Plasma Cosmology - Woo or not

[brantc]

Anyway, I'm glad you have backed off from the nonsensical view that reconnection somehow violates Maxwell's Equations, which IIRC was your view for a long time because you thought reconnection involved broken field lines.

It only violates Maxwells equations if you say that magnetism is providing the energy for the "reconnection" process. But since we all know that magnetism requires a current flow(see my previous post), then with this assumption it does not.

Also magnetism is a field effect so there are no lines, right? Only gradients.

And at every point that the field is changing, it is a scalar(change in amplitude at a single point) not a change in a field line.. Then you can associate a vector with 2 scalars to show the direction of gradient. But you already know that.
The field lines trace gradient contours so if you have an instantaneous change at a point in the gradient, then the calculated field line moves to reflect this but there are no physical lines reconnecting. Only magnetic gradients following the flow of current. As the current changes in amplitude the magnetic gradient changes.

 

[ben m]

It only violates Maxwells equations if you say that magnetism is providing the energy for the "reconnection" process. But since we all know that magnetism requires a current flow(see my previous post), then with this assumption it does not.

No:
a) magnetic fields arise either from current or from dE/dt, remember?
b) Magnetic field energy is indeed magnetic field energy; it's a property of the field, it is NOT a manifestation (as EU people always seem to think) of kinetic energy of the current-carrying particles, or something. Field energy density is proportional to B^2. This is freshman-level stuff; this is why a coiled inductor differs from a straight wire.

Reconnection indeed changes this magnetic field energy into particle kinetic energy.

Also magnetism is a field effect so there are no lines, right? Only gradients.

This is really funny; it's not simply wrong, it's the blunt opposite of a simple, fundamental, interesting fact which is taught in all undergrad E&M classes. It's the E&M equivalent of saying, "Reptiles have mammary glands, right?", or "Helium is a highly reactive metal, right?" No, the magnetic field is a vector field. It's a vector field with nonzero curl, so it's very specifically NOT a gradient of any scalar potential. ("Magnetic scalar potential" can be defined as a useful mathematical fiction in regions of zero current density---i.e. not in a plasma.)

 

[Reality Check]

It only violates Maxwells equations if you say that magnetism is providing the energy for the "reconnection" process. But since we all know that magnetism requires a current flow(see my previous post), then with this assumption it does not.

Magnetism is providing the energy for the reconnection process and it is not a violation of Maxwells equations. To be more exact it is not a violation of the energy conservation principle for electromagnetic fields and charges (Poynting's theorem). This states that the rate of change of the field energy in a region is the negative of the rate at which field energy is flowing out of the region minus the rate that the field is doing work on the charges in that region.

Magnetism does not always require a current flow (as in moving electric charges) e.g. ferromagnetism. In the case of the Sun and stars in general, the convective circulation of the photosphere plasma are the "current flow" creating the solar magnetic field. The solar magnetic field is twisted by differential rotation to form magnetic flux tubes. These rise through the photosphere to cause sunspots, coronal loops and flares.

There are plasma ("current") flows caused by the magnetic flux tubes. These do not create the magnetic flux tubes (they already exist).

What you are forgetting is that this is a process. It starts with energy being stored in the magnetic flux tubes during their creation. It is this energy that is being relased during solar flares.

Also magnetism is a field effect so there are no lines, right? Only gradients.

That is what everyone knows (except maybe MM!) - magnetic field lines are not physical objects. They are a visualization of the magnetic vector field.

 

[Zeuzzz]

attempt2

dunno why I called this an attempt2 as it was actually nothing to do with the first post, and if anything was entirely consistant with it.

Still think that people are flip-flopping about with this 1/r in gravity and EM equations. The fact is that although the simulations you talk about do show filamentary structures they are not of considerable enough mass to be significant and the structure is a transient structure as it has to have a starting point in time where conditions are tentatively assumed.

Cant be bothered to write it again, whats the issue with the following then;

Atronomy and Astrophysics (1999)

 

[brantc]

Reconnection indeed changes this magnetic field energy into particle kinetic energy.

brantc
Also magnetism is a field effect so there are no lines, right? Only gradients.

This is really funny; it's not simply wrong, it's the blunt opposite of a simple, fundamental, interesting fact which is taught in all undergrad E&M classes. It's the E&M equivalent of saying, "Reptiles have mammary glands, right?", or "Helium is a highly reactive metal, right?" No, the magnetic field is a vector field. It's a vector field with nonzero curl, so it's very specifically NOT a gradient of any scalar potential. ("Magnetic scalar potential" can be defined as a useful mathematical fiction in regions of zero current density---i.e. not in a plasma.)

I'm not good at math(just a lowly electronic tech for many hands on years;-) but I do know that a magnetic field around wire using the center of the wire for the origin, drops off in strength as you move outward. If you move outward and pick a point and then rotate around the origin the field does not change.
Any one spot has an amplitude. I made a line between 2 spots pointing outward. So there is a gradient from the center outward.

If there any lines anywhere, my milligauss(http://www.trifield.com/dc_magnetometer.htm) meter and all my magnetic measuring toys dont show that.


Coherent flows of electrons produce a magnetic field(actually an electron has a magnetic field so I wonder whats flowing in it???). The more coherent the group the stronger the magnetic field. At some point because of the differential between to spots (the anode and the cathode)as the current is turned up flux tubes form because the plasma cannot support the required current density. As the flows of electrons are stronger and more coherent a magnetic field forms according the right hand rule(curl- I believe the magnetic field rotates physically around the wire but cant prove it.). In an extreme case the current flow become so strong that a Bennet pinch forms "releasing a burst of radiation".

Thats all I know.

The Large Plasma Device at UCLA.
http://plasma.physics.ucla.edu/pages/gallery.html

 

[Reality Check]

dunno why I called this an attempt2 as it was actually nothing to do with the first post, and if anything was entirely consistant with it.

Still think that people are flip-flopping about with this 1/r in gravity and EM equations.

The fact is that people are not "flip-flopping" about 1/r in gravity and EM equations.
The fact is that any force that varies as 1/r^2 for a point source produces a 1/r force from a infinitely long line of particles.
FYI: both gravity and EM forces vary as 1/r^2 for a point source.

The fact is that although the simulations you talk about do show filamentary structures they are not of considerable enough mass to be significant and the structure is a transient structure as it has to have a starting point in time where conditions are tentatively assumed.

The fact is that the simulations we talk about (the Millennium Run) do show filamentary structures using the mass of the entire universe and for the lifetime of the entire universe.
They start with the condition of the universe at its beginning as shown by observations.

If you have a theory that matches the observations of the universe better than the current one then start a new thread and demonstrate that your theory is better.

We already know that plasma cosmology does not actually exist except as a collection of mostly debunked, frequently mutually exclusive theories whose only common denominator is the personal preference of each PC advocate.

Cant be bothered to write it again, whats the issue with the following then;

http://img707.imageshack.us/img707/5555/plasmaz.jpg

Atronomy and Astrophysics (1999)

What is wrong with it is that it is a image from some paper somewhere.

It looks vaguely like one of Anthony Peratt's papers.
The simple nature of the fatal flaw (his computer simulations do not match reality) puts a great deal of doubt on his expertise in cosmology and even astronomy. Citing one of his debunked papers would be quite silly of you.

Read this thread: Anthony Peratt's Plasma Model of Galaxy Formation.

Galactic plasma filaments should be easily detected.
The large electric current through them will cause synchrotron radiation. There is no evidence for this. See the forum posting Cluster-sized diffuse radio waveband synchrotron radiation and its footnote:

IMHO the movement of filaments through the intergalactic medium will cause shock waves and detectable X-rays (see below).

There is also the problem of why the filaments are not seen in studies of the mass distribution of matter within galactic clusters using gravitational lensing.
See this posting in the extremely long Plasma Cosmology - Woo or Not thread.

Galactic plasma filaments are not stable.
The SPLASH simulation started with 2 columns that were 32 grids high and 6 wide (the grids defined the spatial extent of the simulation). The 1983 paper describing the SPLASH simulation does mention that periodic boundary conditions are imposed (this essentially makes the simulated filaments infinite in length). So it is possible that the factor of 10,000 between the filament lengths in the simulation and model is not a factor. However in my (limited) knowledge of plasma physics, long filaments of plasma are inherently unstable.

The big problem comes because galaxies are dynamic – they move. Galactic clusters also move. Galaxies collide. Galactic clusters collide. Galaxies pass each other and cannibalize each other. The filaments considered alone may be stable but I cannot see them maintaining themselves when they get close or even collide. Not only could separate filaments collide and short circuit their electric currents but a filament could even collide with itself!

The "galactic plasma filaments" are the "galactic dimensioned Birkeland currents" in your image.

 

[Reality Check]

Just to remind everyone that the question that this thread was started with has been answered since the middle of 2008:
The "plasma cosmology" as defined by Zeuzzz, BeAChooser and others is definitely a nonscientific, crackpot theory (not woo).

Zeuzzz gave one definition which resulted in "a collection of scientific theories with a common thread" definition. This common thread seems to be that the theory emphasizes the contribution of plasma in the universe and/or is a steady state cosmological theory. This collection allows the addition of any new theory that matches the criteria regardless of consistency with existing theories in the collection.

He then seemed to retract that definition (despite having contributed several theories to the collection) in favor of another (Lerner's?) definition which is hidden somewhere in the thread. I think that it is this post from 3rd July 2008. It is similar to the first definition, i.e. defines itself as non-science. Science fits theories to the data. Science does not assume that a theory is correct and go looking for data to confirm this (ignoring data that does not match or theories that better match the data).


Contrast this to the definition of the Big Bang theory:

• General Relativity (Hubble's Law, etc. which lead to an hot dense state of the universe)
• Dark matter (motion of galaxies in galactic clusters, mass distribution from gravitational lensing, etc.).
• Dark energy (measured accelerating expansion of the universe)
• Inflation (large-scale structure of the universe).

This is a consistent set of theories that best match the data.

 

[Michael Mozina]

This is dumb. Sure, the anything going on in any plasma (reconnection, or Alfven waves, or shock acceleration, or or the two-stream instability---or, heck, Faraday rotation, cyclotron radiation, dispersion, whatever) is the interaction of charges and field via Maxwell's Equations. In that sense, reconnection is "just" particles responding to Maxwell's Equations, including induction.

Indeed they are.

It's a particular aspect of these equations, describing a certain behavior under certain initial conditions. This behavior has a name, "reconnection", just as "cyclotron radiation" and "relativistic shock acceleration" and "Alfven waves" have names. Physicists are not so childish as to insist that all of these names be ignored because they're "just Maxwell's Equations".

In physics (and all branches of science) the specific use of proper terms is critical to being able to communicate, particularly across multiple branches of "science". Physicists are not that childish as a group, but astronomers in particular are indeed exactly that "childish" Ben, they are living in their own terminology world where nothing in the math relates to actual physics.

If the "change in the magnetic field topology" is all that matters, then why not call a "circuit board" a "magnetic reconnection board"? We can see the topology of the magnetic fields changing all over the board while it's in operation. A change in topology of the magnetic field is expressed (by Alfven) as a change in the circuitry. Alfven was an electrical engineer by trade and he fully appreciated the 'subtle terminologies" and inner workings of plasma. He called 'magnetic reconnection" theories of various flavors "pseudoscience" and preferred instead to express these transfers of energy from the "particle" orientation of MHD theory, whereas you are stuck in the "field" perspective of MHD theory.

If you really want to understand how a specific individual "understands" a specific theory, it's important to "go to the horses mouth". When attempting to understand MHD theory, I thought it best to learn it from the person who invented it, so I bought/read his books.

When reading his earlier works, it's clear he expressed MHD theory in terms of the "field" orientation of MHD theory. In his later works and book he explains the "particle" side of MHD theory and ties it back to particle physics theory and electrical engineering branches of science.

You folks are stuck in the first semester and never took the second semester of MHD theory. You got lazy and opted to never grasp the real physics of what goes on inside the plasma. Alfven fully understood these processes, whereas today's astronomers do not, and it's very clear they do not. Most of you if not all of you never even bothered to read Cosmic Plasma which essentially represents his "particle" explanation of MHD theory. If and when you ever get around to reading it you'll find he speaks in terms of "particles" and "circuits" and explains why your magnetic reconnection board is not a "magnetic reconnection" board it's a "circuit board" with "circuit energies" that have to be considered at the point of "reconnection".

 

[ben m]

I'm not good at math(just a lowly electronic tech for many hands on years;-) but I do know that a magnetic field around wire using the center of the wire for the origin, drops off in strength as you move outward. If you move outward and pick a point and then rotate around the origin the field does not change.
Any one spot has an amplitude. I made a line between 2 spots pointing outward. So there is a gradient from the center outward.

You're thinking of the *magnitude* of the magnetic field, and ignoring the direction. The magnetic field 1cm to the left of a wire is not the same as the magnetic field 1cm to the right---they might be the same magnitude, but they're pointing in opposite directions. Please note that the direction the field is pointing in (tangent to a circle around the wire) is NOT the same as the "gradient" direction in which the field magnitude changes (along radii closer to or further from the wire)

In other words, the magnetic field is a vector quantity. Field lines in a vector field are perfectly well-defined, and are unrelated to (and, often enough, orthogonal to) the lines you'd define by following a gradient in the magnetic field strength.

 

[Michael Mozina]

Just to remind everyone that the question that this thread was started with has been answered since the middle of 2008:
The "plasma cosmology" as defined by Zeuzzz, BeAChooser and others is definitely a nonscientific, crackpot theory (not woo).

Whereas "dark energies", dead inflation deities and "magnetic reconnection" are pure "woo".

 

[Michael Mozina]

It only violates Maxwells equations if you say that magnetism is providing the energy for the "reconnection" process. But since we all know that magnetism requires a current flow(see my previous post), then with this assumption it does not.

I read a bunch of papers before I was convinced that "magnetic reconnection theory" did not violate Maxwell's equations, and FYI some of them actually did. Birn's paper however (and then Parker's original paper) ultimately convinced me it did not violate the equations, it simply mislabeled (and misunderstood) the process which is why Alfven called it "pseudoscience". It misrepresents the process as a sterile "magnetic" process, when in fact it involves moving electrons (circuit energy), moving protons (more 'current flow'), and probably the transfer of kinetic energy from the magnetic field to other "circuits" (aka induction). They simply don't grasp the actual "physics" that goes on because to them is just a big math formula. They don't understand it because they remain willfully ignorant on this topic and all fancy themselves to know more about MHD theory than the guy that wrote it without even reading his book on the particle side of MHD theory. They are lost in their ego's, ignorant of the physics, and they (collectively) have no clue about the "circuit energy" and it's importance at the point of "reconnection".

 

[ben m]

If the "change in the magnetic field topology" is all that matters, then why not call a "circuit board" a "magnetic reconnection board"?

Because the "circuits" you draw on most circuit board are current/voltage paths (separated from each other by insulators) whose behavior is dominated by what voltages you apply where. The most straightforward way to think about how a circuit will behave is to think about which wire is at what voltage, and the behavior is determined by those voltages and by Ohms law, by voltage-dependent transistor physics, etc. You have a lot more energy in capacitors than in inductors.

In space plasma, noone is applying voltages. There are no distinct insulating patches and conductive patches. The only currents are those induced by local, changing B-fields. In many cases, no one is "applying" a B-field, either---the only B-field there is the one generated by those local, induced currents. The magnetic field energy density is comparable to the kinetic or thermal energy densities. Under these circumstances, it makes no sense to talk about circuits---(unless, MM, you're still mistakenly thinking that a "magnetic field line" is the same thing as the line of current that generates the field? I forget if it was you or Zeuzzz or BAC who was guilty of that.)---there are no wires, the wires aren't separated by insulators, there are no substantial voltage drops. It makes a lot of sense to talk about EITHER (a) the B field or (b) the induced current density plus the externally-applied B field. It make no sense to talk about voltages or Ohm's Law.

They're dual to one another, you see. If I tell you the B field, you take the curl and instantly you know the current density. If you tell me the current density, I take Ampere's Law and instantly I know part of the B field (if someone else tells be some boundary conditions I can figure out the total B field.) So, in order to competely specify the E&M conditions in a plasma, physicists find it easier to just specify the B field. It's a good degree of freedom.

 

[Michael Mozina]

Because the "circuits" you draw on most circuit board are current/voltage paths (separated from each other by insulators)

And in a plasma this occurs by a filamentation formation process that evacuates the region around the thread. You can see the "circuits" form in an ordinary plasma ball. A "magnetic rope" is simply a much larger and scaled of version of "circuit" of moving energy.

You don't understand the physics Ben. Alfven did understand it and he explained it, but none of you bothered to read it and you can't tell induction from magnetic reconnection.

The filaments in an ordinary plasma ball will move and change over time. The "change in magnetic topology'' does not create enough "magnetic reconnection energy" to drive the physical process you see inside the ball. The "circuit energy" (the stuff you can't see) is driving the process, not the "induction" caused by changes in the magnetic field topologies over time.

 

[ben m]

And in a plasma this occurs by a filamentation formation process that evacuates the region around the thread. You can see the "circuits" form in an ordinary plasma ball.

A plasma ball---like the desk toy with glowing fingers of plasma---is a high-voltage device. There's a power supply in the base supplying a large AC voltage. The filaments you see are partially ionized channels in an otherwise-neutral gas; they are indeed circuits, and they're carrying currents driven by that giant power supply; they're held as "ropes" by thermal considerations. This has nothing whatsoever to do with magnetic fields, nor induction, and less still to do with space plasmas---which, as I said, are often highly magnetized, more or less uniformly ionized, and do not have a giant high voltage electrode driving current through them.

 

[Michael Mozina]

A plasma ball---like the desk toy with glowing fingers of plasma---is a high-voltage device.

Yes, and so is the sun which is why it generates those million mile per hour "current flows".

 

[ben m]

Yes, and so is the sun which is why it generates those million mile per hour "current flows".

Mainstream astrophysics has a perfectly good magnetic acceleration mechanism for those particle flows. (They are not electrical currents since they are net charge-neutral.) I'm sorry you don't like it.

We've also been through, repeatedly, why the Sun cannot be electrostatically charged. There's no mechanism for charging it up (EU theories want electric fields to work when *repelling* charge from the Sun, but want to ignore them when bringing charge back.) Once charged, if that were doable, there would be a mechanism (which you just described) for running the charge back to zero.

But we've been through this before and I see no point doing it again.

And even if the sun WERE charged, with a long high-voltage wire feeding it charge from a bank of batteries on Proxima Centauri, its emissions would look nothing like those of a plasma globe; as I said, that filamentation is due to "runaway" heating of conducting channels in a cold neutral gas with no notable magnetic fields. Nothing like the solar corona.

 

[Michael Mozina]

Mainstream astrophysics has a perfectly good magnetic acceleration mechanism for those particle flows. (They are not electrical currents since they are net charge-neutral.) I'm sorry you don't like it.

It's not that I "don't like it", it's that it's "not true". You're essentially mislabeling an "electrical discharge" a "magnetic reconnection" event only because you see a change in the topology of the magnetic field during the discharge process. Rhessi and now Fermi have already demonstrated that discharges release gamma rays here on Earth, including annihilation signatures. We point the same equipment at the solar atmosphere and you claim "magnetic reconnection did it". Boloney.

We've also been through, repeatedly, why the Sun cannot be electrostatically charged.

More boloney. Birkeland showed that it must be which is why he "predicted" (real prediction via real experiments) high speed solar wind!

There's no mechanism for charging it up

Any energy source might do.

(EU theories want electric fields to work when *repelling* charge from the Sun, but want to ignore them when bringing charge back.) Once charged, if that were doable, there would be a mechanism (which you just described) for running the charge back to zero.

You need to read some of Alfven's work and particularly some of Birkeland's work with spheres in a vacuum.

And even if the sun WERE charged, with a long high-voltage wire feeding it charge from a bank of batteries on Proxima Centauri, its emissions would look nothing like those of a plasma globe;

They'd look just like Birkeland's "experiments" (real ones mind you) and that is exactly that they do look like.

as I said, that filamentation is due to "runaway" heating of conducting channels in a cold neutral gas with no notable magnetic fields.

Runaway heating from what? Whatever you come up with has to explain a continuous solar wind from a full sphere, 24/7, 365 days a year. Birkeland already did that with "electricity". Let's see you duplicate his with with "runaway heating".

Nothing like the solar corona.

So is it just coincidence, or ironic that he was able to create, film and "predict" 'coronal loops'?

http://www.thesurfaceofthesun.com/images/birkelandyohkohmini.jpg

 

[ben m]

It's not that I "don't like it", it's that it's "not true". You're essentially mislabeling an "electrical discharge" a "magnetic reconnection" event only because you see a change in the topology of the magnetic field during the discharge process.

No, I'm saying that there is no electrostatic voltage involved; that magnetic field lines reconnect as usual; and that energy is transferred from magnetic field energy density to particle kinetic energies.

Rhessi and now Fermi have already demonstrated that discharges release gamma rays here on Earth, including annihilation signatures.

Yes, yes: low-energy gamma rays from Earth, the big capacitor with a big insulating atmosphere and a well-known charge-separation mechanism. If there were electrostatic discharges in the Sun they would make gamma rays, but there are not.

Any energy source might do.

I was asking about charge conservation.

You need to read some of Alfven's work and particularly some of Birkeland's work with spheres in a vacuum.

Birkeland always attached a high-voltage power supply to his sphere with a wire. No one is surprised that Birkeland's sphere was charged via this wire, that it remained charged (via the wire) even though streamers flowed away from it, and no one disputes that a charged, magnetized sphere undergoes weird discharges. The Sun has no such wire.

 

[Reality Check]

Whereas "dark energies", dead inflation deities and "magnetic reconnection" are pure "woo".

Whereas dark energy, inflation and magnetic reconnection are pure science.

The dead "iron sun" deity is definitely woo.

 

[brantc]

Mainstream astrophysics has a perfectly good magnetic acceleration mechanism for those particle flows. (They are not electrical currents since they are net charge-neutral.) I'm sorry you don't like it.

We've also been through, repeatedly, why the Sun cannot be electrostatically charged. There's no mechanism for charging it up (EU theories want electric fields to work when *repelling* charge from the Sun, but want to ignore them when bringing charge back.) Once charged, if that were doable, there would be a mechanism (which you just described) for running the charge back to zero.

But we've been through this before and I see no point doing it again.

And even if the sun WERE charged, with a long high-voltage wire feeding it charge from a bank of batteries on Proxima Centauri, its emissions would look nothing like those of a plasma globe; as I said, that filamentation is due to "runaway" heating of conducting channels in a cold neutral gas with no notable magnetic fields. Nothing like the solar corona.

Honey, I Blew up the Tokamak
"August 31, 2009: Magnetic reconnection could be the Universe’s favorite way to make things explode. It operates anywhere magnetic fields pervade space–which is to say almost everywhere. On the sun magnetic reconnection causes solar flares as powerful as a billion atomic bombs. In Earth’s atmosphere, it fuels magnetic storms and auroras. In laboratories, it can cause big problems in fusion reactors. It’s ubiquitous."

see caption
"The problem is, researchers can’t explain it."
Something very interesting and fundamental is going on that we don’t really understand — not from laboratory experiments or from simulations,” says Melvyn Goldstein, chief of the Geospace Physics Laboratory at NASA’s Goddard Space Flight Center.
http://wattsupwiththat.com/2009/09/...rossed-magnetic-streams-and-magnetic-portals/