A magnetic reconnection primer

[Michael Mozina]

This is all very well, but it is important to keep in mind that theoretical models need to be grounded in empirical work. There are two sources for empirical studies, natural phenomena themselves such as solar flares, studies by satellite missions such as YOKOH, SOHO, TRACE, Hinode etc, where the observations of the geometry and UV, soft and hard X-rays confirms that the reconnection models are progressing on the right lines, and laboratory experiments. With regard to the latter, the problem of scaling arises, in that many of the naturally occurring processes occur on linear scales and at temperatures, densities, pressures and magnetic field strengths that are difficult or impossible to reach in the lab.

This particular paragraph bears further examination.
https://phys.org/news/2006-03-machine-b ... otter.html
https://www.sandia.gov/z-machine/
Actually such temperatures, pressures and field strengths are routinely reached in labs on Earth,

But these pulsed facilities aren't designed for studying topological magnetic field changes, so are not intended for and do not study reconnection.

http://adsabs.harvard.edu/full/1958IAUS....6..135D

As far back as the 1950's, James Dungey was using the term "magnetic reconnection" and "electrical discharge" to describe solar flares. What *exactly* can't you study in the lab, and why on God's green Earth can't you even simulate a sustained planetary aurora yet in a real lab experiment based on "magnetic reconnection'?

The scale change from coronal loops (say 10^8 m) to typical high temperature pressure and magnetic field dimensions (say 10^-3 m to be generous), means that L scales as 10^-11. As temperature scales as L^0, 2-3MK is fine, but plasma pressure and magnetic field strength scales as L^-1, and the latter scaled is 10^5 T and is particularly difficult to achieve simultaneously along with the other conditions, even though it is critical.

This sounds suspiciously like "the dog ate my 3D homework for the last 100 years". How do you figure that strong fields and high temperatures are *sustained* in MRx, and why can't you show us such a process in a real lab experiment yet?

You're welcome to "scale' your models to any size that you like so long as you can get a "scaled down" version to produce a few sustained working simulations as has been true for circuit theory for more than a full century and counting.

[GaryN]

Comparison of current disruption and magnetic reconnection
https://link.springer.com/article/10.11 ... 015-0031-2

[Higgsy]

I'll just leave this here. It is not, by any means the last word on the subject but it's a reasonable step.

Yang, K.E., Longcope, D.W., Ding, M.D. et al. Observationally quantified reconnection providing a viable mechanism for active region coronal heating. Nat Commun 9, 692 (2018), here

It also has links to other related papers.

[Michael Mozina]

I'll just leave this here. It is not, by any means the last word on the subject but it's a reasonable step.

Yang, K.E., Longcope, D.W., Ding, M.D. et al. Observationally quantified reconnection providing a viable mechanism for active region coronal heating. Nat Commun 9, 692 (2018), here

It also has links to other related papers.

And sadly and predictably, this "magnetic reconnection" claim *does not actually work* in a real laboratory experiment, and it doesn't not produce a full sphere working solar corona.

https://www.youtube.com/watch?v=m58-CfVrsN4

A full century ago circuit theory was shown *in a real laboratory experiment* to explain the solar heating "problem", a feature of the solar atmosphere which the mainstream still can't agree on. It also produces "strahl" electrons, planetary aurora, etc. Of course, like everything else in mainstream mythology, their models only work on paper, and they don't do squat in a real experiment in terms of explaining a *sustained* particle acceleration process.

Somewhere along the way astronomers *forgot* the value of actual laboratory experiments, and now they're a century behind in the lab and counting.

From the paper:

Nevertheless, it is not yet clear what fraction of the energy flux carried by Alfvén waves can be dissipated in the corona by any of the mechanisms proposed.

It was clear to Alfven that the answer was *zero*. He called the whole concept "pseudoscience".

And of course we're right back to the key problem with all mainstream claims, specifically *none of it works in a real laboratory experiment*.

[Higgsy]

And sadly and predictably, this "magnetic reconnection" claim *does not actually work* in a real laboratory experiment, and it doesn't not produce a full sphere working solar corona.

https://www.youtube.com/watch?v=m58-CfVrsN4

A full century ago circuit theory was shown *in a real laboratory experiment* to explain the solar heating "problem", a feature of the solar atmosphere which the mainstream still can't agree on. It also produces "strahl" electrons, planetary aurora, etc. Of course, like everything else in mainstream mythology, their models only work on paper, and they don't do squat in a real experiment in terms of explaining a *sustained* particle acceleration process.

I have lost count of the number of times Michael has repeated the same erroneous thing. He's like a stuck record. No-one, no-one has ever, ever modelled a full solar corona with realistic physical processes in the lab (and I doubt that anyone ever will). In the other thread, we are seeing how far from reality Birkeland's experiment was. It is quite clear, knowing what we know today, that the Sun is not charged to 600MV; and indeed because the solar wind is net neutral the Sun cannot have any negative static charge at all. The claim that the solar processes can be explained by a static charge at the Sun is trivially and obviously wrong, and pop goes the basic premise for Birkeland's solar theory and for the SAFIRE experiments.

As for circuit theory, it is also trivially obvious that on its own it is insufficient to explain the complex processes going on in the heating of the corona and the production of the solar wind, because it deals only with scalar quantities (charge, magnitude of current, resistance, inductance, capacitance, voltage sources), it doesn't deal with vector quantities or vector fields or thermodynamics or fluid flow, or, indeed gravity, all of which are critical to the processes throughout the Sun. Pop goes that repeated and utterly erroneous claim of Michael's. In fact it is trivial and obvious that the Birkeland and SAFIRE models of the Sun are completely wrong at the most fundamental level.

From the paper:

Nevertheless, it is not yet clear what fraction of the energy flux carried by Alfvén waves can be dissipated in the corona by any of the mechanisms proposed.

It was clear to Alfven that the answer was *zero*. He called the whole concept "pseudoscience".

You do realise that statement in the paper was about the mechanisms (resonant absorption and phase mixing) for converting Alfven wave energy into heating the corona, and not about reconnection at all, don't you? You're clearly having reading comprehension problems if your claim is that Alfven called Alfven waves pseudoscience, quite apart from your statement being based on the Blessed Alfven fallacy.

You're so eager to diss anything to do with magnetic reconnection, that you can't even be bothered to read the paper properly, and what you do read, you don't understand.

[Solar]

Try this experiment involving plasma dynamics. See: Magnetic Field Line Reconnection Experiment. It contains:

Electric fields
Current sheets
Actual plasma
Return currents
Induced currents
Microwave emission
Ion acceleration via electric field
Voltage drop at cathode sheath where electrons are accelerated
Electron beam-plasma instabilities (turbulence)
Current disruptions (preferable term some would argue)
Double Layer formation
“Particles are accelerated by electric fields, not magnetic fields.”
Langmuir probe (and shortcomings of same)
Whistler mode
No free parameter

One of the references at the bottom of the page leads to:

Magnetic Field Line Reconnection Experiments 5. Current Disruptions and Double Layers: R. L. STENZEL, W. GEKELMAN, AND N. WILD JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 88, NO. A6, PAGES 4793-4804, JUNE 1, 1983

The above paper from 1983 seems to complement the link posted by GaryN ...

Comparison of current disruption and magnetic reconnection A. T. Y. Lui: Geoscience Letters 
volume 2, Article number: 14 (2015)

[Michael Mozina]

Try this experiment involving plasma dynamics. See: Magnetic Field Line Reconnection Experiment. It contains:

Electric fields
Current sheets
Actual plasma
Return currents
Induced currents
Microwave emission
Ion acceleration via electric field
Voltage drop at cathode sheath where electrons are accelerated
Electron beam-plasma instabilities (turbulence)
Current disruptions (preferable term some would argue)
Double Layer formation
“Particles are accelerated by electric fields, not magnetic fields.”
Langmuir probe (and shortcomings of same)
Whistler mode
No free parameter

One of the references at the bottom of the page leads to:

Magnetic Field Line Reconnection Experiments 5. Current Disruptions and Double Layers: R. L. STENZEL, W. GEKELMAN, AND N. WILD JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 88, NO. A6, PAGES 4793-4804, JUNE 1, 1983

The above paper from 1983 seems to complement the link posted by GaryN ...

Comparison of current disruption and magnetic reconnection A. T. Y. Lui: Geoscience Letters 
volume 2, Article number: 14 (2015)

Well, let's see how this 'magnetic reconnection' experiment works, shall we?

This had started in small, fast pinch-type plasmas.

So originally they require "pinch-type" plasma, of the current carrying kind. It seems like UCLA's concepts are going to require a cathode.

Ah yes:

We start with a brief description of the plasma device. Fig. 1a shows a picture of the device which is also shown schematically in Fig. 1b. The heart of the device is a 1m diam hot cathode which produces a dense (1012 cm-3), uniform plasma in a weak axial guide field (10 G) and provides for a large emission current to produce a strong current sheet.

So the heart of this 'magnetic reconnection' device is a cathode, and electric fields, large emission current and strong current sheets. So what's causing the particle acceleration?

Particles are accelerated by electric fields, not magnetic fields. Thus it is important to measure E.

Interesting.

So essentially Higgsy, even though your "experiments" with 'reconnection" begin and end with a cathode and electric fields to accelerate the particles, you're now trying to remove the cathode sun, and the field that makes the whole thing possible to start with? Um, notice a problem?

[JP Michael]

So essentially Higgsy, even though your "experiments" with 'reconnection" begin and end with a cathode and electric fields to accelerate the particles, you're now trying to remove the cathode sun, and the field that makes the whole thing possible to start with? Um, notice a problem?