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Tags Alfven waves , Birkeland currents , hannes alfven , Kristian Birkeland

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Old 7th November 2011, 02:06 PM   #4641
Reality Check
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Originally Posted by Michael Mozina View Post
BZZT! Dungey understood that an E field was induced at that X point and that electrical discharges occur in flares. I suspect Belz does too by now. I only claim to be smarter than you, GM and Clinger.
BZZT! A high school student understands that a changing magnetic field induces an electric field.

The fact that you think that the E Field in induced at the X point indicates that you are not smarter than me (or the hyypothetical high school sudent) at least. The X point is where the B field is zero and unchanging.

Dungey never stated that "electrical discharges occur in flares". Once again you have forgotten about the context. Dungey stated that "electrical discharges (high current densities) occur in MR which is a cause of flares".
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Old 7th November 2011, 02:08 PM   #4642
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Originally Posted by Michael Mozina View Post
The denial-go-round continues. Round and round and round you go, where you'll stop, nobody knows.
The lying-go-round (quote mining) continues. Round and round and round you go, where you'll stop, nobody knows.
Originally Posted by Reality Check View Post
GeeMack was correct: There is no electrical discharge processes involved in solar filament eruptions and CMEs.
Whenever someone just states 'electrical discharge' this is the usual definition of electrical discharge that is impossible in plasma.
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Old 7th November 2011, 02:08 PM   #4643
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Originally Posted by Reality Check View Post
How insane, MM - There is definitely connection:


The only ASSUMPTION is that in order for 2 loops to become 1 they have to merge somehow, i.e. the two loops break. This has been described for 50 years now as a breaking of the magnetic field lines.
No RC. Dungey describes an INDUCED E field at the X point, followed by an electrical discharge. It's still an INDUCTION process as it relates to the release of stored magnetic field energy. No B field lines make or break connection. They simply "bend" and "twist" and create "magnetic flux" that induces an E field in ANY conductor, including plasma. You STILL don't "get it".
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Old 7th November 2011, 02:09 PM   #4644
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Originally Posted by Michael Mozina View Post
Your agreement must mean that you have *FINALLY* realized your error and that you now agree that electrical discharges can and do occur in plasma and in solar flares. Furthermore you agree that no B field lines actually disconnect or reconnect, correct, it's an INDUCED E field that releases the energy?

The attempt to dishonestly misrepresent my comment is noted. My position is, for the most part, aligned with Dungey's in that magnetic reconnection appears to be a reasonable explanation as the driver of solar flares and coronal heating. Dungey didn't use the term "magnetic reconnection" ambiguously, and he didn't equate it with "electrical discharge". He called it magnetic reconnection because that's what it is.
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Old 7th November 2011, 02:15 PM   #4645
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Originally Posted by Michael Mozina View Post
Ya know.....

I really don't "get" you. You personally have the credentials *AND* the knowledge to have explained the INDUCED E field at that x point and the electrical discharges to this crew anytime you chose/choose to do so (still could). Why haven't you FIXED this mess yet? When did you intend to do so?
I cannot fix the mess you are making. The whole book by Somov is full of reconnecting magnetic B field lines.

The acceleration in the current sheet in the E0 direction as you may see in Chapter 6 "Models of Reconnecting Current Layers" where the following intro is given:

Originally Posted by Somov
Reconnection in cosmic plasma serves as a highly efficient engine to convert magnetic energy into thermal and kinetic energies of plasma flows and accelerated particles. Stationary models of the reconnection in current layers are considered in this Chapter. Properties of a stationary current layer strongly depends on a state of plasma turbulence inside it.
Look at figure 6.1 where there is the inflow of the B field lines from top and bottom to the current sheet (however stationarity is assumed, so basically any momentary snapshot will look the same). Now look at the direction of the electric field in that figure, it is coming out of the figure, that is what the circle means, and any accleration processes that are discussed with respect to that electric field are in that direction. Now look at the outflow region of the reconnection on the left and the right side of the current sheet. Where is that directed? That is directed to the left and to the right, driven by the magnetic tension of the field, that you could have read about in the chapters before this one.

So, basically, as usual, you have read the book with your pink EU glasses on and have not understood a word of what you have read, but only interpreted small parts of the book that may have looked like they fitted you predefined assumptions about your "circuit/current/magnet" reconnection or whatever new word you may come up with, and you ran with it, like a child with scissors in its hands.

Point is that Somov shows clearly the mainstream reconnection of B field lines in the first chapters, and in chapter 6 is discussing what is/can happen in the current sheet that has to be present between two regions of oppositely directed magnetic fields.

If you "disagree", I want a *FULL DESCRIPTION* of *WHY* you "disagree" and how you actually see the processes that you think Somov is describing. No more platitudes, you have to *EXPLAIN* to us *EXACTLY* how you see things and "interprete" things that you have read in Somov.

Do the work Mikey, or is it *TOO DIFFICULT* for you?
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Old 7th November 2011, 02:18 PM   #4646
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Originally Posted by GeeMack View Post
The attempt to dishonestly misrepresent my comment is noted. My position is, for the most part, aligned with Dungey's in that magnetic reconnection appears to be a reasonable explanation as the driver of solar flares and coronal heating. Dungey didn't use the term "magnetic reconnection" ambiguously, and he didn't equate it with "electrical discharge". He called it magnetic reconnection because that's what it is.
You two are still clueless by choice since neither of you has read a book on plasma physics. NO (AS IN ZERO) B OR H field lines "disconnect" or "reconnect". They FLUX. Their movement as they twist and bend inside of a conductor, INDUCES an E field at the X, which results in an "electrical discharge" in plasma. Wake up and smell the coffee. You, RC and Clinger need to do some actually reading of an actual plasma physics textbook. All three of you are still utterly clueless and all three of you still seem to think B field lines "disconnect" and "reconnect"! Dungey was a brilliant man, but he underestimated the power of a willful, angry ignorance. Bad choice of names. Wow, have I paid a HUGE price for that word "reconnection' in terms of time spent educating ignorant EU HATERS!

Last edited by Michael Mozina; 7th November 2011 at 02:19 PM.
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Old 7th November 2011, 02:25 PM   #4647
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Originally Posted by Michael Mozina View Post
No RC. Dungey describes an INDUCED E field at the X point, followed by an electrical discharge.
No MM.
Dungey describes an changing magnetic field (MR). That changing magnetic field INDUCES an E field everywhere except at the X point where the B field is zero and unchanging, followed by an "electrical discharge" which in modern terms is a high current density.

So when we refer to Dungey's 60 year old paper, we can use "electrical discharge" because he used the term.
But modern solar flares have high current densities. Trying to call these "electrical discharges" is outdated as calling an electron a corpuscle (Thompson's term for an electron in an atom).
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Old 7th November 2011, 02:27 PM   #4648
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So RC, do B field lines disconnect and reconnect or just flux? Is an E field *INDUCED* at the X point? Is the result an "electrical discharge in plasma"?

Last edited by Michael Mozina; 7th November 2011 at 02:28 PM.
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Old 7th November 2011, 02:34 PM   #4649
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Originally Posted by tusenfem View Post
I cannot fix the mess you are making. The whole book by Somov is full of reconnecting magnetic B field lines.
Ah, it actually is a conceptual/knowledge problem evidently. PS's error, followed by RC's error (followed by your error) provides valuable insight into the actual conceptual problem. Thanks for that. I mean that.

Somov is working in "current carrying" plasma (as least in my book). The "reconnection" he's describing at the X point is an INDUCED E field followed by CURRENT. The term "reconnection" is sloppy when looking at B field lines that have no beginning or ending, but can bend and twist like Gumby. That FLUX will in fact INDUCE current, but no B lines need to be broken or reconnected. The only thing that has to occur in a plasma to induce an E field is FLUX, not RECONNECTION. All of you share a common misconception, apparently even you tusenfem. Flux is not the same as reconnecting B lines. Somov describes INDUCED E field and current and current sheets. Chapter 16 is devoted to explaining the process (mostly verbally) from the E orientation.

No B field lines actually "reconnect", there is just "flux" which you can "reconnect" with a charged particle via INDUCTION.

Last edited by Michael Mozina; 7th November 2011 at 02:35 PM.
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Old 7th November 2011, 02:54 PM   #4650
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Originally Posted by Michael Mozina View Post
Ah, it actually is a conceptual/knowledge problem evidently. PS's error, followed by RC's error (followed by your error) provides valuable insight into the actual conceptual problem. Thanks for that. I mean that.
There is no conceptual/knowledge problem.
People in this thread (except you) and thousands of scientists call magnetic reconnection this because magnetic field lines can break and reconnect.
The way I think of it is that they are undefined at the neutral point (B=0 means no magnetic field lines). So any field line that crosses the neutral point becomes undefined there ("breaks") and then becomes defined as it leaves ("reconnects").

Somov is working in plasma - all plasma carries current so "current carrying plasma" is redundant.

The "reconnection" he's describing at the X point is magnetic reconnection as he states.
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Old 7th November 2011, 02:57 PM   #4651
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Originally Posted by Reality Check View Post
The "reconnection" he's describing at the X point is magnetic reconnection as he states.
Dungey describes the process you're calling "magnetic reconnection" as an INDUCED (not reconnected) E field, followed by an ELECTRICAL discharge (tons of current). Was he correct? Yes or no? There's absolutely no need for B line "reconnection" when a simple "flux" in plasma works fine to explain INDUCED E fields RC. You lose by a simple Occum's razor argument.

Last edited by Michael Mozina; 7th November 2011 at 02:59 PM.
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Old 7th November 2011, 03:04 PM   #4652
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Originally Posted by Michael Mozina View Post
So RC, do B field lines disconnect and reconnect or just flux? Is an E field *INDUCED* at the X point? Is the result an "electrical discharge in plasma"?
So MM:
  • B field lines disconnect and reconnect as stated by scientists in thousands of publications (e.g. Somov).
  • An E field is *NOT INDUCED* at the X point (B=0 and unchaging).
  • The MR induces an E field away from the X point (where B is not zero and changes).
  • That E field accelerates charged particles. There is no "electrical discharge" at all.
What the magnetic fields do is squeeze plasma into a smaller area.This squeezing creates a high current density.

And that is it ... unless you cite old papers like Dungey where Dungey's 'electric discharge' = high current density in magnetic reconnection.
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Old 7th November 2011, 03:04 PM   #4653
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PS....

In retrospect PS, "Thank you". I really didn't understand the idea that you were trying to convey until near the end of our conversation when I finally realized that you were confusing "bending and twisting" of the magnetic field lines (magnetic flux) with 'B field line reconnection'. Once RC made the same mistake, I FINALLY understood why you folks don't "get it". You're essentially confusing magnetic FLUX with "B field line reconnection". It's a simple enough error, one addressed in that paper that I provided you with, but it seems to be a very COMMON misconception. At least now I know where the problem comes from, and I now know how to address it. In that sense at least, it was worth it.
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Old 7th November 2011, 03:18 PM   #4654
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Originally Posted by Reality Check View Post
What the magnetic fields do is squeeze plasma into a smaller area.This squeezing creates a high current density.
Wow, you got something right! How high does the current get according to Dungey?

Last edited by Michael Mozina; 7th November 2011 at 03:19 PM.
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Old 7th November 2011, 03:22 PM   #4655
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Originally Posted by Michael Mozina View Post
Dungey describes the process you're calling "magnetic reconnection" as an INDUCED (not reconnected) E field, followed by an ELECTRICAL discharge (tons of current). Was he correct?
I cannot answer because I suspect that you are misinterpreting Dungey (or just lying):
MM: cite Dungey's "'electrical discharge' that releases all that stored EM energy"

However you are displaying your ignorance once again though .
Eric Priest, Terry Forbes, Magnetic Reconnection, Cambridge University Press 2000, ISBN 0-521-48179-1, contents and sample chapter online
Quote:
Then J.W. Dungey (1953), who was a student of Hoyle, showed that such a current sheet can indeed form by the collapse of the magnetic field near an X-type neutral point, and he was the first to suggest that "lines of force can be broken and rejoined".
That is what is known now as magnetic reconnection and by 1958 that was what Dungey was calling it.

So Dungey has
  1. The collapse of the magnteic field (MR) causing
  2. An induced electrical field causing
  3. Your assertion of "tons of current".
Can we take that this is you stating that solar flares are caused by
  1. The collapse of the magnteic field (MR) causing
  2. An induced electrical field causing
  3. Your assertion of "tons of current".
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Old 7th November 2011, 03:22 PM   #4656
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Originally Posted by Reality Check View Post
That E field accelerates charged particles. There is no "electrical discharge" at all.
Care to walk Belz and me through that particular rationalization? Of course it's an 'electrical discharge' RC. Dungey used the term "electrical discharge" EXPLICITLY. You're basically in denial of the words he actually used and the math, and the whole ball of wax! Nothing like pure denial. You're a tough nut to crack RC. I've seen creationists evoke denial before, but not to such EPIC (literally solar flare) proportions.
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Old 7th November 2011, 03:30 PM   #4657
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Originally Posted by Reality Check View Post
And a bit of ignorance: Dungey had little to with the namimg of MR. The name came from Parker (1957).
Whoops - made a small mistake there.
It was Parker (1957) who first used reconnection in the context of magnteic field lines.
It was Dungey who was influential in popularizing the term magnetic reconnection in his 1958 book "Cosmic Electrodynamics".
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Old 7th November 2011, 03:39 PM   #4658
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Originally Posted by Michael Mozina View Post
Care to walk Belz and me through that particular rationalization? Of course it's an 'electrical discharge' RC.
So the LHC which accelerates charged particles is an electrical discharge ?
It is a fact: When a particle is accelerated by an E field, we call it an accelerated particle (general case).
If it is the breakdown of a dielectric medium that allows the particle to be accelerated by an E field, then we call this an electrical discharge (Anthony Peratt's definition of electrical discharge).

Originally Posted by Michael Mozina View Post
Dungey used the term "electrical discharge" EXPLICITLY.
How idiotic, MM: I know Dungey used the term "electrical discharge" EXPLICITLY. I have been agreeing with you about this for months.

Originally Posted by Michael Mozina View Post
You're basically in denial of the words he actually used
You're in total denial of the meaning and context of the words he actually used: Dungey's 'electric discharge' = high current density in magnetic reconnection.
Modern papers do not use this term.

Last edited by Reality Check; 7th November 2011 at 04:53 PM.
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Old 7th November 2011, 03:48 PM   #4659
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Hey Clinger, did you ever finish that freshman homework assignment?
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Old 7th November 2011, 04:06 PM   #4660
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Originally Posted by Reality Check View Post
There is no conceptual/knowledge problem.
People in this thread (except you) and thousands of scientists call magnetic reconnection this because magnetic field lines can break and reconnect.
The "people" in this thread that actually believe that are the biggest EU HATERS left standing (if you can call you and GM "still standing"). I'll give t a pass here because in his case I'm certain it's an "honest" mistake. In your case however, and in GM's case, your opinions are born of pure ignorance and laziness, so no pass for you two.

Quote:
The way I think of it is that they are undefined at the neutral point (B=0 means no magnetic field lines). So any field line that crosses the neutral point becomes undefined there ("breaks") and then becomes defined as it leaves ("reconnects").
That's a nice way to "think about it" I guess, but it's wrong! E fields in plasma are induced by MAGNETIC FLUX, not 'magnetic reconnection".

Quote:
Somov is working in plasma - all plasma carries current so "current carrying plasma" is redundant.
Not necessarily. It is theoretically possible to have a plasma that isn't in a current carrying state.

Quote:
The "reconnection" he's describing at the X point is magnetic reconnection as he states.
It's also an ELECTRICAL DISCHARGE as Dungey explains. It's also the result of an INDUCED E field. All that is required to induce the E field is FLUX, not 'reconnection". You, PS and tusenfem are all making the exact same mistake. You're confusing "bending", "twisting" and "fluxing" of the magnetic field with "B field line reconnection".

Last edited by Michael Mozina; 7th November 2011 at 04:08 PM.
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Old 7th November 2011, 04:44 PM   #4661
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a simple derivation of magnetic reconnection, part 3

To review the derivation so far:
  1. part 1 and its erratum used one of Maxwell's equations to derive the magnetic field B around a current-carrying rod.
  2. part 2 expressed that magnetic field in both cylindrical and Cartesian coordinates.
Both of those results are often found within introductory textbooks.

In this part of the derivation, we go beyond introductory textbooks by showing that the magnetic field around four current-carrying rods reproduces
We will show that this particular magnetic field is a counterexample to three myths that are often repeated by people who don't understand magnetic fields and their associated mathematics.

In part 4, I will describe a simple variation of the experiment I've been suggesting to Michael Mozina and prove that the topology of the magnetic field changes during that experiment. As Yamada et al explain in their appendix, that change in the topology of the magnetic field is what we mean by magnetic reconnection.


The physical experiment

We may as well assume the experiment will be run in a perfectly shielded room that contains a perfect vacuum. (We needn't worry about the expense, because Michael Mozina isn't going to run this experiment anyway.)

We position four vertical conducting rods in parallel, each exactly one meter away from the origin of our coordinate system. One rod will be exactly one meter to the west of the origin, another will be exactly east of the origin, one will one meter north, and the other rod will be one meter south.

Sparing no expense, we will run 1000 amperes of well-regulated direct current through each rod. That current will run upward through the west and east rods, but will run downward through the north and south rods. By symmetry, the magnetic field will look the same in any plane that intersects the four rods at a right angle. We will view that magnetic field from above.


Magnetic field around a single rod at the origin

In part 2 of this derivation, we calculated the magnetic field around a single rod positioned at the origin. As everyone who has passed a freshman-level course in electromagnetism should know, that magnetic field looks like this:



The colors in that graph reveal the intensity of the magnetic field. The current-carrying rod is at the center of the white disk, with the current travelling toward you out of the xy plane you're viewing. The disk is white because I'm using white to indicate the most intense parts of a magnetic field. The intensity of the magnetic field decreases as you travel away from the rod, so you can infer the color scale I'm using from the graph above. I'm using black to indicate the least intense parts of a magnetic field.

The gray lines show a few of the uncountably infinite number of magnetic field lines. The arrows show the direction of the magnetic field along each line. By using colors to show intensity and magnetic field lines to display direction, my graphs convey more information about the magnetic field than can be deduced from black-and-white graphs of magnetic field lines alone.


Magnetic field around a single rod away from the origin

We now modify our equation for the magnetic field around a rod at the origin to obtain an equation for the magnetic field around a single rod that's perpendicular to the xy plane and intersects that plane at a point p=<x0,y0>:
<br />
\[<br />
\begin{align*}<br />
\hbox{{\bf B}}^{(p)} &= \hbox{{\bf B}}^{(p)} (x, y, z, t) = \hbox{{\bf B}}^{(p)} (t) (x, y, z) \\<br />
&= \frac{\mu_0}{2 \pi} \frac{I^{(p)}(t)}{(x-x_0)^2+(y-y_0)^2}<br />
\left( - (y-y_0) \, \hbox{{\bf e}}_x + (x-x_0) \, \hbox{{\bf e}}_y \right)<br />
\end{align*}<br />
\]<br />
where ex and ey are the unit vectors in the x and y directions.


Magnetic fields around multiple rods

Applying that equation to our four rods, we define
<br />
\[<br />
<br />
\begin{align*}<br />
p_E &= \langle 1, 0 \rangle \\<br />
p_W &= \langle -1, 0 \rangle \\<br />
p_N &= \langle 0, 1 \rangle \\<br />
p_S &= \langle 0, -1 \rangle \\<br />
I_E(t) &= I^{p_E}(t) = \hbox{{1000 amperes}} \\<br />
I_W(t) &= I^{p_W}(t) = I_E(t) \\<br />
I_N(t) &= I_S(t) = - I_E(t) = - I_W(t) \\<br />
\hbox{{B}}_E &= \hbox{{B}}^{(p_E)} \\<br />
\hbox{{B}}_W &= \hbox{{B}}^{(p_W)} \\<br />
\hbox{{B}}_N &= \hbox{{B}}^{(p_N)} \\<br />
\hbox{{B}}_S &= \hbox{{B}}^{(p_S)} \\<br />
\hbox{{B}}_2 &= \hbox{{B}}_E + \hbox{{B}}_W \\<br />
\hbox{{B}}_4 &= \hbox{{B}}_E + \hbox{{B}}_W + \hbox{{B}}_N + \hbox{{B}}_S<br />
\end{align*}<br />
\]<br />
By superposition (which was the last of our five equations in part 1 and its erratrum), B2 is the magnetic field around the east and west rods when no current is flowing through the north and south rods. B4 is the magnetic field when 1000 amperes is flowing through each rod, with the north and south rods carrying their current in the opposite direction from the east and west rods.


Dungey's figure 2

B2 looks like this:



That reproduces the "figure eight" field of the second figure in [Dungey 1958]:



The magnetic field's intensity is zero at the neutral point N, which is the point at which magnetic field lines merge or separate. For a closer look at two magnetic field lines that are almost but not quite touching at the neutral point, we can zoom in:



That magnetic field gives us a counterexample to two myths about magnetic field lines.


Myth 1: magnetic field lines have constant intensity

It's easy to see that all of the magnetic field lines shown in the graph above travel through points of different colors. Since different colors indicate different intensities of the magnetic field, it is obvious that the intensity of the magnetic field varies as we follow those magnetic field lines.


Myth 2: magnetic field lines are isobars (contour lines)

Since the intensity of the magnetic field can vary as we follow a magnetic field line, magnetic field lines are not always isobars. The isobar myth comes from looking only at the simplest magnetic fields, and from trying to explain what's going on in terms that might be comprehensible to a humanities major. Contour lines are a metaphor, but that metaphor is not exact or precise.


Dungey's figure 1

Dungey's figure 1 shows a classical example of magnetic reconnection at the neutral point of an X-type magnetic field:



Because our four conducting rods are positioned symmetrically, running current through all four rods (with positive current in the east and west rods, and negative current in the north and south) gives us a more symmetrical magnetic field:



That's a graph of B4. Zooming in improves its resemblance to Dungey's figure:



Rotating the above graph by 90 degrees gives us a corrected version of figure 3a from [Yamada et al 2010]:



Note, however, that there's a mistake in that figure 3a: The arrows are reversed on the line that runs from the northwest to the southeast. Rotating my graph by 90 degrees shows the correct direction of those arrows.

We now have a clear counterexample to yet another myth.


Myth 3: Magnetic field lines can neither begin nor end

In my two colored graphs of the magnetic field around four conducting rods, there are two magnetic field lines that begin at the neutral point and two other magnetic field lines that end at the neutral point.

The magnetic field line that runs from the northeast toward the neutral point is decreasing in intensity as it approaches the neutral point, and ends completely at that neutral point. The same is true of the magnetic field line that runs from the southwest toward the neutral point.

The magnetic field line that runs from the neutral point toward the northwest begins at the neutral point. The same is true of the magnetic field line that runs from the neutral point toward the southeast.

Do these magnetic field lines violate Gauss's law for magnetism? Not at all!

I have already sketched a geometric proof that Gauss's law holds for the magnetic field generated by a single current-carrying rod. That result is confirmed by starting from its equation and calculating the divergence. By linearity, Gauss's law must therefore hold for the magnetic field around four such rods. That result can also be confirmed by starting from the equation for B4 and calculating its divergence.

The idea that Gauss's law prevents magnetic field lines from beginning or ending is a fairy tale. Gauss's law doesn't really talk about magnetic field lines at all. Gauss's law is really about certain integrals and limits.

Gauss's law for magnetism says the magnetic flux through any smooth closed surface is zero. That's true at the neutral point: Intuitively speaking, the two lines that end there are offset by the two lines that begin there.

(Those four lines have measure zero anyway, but those who know what that means will be able to confirm Gauss's law for themselves. Throughout this derivation, I've been trying to limit myself to math that sophomore physics majors should understand.)


Conclusion to part 3

J W Dungey was one of the pioneers who suggested that solar phenomena might be explained by magnetic reconnection. The two-dimensional field shown in figure 1 of [Dungey 1958] can be reproduced and understood in vacuo, with no currents or electric field at all within the region of space shown in that figure.

That magnetic field also gives us a simple counterexample to three common myths about magnetic field lines.

Dungey's X-shaped magnetic field is of fundamental importance for understanding magnetic reconnection. In part 4 of this derivation, I will prove that magnetic reconnection must occur during a simple variation of the experiment I suggested to Michael Mozina almost a year ago, on 28 December 2010.



References

[Dungey 1958] J W Dungey. The neutral point discharge theory of solar flares. A reply to Cowling's criticism. Proceedings of Electromagnetic Phenomena in Cosmical Physics, edited by Bo Lehnert. International Astronomical Union number 6, Cambridge University Press, page 135.

[Yamada et al 2010] Masaaki Yamada, Russell Kulsrud, and Hantao Ji. Magnetic reconnection. Reviews of Modern Physics volume 82, January-March 2010, pages 603-664.
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Old 7th November 2011, 04:52 PM   #4662
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Originally Posted by Michael Mozina View Post
...gibberish....I'll give t a pass here because in his case I'm certain it's an "honest" mistake. In your case however, and in GM's case, your opinions are born of pure ignorance and laziness, so no pass for you two.
That is idiotic so there is no pass for you.
A simple literature search shows that thousands of scientists use the term magnetic reconnection as I state:
Quote:
People in this thread (except you) and thousands of scientists call magnetic reconnection this because magnetic field lines can break and reconnect.
And the definition of magnetic reconnection is a change in magnetic field topology where field lines can break and reconnect.

Originally Posted by Michael Mozina View Post
That's a nice way to "think about it" I guess, but it's wrong! E fields in plasma are induced by MAGNETIC FLUX, not 'magnetic reconnection".
That is wrong. E fields in plasma are induced by CHANGING MAGNETIC FIELDS, e.g. magnetic reconnection.

Magnetic flux is a measure of the magnetic field through a surface.
Quote:
Magnetic flux (most often denoted as Φm), is a measure of the amount of magnetic B field (also called "magnetic flux density") passing through a given surface (such as a conducting coil).
A changing magnetic flux can be caused by a changing magnetic field.


So now your concept of Dungey's 'electrical discharges' are even further from the cause of solar flares
  1. Magnetic reconnection causes
  2. A changing MAGNETIC FLUX which causes
  3. A changing electric field which causes
  4. Charged particles to be accelerated.
  5. You have the fantasy that this is Dungey's 'electrical discharges'
The proper description is
  1. Magnetic reconnection squeezes plasma
  2. Current sheets get denser. This is a higher current density.
  3. Many years ago some authors called this 'high current density' 'electrical discharge'. This is no longer the case.
Originally Posted by Michael Mozina View Post
It is theoretically possible to have a plasma that isn't in a current carrying state.
No it is not. A material that 'isn't in a current carrying state' is an insulator. Plasmas are ionized. They can alway conduct.
It may be theoretically possible to have a plasma that has no currents in it, maybe an extremely thin one at a low temperature in a uniform EM field.
Astrophysical plasmas have currents in them.

Originally Posted by Michael Mozina View Post
It's also an ELECTRICAL DISCHARGE as Dungey explains.
You are lying.
Dungey never calls magnetic reconnection an ELECTRICAL DISCHARGE.

He calls the process of magnetic field lines breaking and reconnecting MAGNETIC RECONNECTION.

He calls a high current density an ELECTRICAL DISCHARGE.
Dungey's 'electric discharge' = high current density in magnetic reconnection.
Quote:
Originally Posted by D'rok
Originally Posted by Dungey (1953 paper)
A 'discharge' will be a region [of a large mass of ionized gas in a more or less complicated state of motion] in which the electrons are accelerated to high energies by the electric field, so that all the electrons are moving in the same direction with large velocities.
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Old 7th November 2011, 05:16 PM   #4663
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Excellent, thank you W.D.Clinger.

"...The isobar myth comes from looking only at the simplest magnetic fields, and from trying to explain what's going on in terms that might be comprehensible to a humanities major."
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Old 7th November 2011, 05:46 PM   #4664
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Myth 1: magnetic field lines have constant intensity
It's easy to see that all of the magnetic field lines shown in the graph above travel through points of different colors. Since different colors indicate different intensities of the magnetic field, it is obvious that the intensity of the magnetic field varies as we follow those magnetic field lines.
To my layman's sense of this, the above seems to violate Gauss's law. What am I missing?
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Old 7th November 2011, 05:48 PM   #4665
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Originally Posted by W.D.Clinger View Post
Myth 3: Magnetic field lines can neither begin nor end

In my two colored graphs of the magnetic field around four conducting rods, there are two magnetic field lines that begin at the neutral point and two other magnetic field lines that end at the neutral point.
Other than your handwavy claim, what EVIDENCE (published) do you have that ANY of those lines have a "beginning" or "ending" even if they happen to occupy the same space? Why did you (RANDOMLY?) pick THOSE TWO lines out of the whole bunch to claim those two particular lines that you selected have a "beginning" or an "ending"? As far as I can tell that's still a completely RANDOM claim.

Other than the fact they happen to occupy the same space, what makes those two particular lines so "special"?

FYI, I can't wait for the next installment when you presumably explain the kinetic energy release.

Last edited by Michael Mozina; 7th November 2011 at 06:02 PM.
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Old 7th November 2011, 05:59 PM   #4666
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Could you also explain why you have THOSE TWO CENTER magnetic lines marked differently in terms of the directional arrows in comparison to all the other magnetic lines? Every other magnetic line in your diagram is ONE DIRECTIONAL. On those two lines however, two of the arrows point into the X on one line and two arrows point out, away from the X on the other. What's up with that?

Last edited by Michael Mozina; 7th November 2011 at 06:02 PM.
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Old 7th November 2011, 06:21 PM   #4667
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Originally Posted by Michael Mozina View Post
Other than your handwavy claim, what EVIDENCE (published) do you have that ANY of those lines have a "beginning" or "ending" even if they happen to occupy the same space?
How ignorant, MM: He has every textbook published on magnetic reconnection and every paper on magnetic reconnection supporting that magnetic lines break and reconnect.

He is not hand waving. He is stating a fact.

Originally Posted by W.D.Clinger View Post
...
The magnetic field line that runs from the northeast toward the neutral point is decreasing in intensity as it approaches the neutral point, and ends completely at that neutral point. The same is true of the magnetic field line that runs from the southwest toward the neutral point.

The magnetic field line that runs from the neutral point toward the northwest begins at the neutral point. The same is true of the magnetic field line that runs from the neutral point toward the southeast.
...
There is no magnetic field at the neutral point (B=0). So there can be no magnetic field lines there.
We have two diagonal field lines that cross the neutral point.
They cannot exist at the neutral point.
They thus end & begin at the neutral point.
We may as well use the arrows pointing along the magnetic field to decide which ones end and which ones start. The field lines that go in the decreasing direction thus end at the neutral point while the other 2 begin.

These two diagonal magnetic field lines are magnetic field lines that are broken.

These two diagonal magnetic field lines are examples of an infinite number of field lines that cross the neutral point and are broken because they do not exist there.
P.S. there are an infinite number of field lines that go through any other point in the magnetic field - isn't infinity great!

Also do not get confused by the diagram having actual lines at the neutral point. This is a problem with the real world where it is impossible to zoom in an infinite amount.
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Old 7th November 2011, 06:36 PM   #4668
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Originally Posted by Michael Mozina View Post
Could you also explain why you have THOSE TWO CENTER magnetic lines marked differently in terms of the directional arrows in comparison to all the other magnetic lines?
They are not marked really differently. They merely have 2 arrows where the others have 1 in order not to obstruct the neutral point.
Originally Posted by W.D.Clinger View Post
The gray lines show a few of the uncountably infinite number of magnetic field lines. The arrows show the direction of the magnetic field along each line.
For example look the the lines at the top. See as you get closer to the center the lines get more and more curved and the bottom of the curve gets closer to the neutral point?
Now imagine drawing a field line that is much closer than width of the arrow to the neutral point. The arrow will cover the neutral point. Now repeat this with the left, right and bottom curves.

I think that you can see that the center of the diagram would be a mess.
So to clarify where the lines seem to cross, W.D. Clinger put the arrows further out.
Of course the field lines can never cross because the magnetic field = 0 at the neutral point and there are no field lines if there is no magnetic field. Thus the field lines are broken at the neutral point.
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Old 7th November 2011, 06:41 PM   #4669
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Originally Posted by Michael Mozina View Post
Certainly not. Dungey obviously had no problem with electrical discharges in plasma. Peratt has no problem with them. It's only the half dozen or so folks in this thread that are "haters".
Aside from two people, can you demonstrate that this is a majority opinion amongst relevant authorities ?
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Old 7th November 2011, 06:46 PM   #4670
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Now... if we could dispense with the name calling and sarcasm, I might actually bother to read the posts on here.
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Old 7th November 2011, 06:59 PM   #4671
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Originally Posted by Michael Mozina View Post
Could you also explain why you have THOSE TWO CENTER magnetic lines marked differently in terms of the directional arrows in comparison to all the other magnetic lines? Every other magnetic line in your diagram is ONE DIRECTIONAL. On those two lines however, two of the arrows point into the X on one line and two arrows point out, away from the X on the other. What's up with that?

Those two lines aren't really different from any of the other infinite number of lines represented by the illustration...


Well, other than at the point where they appear to cross they are about to do a little reconnecting...


Magnetic reconnection!
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Old 7th November 2011, 07:03 PM   #4672
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W.D.Clinger
Myth 1: magnetic field lines have constant intensityIt's easy to see that all of the magnetic field lines shown in the graph above travel through points of different colors. Since different colors indicate different intensities of the magnetic field, it is obvious that the intensity of the magnetic field varies as we follow those magnetic field lines.
Originally Posted by Perpetual Student View Post
To my layman's sense of this, the above seems to violate Gauss's law. What am I missing?
After thinking about this a bit more, it seems to me that the only way the above could be true and not violate ∇∙B = 0 is if the magnetic lines spread out as they decrease in intensity or concentrate as they increase in intensity. Is that it?
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Old 7th November 2011, 07:18 PM   #4673
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Originally Posted by Belz... View Post
Aside from two people, can you demonstrate that this is a majority opinion amongst relevant authorities ?
I think we'll have to decide who's a relevant authority. Dungey and Giovanellli seem like THE TWO primary instigators of this theory. Alfven "dissed" the whole concept of reconnecting B lines. He literally called it "pseudoscience". The only relevant references that I know for sure understand the issue from both the E and B orientations are Giovanelli (electrical discharge), Dungey (electrical discharge), Peratt (electrical discharge), and Somov (E induced at X, current reconnection), and the UCLA group that we were discussing earlier that explained the process using circuit theory and ordinary induction.

I can't use Alfven as authority per se, or we have to just toss out the whole concept entirely and replace it with his double layer paper instead, making it OBVIOUS that we're talking about induction and current sheet acceleration. That would be my personal preference mind you (toss out it), but Dungey's description of an E induced process that results in an electrical discharge is essentially Alfven's description of double layer transaction. I can work with it.

Last edited by Michael Mozina; 7th November 2011 at 07:29 PM.
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Old 7th November 2011, 07:33 PM   #4674
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Originally Posted by Perpetual Student
After thinking about this a bit more, it seems to me that the only way the above could be true and not violate ∇∙B = 0 is if the magnetic lines spread out as they decrease in intensity or concentrate as they increase in intensity. Is that it?
Yes!

(I'm going to go ahead and post the response I had written before you wrote the above, because it might help someone else. But you figured it out all by yourself!)

Originally Posted by Perpetual Student View Post
Quote:
W.D.Clinger
Myth 1: magnetic field lines have constant intensity
It's easy to see that all of the magnetic field lines shown in the graph above travel through points of different colors. Since different colors indicate different intensities of the magnetic field, it is obvious that the intensity of the magnetic field varies as we follow those magnetic field lines.
To my layman's sense of this, the above seems to violate Gauss's law. What am I missing?
Recall the two correct statements of Gauss's law:
  • ∇∙B=0
  • S B∙dA = 0 (where S is a smooth closed surface and dA is normal to the surface and directed outward)
The first (differential) form can be proved directly from the equation for B4 using the standard formula for calculating a divergence in Cartesian coordinates.

The second (integral) form looks harder to prove, but here's the intuitive reason it holds: Take S to be a "box" with six curved sides such that
  • the front and back sides are perpendicular to the magnetic field lines that pass through them, and
  • the other four sides are parallel to the magnetic field lines.
Let's distinguish the front and back of the box by saying the magnetic field lines enter at the back and leave at the front. That means the total flux through the box S is obtained by subtracting (the absolute value of) the flux that enters the back from the flux that leaves the front.

By construction, the field lines that leave through the front are in one-to-one correspondence with the field lines that enter through the back, so you're probably assuming that the area of the front is the same as the area of the back. That's not necessarily so, and it's necessarily not so if the field lines that enter through the back are decreasing in intensity as they travel through the box S. In that case, the area of the front is greater than the area of the back by precisely the amount needed to compensate for the fact that the magnetic field lines are weaker when they leave the front than when they enter at the back.

Once you understand what's going on with closed surfaces that have the characteristics we assumed above, you can generalize to arbitrary smooth surfaces by approximating those surfaces by sums of a whole bunch of closed surfaces that have the characteristics we assumed. (If you remember how to prove Stokes's theorem, the approximation technique is the same.)

Originally Posted by Michael Mozina View Post
Other than your handwavy claim, what EVIDENCE (published) do you have that ANY of those lines have a "beginning" or "ending" even if they happen to occupy the same space?
One of the nice things about science and math is that we can calculate for ourselves without having to search the literature to see whether some authority figure has already published the particular result we need.

That doesn't help people who don't know how to calculate. I can try to teach them how to calculate, but those who are determined not to bark math will inevitably be left behind.

Originally Posted by Michael Mozina View Post
Why did you (RANDOMLY?) pick THOSE TWO lines out of the whole bunch to claim those two particular lines that you selected have a "beginning" or an "ending"? As far as I can tell that's still a completely RANDOM claim.
I have highlighted the key phrase.

The four (not two) lines were not chosen randomly. They are the only four lines shown in Dungey's figure 1 that begin or end at the neutral point. That's a trivial calculation; if I believed you would try to understand that calculation, I'd show it to you.

As Reality Check said, there are infinitely many such lines, but each xy plane that's perpendicular to the four rods contains only 4 of them.

Originally Posted by Michael Mozina View Post
Other than the fact they happen to occupy the same space, what makes those two particular lines so "special"?
They don't occupy the same space. That too is trivial.

Originally Posted by Michael Mozina View Post
Could you also explain why you have THOSE TWO CENTER magnetic lines marked differently in terms of the directional arrows in comparison to all the other magnetic lines? Every other magnetic line in your diagram is ONE DIRECTIONAL. On those two lines however, two of the arrows point into the X on one line and two arrows point out, away from the X on the other. What's up with that?
If you're referring to the graph of B4, the four (not two) lines that begin or end at the neutral point are the only four lines in that plane that begin or end at the neutral point. All four lines are unidirectional; your belief that they are bidirectional comes from your mistaken belief that they are two lines rather than four.

If you're referring to the graph of B2, then the two magnetic field lines that appear to meet at the neutral point do not quite meet. As can be seen from the closeup when you zoom in, they are not quite touching.

On the other hand, that xy slice of B2 does have two magnetic field lines that end at the neutral point, and another two lines that begin at the neutral point, just as in the xy slice of B4. With B2, however, I chose not to display those particular lines. (With B4, the four lines that begin or end at the neutral point are straight, which makes it easier to prove they begin or end at the neutral point. With B2, the lines that begin or end at the neutral point are not straight.)

(Another addendum: GeeMack's explanation was reasonable given the finite resolution of my graphs, but my graph for B4 really does attempt to show the four magnetic field lines that begin or end at the neutral point. With finite resolution, of course, it was impossible for GeeMack to tell that from my graphs alone. He'd have to see my calculations, which I haven't posted.)

Last edited by W.D.Clinger; 7th November 2011 at 07:36 PM. Reason: added word in gray
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Old 7th November 2011, 07:34 PM   #4675
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Originally Posted by Michael Mozina View Post
I think we'll have to decide who's a relevant authority. Dungey and Giovanellli seem like THE TWO primary instigators of this theory.

James Dungey was one of the earlier physicists to work out how magnetic reconnection explains the energy release of solar flares and the heating of the corona. It would be a gross misrepresentation of his position to suggest he advocated some kind of bizarre cathode electric Sun conjecture with lightning-like solar flares.
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Old 7th November 2011, 07:36 PM   #4676
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Quote:
In my two colored graphs of the magnetic field around four conducting rods, there are two magnetic field lines that begin at the neutral point and two other magnetic field lines that end at the neutral point.
Could you explain how any magnetic B line "begins" anywhere? I can see how a MAGNET can be thought of as a "beginning" point, or more accurately the "source of" a magnet field, by how could any magnetic field "begin" in a "vacuum"?
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Old 7th November 2011, 07:37 PM   #4677
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Originally Posted by Michael Mozina View Post
Alfven "dissed" the whole concept of reconnecting B lines. He literally called it "pseudoscience".
Actually (for the umpteenth time!) Alfven "dissed" the whole concept of the inappropriate use of the the frozen concept.
ETA: He actually called it "pseudo-science" to match his calling plasma with frozen in field lines "pseudo-plasma".


The rest is your usual taking the term electrical discharge out of context:
  • Giovanelli (high current density = electrical discharge),
  • Dungey (high current density = high electrical discharge)
  • Peratt (electrical discharge = the energy release from the breakdown of a dielectric medium which is impossible in a plasma )
  • And Somov (E induced at X, current reconnection)
    Change in B induces E never at X where B never changes but away from X, standard MR change Iin B allows current sheets to reconnect.

Last edited by Reality Check; 7th November 2011 at 07:50 PM.
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Old 7th November 2011, 07:39 PM   #4678
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Originally Posted by GeeMack View Post
James Dungey was one of the earlier physicists to work out how magnetic reconnection explains the energy release of solar flares and the heating of the corona.
Yep. Too bad for you he claimed the process involved induced E fields and ELECTRICAL DISCHARGES. He rains all over your denial parade.
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Old 7th November 2011, 07:48 PM   #4679
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Originally Posted by Michael Mozina View Post
Originally Posted by GeeMack View Post
James Dungey was one of the earlier physicists to work out how magnetic reconnection explains the energy release of solar flares and the heating of the corona.
Yep.

It's good that we all agree on this. It would be a gross misrepresentation of Dungey's position to suggest he advocated some kind of bizarre cathode electric Sun conjecture with lightning-like solar flares.
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Old 7th November 2011, 07:49 PM   #4680
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Quote:
Recall the two correct statements of Gauss's law:
∇∙B=0
∮S B∙dA = 0 (where S is a smooth closed surface and dA is normal to the surface and directed outward)
The first (differential) form can be proved directly from the equation for B4 using the standard formula for calculating a divergence in Cartesian coordinates.

The second (integral) form looks harder to prove, but here's the intuitive reason it holds: Take S to be a "box" with six curved sides such that
the front and back sides are perpendicular to the magnetic field lines that pass through them, and
the other four sides are parallel to the magnetic field lines.
Let's distinguish the front and back of the box by saying the magnetic field lines enter at the back and leave at the front. That means the total flux through the box S is obtained by subtracting (the absolute value of) the flux that enters the back from the flux that leaves the front.

By construction, the field lines that leave through the front are in one-to-one correspondence with the field lines that enter through the back, so you're probably assuming that the area of the front is the same as the area of the back. That's not necessarily so, and it's necessarily not so if the field lines that enter through the back are decreasing in intensity as they travel through the box S. In that case, the area of the front is greater than the area of the back by precisely the amount needed to compensate for the fact that the magnetic field lines are weaker when they leave the front than when they enter at the back.

Once you understand what's going on with closed surfaces that have the characteristics we assumed above, you can generalize to arbitrary smooth surfaces by approximating those surfaces by sums of a whole bunch of closed surfaces that have the characteristics we assumed. (If you remember how to prove Stokes's theorem, the approximation technique is the same.)
Thanks.
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