From the Southwest Research Institute:
For immediate release
San Antonio — Sept. 29, 2010 — The unusual “knot” in the bright, narrow ribbon of neutral atoms emanating in from the boundary between our solar system and interstellar space appears to have “untied,” according to a paper published online in the Journal of Geophysical Research.
Researchers believe the ribbon, first revealed in maps produced by NASA’s Interstellar Boundary Explorer (IBEX) spacecraft, forms in response to interactions between interstellar space and the heliosphere, the protective bubble in which the Earth and other planets reside. Sensitive neutral atom detectors aboard IBEX produce global maps of this region every six months.
Analyses of the first map, released last fall, suggest the ribbon is somehow ordered by the direction of the local interstellar magnetic field outside the heliosphere, influencing the structure of the heliosphere more than researchers had previously believed. The knot feature seen in the northern portion of the ribbon in the first map stood apart from the rest of the ribbon as the brightest feature at higher energies.
While the second map, released publicly with the just-published paper, shows the large-scale structure of the ribbon to be generally stable within the six-month period, changes are also apparent. The polar regions of the ribbon display lower emissions and the knot diminishes by as much as a third and appears to “untie” as it spreads out to both lower and higher latitudes.
“What we’re seeing is the knot pull apart as it spreads across a region of the ribbon,” says Dr. David J. McComas, IBEX principal investigator and an assistant vice president at Southwest Research Institute in San Antonio. “To this day the science team can’t agree on exactly what causes the knot or the ribbon, but by comparing different sky maps we find the surprising result that the region is changing over relatively short time periods. Now we have to figure out why.”
As the IBEX spacecraft gathers a wealth of new information about the dynamic interactions at the edge of the solar system — the region of space that shields our solar system from the majority of galactic cosmic ray radiation — the IBEX team continues to study numerous theories about the source of the ribbon and its unusual features.
The paper, “The evolving heliosphere: Large-scale stability and time variations observed by the Interstellar Boundary Explorer,” by D.J. McComas, M. Bzowski, P. Frisch, G.B. Crew, M.A. Dayeh, R. DeMajistre, H.O. Funsten, S.A. Fuselier, M. Gruntman, P. Janzen, M.A. Kubiak, G. Livadiotis, E. Mobius, D.B. Reisenfeld, and N.A. Schwadron, was published online Sept. 29 in the American Geophysical Union’s Journal of Geophysical Research.
IBEX is the latest in NASA’s series of low-cost, rapidly developed Small Explorers space missions. Southwest Research Institute in San Antonio leads and developed the mission with a team of national and international partners. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the Explorers Program for NASA’s Science Mission Directorate in Washington.
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h/t to Dr. Leif Svalgaard, who offers us a look at the paper here
Post Scipt:
The THEMIS arrayed multiple satellite probe collects raw data as it intercepts the body of plasma it’s set to observe & measure, then the scientists analyse & interpret the collected raw data.
The analysis & interpretation converts the raw data into a spatial & temporal three dimentional map of the body of plasma, specifically, the location, direction, and velocity of the charged particles. Plus the rate of acceleration of the charged particles and, the location, direction, and velocity of those accelerated charged particles. And, the magnetic fields, electric fields, and electric currents (free electrons & ions) associated with the movements of those charged particles.
The spatial & temporal three dimentional map , thus created, of the physical dynamics of that body of plasma is the map of the “rest frame” of that body of plasma.
Just as when a scientist in his plasma laboratory creates a three dimentional map of the physical interactions of a plasma body, the scientist is creating a map of the plasma in the “rest frame”.
Pochas:
It should be noted that the free electrons & ions in a body of plasma can move at the same speed without “shorting out” and becoming neutral atoms as long as the required critical ionization velocity of the free electrons & ions is exceeded by those free electrons & ions.
Wikipedia entry for critical ionization velocity:
“Critical ionization velocity (CIV, also called Critical velocity, CV) is the relative velocity between a neutral gas and plasma (an ionized gas), at which the neutral gas will start to ionize. If more energy is supplied, the velocity of the atoms or molecules will not exceed the critical ionization velocity until the gas becomes almost fully ionized.”
http://en.wikipedia.org/wiki/Critical_ionization_velocity
Of interest, Hannes Alfven, 1970 Nobel prize winner in physics, predicted critical ionization velocity in 1942.
Wikipedia:
“The phenomenon [critical ionization velocity] was predicted by Swedish engineer and plasma scientist, Hannes Alfvén, in connection with his model on the origin of the Solar System (1942). At the time, no known mechanism was available to explain the phenomenon, but the theory was subsequently demonstrated in the laboratory.”
pochas says:
October 4, 2010 at 10:16 pm
Can’t be. The electrons and protons are moving at vastly different speeds.
No, their bulk speeds [away from the Sun] are the same.
James F. Evans says:
October 5, 2010 at 8:01 am
If THEMIS, moving in a different vector (direction) and speed, detects electric fields & electric currents as its flight path intersects, at the same time & location, the flight path of the Svalgaard hypothetical satellite observer, “moving away from the Sun with the same speed as the solar wind”, are those real electric fields & currents?
They will measure a very different electric field, of course. Both are equally real.
The Critical Velocity has nothing to do with the solar wind, as the latter is already completely ionized at the Sun.
In Alfven’s book Cosmic Plasma, on page 12, Hannes explains “”The motion of a charged particle can be completely describe as caused by an electic field E1. If we make a relativistic transformation from the coordinate system which moves with the particle velocity v in relation to a coordinate system at rest, we in the latter coordinate another electric field E2″
Dr. Svalgaard wrote: “They will measure a very different electric field, of course. Both are equally real.”
I appreciate your statement. Thank you. In your opinion what is the difference between the two electric fields?
I appreciate your taking the time & effort to find, review, and present the passage from Hannes Alfven’s book, Cosmic Plasma.
Please, could you explain, in your opinion, what Alfven meant by the passage you kindly presented.
(Perhaps, a broader passage could bring context to Alfven’s statement.)
James F. Evans says:
October 6, 2010 at 10:46 am
Please, could you explain, in your opinion, what Alfven meant by the passage you kindly presented.
As I have said so many times, he is saying [as every physicist will] that it is meaningless to speak about an ‘absolute’, ‘real’ electric field, as the electric field depends on the reference frame of the observer. Two observers moving relative to each other will measure different electric fields. You can think of a case where the two observers at a given instant pass very close to each other, so they at that instant are at the same location.
Now, this is not worth spilling more words on as that is accepted by every physicist and matches all measurements and experiments [which is why it is accepted].
(Perhaps, a broader passage could bring context to Alfven’s statement.)
Go read his book.
James F. Evans says:
October 6, 2010 at 10:46 am
In your opinion what is the difference between the two electric fields?
To be specific: in the solar wind the electric field is zero. Seen from the [almost stationary] Earth of satellite orbiting the Earth, the electric field of the 400 km/s solar wind with a magnetic field of 5 nT, the electric field would be 400,000*5/10^9 = 0.002 Volt/meter.
Dr. Svalgaard:
You contradict yourself.
First your state there is “no electric field” in the “rest frame” [the Svalgaard hypothetical observer, “moving away from the Sun with the same speed as the solar wind”]:
Leif Svalgaard says, October 1, 2010 at 10:43 pm:
“In the rest frame of a plasma there is no electric field and hence no electric current.”
That’s a far cry from this exchange:
James F. Evans says:
October 5, 2010 at 8:01 am
“If THEMIS, moving in a different vector (direction) and speed, detects electric fields & electric currents as its flight path intersects, at the same time & location, the flight path of the Svalgaard hypothetical satellite observer, “moving away from the Sun with the same speed as the solar wind”, are those real electric fields & currents?”
And, Dr. Svalgaard answered, October 5, 2010 at 10:41 pm: “They will measure a very different electric field, of course. Both are equally real.”
Then:
Dr. Svalgaard wrote: “Two observers moving relative to each other will measure different electric fields.”
So, which is it?
“In the rest frame of a plasma there is no electric field and hence no electric current.”
Or is it:
“They will measure a very different electric field, of course. Both are equally real.” And: “Two observers moving relative to each other will measure different electric fields.”
Did it become untenable to claim, “In the rest frame of a plasma there is no electric field and hence no electric current.”, when confronted with contradictory facts & evidence?
Dr. Svalgaard, “…that is accepted by every physicist and matches all measurements and experiments.”
Then it would be easy enough to provide a link or citation to at least one measurement or experiment supporting your assertion. Considering your contradictory statements, above, on the matter, your assurance isn’t persuasive.
Regarding Hannes Alfven’s book Cosmic Plasma (1981), it’s hard to find. It’s possible Dr. Svalgaard may be taking Alfven’s passage out of context since he refuses to provide the larger contextual passage the quoted statement comes from.
James F. Evans says:
October 6, 2010 at 12:44 pm
“Two observers moving relative to each other will measure different electric fields.”
This is true at all times and for all physical objects. Plasma or not. For plasmas in particular, the electric field they will measure if moving with the plasma is 0 volt/meter.
Then it would be easy enough to provide a link or citation to at least one measurement or experiment supporting your assertion.
Since it follows from Maxwell’s equations [and special relativity which is really derived from Maxwell’s equations], any measurement that supports Maxwell and Special Relativity [and I don’t know of any that does not – within the non-quantum domain] will do.
Regarding Hannes Alfven’s book Cosmic Plasma (1981), it’s hard to find. It’s possible Dr. Svalgaard may be taking Alfven’s passage out of context since he refuses to provide the larger contextual passage the quoted statement comes from.
Not worth responding to. Go wash your mouth out with soap. You might find the context here: http://books.google.dk/books?id=ZjwoGlIxvLUC&pg=PA11&dq=alfven+cosmic+plasma&source=gbs_toc_r&cad=3#v=onepage&q=alfven%20cosmic%20plasma&f=false
if WordPress doesn’t mangle the link.
Here you can learn more about the electric fields in different reference frames:
http://plasma.swarthmore.edu/brownpapers/BrownPoP99.pdf
And how the frame concept is important for the reconnection process:
“The paradigm for magnetic reconnection is the merger of two parcels of magnetofluid with anti-parallel flux ~see Fig. 1. In the rest frame of either parcel, there is no electric field and no velocity; simply magnetofluid at rest. The velocities of the parcels stagnate to zero at a neutral sheet which defines a new frame of reference. In the rest frame of the neutral sheet, the parcels are moving in towards the layer. The role of the electric field is non-dissipative i.e., purely convective outside the layer. When the parcels stagnate, the electric field becomes dissipative inside the layer and E =nJ. This directed electric field is capable of heating plasma and accelerating charged particles
to high energies.”
Dr. Svalgaard, thank you for providing the Google link to Hannes Alfven’s Book, Cosmic Plasma. I appreciate your making the book available to myself and the readers.
Dr. Svalgaard quoted a statement from Alfven’s book, Casmic Plasma, page 12:
”The motion of a charged particle can be completely describe as caused by an electic field E1. If we make a relativistic transformation from the coordinate system which moves with the particle velocity v in relation to a coordinate system at rest, we in the latter coordinate another electric field E2″
First, Dr. Svalgaard, omits a sentence in the middle of the paragraph:
“A magnetic field exerts a neglible force on a particle at rest”.
And omits the word, “However,” at the start of the next sentence and wrongly capitalized the “i” in “if”, leaving the impression there weren’t words left out, let alone a whole sentence.
Second, Dr. Svalgaard, omits the mathematical equation:
E= E’ – v x B
Third, Dr. Svalgaard incorrectly notatated “E” [electric field] in Alfven’s statement, by denoting “E” as…”E1″ and “E2”, when the proper notation is “E’ ” and “E”.
This is the proper quotation:
”The motion of a charged particle can be completely describe as caused by an electic field E’. A magnetic field exerts a neglible force on a particle at rest. However, if we make a relativistic transformation
E= E’ – v x B
from the coordinate system which moves with the particle velocity v in relation to a coordinate system at rest, we in the latter coordinate another electric field E.”
And, the next sentence (which Dr. Svalgaard left off):
“It is convient to use a coordinated system at rest and describe the motion of the particle by the velocity v. In this coordinate system the force acting on the charged particle is
f = e (E+v x B)
where B is given Equation (1).”
[Equation (1) can be viewed by linking the book and scrolling to page 11.]
Beyound the troubling omission of an entire sentence from the middle of the quoted statement (without indication of said omission), and omission of the mathematical equation, and the incorrect notation, and leaving out the next sentence from Alfven’s statement and the “force” mathematical equation, is the overall misleading impression Dr. Svalgaard made by his serial omissions.
Hannes Alfven, first states that a charged particle’s motion can be determined by an electric field. And, contrary to Dr. Svalgaard’s repeated statements, magnetic fields have “neglible force on a particle at rest”.
But, just as assuredly, Alfven knew that magnetic fields must be part of the total “force” equation, so, his series of mathematical equations and relativistic transformation is a mathematical progression to include the magnetic force in a final mathematical equation to represent the total forces.
There are not “two” electric fields at the same time & location.
It is mathematical pedigogical device.
Alfven isn’t claiming that there are actually two seperate electric fields in the same time and location, but rather, there is an electric field causing particle motion which can be represented by an equation without reference to magnetic fields, but the magnetic field must be incorporated into the total “force equation”
f = e (E+v x B)
[B is magnetic field]
to have an a complete mathematical equation representing the total forces on the charged particle.
All in all, it appears Dr. Svalgaard was misleading in a number of different respects.
James F. Evans says:
October 6, 2010 at 5:16 pm
I omitted mathematical details which you do not understand anyway. The important point is still:
”The motion of a charged particle can be completely describe as caused by an electic field E’. […] from the coordinate system which moves with the particle velocity v in relation to a coordinate system at rest, we [have] in the latter coordinate [system]another electric field E.”
I have inserted some words that you left out…
No, Dr. Svalgaard, Alfven is doing a “reduction of terms” so he can reduce all the mathematical terms for the seperate forces into a single mathematical equation which expresses the total force involved.
Alven is not saying there are multiple realities for the same time & location (which is your erroneous conclusion).
Dr. Svalgaard, you do know how to progress through a “reduction in terms” mathematical exercise, don’t you?
But that doesn’t excuse omitting a whole sentence in the middle of the passage, does it?
“A magnetic field exerts a neglible force on a particle at rest”.
It’s poor form to leave out an entire sentence from the middle of a quote…especially without letting the readers know you are doing that.
Leaving out mathematical equations which are an integral part of Alfven’s line of reasoning is also poor form.
James F. Evans says:
October 6, 2010 at 8:23 pm
It’s poor form to leave out an entire sentence from the middle of a quote…especially without letting the readers know you are doing that.
So much for my attempt of making things easy for you to understand…
Anyway, what Alfven was saying [and what everybody else, including me, understands] is that the electric field you measure depends on the speed with which you are moving. Just like the length of an object or the duration of a process.
Leif Svalgaard says:
October 6, 2010 at 8:58 pm
Anyway, what Alfven was saying [and what everybody else, including me, understands] is that the electric field you measure depends on the speed with which you are moving.
Even Wikipidia has it correct: wikipedia.org/wiki/Electric_current
“The theory of Special Relativity allows one to transform the magnetic field into a static electric field for an observer moving at the same speed as the charge in the diagram. The amount of current is particular to a reference frame (who is measuring the current or charge velocity).”
In some ways you weaken your case by denying this basic fact of Nature.
Dr. Svalgaard:
Even supporters of General Relativity don’t claim it operates at the atomic level.
And it also conflicts with Quantum Mechanics, as well.
With all due respect, it is you who ignore well established Laws of Nature such as the repeatedly demonstrated physical law that the “motion of charged particles cause a magnetic field”.
Regarding Hannes Alfven’s book Cosmic Plasma, it is important to read the entire part you kindly linked, which upon reading makes clear your misrepresentation.
Dr. Svalgaard wrote: “Anyway, what Alfven was saying [and what everybody else, including me, understands] is that the electric field you measure depends on the speed with which you are moving.”
Please, Dr. Svalgaard, that is another misrepresentation of Alfven’s work in the section you linked to. Read the enire linked section, it perfectly clear Alfven never makes reference to anything remotely like “the electric field you measure depends on the speed with which you are moving.”
Alfven’s reference to “relativistic transformation” is not to General Relativity or even its concepts, but rather, Alfven is referring to the transformation from the magnetic field perspective (and mathematical formalism) to the electric current perspective, and the mathematical equations that take those electric currents explicitly into account.
First, what’s clear from reading the entire section is that Alfven is making a conversion from the mathematical formalism of magnetic field equations which in large part omits the particle motion considerations.
Magnetic mathematical formalism refers to electric currents as “curl” B, which Alfven notes is acceptable for some uses, but not for other uses where it is not applicable and has limitations for accurately measuring electric fields & electric currents. Alfven then proceeds to “translate” this into a mathematical equation, so that “electric current is taken account explicitly” (Alfven), in other words, charged particle motion is taken into explicit account. Alfven does this so that electric currents can explicitly mappped out on a three-dimentional coordinate system.
Your representations of Alfven’s work are seriously flawed. It’s one thing to disagree with another scientist’s work, it’s an entirely different matter to misrepresent that work.
In regards to the so-called “magnetic reconnection” paper you presented, I understand your reluctance to present the paper because it’s a prime example of psuedoscience:
“FIG. 1. Magnetic reconnection paradigm. Merging parcels of magnetofluid
have no electric field in their respective rest frames. By special relativity,
in any other frame ~in particular, that of the neutral sheet! the relation E
1v3B50 holds. At the neutral sheet, the velocities stagnate to zero so the
role of the electric field becomes dissipative.”
The above passage is the money quote from the paper. But the assertion there is “no electric field” is based on the mathematical formalism, E + VxB = 0, derived from magnetohydrodynamics (MHD), not empirical laboratory experiments with plasmas.
Hannes Alfven and many other scientists have repeatedly demonstrated that the formalism of MHD is an approximation that does not hold up in tenuous bodies of space plasms.
Of note, the approach adopted by Yamada and Ono and reported in the 1999 Brown paper you linked has been ignored by more recent “magnetic reconnection” papers which do specifically observe & measure electric fields (these papers actually map out the Electric Double Layer under the erroneous “magnetic reconnection” label) when in situ satellite probes collected the data.
Your purpose is clear. Such as it is, and it has little or nothing to do with advancing scientific knowledge.
Again, as opposed to the Yamada and Ono approach which ignores electric field & charged particle motion, the modern Electromagnetic framework takes into account magnetic fields, electric fields, charged particle location, direction, velocity & charged particle acceleration.
Your scientific understanding, as expressed by your endorsement of the Yamada and Ono approach, is antiquated.
James F. Evans says:
October 8, 2010 at 8:44 am
Your purpose is clear. Such as it is, and it has little or nothing to do with advancing scientific knowledge.
I give up on you. Just like I have given up on people who claim the Earth is 6000 years old. You will not learn. You cannot learn. Your loss.
Dr. Svalgaard:
You disagree with Alfven. I’m a messenger, here.
But your naked contempt for anybody who disagrees with you is evident.
“However, another translation which is equally important is the translation between a magnetic field description and a current description of plasma phenomena.” — Hannes Alfven, Cosmic Plasma.
You not only disagree with Alfven, but his associates, and the scientific body of knowledge demonstrated in plasma laboratories around the world and, now, in situ satellite probes collecting data out in space.
And the scientific observations & measurements will keep building up from in situ satellite probes. All this mass of data will be collected via in situ probes measuring magnetic fields, electric fields, charged particle location, direction, velocity & charged particle acceleration.
Yes, anybody who firmly disagrees with Dr. Svalgaard is to be equated to “people who claim the Earth is 6000 years old.”
The Science disagrees with you, Dr. Svalgaard, so I will continue pointing out observations & measurements…that’s where the rubber meets the road. Hannes Alfven knew this…Kristian Birkeland knew this…Irving Langmuir knew this.
Leif Svalgaard says:
October 5, 2010 at 10:41 pm
pochas says:
October 4, 2010 at 10:16 pm
Can’t be. The electrons and protons are moving at vastly different speeds.
No, their bulk speeds [away from the Sun] are the same.
🙂
James F. Evans says:
October 8, 2010 at 11:25 am
Yes, anybody who firmly disagrees with Dr. Svalgaard is to be equated to “people who claim the Earth is 6000 years old.”
Indeed, on the issue of elementary plasma physics and the EU, it is so. And these people are as steadfast in their faith as you and the EU cult. Not much can be done about this.
Dr. Svalgaard, you disagree with Hannes Alfven, 1970 Nobel prize winner in physics.
So, is Hannes Alfven equated to “people who claim the Earth is 6000 years old”?
http://books.google.dk/books?id=ZjwoGlIxvLUC&pg=PA11&dq=alfven+cosmic+plasma&source=gbs_toc_r&cad=3#v=onepage&q=alfven%20cosmic%20plasma&f=false
With all due respect, I’ll stand with Alfven and his work.
James F. Evans says:
October 11, 2010 at 1:24 pm
Dr. Svalgaard, you disagree with Hannes Alfven, 1970 Nobel prize winner in physics.
You do not understand Alfven’s work at all. So your stand has no relevance.