

J = sigma ( E + V x B ).

Or solving for the electric field,

E = eta J - V x B.

Note, if the plasma is ideal (eta = 0), there is no electric field in the plasma rest frame, and the electric field in the lab frame is simply, E = - V x B. By the way, the velocity you quote above is nothing more than the velocity of the frame transformation; solving for the velocity, V = E x B/B^2. But I digress. ... One can use a more complex Ohm's Law than J = sigma E. For example the conductivity transport in the generalized Ohm's law includes Hall effects, and particle pressure effects, etc. (it can be derived by taking the difference of ion and electron Vlasov 2nd moment equations). Without loss of generality, and for illustrative simplicity, let just assume eta = constant.

Substituting this electric field into Faraday,

dBdt + curl ( eta J - V x B ) = 0

Substituting the non-relativistic Ampere-Maxwell equation for the current, J ~ curl B,

dBdt + eta curl ( curl B ) - curl ( V x B ) = 0

After some algebra, and using a well known vector identity curl ( curl B ) = del ( del.B ) - ( del.del ) B, we find,

dBdt = curl ( V x B ) + eta ( del.del ) B

This is the resistive MHD induction equation. It consists of a convection term, curl ( V x B ), and a resistive term, eta ( del.del ) B. Ideal MHD is included within this equation (for a perfectly conducting plasma, eta = 0). Including an arbitrarily small resistivity, over the vast majority of the system | curl ( V x B ) | >> | eta ( del.del ) B |, and the plasma behaves as if it were effectively ideal (you can carry around the resistive term all you want through the calculation, but it will be negligible compared to the convective term). However, in the vicinity of singular lines, the resistive term of the MHD induction equation above can become comparable to, or greater than, the convective term, | curl ( V x B ) | ~ | eta ( del.del ) B |. The magnetic field itself vanishes, while the laplacian of B (i.e., ( del.del ) B ) does not (a function can have a zero value, with a non-zero derivative, and a non-zero 2nd derivative at a point). In the vicinity of the singular line, the resistive dissipation term is dominant, breaking the plasma "ideal-ness".

Reconnection does not occur in an ideal plasma; nobody is arguing that; nobody has ever argued that. The process requires resistive dissipation, which is absolutely included in the MHD framework. Reconnection is a qualitative description. Two plasma parcels can be connected by a field line at a fixed time. Allow the plasma to evolve dynamically, and self consistency - with no mention of field line evolution. If those two plasma parcels remain in regions where the convective term dominates the resistive term, | curl ( V x B ) | >> | eta ( del.del ) B |, we can say with negligible error that the magnetic field was frozen into those parcels of plasma (the error being related to the relative strength of the resistive to convective term). If after integrating the field line maps at a later fixed time, those same two plasma parcels are not joined by a single field line, then the phenomenon we describe qualitatively as "reconnection" has occurred. For this to happen, a dissipative region must be present somewhere in the system. I'm not missing your argument. You clearly do not understand the full physics that you are arguing against. Stop quote-mining scientists. I know Vasyliunas himself, and he understands that reconnection is a real phenomenon. —Preceding unsigned comment added by 99.33.68.252 (talk) 05:16, 5 March 2011 (UTC)

I know Vasyliunas himself, and he understands that reconnection is a real phenomenon.

I'm not arguing that nothing is occurring at all; I am arguing that it is a result of a double layer explosion between two electrified fields of plasma. Plasma itself is never ideal, ergo any claims that the "magnetic field was frozen into those parcels of plasma" are wrong. Adding in resistive dissipation to an MHD model will not produce results that will be able to tell you WHY this phenomena is occurring in space at all.

Fälthammar explains exactly why it is entirely wrong to claim that you can integrate a field line between two parcels over time and space. While your equations produce "correct" theoretical results, they are WRONG because they do not correctly reproduce reality. And because they do not correctly depict reality, you will forever be spinning your wheels trying to concoct some manner of craziness to explain WHY these events are occurring.

Of course, that's the whole point of your exercise, isn't it? To ride the government gravy train forever. If you guys were to actually present a fully formed theory that explained WHY all these events are occurring, there would be no reason to continue funding your research since we would have all the answers.

Look up Stability of a spherical double layer produced through ionization and Double layers and circuits in astrophysics if you want a simple answer that explains WHY "magnetic reconnection" is occurring in space.--76.170.55.28 (talk) 16:34, 5 March 2011 (UTC)

While you keep throwing quotes at me, as if I'm not familiar with ideal MHD, or inviscid flow theory, and plasma stability theory, I've showed you mathematically (using the equations of Faraday and Ampere, as well as Ohm) how a real plasma can behave as if it were ideal, and how you can quantify the error of "ideal-ness". Again, if the ratio of resistive to convective terms is 1 part in a million, or a billion, the real plasma is effectively behaving as if it were ideal. I've explained how the difference in field line maps at different times implies a qualitative description of reconnection. Again, mathematically, every vector field admits a flow (also known as field lines). Magnetic field lines are found by solving the equations, dx/Bx = dy/By = dz/Bz. This field line map is built with the vector field B(t), and therefore evolves exactly like the vector field. The field line evolution will, in general be different from the velocity field line evolution, which satisfies it's own set of field line equations, dx/Vx = dy/Vy = dz/Vz, and evolves according to the V(t). In general, these two different field evolutions are not the same (as is well known). In the exactly ideal case, the evolutions of the the flow streamlines and the magnetic field lines are in sync. In other words, if a given pair of space curves that are a streamline and magnetic field line intersect, ideal evolution means these same two space curves will always intersect; and non-ideal evolution means that the given two space curves will slip away from each other. If the system is such that the ratio of resistive-to-convection terms is exactly zero, then the magnetic field is said to be exactly frozen-in to the plasma; and two intersecting space curves never slip away from each other. A real plasma can behave as if it were effectively ideal, if the ratio of the resistive-to-convection terms is very very small (the inverse of this ratio, by the way, is called the Magnetic Reynolds number, or the Lunquist number). If that ratio is very very small, dissipative effects are negligible and the real plasma behaves as if it were very nearly ideal; intersecting space curves slip away from each other very slowly, and only by a very small displacement. The displacement (i.e., the error between ideal and non-ideal behavior) scales with the resistive-to-convective ratio. In ideal systems this means plasma parcels everywhere along that given magnetic field line, all move along their streamline trajectories, the continuum set of which are intersecting sync with that field line. In very-nearly ideal systems, that dense set of streamlines slip away from the given magnetic field line only very small distances. In systems with a current sheet, resistive effects become important in the vicinity of the current sheet. And so while the plasma very far away from the singular line behaves very nearly ideal, the dynamics in the vicinity of the current sheet break the idealness, and the plasma parcels that were once connected by the same field line, are not longer connected by the same field line. Hence the term, reconnection. Again, the process is not the double-layer instability which you are advocating. The double-layer instability is well known, and well studied, and has been discarded as a candidate for explaining the reconnection phenomenon after thorough, worldwide, analytic and numerical investigations, laboratory experiments, and observations. Not that the double-layer instability is not an interesting phenomenon in-and-of itself, and not that it does not have interesting applications in space and fusion plasmas. If the phenomenon of reconnection was actually the double-layer instability, do you really think that nobody would have noticed this? Do you honestly believe that it would not have caught on like wild fire in the astrophysical plasma and fusion research communities?

Oh wait. It's a giant, worldwide conspiracy to keep the vast majority of astrophysicists, plasma physicists, fusion scientists, turbulence researchers, and engineers all over the world, all paid on the govt gravy train - because the govt is the only one funding astrophysical, plasma, fusion, fluid and turbulence research, and all get paid oh so well. Because there really is no such thing as peer review in the journals or the proposal review panels. Seriously? Govt gravy train? ... Ok. You figured it out. The vast majority of astrophysicists, plasma physicists, and fusion researchers, throughout the entire world - from US govt labs like NOAA, NASA, and Los Alamos, to private labs like UCAR, CFA, and JPL, to titan private defense corporations like Lockheed Martin, Raytheon, and Boeing, to small private companies like Predictive Science Inc, to pretty much every single major public and private university like Michigan, Harvard, Princeton, CalTech, Dartmouth, Univ of New Hampshire, Martyland, Arizona, UCLA (etc. etc. etc.), as well as all their counterparts in Canada, Mexico, Brazil, Chile, Argentina, the UK, Germany, France, Austria, Switzerland, Spain, Portugal, Italy, Greece, Turkey, Egypt, Iran, Russia, China, India, Australia, South Korea, and Japan - don't really understand science at all. We didn't really spend 6 years in graduate school taking courses like mechanics, statistical physics, electrodynamics, fluid mechanics, thermodynamics, quantum mechanics, or any of the math analysis stuff. Nor have we spent years researching ever conceivable aspect of this stuff, and discussing this stuff with each other. Nobody has ever thought about the issues you are discussing. As a group, we have never investigated every conceivable plasma instability in astrophysical systems, or fusion systems, or planetary magnetospheres, or stellar winds, or accretion disks, or pretty much every situation we can possibly think of. We are fabricating observations, experimental results, and incorrectly solving the equations of particle kinetics, Maxwell, fluid dynamics, and turbulence - if we ever knew how to write them down correctly in the first place. You know, cause we've all been indoctrinated by our liberal elitist university professors, who really want to impose a new world order. We're all just taking our marching orders from Al Gore, who says, "Let's go boys. RIDE THAT GOVT GRAY TRAIN." Seriously, it's not a conspiracy. Everybody is constantly questioning, checking, and verifying everyone else. You might have read some papers, or maybe you took a class or two, buy you clearly are not familiar with the full body of scientific work (analytical framework that has been thoroughly justified over and over, numerical solutions, laboratory experiments, and astrophysical observations) that has been accumulated, and you clearly do not work in the fields of astrophysics, plasma physics, or fusion science. —Preceding unsigned comment added by 64.134.228.7 (talk) 19:22, 5 March 2011 (UTC)

There most certainly is a grand conspiracy. It happens every time the government takes money from me against my consent and hands it to people like you. You people are incapable of seeing the obvious because the obvious would put you out of a job. It is clear that the double layer explosion is a natural consequence of electrified plasma which obeys Kirchhoff's circuit rules. It is also blatantly clear that the double layer explosion accounts for every single thing that is observed in a "reconnection" event. It is also clear that there can be no "reconnection" of "field lines" - ever. --76.170.55.28 (talk) 23:41, 5 March 2011 (UTC)

LOL. "There most certainly is a grand conspiracy." Yes! The entire professional astrophysics, plasma physics, fusion research, fluid dynamics, aerospace, and turbulence communities across the entire world is conspiring to disagree with your position - and have shown again and again for decades that the double-layer instability and reconnection two different phenomenon. But, if you are so sure of this, by all means join the conversation - of course, joining conversation means you will have to understand what has already been done and why, so that you may understand why the field has developed as it stands. By all means, you are free to get a Ph.D. in physics from any university you wish, and come to work in the field. You are free to submit papers to the peer reviewed literature. You are free to attend our conferences/meetings/workshops. You are free to propose to our peer-reviewed competitions. In effect, you are free to make your case that all reconnection events are just double-layer instabilities. If reconnection has been definitively figured out, that means everybody can move onto other exciting research. We encourage you to join the conversation. —Preceding unsigned comment added by 64.134.228.7 (talk) 00:29, 6 March 2011 (UTC)

Pointing out that standing theories of magnetic reconnection are wrong because the models do not obey known circuit laws does not require me to change my current occupation. It is YOUR JOB to base your research on the known laws of physics. That is why I am paying you. Alfvén, Fälthammar, Scott, Peratt, and a host of other researchers have clearly laid out why the standing theory is wrong. It only takes ONE paper to demonstrate that a theory is predicated on WRONG assumptions, there is nothing more that needs to be said in this regard. Future research can not simply ignore the findings of these men and continue on as if there is no problem. --76.170.55.28 (talk) 00:58, 6 March 2011 (UTC)

Alright. This is conversation is silly. You clearly do not understand what you are talking about. You obviously are completely unaware of the vast majority of peer-reviewed work that the current description is built upon. You are do not understand of the physical differences between electrical circuits and plasma physics, or the difference between astrophysical plasmas and laboratory plasmas, or how Maxwell's equations apply to electrified gases on different scales. You are obviously unaware of all of the work that has been done, and redone, and rederived, and rejustified, over and over again over decades to build the theory to it's current state. The fact that the science community has rejected the suggestions of various people as explanations of a given phenomenon, who have contributed excellent work, is not a giant conspiracy. Nobody is ignoring their work. It simply means that the suggestions have been considered, discussed, tested, and shown simply to be a different phenomenon. Do you honestly believe someone like Alfven would not be taken seriously when he gives some input to the conversation? It is possible that "Alfven, Fälthammar, Scott, Peratt, and a host of other researchers" have simply argued why the accepted reconnection theory is incorrect, are simply incorrect themselves. (In fact, I have shown above why Donald Scott's paper is nothing but Donald Scott refuting, correctly, nothing more than his own misunderstandings of reconnection theory; doesn't mean he is a bad physicist, just that he misunderstood the conversation.) We have real laboratory experiments, run by excellent plasma physicists who thoroughly understand the science, engineering, and the intimate details of their own experiments, that unambiguously show the magnetic field changing it topology. We have observations that unambiguously show the magnetic field changing its topology. No ONE paper, no amount of papers, can tear that down. Again, not a worldwide conspiracy; not a worldwide general misunderstanding of the laws of physics. —Preceding unsigned comment added by 99.33.68.252 (talk) 01:55, 6 March 2011 (UTC)

What I find silly is that you are still in here trying to convince me that magnetic fields can "reconnect" and that you people are somehow able to follow a particular field line across space and time in two entirely different plasma parcels. This is on top of ignoring the circuits which must be present across the entire system. As Alfvén says "As neither double layer nor circuit can be derived from magnetofluid models of a plasma, such models are useless for treating energy transfer by means of double layers. They must be replaced by particle models and circuit theory. " --76.170.55.28 (talk) 02:05, 6 March 2011 (UTC)

Reconnection has been well studied within the particle kinetic framework too - outside the range of the MHD continuum framework (another, fact that you seem to be unaware of). The fact that this phenomenon is simply not the double-layer instability has been shown exhaustively. The science has advanced far beyond Alfven, who by the way has been dead since 1995, and therefore unable to contribute to the conversation. You offer scientists such as Forrest Mozer and Stewart Prager, to try to support your point - clearly unaware of their roles in building the general theory of magnetic reconnection as it currently stands. These people are in the conversation; nobody is ignoring their work. For excellent peer-reviewed reviews of the current state of the science, from laboratory physics to astrophysical plasma observations, from particle kinetics to fluid mechanics, from analytic theory to numerical solutions, with exhaustive reference lists to learn more, see:

M. Yamada, R. Kulsrud, and H. Ji, "Magnetic Reconnection", Reviews of Modern Physics 82, 603 (2010) ... take note of the acknowledgements where you will find Forest and Prager.

E. Zweibel and M. Yamada, "Magnetic Reconnection in Astrophysical and Laboratory Plasmas", Annual Review of Astronomy and Astrophysics 47, 291 (2009)

I am aware, and I am also aware that they are making the same errors which are clearly laid out by Fälthammar and they are ignoring the circuits which must exist in the plasma to begin with because they start from the position of a perfectly conductive fluid. By starting from this position, they conveniently get to ignore the circuits which must be present prior to any events which take place within it. There can never be magnetic reconnection because any field line is always a closed loop. Therefore any attempt to explain why field lines merge and snap must first explain how it is possible that a field line can become an open ended line. Of course, this is impossible. Thus, the entire field of "magnetic reconnection" research amounts to nothing more than a massive squandering of resources since the answer to what is occurring is SIMPLE and OBVIOUS if one simply views the entire circuit. There are no "reconnecting" magnetic fields, only exploding double layers.--76.170.55.28 (talk) 03:07, 6 March 2011 (UTC)

You are obviously not aware. I can tell you are not aware, by your statement that, "they start from the position of a perfectly conductive fluid." You, and the Fälthammar paper you point to, are mistaken about this. Dissipation effects are absolutely accounted in reconnection science. As well, you seem to be unaware of - given by your statement that you think that somehow the science hinges on "open ended" field lines - is that nobody ever catches a field line that has and end. Never. Not in any numerical experiment; not in any laboratory experiment; not in any astrophysical observation - no matter the time cadence. But the phenomenon of reconnection does not rest on open ended field lines. Reconnection theory describes the topology change of the magnetic field, and associated energy conversions, that occurs as a consequence of dissipative effects. And there is clear, unambiguous evidence of magnetic field topology does change, which can is only illustrated with the useful graphic field line concept representing the configuration of the magnetic field. In addition, there is clear and unambiguous evidence in analytic studies, numerical investigations, laboratory experiments, and astrophysical observations that reconnection phenomena is different than the double-layer instability. If reconnection were simply and obviously the double-layer instability, it would have been picked up and run with a decades ago. So this "massive squandering of resources" is simply your opinion; one clearly built on other people's thoughts, as opposed making an informed decision based upon the full state of the science. —Preceding unsigned comment added by 99.33.68.252 (talk) 03:53, 6 March 2011 (UTC)

Magnetic reconnection doesn't rest on a topology change. If it did, it wouldn't be called magnetic reconnection. It would be called an exploding double layer, which is what it is. It is called magnetic reconnection because the physicists who first attempted to figure it out used MHD theory assuming the plasma was an infinitely conductive fluid. When it was determined that there was no possible way that such a simulation could account for the speed of the topology change, ad hoc resistivity was then added into the simulation to make it jive with what was observed. But the theory itself has not deviated away from its origins in the slightest. You are defending a scientific fraud. And no, there are no experimental observations that show there is a fundamental difference between a double layer explosion and "magnetic reconnection" observations. - none.--76.170.55.28 (talk) 06:17, 6 March 2011 (UTC)

"Magnetic reconnection doesn't rest on a topology change. If it did, it wouldn't be called magnetic reconnection." Statements like this show that you either unaware of, or do not understand the concepts being discussed in reconnection. Topology change means (mathematically) a change in the connectivity in magnetic field line mapping used illustrate the magnetic field geometry.

It is simply incorrect to say "the theory itself has not deviated away from its origins in the slightest." Regardless of the framework the physicists first used attempting to figure out the phenomenon, the field has advanced far beyond that. You are correct to point out that the attempts to describe solar flares with the Sweet-Parker model, found the reconnection rate in a Sweet-Parker current sheet was far too slow to "jive" with what is observed. But Petchek reconnection for example, utilizes hydromagnetic shocks to self-consistently increase the reconnection rate - a perfectly valid, perfectly viable model - fundamentally different from the original sweet-parker model. You are absolutely mistaken to think reconnection is only studied within the original MHD framework. Reconnection is being thoroughly studied in full particle kinetics (see Shay et al. 1998, Shay and Drake 1998, Birn et al. 2001, Rogers et al. 2001, Drake et al. 2003, Jemella et al., 2003, Servidio et al. 2009 and 2010, Cassak et al. 2009, Cassak And Drake 2010) - an entirely different framework from the MHD continuum.

You are incorrect to say, " there are no experimental observations that show there is a fundamental difference between a double layer explosion and 'magnetic reconnection' observations. - none.--". These are two different mechanisms that exhibit some similar characteristics and some different characteristics. One difference is that double-layer formation requires a current density above a certain threshold (called the Bohm threshold), while no such current threshold is required (or observed) for the onset of reconnection. A double-layer model was suggested by Alfven and Carlquist in 1967 (and expanded upon by Carlquist 1969, and 1972) to explain solar flares, by which a current-driven MHD instability could lead to the formation of a double layer in a current carrying flare loop, analogous to a discharge tube. This model was subsequently analyzed by many researchers (Berk and Roberts 1967, Smith and Priest 1972, Goertz and Joyce 1975, among many others). These researchers found that when applied to observed solar flare parameters, although the timescales for energy release were comparable, the required current density for the existence of a double-layer is larger than current densities observed in flare loops (Morten and Severny 1968, Title and Andelin 1971) - an *observable* difference between flare production by double-layer dynamics, and reconnection dynamics. Another observable difference between reconnection and double-layers, is that kinetic dynamics of reconnection is controlled by whistler waves; there is no evidence of whistler waves in double-layers dynamics. The bottom line is double-layer formation, and stability is well-known, and well-studied, and is simply different from reconnection. The dynamics of double-layers continues to be researched in it's own right - there are plenty of peer-reviewed papers that discuss double-layer formation and stability in the context of solar flares by the VERY SAME researchers who are also investigating flare reconnection (see Li et al. 2010). Reconnection is being observed in plasma systems in which no double-layer is formed at all, in both fully kinetic numerical simulations (see Cassak et al. 2005, 2006, 2007, 2010), and experimental laboratory systems (Yamada et al. 2010, Dorfman et al. 2008). These researchers know what a double layer is, and can recognize double-layer dynamics, and other current driven instabilities in their systems (see Yamada and Raether 1975, Seiler et al. 1976, Yamada and Hendel, 1978). Conversely, double-layers form and dissipate in magnetized plasma systems in which no characteristics of reconnection is observed - there is plenty of evidence in the material processing by plasma processes. Believe whatever you want to believe about reconnection and double-layers, but know the facts before you call professional physicists stupid! —Preceding unsigned comment added by 64.134.239.111 (talk) 22:52, 6 March 2011 (UTC)

there is no evidence of whistler waves in double-layers dynamics

LOL --76.170.55.28 (talk) 20:12, 7 March 2011 (UTC)

Wonderful! There is still no evidence of whistler waves in double-layer dynamics. This paper you posted says that double-layer dynamics produces hf radiation with a range of 300-500 MHz, 4 orders of magnitude greater than the high end of the whistler wave range (300 Hz - 30 kHz). The hf radiation excites a lower-freq wave, 20-40 MHz (still at least 3 orders of magnitude greater than the high end of whistler waves), evanescent in the high density surrounding plasma (i.e., these wave lose energy as they travel through the plasma). There is speculation that these waves might reach the whistler range far from the source - suggested by Volwerk in 1993. So ... again ... there is no evidence of whistler waves produced by double-layers. To recap, double-layer dynamics produce hf radiation, 4 orders of magnitude greater than the whistler wave range. The evanescence of the hf radiation in the surrounding plasma is only speculated to reach the whistler range far from the source. Whistler waves associated with reconnection occurs in the dissipation/reconnection region where the electrons decouple from the ions, driving the electrons away from the magnetic x-line (Drake et al., 2008). —Preceding unsigned comment added by 137.79.89.69 (talk) 19:10, 8 March 2011 (UTC)

A Laboratory Investigation of Potential Double Layers, Leung P. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870013880_1987013880.pdf from pdf page 97, document page 91: "It should be noted that before the ignition of BPD, the double layer becomes unstable, and large amplitude potential fluctuations are observed. Figure 9a shows the fluctuations in the local electric field as measured by the diagnostic electron beam. The electric field fluctuates at a frequency of approximately 1 kHz."

That pdf has an entire collection of works on the double layer mechanism and its known properties. You should read all of it.--158.61.151.200 (talk) 21:41, 8 March 2011 (UTC)

As a plasma astrophysicist, I am very interested in double-layers, and, for that matter, every other dynamic plasma process - so, thank you for the paper. More specifically, as this conversation has developed, it seems to me we are arguing two separate issues: whether natural phenomenon (for example, the solar flare) are the result of the double-layer instability or driven by reconnection ... versus ... whether the double-layer instability as a dynamics process is itself different from the reconnection mechanism. Regarding the former, whether the driving mechanism behind phenomenon such as solar flares is a double-layer instability or reconnection, we, plasma astrophysicists, are not invested in one or the other. We simply want to know is what is going on. If the double-layer instability is the responsible driving mechanism - great! That means the problem has been solved, and we can move on to something else. Our livelyhoods do not hinge on whether natural phenomenon are driven by one dynamic process or another. Would you suggest for example Alfven waves are pseudoscience? Of course not. And we are doing plenty of research on the effects of Alfven waves in plasma astrophysics - which is paying our salaries as well. The double-layer instability model for solar flares (for example) was proposed by Alfven in the late 1960's, and has been thoroughly studied since. Certainly, there are reasons for its suggestion, the mechanism fit various of the observable parameters - for example, the very same astrophysicists researching reconnection mechanism have recognized double-layer dynamics in the suppression of energetic electron transport in flares. Nobody is arguing that double-layers don't exist, but there are also various observable parameters that are not explained by the double-layer model. Solar astrophysicists have proposed plenty of flare-driving mechanisms (fundamentally different from BOTH the double-layer model and reconnection), and will continue to argue as to which is the correct driving mechanism until we can get in the middle of a flare itself and measure what's happening. But until that happens, for many reasons that astrophysicists - who are familiar with, and recognize double-layer dynamics (the review you point to above is nearly 25 years old) - have, on the whole, accepted the reconnection model to explain solar flares. Regarding the latter issue, though, the reconnection mechanism itself as a dynamic phenomenon is separate and wholly different from the double-layer instability. There are plenty of particle kinetic reconnection calculations, dedicated laboratory reconnection experiments, as well as the fusion experiments that are simply not consistent with double-layer dynamics - evidence that, as a dynamic process, reconnection is itself a mechanism different from double-layer dynamics. —Preceding unsigned comment added by 137.79.89.69 (talk) 23:20, 8 March 2011 (UTC)

Physical reality says there is no such thing as magnetic reconnection because there is no such thing as an open ended field line. Therefore any effort expended on magnetic reconnection pseudoscience is a waste of my tax dollars. The entire circuit must be analyzed, and I'm not just talking about solar flares. While there are certainly all sorts of plasma phenomena that are not related to the double layer, there are no "magnetic reconnection" phenomena that can not be accounted for by the dynamics of double layers. What astrophysicists "accept" is immaterial to what physical reality says is the truth. Physical reality does not change itself to accommodate theory. The majority of astrophysicists accept the notion that an object the size of an asteroid can spin around at near light speed and emit a beam of energy detectable across galactic distances. The majority of astrophysicists accept that an entirely undetectable form of matter exists and composes >90% of the universe. I am convinced that astrophysicists would believe in Santa Claus if that is what kept their paychecks flowing. —Preceding unsigned comment added by 158.61.151.200 (talk) 00:16, 9 March 2011 (UTC)

You are incorrect that magnetic reconnection as a mechanism for energy release, is different from double-layer dynamics. Just as you have given me a double-layer physics review paper, I've given you ample scientific evidence which you choose not to accept. —Preceding unsigned comment added by 64.134.224.21 (talk) 00:29, 9 March 2011 (UTC)

The only evidence to suggest that magnetic reconnection is somehow fundamentally different from a double layer explosion is predicated on scientists refusal to close the circuit. They can't see where it starts and where it terminates, so they act as if it does not exist. It does exist, and it MUST exist, since this is the only way one can avoid wandering off into the pseudoscience of open ended field lines. There's a whole lot of evidence to suggest that closing the circuit solves all the problems.--158.61.151.200 (talk) 01:01, 9 March 2011 (UTC)

I have to agree that the whole subject of "magnetic reconnection" is the most appalling sort of institutional pseudoscience. In first-semester physics at Cornell Prof. David Mermin showed why, and many other basic physics courses teach the same thing. Magnetic field lines simply aren't real entities. Field lines shown with iron filings are due to the field-concentrating of the iron particles. Feynman noted in his lectures that magnetic fields are a purely relatavistic effect arising from the motion of charges (currents) and magnetic fields have no independent existence apart from currents. Even taking magnetic field lines as a metaphorical way of speaking about the closed-loop forms of the field ("magnetic circuits"), it is not possible for the lines to ever be anything but closed loops since there are no magnetic monopoles. Thus there can be nothing to reconnect. The currents are the real thing, the magnetic fields are derived from the currents; the magnetic field lines are a fiction. Astrophysicists just reveal their basic incompetence as physicists when they talk about "reconnection". Enon (talk) 03:40, 11 July 2009 (UTC)

An astrophysicists reply to this dissenting section ...

First of all ... OF COURSE magnetic field lines do not exist. Nobody actually thinks they do. The magnetic lines of force are a graphic and useful concept invented by Michael Faraday in the nineteenth century for representing the configuration of the magnetic field. In this case, they are a useful construction to describe the very very real phenomenon that is the rapid conversion of magnetic energy to bulk plasma kinetic energy, and particle acceleration. We attach the label "magnetic reconnection" because this process changes the topology of the magnetic connection between distant elements of plasma. The solar flare is indisputable evidence that the phenomenon we call "magnetic reconnection" is true. Only the magnetic field contains enough energy to drive the solar flare, and the timescale is way too fast for resistive diffusion of the magnetic field through the coronal plasma to be the driver.

And more importantly, you clearly don't understand relativity and electricity and magnetism.

Consider the basic property of magnetic fields and their intimate association with electric currents. That there is no magnetic field without an associated current (in this case, we are not concerned with rapidly varying electric and magnetic fields such that the displacement current is important - only the flow of charge through a wire). Magnetic fields for laboratory purposes are usually produced by forcing an electric current through a coil of wire, i.e., an electromagnet. The effect is often enhanced by placing iron inside the coil, to take advantage of the electric currents that naturally flow inside iron atoms and are easily aligned to supplement the currents forced through the coil of wire. With a suitably designed iron circuit around the coil of wire the strength of the field obtained from a current in a wire can be enhanced a thousandfold. As a consequence of our familiar means of making magnetic field, we have developed the habit of saying that the electric current causes the magnetic field. The energy is introduced via the electric current and gives rise to the magnetic field.

But now suppose that we have built a large electromagnet with a large iron core so that it operates efficiently. We have closed the switch connecting the coil to a d.c. generator, building up substantial electric current through the coil and producing a magnetic field of, say, 10000 G in the iron core. Having accomplished this, we open the switch in order to shut off the power. What you will discover is that the current does not immediately cease to flow. Indeed, if we cut off the power by opening the switch, the electric current will arc across the open switch for several seconds (perhaps doing considerable damage to the switch) before dying away. The reason is that the current cannot stop until the magnetic field is gone, and the magnetic field cannot disappear until it's energy is dispersed in some way. As the magnetic field decays, it disappears by shrinking back into the coil, crossing over many turns of wire and inducing an enormous electromotive force (or alternatively, the magnetic flux through the coil is decreasing and hence there is an induced e.m.f.) which keeps the current going, regardless of whether the switch is open or not. Forcing the current through the coil (and arcing across the the open switch) consumes the energy of the magnetic field so that the field soon dies away. (In fact, if the electromagnetic is made of superconducting wire, there is no dissipation of energy whatsoever. The magnetic field persists in the coil without diminishing for as long as the low temperature necessary for the superconductivity of the wire is maintained.) During this phase of operation it is meaningless to say the current is causing the field. Indeed, the field is causing - inducing - the current. The energy is flowing from the field into the wires and our open switch may be burned and melted by the energy delivered from the field.

In the astrophysical universe there are no wires which carry electric current and energy from a region of generation into a distant active site. Hence there are few general circumstances of which we are aware where one can say unambiguously that the current causes the magnetic field. In nature, in the absence of insulating materials to channel and direct the flow of electric currents, the generator supplying the power and the electromagnet producing the magnetic field, are one and the same, a single amorphous mass of gas. Since both the current and the magnetic field have energy associated, it is equally valid to take either one as the primary quantity - analogous to the fact that the structure of relativity removes any preferred reference frame. In fact, given a frame with both electric and magnetic fields, you can always Lorentz boost to a frame in which the electric field is zero, but you can never transform away the magnetic field. Thus, astrophysicists take the magnetic field as the primary quantity, and the currents induced by a changing magnetic field as the derived quantity.

Stop quoting famous scientists until you understand physics yourself. Pretending to be smart and being educated are two very different things, and people recognize it right away. You're like the guy who buys a bronze star at a garage sale, pins it to his lapel, and tells everyone to call him "Sarge". Nobody likes that guy! —Preceding unsigned comment added by 128.164.215.110 (talk) 22:49, 30 July 2009 (UTC)

The self-described astrophysicist above wrote:

We attach the label "magnetic reconnection" because this process changes the topology of the magnetic connection between distant elements of plasma.'

My point is that there can be no disconnection of the magnetic isopotential surfaces ("field lines") in the first place, they must always be closed. Hence they cannot "reconnect", any more than the contours on a topographical map can.

The solar flare is indisputable evidence that the phenomenon we call "magnetic reconnection" is true. Only the magnetic field contains enough energy to drive the solar flare, and the timescale is way too fast for resistive diffusion of the magnetic field through the coronal plasma to be the driver.

This may be true, for some meaning of "reconnection" that does not invove open field lines reconnecting, but your explanation is so terse as to be uninformative and may have some contrafactual theoretical presuppositions built into it, such as "resistive diffusion of the magnetic field", (whatever that is supposed to be) being the only competing hypothesis rather than conventional plasma dynamic observations, e.g. tufting, double-layer instability.

And more importantly, you clearly don't understand relativity and electricity and magnetism.

Take it up with Feynman. IIRC, the section showing that magnetism is exclusively a relativistic effect of motion of charges is book 2 Ch. 25 of his lectures. There are no magnetic monopoles, so magnetism is always going to be linked to the motion of charges.

You say first:

"...the electric currents that naturally flow inside iron atoms..."

but then later conclude:

"During this phase of operation it is meaningless to say the current is causing the field. Indeed, the field is causing - inducing - the current."

so by your own account there is not one current, but two, one in the coil and one in the core. The field in the core is also due to a current, so your argument that the field exists apart from currents is self-refuted.

Inductance is very much like inertia because it derives from inertia. Your argument would be stronger without the core in the thought-experiment, and without the core there would still be (weaker, briefer) arcing across the switch. The coil stored energy in the field running through its axis. Parts of this field extended beyond the coil, but it all passed through the coil's axis. when the switch was opened, the current did not immediately stop, the charges piled up on one contact and continued to flow away from the other, creating a huge voltage, (further multiplied by the rapidly decreasing capacitance between the switch contacts as they separated) which ionized the air, creating a plasma conducting path so that the current could continue to flow. However the increased resistance started to reduce the current, and thus the field. The decreasing field through the coil acted on the free charges in the coil, acting as part of their motional inertia and keeping them flowing; the coil's geometry multiplied this self-inductive effect. A better thought-experiment would be a superconducting solenoid quenching (getting too hot or with too much magnetic field to remain superconductive). The current is decelerated more rapidly due to ohmic heating destroying the superconductivity in a runaway feedback cycle, the inertial energy converts to heat more rapidly, but the situation is still basically the same. No matter what situation one can dream up, the magnetic field follows the current with a light-speed lag.

In the astrophysical universe there are no wires which carry electric current and energy from a region of generation into a distant active site.

But there is a variably conductive plasma with higher conductive regions and lower conductive regions self-organizing into a variety of structures such as filaments which can serve as conductors and double-layers which can act like insulation.

Hence there are few general circumstances of which we are aware where one can say unambiguously that the current causes the magnetic field. In nature, in the absence of insulating materials to channel and direct the flow of electric currents,...

No, barring hypothetical monopoles, in all cases magnetic fields are caused by moving charges or the equivalent (e.g. ferromagnetics, not a major factor on astronomical scales). If you see evidence of magnetic fields in space, there will be corresponding currents causing those fields. Any other hypothesis has a massive burden of proof to overcome in the face of basic physics.

Stop quoting famous scientists until you understand physics yourself. Pretending to be smart and being educated are two very different things, and people recognize it right away.

Hmm. I'll bite. If you are a physicist, what, if any, aspects of non-quantum relativistic electromagnetic field theory cannot be derived from the four-current? (To answer this question you need to know the Geometric Algebra of Spacetime / Spacetime Algebra (STA) / (+---) signature, real-valued Clifford Algebra). If there are any, then you may be right, if not, then I am. Enon (talk) 06:00, 28 October 2009 (UTC)

Several points of note ...

That field lines follow iso-contours of the vector potential is not always true. In fact, it is only true or an ideal, incompressible (magnetized) plasma, and in situations in which 1 coordinate is cyclic (i.e., the problem is effectively 2 dimensional).

Magnetic induction has nothing to do with particle inertia. If that were the case, since the electron inertia is so small, as soon as the switch is opened the B-field would cease to exist nearly instantaneously. This is not the case. The timescale over which the magnetic energy must dissipate is much much (much much much) longer than the timescale for the electrons to stop moving. A changing magnetic field induces an emf, which in turn drives a current, and the energy is dissipated resistively. If the induction experiment were carried out in an infinitely conductive coil, then the magnetic field energy could not dissipate.

The point you are missing here is that both the magnetic field and the current have energy, and therefore both are substantial quantities. Maxwell's equations do not say which is the primary quantity and which is the secondary. Currents generate fields (of course). But changing fields also drive changing currents as well. Systems always want to move to a lower energy state. Driven systems always move to maximum allowable dissipation, limited by the plasma transport parameters. Within a magnetized plasma, currents and flow fields are different quantities; currents are the difference in the motions of the pos and neg charges. In a highly conductive plasma, the flow fields may move the magnetic field around, which induce changes in the current systems. In a highly resistive plasma, the magnetic field slips through the plasma generating heat (i.e., resistive dissipation). In the former case, the work done by the flow on the field goes into inducing changes in the currents. In the latter, the work done by the flow on the field goes into heat. In a moderately conductive plasma, the work done goes into some combination of both.

We have observations of "magnetic reconnection". Movies in which you can watch the field topology change in a manner consistent with the description (i.e., the magnetic field connection between distant parcels of plasma changes). Now it is absolutely true that the phenomenon in which magnetic energy is rapidly converted to kinetic energy, heat, and particle acceleration in a resistive plasma, that we call "magnetic reconnection", is an active area of research in astrophysical, solar, space, and laboratory plasma physics. We do not fully understand the process yet. I (and many other researchers in the field) agree, the description in terms of field lines is misleading, and a better description might emphasize flux transfer between topological domains (without at all mentioning field lines). I'm not going to say any more about this. Take Jackson, a couple plasma physics courses, and get to know the current research (both theoretical and observational) in the field of plasma astrophysics. There is a reason that 50 years of research have built this picture. Then we'll talk. —Preceding unsigned comment added by 137.79.89.69 (talk) 19:16, 29 October 2009 (UTC)

That field lines follow iso-contours of the vector potential is not always true.

I was making an analogy between magnetic field "lines" and contours on topographical maps. Both are always closed loops / surfaces. I should note that there is no such thing as an incompressible plasma, nor does your caveat hold in a full 4-dimensional treatment. If you account for currents and fields separately, you might say that the magnetic field is decoupled from the vector potential, and even the scalar potential, but there are mathematical reasons in the very definition of fields that such an approach must be wrong. Any approach that does not treat the motion of charges and fields as interdependent parts of a single thing is unphysical.

Magnetic induction has nothing to do with particle inertia.

Almost true, but this is just responding to another analogy - notice I said "much like inertia". The total effective intertia of the current is not just the rest-mass*velocity but the electromagnetic "inertia" in the field as well, which must be counteracted to bring the charges back to rest. The rest of your paragraph shows we don't really disagree on this point.

The point you are missing here is that both the magnetic field and the current have energy, and therefore both are substantial quantities. Maxwell's equations do not say which is the primary quantity and which is the secondary.

No, the current is primary - the relatavistic version of Maxwell's equations in geometric algebra form condenses to a single equation: the gradient of the force equals the four-vector current (Del F = J / (c * e_0). This is not a mere trick, the equation is useful in this form. Equations starting from the electric and magnetic fields will be less compact in any proper system of notation that doesn't move the complexity into special-purpose definitions, so from information / description theory (Occam's razor quantified) the current is the more fundamental entity.

We have observations of "magnetic reconnection". Movies in which you can watch the field topology change in a manner consistent with the description (i.e., the magnetic field connection between distant parcels of plasma changes).

These are simulations, not observations, and sweep some things under the rug - the full four-dimensional treatment shows that there had to be a four-current to set up the situation that is entered by hand as boundary / initial conditions in the simulation. Magnetic fields (of any sort) and currents imply each other. The magnetic fields in an electromagnetic wave may be distant in 3-D from the moving charges that created them, but in a 4-D sense, they are still touching. In the context of (real, resistive) plasma, the greater the resistance, the less the (3-D) spatial separation of currents and fields can be.

Now it is absolutely true that the phenomenon in which magnetic energy is rapidly converted to kinetic energy, heat, and particle acceleration in a resistive plasma, that we call "magnetic reconnection", is an active area of research in astrophysical, solar, space, and laboratory plasma physics. We do not fully understand the process yet. I (and many other researchers in the field) agree, the description in terms of field lines is misleading, and a better description might emphasize flux transfer between topological domains (without at all mentioning field lines).

I agree with you, but hope the description will move further towards the more physically fundamental quantities of charge and distance (currents in four dimensions). Certainly there needs to be an end to talking about magnetic field lines crossing, "terminating at a pole", or "open field lines". Enon (talk) 23:40, 30 October 2009 (UTC)

1) In *real* plasma physics and fluid/gas dynamics, "incompressibility" implies the relevant velocity field is divergence free; no matter what you are working with: a *real* gas/plasma/whatever. This follows directly from continuity (i.e., conservation of mass). 2) We absolutely have OBSERVATIONS of magnetic reconnection. If I were talking about simulations, I would've said simulations. We have observations from the Hinode, STEREO, TRACE, and SOHO missions showing reconnection in the solar corona. There are movies of the solar corona, taken with EUV and X-ray cameras on these satellites, showing the magnetic connection between distant parcels of plasma changing! You can watch it happen. It is also happening closer to home as well; at the Earth's magneto-pause and in the mageto-tail. The Aura are a direct consequence of magnetic reconnection. 3) The label "open field lines" always comes with the qualifier. In solar coronal astrophysics, we talk about open field with the caveat that the field lines that pass from the solar interior, and pass through the low-beta coronal environment into the solar wind, and closing back to the solar interior hundreds of AU away, or connecting to the interstellar, or even the intergalactic magnetic field. In the solar coronal astrophysics context, the term "closed" describes the field that closes back into the interior, remaining within the low-beta coronal environment. 4) The equation you quoted above is simply the 2 inhomogeneous Maxwell's equations repackaged into a more compact form (the other 2, homogeneous equations are wrapped up in the Jacobi identity expansion of the Faraday tensor: Fab,c + Fbc,a + Fca,b = 0). There is no new information in the equation you quoted. Maxwell's equations in the familiar form are already Lorentz invariant. Del F = Constant * J has non-trivial solutions to the source-free case (set J = 0). The simplest case are constant fields. In this case, the fields can exist without charges/currents to maintain them.

The bottom line is that magnetic reconnection is a real phenomenon. It's not pseudo-science. It's not a fundamental misunderstanding by astrophysicists. It's not a conspiracy between the best astrophysicists in the world (who went to different schools, grew up in different times, and work at different laboratories/universities all over the world) to promote some established thought. Science doesn't work that way; everybody is always questioning everybody else. —Preceding unsigned comment added by 137.79.89.69 (talk) 17:48, 2 November 2009 (UTC)

In this case, the fields can exist without charges/currents to maintain them

LOL

The real world disagrees with your claims. While it may be possible to concoct a physical theory predicated on Einsteinian relativistic mechanics that supports your suppositions, unless you can demonstrate them in a lab, it's all mental masturbation.

--76.170.55.28 (talk) 07:16, 22 February 2011 (UTC)

"LOL" Maxwell's equations have source-free solutions. That's the real world, not metal masturbation. Perhaps you should take an E&M class before you speak. — Preceding unsigned comment added by 137.79.89.69 (talk) 21:57, 24 June 2011 (UTC)

THEMIS results

While editing the page on Aurora, I noticed this page had no information on the THEMIS results. I just cut n pasted my original paragraph from the THEMIS page.--Derekmcd (talk) 04:46, 7 January 2009 (UTC)

Figure

A problem with the figure is that the out-of-plane current density is marked outside of the diffusion region but not inside of it. Typically, the central parts of the diffusion region are where the current density is greatest. There should be green circled dots going through the center where the in-plane magnetic field goes to zero. Spacehippy (talk) 00:52, 12 June 2009 (UTC)

I like the new animated figure! However, it would be good to show that the out-of-plane current density is strongest near the X-point rather than constant along the outflow direction. The ideal $-\mathbf {V} \times \mathbf {B}$ electric field starts to contribute as the outflow speed builds up and $\eta \mathbf {J}$ becomes less important. Spacehippy (talk) 01:47, 10 September 2009 (UTC)

Alfvén missing from article

I did a search and can't find the word "Alfvén" anywhere in the current article. Credible sources on this article list Alfvén as the originator of the phrase [Alfvén, 1976], so how can this article not include the originator of the phrase? Or is this a search error? FX (talk) 17:49, 28 August 2009 (UTC)

Not sure who your "credible sources" are, but Alfven was not the originator of the phrase "magnetic reconnection". Dungey coined the term in the 1950s. In fact, Alfven only introduced the MHD framwork into the the development of the process of magnetic reconnection. To be sure, the development of MHD was a major step forward in our understanding and description of astrophysical plasmas. But the development of the specific process that is "magnetic reconnection" in reality had very little to do with Alfven at all. In fact, the development of the process is tied to solar flares (and the term "reconnection" had come along nearly 20 yrs before this Alfven 1976 paper you speak of).

- Solar flares were described scientifically in 1859 (Carrington, MNRAS, 1859; Hodgeson, MNRAS, 1859)

- First pictures were taken by Hale (Hale, Astron. Astrophys., 1892)

- Magnetic fields discovered in sunspots (Hale, ApJ, 1908a)

- Vortical flow discovered around sunspots (Hale, ApJ, 1908b)

- MHD described by Alfven (Aflven, Nature, 1942) - previously solar physics was described in terms of simply hydrodynamics.

- Observational study of solar flares: "[M]ost eruptions can be associated with particular spot groups." (Giovanelli, ApJ, 1939)

- New electromagnetic theory of solar flares. Noticed the sun spot field cancels the background field at the "neutral point". Electric fields near neutral points can accelerate particles and drive currents. "The localization of these phenomenon in the neighborhood of sunspots suggests a basis of an explanation of solar flares." (Giovanelli, MNRAS, 1947)

- Hoyle applied Giovanelli ideas to both flares and auroral phenomenon (Hoyle, Some Recent Researches in Solar Physics, 1949)

- Dungey (Hoyle's student) showed a non-zero resistivity allowed the topology of the magnetic field to change near a neutral point (Dungey, Phil. Mag., 1953). Dungey suggested this same effect applies to the earth's magnetosphere, and coined the phrase "magnetic reconnection".

- Sweet suggested a solar flare model using the Giovanelli/Dungey mechanism at the International Astronomical Union Symposium No. 6, in 1956 (Proceedings published in 1958, Electromagnetic Phenomena in Cosmic Physics)

- Parker rigorously analyzed Sweet's theory and showed the predicted rate was much too slow to explain the observed energy release rates (Parker, JGR, 1957)

- By 1963, the descriptive term "reconnection" was well entrenched within the nomenclature of the field as embodied by the article entitled, "The Solar-Flare Phenomenon and the Theory of Reconnection and Annihiliation of Magnetic Fields." Parker, E. N. 1963, ApJ Supp. Ser., 8, 177

—Preceding unsigned comment added by 141.211.231.68 (talk) 21:31, 7 September 2009 (UTC)

Alfvén isn't in the article because he never believed in this nonsense. He wrote numerous papers refuting the entire concept which mainstream science has since swept under the carpet. See the sections above for links to several of his papers that demonstrate quite clearly why the entire concept is a scientific fraud.--76.170.55.28 (talk) 08:17, 22 February 2011 (UTC)

We, the actual scientific community, have 50 years of research, and hundreds of thousands of peer-reviewed journal papers (in every one of the well-established, professional, peer-reviewed, scientific journals that deal in any way with plasmas, astrophysics, fusion, fluid dynamics, or mathematics), observing, studying, investigating, the very real phenomenon of magnetic reconnection. We have actual observations from international satellite missions observing the sun and solar wind (SOHO, TRACE, STEREO, SDO, Hinode, etc.), as well as an entire collection of Geospace and Magnetospheric missions, all showing direct (in which you can actually see the field topology change), and indirect (effects of reconnection in the plasma data) evidence of magnetic reconnection. We have laboratory experiments studying the physics of magnetic reconnection where they are measuring, and mapping the field topology evolution going on at MIT (Versatile Toroidal Facility) and Princeton (MRX Experiment) to name only two - not to mention the hundreds of magnetic-confinement fusion experiments that observe reconnection, and have to contend with the effects of reconnection-induced loss of confinement. Of course, there are also the thousands of numerical simulations, solving the equations of Maxwell, Vlasov, Boltzmann, and fluid dynamics in a self-consistent manner, all of which show the phenomenon of magnetic reconnection - whether the simulation meant to study reconnection or not. Scientists are *always* questioning one-another's conclusions, trying to reproduce one another's findings - this isn't religion! So, I think we will take the 50 years of evidence collected by the scientific community from real astrophysical observations, real laboratory experiments, as well as analytic and numerical investigations to provide the accepted picture of magnetic reconnection, over your 4 articles - regardless of who wrote them. —Preceding unsigned comment added by 137.79.89.69 (talk) 01:05, 4 March 2011 (UTC)

Dungey missing from article

According to somebody, Dungey coined the term. Yet he is missing from the article as well.

In fact Dungey and Dungey cycle are missing as well.FX (talk) 23:17, 7 September 2009 (UTC)

Though I did not write this section, the reason that Dungey is not mentioned is likely because it's not really important who coined the phrase "magentic reconnection", the article is about the process itself. In fact, E. N. Parker played a much much larger role in the development of the process over the last 40 - 50 yrs, and he is not mentioned either. The phenomenon of "magnetic reconnection" is a very active field of research today, with a whole host of folks working on understanding it - some of whom are making even larger contributions.

In my opinion "magnetic reconnection" is a terrible name for the process because it evokes thought in terms of field lines - which do not exist. At a fixed time, you can integrate as many field lines as you want. But there is no unique way to follow the dynamics of a single field line from one instant to the next, unless the evolution is ideal - but even then you are following the evolution of a parcel of plasma, always attached to the same field line. Reconnection is by definition a non-ideal (i.e., resistive) process. The process of "reconnection" can, in fact, be defined without invoking the idea of field lines at all. Noting that the field is the primary quantity, and "reconnection" couples the plasma thermodynamic properties to the magnetic field. Once the field has stressed enough to form a current sheet, the "reconnection" process relaxes the system to a lower energy state (on timescales faster than simple diffusion) through local topological changes, and dissipating the current sheet. The process converts the excess magnetic energy of the sheared field components into plasma kinetic energy, heat, and particle acceleration. Even though the connectivity between disconnected parcels of plasma (i.e., field line) changes from one fixed time to the next, the global topological structures remains intact (i.e., the picture in the main article always has 4 flux domains) - the process of "reconnection" only shifts flux between topological domains. Thus, the process of magnetic reconnection is an energy conversion process in which the magnetic energy associated with current sheets is dissipated through flux exchange between global topological domains => no reference to field lines. But we're stuck with the name "reconnection" since its inception in the 1950s. —Preceding unsigned comment added by Jkedmond (talk • contribs) 22:17, 11 September 2009 (UTC)

Adding organization

I just added a description of the Sweet-Parker model as well as shorter descriptions for Petschek reconnection and collisionless reconnection. In the first paragraph, I attempted to define reconnection without the use of magnetic field lines, as per the prior discussion. To clarify one change I made for the first paragraph: magnetic reconnection is not a description of the tearing mode instability. Rather, the tearing mode is just one of many forms of magnetic reconnection. Spacehippy (talk) 03:58, 22 January 2011 (UTC)

When the MHD approximation may be applied to a plasma of finite conductivity, magnetic reconnection most certainly IS the tearing mode (see H. P. Furth, J. Killeen, and M. N. Rosenbluth 1963, Phys. Fluids 6, 459)

In response to the above comment: Magnetic reconnection occurs very often without the tearing mode present. The tearing mode [like the plasmoid instability recently discussed by Loureiro et al. (2007)] involves the formation of a chain of magnetic islands within a current sheet. Single X-line reconnection therefore does not need to involve the tearing instability. As I understand it, Furth et al. did not make the case that all reconnection was the tearing instability, but rather just looked at the linear instability in a specific configuration. Could you explain your reasoning for the assertion that all magnetic reconnection is the tearing mode? Spacehippy (talk) 19:03, 20 December 2011 (UTC)

I only assert that within the framework of resistive MHD, reconnection is the tearing mode. In single-fluid resistive MHD, the tearing mode is the only mechanism that can break the flux as required by the definition of reconnection. All other instabilities are ideal. Yes, FKR only analyzed the linear case in an current sheet of infinite extent. Velli et al., showed that the fastest growing mode for a sheet of finite length was almost as long as the sheet itself. In addition, studies of MHD current sheet formation in low-beta plasmas found that the plasma collapse about the null-point may not grow the current sheet long enough for more than 1 (or 2) tearing mode wavelengths at the time of reconnection onset - which look like a single x-line. Of course, when you expand the physics to include multiple fluid species, and/or kinetic effects, then you expand the realm of possible of flux-breaking mechanisms as given by the generalized Ohm's Law. Loureiro et al., 2007, set a stability limit, based on steady state flow conditions, on the aspect ratio of a Sweet-Parker current sheet (L/d ~100/1); there was still a resistive mechanism assumed in order to break the flux. — Preceding unsigned comment added by 108.211.200.197 (talk) 04:00, 16 January 2012 (UTC)

There are modes of reconnection in resistive MHD that would be hard to call tearing. For example, the spine/fan modes of 3D reconnection have a very different setup than the tearing mode (see, for example, Fig 1 in the review article by Pontin 2011). We should also be careful about the definition of tearing. In the communities I'm in (solar physics, basic reconnection physics), the term tearing applies pretty specifically to cases where islands form in a current sheet. In particular, most of the people I work with would not describe single X-line reconnection as being a manifestation of tearing. Spacehippy (talk) 18:29, 19 January 2012 (UTC)

Edmondson et al., 2009 and 2010a and 2010b, Pariat et al., 2010, or any one of Lynch et al. "breakout simulations" all showed that in fully-3D, fully-dynamic MHD, the stressing of the 3D null-point (spine/fan) topology exhibits the very same plasma collapse / current sheet formation predicted by Syrovatskii, 1981, and the subsequent reconnection qualitatively consistent with the MHD tearing mode. Their simulations did not include a physical resistivity model, but instead left the flux breaking mechanism to numerical dissipation, so they could not make a statement about the reconnection rate, or the fastest-growing mode. However, the simulations are perfectly valid in that the particular evolution and dynamics of the magnetic field structure, the plasma collapse, the separation of the spines, the generation of the reconnection current sheet, are governed by the large-scale Lorentz stresses given by the line-tied boundary motions. The actual amount of separation depends on the specifics of the dissipation mechanism (and in the case of simulations, the numerical scheme applied; an MHD code's ability to hold a magnetic current sheet is in some sense analogous to a shock-capturing hydrodynamic code). A system with relatively high dissipation will exhibit relatively-small spine separation, and a system with relatively low dissipation will show a relatively large spine separation. In general though, what looks like 3D null-point reconnection, is always accompanied by a plasma collapse / current sheet formation as predicted by Syrovatskii, if even very small. And as I pointed out above, Velli et al., 1990, showed that the fastest growing mode in a sheet of finite length is nearly as long as the sheet, thus only one (or possibly two) x-points occur along the length; in other words, you're not going to see a series of repeating x and o points in a sheet of finite length; that is an artifact of the infinite slab assumption. — Preceding unsigned comment added by 141.212.197.128 (talk) 22:56, 19 January 2012 (UTC)

For inclusion of this statement in the article, Wikipedia requires verifiability and no original research. To include the above assertion in the article, there should be a citation for a source that specifically says something very similar. If we have to do significant interpretation, that would fall under the category of original research. Spacehippy (talk) 18:29, 19 January 2012 (UTC)

This article has been lacking organization, and with these changes it is now only *mostly* disorganized. If you add things, please add them within new or old section headings. It would be good to add figures for Sweet-Parker reconnection, Petschek reconnection, and two-fluid reconnection. There should be more discussion of reconnection in solar flares, as well as the evidence that reconnection occurs during these events (cusp-like structures, observations of downflows, etc.). What is there about Petschek and two-fluid/collisionless reconnection needs to be expanded, corrected, and cleaned up (including my contributions). I have studied reconnection in the context of solar physics and laboratory plasmas, so it would be helpful for others besides me to fix up the parts on reconnection in space plasmas and the magnetosphere. Spacehippy (talk) 03:58, 22 January 2011 (UTC)

How about we just mark this whole article as pseudo-science instead, since any theory that proposes magnetic reconnection is obviously in violation of Maxwell's equations and Kirchhoff's circuit laws. Any model that does not conform to the known laws of physics must be regarded as pseudo-science. Regardless of the Einsteinian justifications presented, there has never been, and never will be, verifiable proof that magnetic monopoles exist. Therefore it is impossible for any kind of "reconnection" of magnetic fields to occur. There is only exploding double layers - period. We have 4 peer reviewed papers, two of which come from Alfven himself, explaining exactly why this is so. --158.61.151.200 (talk) 00:13, 24 February 2011 (UTC)

"How about we just mark this whole article as pseudo-science instead ... We have 4 peer reviewed papers, two of which come from Alfven himself, explaining exactly why this is so."

... And we, the actual scientific community, have 50 years of research, and hundreds of thousands of peer-reviewed journal papers (in every one of the well-established, professional, peer-reviewed, scientific journals that deal in any way with plasmas, astrophysics, fusion, fluid dynamics, or mathematics), observing, studying, investigating, the very real phenomenon of magnetic reconnection. We have actual observations from international satellite missions observing the sun and solar wind (SOHO, TRACE, STEREO, SDO, Hinode, etc.), as well as an entire collection of Geospace and Magnetospheric missions, all showing direct (in which you can actually see the field topology change), and indirect (effects of reconnection in the plasma data) evidence of magnetic reconnection. We have laboratory experiments studying the physics of magnetic reconnection where they are measuring, and mapping the field topology evolution going on at MIT (Versatile Toroidal Facility) and Princeton (MRX Experiment) to name only two - not to mention the hundreds of magnetic-confinement fusion experiments that observe reconnection, and have to contend with the effects of reconnection-induced loss of confinement. Of course, there are also the thousands of numerical simulations, solving the equations of Maxwell, Vlasov, Boltzmann, and fluid dynamics in a self-consistent manner, all of which show the phenomenon of magnetic reconnection - whether the simulation meant to study reconnection or not. Scientists are *always* questioning one-another's conclusions, trying to reproduce one another's findings - this isn't religion! So, I think we will take the 50 years of evidence collected by the scientific community from real astrophysical observations, real laboratory experiments, as well as analytic and numerical investigations to provide the accepted picture of magnetic reconnection, over your 4 articles - regardless of who wrote them. —Preceding unsigned comment added by 137.79.89.69 (talk) 01:01, 4 March 2011 (UTC)

I explain exactly why those experiments are a complete joke here.

In fact, let us quote your beloved liars:

“at least half of the increased ion energy must be due to nonclassical processes, consistent with the resistivity enhancement. ” 

Please explain exactly what "nonclassical processes" are. --158.61.151.200 (talk) 19:25, 4 March 2011 (UTC)

"Non-classical processes, consistent with the resistivity enhancement" very simply means the resistive transport model required is not the classic Spitzer resistivity model derived from collisional particle kinetics arguments. —Preceding unsigned comment added by 137.79.89.69 (talk) 23:25, 4 March 2011 (UTC)

Attempts To Delete Criticism Section

Any attempt to eliminate the criticism section is wrong.

The criticism section is fully sourced and is based on the criticism of one of the most eminent plasma physicists of the 20th century.

The fact that magnetic reconnection "violates approximate conservation laws" automatically makes the entire subject open to any and all criticism.

Further, claims that this section is purely "of historical interest" are falsified by the fact that research papers published as late as 2007 have reexamined Alfven's take on magnetic reconnection. The laws of physics do not change over time.

Any attempt to eliminate the section is nothing more than scientific censorship. Whether you personally disagree with Aflven's take on reconnection or not has no bearing on his arguments being fairly represented here on wiki. A "consensus" is obviously not required to present criticism, if that was the case, there would be no criticism sections of any scientific topic in Wiki at all.

--158.61.151.200 (talk) 17:51, 18 March 2011 (UTC)

Wikipedia should not be used as a platform for one person's fringe viewpoints which do not have rigorous scientific backing. Please keep the discussion on the talk page content based. Additionally, it is not reasonable to treat magnetic reconnection as a giant conspiracy theory. The definition of the frozen in condition does need to be defined carefully, which has been done (e.g., Priest & Forbes, Magnetic Reconnection, 2000, p. 23). In ideal MHD, the frozen in condition states that if two infinitesimal parcels of plasma are threaded to the same magnetic field line at one time, the two parcels of plasma will be threaded by a magnetic field line at any later time. This does not require any concept of magnetic field line motion as criticized by Alfven and others, since it does not require the field line to be the same at either time. Spacehippy (talk) 23:09, 18 March 2011 (UTC)

Such claims are preposterous. The criticisms were leveled by a Nobel prize winning plasma physicist at a NASA symposium on astrophysical plasma. His criticisms are not "fringe science". What is fringe science is the standard theory which blatantly violates the known laws of physics, and even admits as much. Besides that, Alfven is not only criticizing the standing theory of magnetic reconnection (of which there are several - which obviously means at least one, if not all of them, are wrong), but he is also proposing his own theory, which deserves to be placed among the others for consideration.

--Michael.suede (talk) 23:12, 18 March 2011 (UTC)

Wikipedia policy states: "If a viewpoint is held by an extremely small (or vastly limited) minority, it does not belong in Wikipedia regardless of whether it is true or not and regardless of whether you can prove it or not, except perhaps in some ancillary article." I am a researcher in the field of plasma physics and astronomy. I have studied magnetic reconnection in detail for the last seven years. I can attest that the viewpoint in the section I am trying to delete is held by an extremely small minority. Alfven's hypotheses on this have not held up with the test of time, and magnetic reconnection is strongly accepted by plasma physicists and astrophysicists in general. Valid criticisms about magnetic reconnection are not whether or not it exists or obeys the laws of physics. I promise, if magnetic reconnection blatantly violated the laws of physics, the hundreds of plasma physicists, space scientists, and astronomers studying reconnection would have noticed. Rather, the importance of magnetic reconnection in various scenarios is still an open matter of debate. Laboratory evidence for magnetic reconnection is overwhelmingly strong, magnetospheric evidence is very strong, and solar evidence is fairly strong. Astrophysical evidence is less certain. After doing a websearch, I noticed this website, in which the author of this section requested others to engage in an edit war. I think it is time to call in an arbitrator. Spacehippy (talk) 01:35, 19 March 2011 (UTC)

This is not some random viewpoint. This is a peer reviewed published criticism of magnetic reconnection given by a Nobel prize winning astrophysicist at a NASA symposium. The "apparent conservation violation" is readily admitted to by astrophysicists. They have no explanation for it. This is even evident in main article itself. Further, it is not just Alfven making these criticisms. If you read the conference papers and the other papers that are referenced, you will find a large number of people supporting his view points. I am not citing some random web blog from joe blow, I am citing several sources from major physics publications.

I have to ask what is the harm done in allowing this criticism to stand? Who is harmed by this criticism? You? Your job? Why is it so vitally important to you that this criticism be removed? Does it violate the laws of physics in some way? Does it scare you to think that people might get information that they can then base their own opinions on? Encouraging others to edit wikipedia to prevent people like you from engaging in vandalism is a good thing.--76.170.55.28 (talk) 01:45, 19 March 2011 (UTC)

I was hoping to use this article as an educational tool for a student who will be working with me on a summer project. With the section you added, this article is no longer appropriate as a reference. Spacehippy (talk) 02:51, 19 March 2011 (UTC)

I tagged the article regarding factual accuracy as well as placing undue weight on matters relative to the subject matter as a whole. The two of us should let this rest, and let others comment on these concerns, and perhaps read this comic in the meantime. Spacehippy (talk) 03:11, 19 March 2011 (UTC)

• "I am a researcher in the field of plasma physics and astronomy. I have studied magnetic reconnection in detail for the last seven years."Spacehippy
• "I was hoping to use this article as an educational tool for a student who will be working with me on a summer project. With the section you added, this article is no longer appropriate as a reference." Spacehippy

Anyone who does any serious research of any topic, knows that Wikipedia is not considered a scholarly resource. The closest I personally come to using Wikipedia (which is seldom) is to find references to well-researched material. It's the last place I look, if at all. Let's hope your own seven years of study were not done using such an unreliable resource. Had you not been aware of Alfven's work until now? On any scientific topic, don't you think it is wise to offer up valid criticisms? You know, those published in peer-reviewed journals and supported (in this case) by NASA and the like. No-one is saying the criticism is correct, but it has been made, and not by some wannabe, but by one of the founding fathers of plasma physics. It at least should rate a mention if you want your student to have access to all of the facts... Davesmith au (talk) 03:54, 19 March 2011 (UTC)

Any scientific hypotheses or implied facts that are not strongly referenced must be removed, whoever added them to the article. This goes for most of the long lead section. Kudpung (talk) 12:12, 19 March 2011 (UTC)

If you actually bothered to read the reference cited, you would see that there is nothing implied or taken out of context.--Michael.suede (talk) 18:59, 19 March 2011 (UTC)

This is just standard Plasma Cosmology stuff, no? It does not belong here, as it is not taken seriously by the astrophysics community. It is not Velikovsky level, certainly, but neither did the idea pan out; a minor historical footnote, at best. Jackson (3rd ed.) does not caveat "reconnection" or "frozen in"; are there any comparable sources that do? There is really nothing wrong with violating an approximate conservation law - that is just a term for describing a relation that holds for a wide variety of physical situations, particularly if it holds for "familiar" conditions.

If we really need to keep this section (which we should not), at the very least it needs to be trimmed of the excessive quotes. The idea is fairly complex, but can be explained without importing whole sections of other works. The current section is also misleading, as it appears to present an active scientific debate where the astrophysics community gives similar weight to each side; this is not the case.

@Spacehippy - REU program? Good on you; the balance between trying to get some non-trivial result out of them without either leading them by the hand or completely swamping them is tricky. - 2/0 (cont.) 18:06, 19 March 2011 (UTC)

It does represent an active scientific debate. Did you not read the 2007 papers that were cited? The debate is not over, and it will only intensify as the current MHD models of reconnection do not explain, nor accurately predict, observations of double layer energy transfer. None of the MHD models presented can account for all observations of "reconnection", while Alfven's theory can. There is a reason why there are several models listed in the main article. It is because none of them can accurately account for all observations.--Michael.suede (talk) 19:07, 19 March 2011 (UTC)

• This section is just collection of number misquoted citations from various mainstream papers. The citations are purposefully selected to misrepresent the cited papers. The only recent paper that is critical of reconnection is by an odd electricity professor, who suddenly decided that he knows a lot about cosmic plasma (when, in fact, he seems to know very little). All other modern papers are about parallel electrical fields and their role (sic!) in reconnection. Ruslik_Zero 20:15, 19 March 2011 (UTC)

You must not be able to read very well, considering half the section is direct quotations from the papers themselves.--Michael.suede (talk) 21:32, 19 March 2011 (UTC)

I posted this edit war on both the administrators' noticeboard for edit warring and the fringe theories noticeboard and a one month block was imposed on the user in question. The behavior on this talk page (personal insults, etc.) didn't help his case. So, barring sockpuppets or anonymous edits, the current edit war is over. I will alert administrators if it continues. Spacehippy (talk) 04:12, 21 March 2011 (UTC)

The following is a list of links for the best known observational evidence for magnetic reconnection, including in laboratory, space, and solar plasmas. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29. A few thousand more peer-reviewed articles on magnetic reconnection are available at NASA ADS. Some may require journal subscriptions through, for example, a college or university, but preprints are sometimes available (unfortunately a large fraction of scientific literature is not open access). Spacehippy (talk) 21:40, 24 March 2011 (UTC)

Time to archive this talk page?

This talk page is getting extremely bulky, and is probably a good candidate for archiving. In particular, it is not helpful that this talk page turned into a flame war. There are guidelines here. Thoughts? Suggestions? Spacehippy (talk) 04:12, 21 March 2011 (UTC)

Archiving this talk page seems premature, considering the guidelines re: archiving. The discussion is not old, and is certainly not obsolete. Why the rush?Davesmith au (talk) 03:01, 25 March 2011 (UTC)

Much of the content of this talk page has been dominated by one person who thinks magnetic reconnection is a government conspiracy for scientists to get taxpayer money. It is full of personal attacks and POV pushing by someone trying to use this article as a platform to prove their fringe theory. The fraction of the comments here which are intended to help improve this article through consensus building and cooperation is appallingly low. Talk pages should be used as a tool for improving the article and coming to consensus (see the banner at the top of the page). I am of the position that archiving what is here now will significantly improve the tone and usefulness of this talk page. This discussion may not be old, but I do not feel that it contributes anything towards making this a better article. As it stands, constructive suggestions on this page are pretty well hidden. Spacehippy (talk) 04:35, 25 March 2011 (UTC)