From the University of Chicago
Satellite reveals surprising cosmic ‘weather’ at edge of solar system
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The first solar system energetic particle maps show an unexpected landmark occurring at the outer edge of the solar wind bubble surrounding the solar system. Scientists published these maps, based mostly on data collected from NASA’s Interstellar Boundary Explorer satellite, in the Oct. 15 issue of Science Express, the advance online version of the journal Science.
“Nature is full of surprises, and IBEX has been lucky to discover one of those surprises,” said Priscilla Frisch, a senior scientist in astronomy & astrophysics at the University of Chicago. “The sky maps are dominated by a giant ribbon of energetic neutral atoms extending throughout the sky in an arc that is 300 degrees long.” Energetic neutral atoms form when hot solar wind ions (charged particles) steal electrons from cool interstellar neutral atoms.
IBEX was launched Oct. 19, 2008, to produce the first all-sky maps of the heliosphere, which reaches far beyond the solar system’s most distant planets. Extending more than 100 times farther than the distance from Earth to the sun, the heliosphere marks the region of outer space subjected to the sun’s particle emissions.
The new maps show how high-speed cosmic particle streams collide and mix at the edge of the heliosphere, said Frisch, who co-authored three of a set of IBEX articles appearing in this week’s Science Express. The outgoing solar wind blows at 900,000 miles an hour, crashing into a 60,000-mile-an-hour “breeze” of incoming interstellar gas.
Revealed in the IBEX data, but not predicted in the theoretical heliosphere simulations of three different research groups, was the ribbon itself, formed where the direction of the interstellar magnetic field draping over the heliosphere is perpendicular to the viewpoint of the sun.
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  IMAGE: Priscilla Frisch, Senior Scientist in Astronomy & Astrophysics, and member of the science team, Interstellar Boundary Explorer. Collaborating with former UChicago astronomer Thomas F. Adams, she made the first spectrum… |
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Energetic protons create forces as they move through the magnetic field, and when the protons are bathed in interstellar neutrals, they produce energetic neutral atoms. “We’re still trying to understand this unexpected structure, and we believe that the interstellar magnetic forces are associated with the enhanced ENA production at the ribbon,” Frisch said.
IBEX shows that energetic neutral atoms are produced toward the north pole of the ecliptic (the plane traced by the orbit of the planets around the sun), as well as toward the heliosphere tail pointed toward the constellations of Taurus and Orion. “The particle energies change between the poles and tail, but surprisingly not in the ribbon compared to adjacent locations,” Frisch said.
IBEX is the latest in NASA’s series of low-cost, rapidly developed Small Explorers space missions. Southwest Research Institute in San Antonio, Texas, 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.
Citations: N. A. Schwadron, M. Bzowski, G. B. Crew, M. Gruntman, H. Fahr, H. Fichtner, P. C. Frisch, H. O. Funsten, S. Fuselier, J. Heerikhuisen, V. Izmodenov, H. Kucharek, M. Lee, G. Livadiotis, D. J. McComas, E. Moebius, T. Moore, J. Mukherjee, N.V. Pogorelov, C. Prested, D. Reisenfeld, E. Roelof, G.P. Zank, “Comparison of Interstellar Boundary Explorer Observations with 3-D Global Heliospheric Models,” Science Express, Oct. 15, 2009.
H.O. Funsten, F. Allegrini, G.B. Crew, R. DeMajistre, P.C. Frisch, S.A. Fuselier, M. Gruntman, P. Janzen, D.J. McComas, E. Möbius, B. Randol, D.B. Reisenfeld, E.C. Roelof, N.A. Schwadron, “Structures and Spectral Variations of the Outer Heliosphere in IBEX Energetic Neutral Atom Maps,” Science Express, Oct. 15, 2009.
D.J. McComas, F. Allegrini1, P. Bochsler, M. Bzowski, E.R. Christian, G.B.Crew, R. DeMajistre, H. Fahr, H. Fichtner, P.C. Frisch, H.O. Funsten, S. A. Fuselier, G. Gloeckler, M. Gruntman, J. Heerikhuisen, V. Izmodenov, P.J anzen, P. Knappenberger, S. Krimigis, H. Kucharek, M. Lee, G. Livadiotis, S. Livi, R.J. MacDowall, D. Mitchell, E. Möbius, T. Moore, N.V. Pogorelov, D. Reisenfeld, E. Roelof, L. Saul, N.A. Schwadron, P.W. Valek, R. Vanderspek, P. Wurz, G.P. Zank, “Global Observations of the Interstellar Interaction from the Interstellar Boundary Explorer-IBEX”, Science Express, Oct. 15, 2009.
Related links:
Animation shows how energetic neutral atoms are made in the heliosheath when hot solar wind protons grab an electron from a cold interstellar gas atom. The ENAs can then easily travel back into the solar system, where some are collected by IBEX. Credit: NASA/GSFC http://www.swri.org/temp/ibexscience/DM/SP_draft1.mov
Solar Journey: The Significant of Our Galactic Environment for the Heliosphere and Earth, Priscilla C. Frisch, editor. http://www.springer.com/astronomy/practical+astronomy/book/978-1-4020-4397-0
IBEX Web page at Southwest Research Institute http://ibex.swri.edu/
NASA’s Interstellar Boundary Explorer mission http://www.nasa.gov/mission_pages/ibex/index.html
To view a video related to this research, please visit http://astro.uchicago.edu/%7Efrisch/soljourn/Hanson/AstroBioScene7Sound.mov
Here is another press release on IBEX from Boston University:
IBEX discovers that galactic magnetic fields may control the boundaries of our solar system
NASA mission reveals impact of galaxy’s magnetic fields
(Boston) – The first all-sky maps developed by NASA’s Interstellar Boundary Explorer (IBEX) spacecraft, the initial mission to examine the global interactions occurring at the edge of the solar system, suggest that the galactic magnetic fields had a far greater impact on Earth’s history than previously conceived, and the future of our planet and others may depend, in part, on how the galactic magnetic fields change with time.
“The IBEX results are truly remarkable, with emissions not resembling any of the current theories or models of this never-before-seen region,” says Dr. David J. McComas, IBEX principal investigator and assistant vice president of the Space Science and Engineering Division at Southwest Research Institute. “We expected to see small, gradual spatial variations at the interstellar boundary, some 10 billion miles away. However, IBEX is showing us a very narrow ribbon that is two to three times brighter than anything else in the sky.”
A “solar wind” of charged particles continuously travels at supersonic speeds away from the Sun in all directions. This solar wind inflates a giant bubble in interstellar space called the heliosphere — the region of space dominated by the Sun’s influence in which the Earth and other planets reside. As the solar wind travels outward, it sweeps up newly formed “pickup ions,” which arise from the ionization of neutral particles drifting in from interstellar space. IBEX measures energetic neutral atoms (ENAs) traveling at speeds of roughly half a million to two and a half million miles per hour. These ENAs are produced from the solar wind and pick-up ions in the boundary region between the heliosphere and the local interstellar medium.
The IBEX mission just completed the first global maps of these protective layers called the heliosphere through a new technique that uses neutral atoms like light to image the interactions between electrically charged and neutral atoms at the distant reaches of our Sun’s influence, far beyond the most distant planets. It is here that the solar wind, which continually emanates from the Sun at millions of miles per hour, slams into the magnetized medium of charged particles, atoms and dust that pervades the galaxy and is diverted around the system. The interaction between the solar wind and the medium of our galaxy creates a complex host of interactions, which has long fascinated scientists, and is thought to shield the majority of harmful galactic radiation that reaches Earth and fills the solar system.
“The magnetic fields of our galaxy may change the protective layers of our solar system that regulate the entry of galactic radiation, which affects Earth and poses hazards to astronauts,” says Nathan Schwadron of Boston University’s Center for Space Physics and the lead for the IBEX Science Operations Center at BU.
Each six months, the IBEX mission, which was launched on October 18, 2008, completes its global maps of the heliosphere. The first IBEX maps are strikingly different than any of the predictions, which are now forcing scientists to reconsider their basic assumptions of how the heliosphere is created.
“The most striking feature is the ribbon that appears to be controlled by the magnetic field of our galaxy,” says Schwadron.
Although scientists knew that their models would be tested by the IBEX measurements, the existence of the ribbon is “remarkable” says Geoffrey Crew, a Research Scientist at MIT and the Software Design Lead for IBEX. “It suggests that the galactic magnetic fields are much stronger and exert far greater stresses on the heliosphere than we previously believed.”
The discovery has scientists thinking carefully about how different the heliosphere could be than they expected.
“It was really surprising that the models did not generate features at all like the ribbon we observed,” says Christina Prested, a BU graduate student working on IBEX. “Understanding the ribbon in detail will require new insights into the inner workings of the interactions at the edge of our Sun’s influence in the galaxy.”
Adds Schwadron,”Any changes to our understanding of the heliosphere will also affect how we understand the astrospheres that surround other stars. The harmful radiation that leaks into the solar system from the heliosphere is present throughout the galaxy and the existence of astrospheres may be important for understanding the habitability of planets surrounding other stars.”
IBEX is the latest in NASA’s series of low-cost, rapidly developed Small Explorers space missions. Southwest Research Institute in San Antonio, Texas, 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.
The Center for Space Physics at Boston University carries out a wide variety of research in space physics including: space plasma physics, magnetospheric physics, ionospheric physics, atmospheric physics, and planetary and cometary atmospheric studies.
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Dr. Leif Svalgaard wrote: “In plasmas there is no electric field because the conductivity is so high that charge imbalances are shorted out immediately.”
This is the second time in this comment thread you have made that unsupported assertion.
After the first time you made that naked assertion I presented your statement.
“Dr. Svalgaard wrote: ‘It is just that there are no electric fields in the rest frame of a highly conducting plasma, as they are immediately shorted out.'”
And asked this question: “Any in situ satellite probe observation & measurement to confirm that statement or is it just speculation or conjecture?”
It is a direct question, which in scientific discourse requires a direct answer.
Either a direct answer of yes, here is the report of the in situ satellite probe observations & measurements; or no, there is no in situ observation of that kind to report.
Instead, you repeat your naked assertion.
This is a disingenuous response.
You are passing off your unsupported speculation as opposed to responding forthrightly to the question.
You can do better than that Dr. Svalgaard.
vukcevic (10:36:57) :
Not always. There is such thing as a field aligned current in plasma
Let me elaborate a bit on this [for the zillionth time, it seems]. In an undisturbed cosmic plasma [e.g. the free flowing solar wind] there is no electric field in the rest frame of the plasma, and thus no acceleration of charged particles. If you impede the flow in some way [e.g. by placing the Earth’s magnetic field in the way, or the shocked material in the termination shock, or reconnection in solar flares] the changing magnetic field induces a [short-lived] electric field that can accelerate charged particles near it. These particles now move at a different [usually much higher] speed than the bulk flow of the plasma, and will speed away from the acceleration location. Because it is easier to propagate along the magnetic field than across it, you get a short-lived spurt of field-aligned current, Particles from solar flares will for example follow the HMF’s spiral from the Sun to the Earth. The Heliospheric current is not such a field aligned current, but is a ‘drift’ current. The Ring Current in the Van Allen belts is another example of such a drift current.
Leif Svalgaard (10:55:32) :
No. Only when the plasma is under conditions where the free movement of the plasma is hindered by conditions external to the plasma that results in finite resistivity.
I would suggest that is precisely case here:the plasma is hindered by conditions external to the plasma.
There are two points here to be made:
a) I am a ‘free agent’ speculating a possibility.
b) You are experienced and knowledgeable scientist assuming you knowledge of the far reaches of heliosphere is to you ‘known certainty’.
I can accept that my speculations more offten than not, are way of the mark or even wrong, but occasionally if not on the target, at least somewhere in the vicinity.
You also should be prepared to accept that many things about heliosphere (and even our own magnetosphere) are still within realm of speculation, based on known science granted, but still highly unpredictable.
Personally, what matters here is not prevailing in the debate (probably not possible), but logically testing the intuition led ideas.
Thank you for your very valuable contributions.
I shall call it a day,
Dr.Svalgaard wrote: “Let me elaborate a bit on this [for the zillionth time, it seems]. In an undisturbed cosmic plasma [e.g. the free flowing solar wind] there is no electric field in the rest frame of the plasma, and thus no acceleration of charged particles.”
For the zillionth time, please provide in situ satellite probe observations & measurements which support this assertion.
Or acknowledge there are no in situ satellite probe observations to provide.
Failure to do so leads to only one conclusion:
There are NO in situ observations & measurements to support your assertion, but you can’t bring yourself to admit that; and you keep repeating an unsuported assertion because it is YOUR DOGMA, and you’re sticking to it no matter what.
That kind of opinion deserves no credence whatsoever.
(Every time I see you present this, so far, unsupported assertion, I will ask for in situ satellite probe reports of observation & measurement that supports the assertion.)
I urge readers to give the weight an opinion deserves when a scientist refuses to backup his opinion with scientiftic evidence.
It is a sad state of affairs when dogma collides with reality.
Zeke the Sneak (11:36:40) :
“Electric Sun Verified”M
The [fatal] problem with this is how the z-pinch knows where the Sun is.
James F. Evans (11:42:37) :
<Electric currents certainly do play a vital role in events in space
Of course they do. Everything interesting is done by currents. That is not the issue, which is that the currents are created by plasmas moving in magnetic fields.
James F. Evans (11:58:51) :
“In plasmas there is no electric field because the conductivity is so high that charge imbalances are shorted out immediately.”
This follows directly from Maxwell’s equations [for which there is ample experimental support]. It can also be seen from simpler considerations. The important point is the large charge to mass ratio of the electron [e/m = 5×10^17 cgs]. One volt of potential difference [that is electric field] accelerates an electron to 600 km/sec, so it is evident that even a very small electric field would produce an immense current [flow of electrons]. So the electric field is limited to extremely small values by the highly mobile electrons. Consider the case of a plasma dense enough that Ohm’s law applies, i.e. j = s E, where E is the electric field in the frame of reference moving with the local plasma. For ionized hydrogen, the electrical conductivity, s, is 2×10^7 T^(3/2)/sec [Spitzer, 1956], where T is the temperature. Ampere’s law 4pi j = c curl B says then that 4pi j ~ cB/l [order of magnitude] where l is the typical length scale of variation of the magnetic field B. With E=j/s, you get that E/B = c/(4pi s l) = 10^(-4)/l * (10^4/T)^(3/2), where l is measured in centimeters. For ionized hydrogen T is in excess of 10,000 K. So even with l being as small as 1 km, it follows that E/B less than 10^(-9). On the larger scales of the solar wind, stars, and galaxies, E/B becomes completely negligible. It is then evident that the electric stresses [measured by E^2] are completely insignificant in comparison to the magnetic stresses [measured by B^2]. The ratio of the stresses being (E/B)^2. So, in short, the extremely lightness of the electron ensures that it will very quickly find the positive charges and short out any imbalance. In fact, even if you create an imbalance, it will disappear in a time comparable to the Landau damping time of a plasma oscillation.
vukcevic (12:26:50) :
I would suggest that is precisely case here:the plasma is hindered by conditions external to the plasma.
The resulting field-aligned ‘currents’ are the result of acceleration e.g. by the shock and do not drive anything. They are just a way of getting rid of the garbage to let the plasma adjust to the changed conditions. The fundamental issue is that you still after all this time cannot understand that movements of the plasma in the presence of a magnetic field is the mechanism by which things happen and not electrical currents [driven by what emf?] which are only side effects.
I can accept that my speculations more often than not, are way of the mark or even wrong, but occasionally if not on the target, at least somewhere in the vicinity.
As long as they make physically sense. All too often you cling to speculations long after their ‘sell-by date’ and they are ‘not even wrong’. Things have to make sense to be wrong.
You also should be prepared to accept that many things about heliosphere (and even our own magnetosphere) are still within realm of speculation, based on known science granted, but still highly unpredictable.
We speculate a lot, but always tempered by actual knowledge. And do not succumb to the Al Gore maxim: ‘if you don’t know anything, everything is possible’.
testing the intuition led ideas.
must fall at once, when they have been shown to be untenable. For example, it serves no purpose to continue to harp on field-aligned currents month after month after month after the concept and their applicability/inapplicability have been explained. Same thing with magnetic influences travelling upstreams in the supersonic solar wind.
James F. Evans (13:04:09) :
“there is no electric field in the rest frame of the plasma, and thus no acceleration of charged particles.”
Vytenis Vasiliunas has an elementary derivation here:
http://www.leif.org/EOS/2001GL013014.pdf
His conclusion:
(1) a given plasma bulk flow produces an electric field,
(2) a given electric field does not produce a plasma bulk
flow. The general result can also be derived as a simple
consequence of conserving the total (plasma plus electromagnetic field) linear momentum.
Dr. Svalgaard:
The direct answer to my question is “no” there aren’t any in situ satellite probe observations & measurements to provide.
However, I do appreciate that you explained the reasoning of your opinion by way of abstract construction. And, I appreciate the Vasylifinas paper.
Comments in the paper are revealing and instructive:
“…it all depends on what approach to describing plasmas one has adopted and what one’s views are in the ongoing controversy on whether the magnetic field and the plasma flow or the electric current and the electric field are to be treated as the primary variable.”
There is a controversy on this subject.
As opposed to your absolutist, black and white assertion, which when the curtain is pulled back, is not based on observation & measurement, the requirement of empirical science, but, rather, on abstract constructions.
The paper is wrong on two counts. One, abstract mathematical construction divorced from observation & measurement is not physics, notwithstanding the assertion to the contrary in the paper. Two, “thought experiments” are nothing but unproven hypothesis until a series of empirical experiments are conducted that either falsify the hypothesis or validate the hypothesis.
Nothing of the sort has been conducted as a result of your mathematical construction (hypothesis) or Vasylifinas’ mathematical construction (hypothesis).
Vasylifinas specifically relies on “thought experiments” as he states in the paper: “…this Letter can thus be answered by means of two thought experiments…”
To derive absolutist assertions on mere “thought experiments” is questionable scientific method.
Dr. Svalgaard, you are entitled to an opinion, but it is only an opinion, and your couching that opinion in absolutist terms is unwarranted. The opinion is not based on compulsion by way of observation & measurement, but on theoretical constructs (I suspect driven by ideological dogma).
Your opinion is not “the Science” in astrophysics, but only one of many voices.
You would be wise to remember that.
James F. Evans (18:19:43) :
The direct answer to my question is “no” there aren’t any in situ satellite probe observations & measurements to provide.
I don’t think you understand how science works. If there is solid experimental evidence for a physical law, then the deductions from that law are also valid. We don’t make expensive in situ experiments to measure something that isn’t there.
There is a controversy on this subject.
There are people that do not understand the issue, hence the derivation by Vasiliunas. There is no controversy; there is sloppy use of concepts, that from time to time must be pointed out and corrected.
The paper is wrong on two counts. One, abstract mathematical construction divorced from observation & measurement is not physic […]
To derive absolutist assertions on mere “thought experiments” is questionable scientific method.
Here are some famous and important thought experiments: http://en.wikipedia.org/wiki/Thought_experiment#Physics
Physics is built on such thought experiments. Einstein was particularly good at it.
Thought experiments and mathematical deductions from the laws are absolutely valid. Example: as a thought experiment, I’ll drop a stone from the Leaning Tower of Pisa. Based on Newton’s laws, I can now calculate how long time it will take the stone to reach the ground. Because Newton’s laws have been verified repeatedly, the calculation based on the thought experiment will be correct, and if I actually did it, I’ll invariably find the correct result.
Absolutist abstraction derived from experimentally derived laws is very much science; that’s why we find the laws, so that we can calculate in absolute black and white terms what will happen. If we couldn’t, there wouldn’t be any science. Now, there is a good difference with the Electric Universe cult, because the EU cannot make calculations, only hand waving, false analogies.
Your opinion is not “the Science” in astrophysics, but only one of many voices.
My opinion is called ‘the Scientific Method’.
None of the voices in Astrophysics endorse the Electrical Universe.
I can see from your posts that you have no idea about science, the scientific method, and physical laws, so consider this blog to be your chance to learn something [for free, even].
NASA IBEX special report. In it, this select panel of experts on the project, explain their discoveries. Nice press release and good PR work on their part. Its 41 minutes long. Should go check it out.
m.youtube.com/watch?v=mTnwjd8CF1c&hl=en&gl=US&client=mv-google
Dr. Svalgaard wrote: “If there is solid experimental evidence for a physical law, then the deductions from that law are also valid. We don’t make expensive in situ experiments to measure something that isn’t there.”
Your statement is nonsense.
How do you know an electric field and an electric current isn’t there in space?
“Well, I have these mathematical equations that tell me. There is no reason to conduct observation & measurement to confirm or falsify what we already know.”
Following your rational, once Science had an equation we wouldn’t do any experiments.
Of course, your rational also ignores the fact that electromagnetism is non-linear and the equations are the Heavyside reductions, which makes them more managable for differential equations (which is fine), but for the kind of theoretical extrapolation you engage in, it’s problematic.
The idea that with mathematics Science can dispense with empirical testing is the same kind of rational relied upon by Man-made gobal warming proponents.
That kind of reasoning spells the intellectual bankruptcy of a scientist.
Dr. Svalgaard: “There are people that do not understand the issue…”
In your opinion.
What you really mean is that everybody that disagrees with your opinion is wrong.
Thought experiments are fine for hypothesis, but the life blood of empirical science is observation & measurement. Any scientist who claims it isn’t…well, isn’t much of a scientist.
Mathematical deductions — engineering is fine where the physical properties have been quantified and the quantification has been verified by empirical observation & measurement via the Scientific Method.
To make a point I need to reprise a couple of prior passages:
NASA: “Moreover, electric current causes magnetic fields…”
Dr. Svalgaard responded: “In general, it takes an electric current to create a magnetic field in ordinary life [and that was what NASA’s piece was about]. In cosmic plasmas the magnetic field is the cause of the currents in material moving relative to the magnetic field.”
No, NASA’s piece was not limited to “ordinary life” (as if special, “new” physics applies only to space), it was foundational explanation of how electromagnetism works, both on the Earth’s surface and in space (there was no distinction made in the NASA webpage) — afterall, the whole website is dedicated to explaining space dynamics (a little detail that Dr. Svalgaard ignores).
That’s the point: Science knows electric current causes magnetic fields via classical physics and NASA provides this explanation for their solar system website.
But your opinion invokes “new” physics that “only” happen in space???
And you have the arrogance to insist no experiments are needed to validate this “new” physics hypothesis???
Sorry, Dr. Svalgaard, but invoking a “new” physics hypothesis, and then turning around and stating it doesn’t need to be tested in situ to see if the hypothesis is valid doesn’t even come close to meeting the standards of the empirical scientific method.
Dr. Svalgaard: wrote: “My opinion is called ‘the Scientific Method’.”
What a bunch of malarkey!
If you want my opinion, it’s just another variant on attempting to sell the “Big Lie”.
The emperor has no clothes…
James F. Evans (23:56:57) :
Mathematical deductions — engineering is fine where the physical properties have been quantified and the quantification has been verified by empirical observation & measurement.
The equations [Maxwell’s and Newton’s] have been verified by observations and therefore one can perform mathematical deductions and calculations from them. The equations are just a shorthand for the overwhelming experimental evidence behind them.
This is the difference between real science and EU [which has no equations and therefore does not allow calculations to be experimentally tested]
NASA provides this explanation for their solar system website.
Their website states specifically: “The dynamic interaction of the plasma and magnetic field produces electrical fields and currents in the North and South polar regions.”
This is the crucial point you need to understand.
The one thing that stood out to Dr. McComas was the finite detail discovered around the heliopause. If I understand this correctly, there is a finite boundary defined at the heliosheath. Its that boundary between the termination and bow shock points that Dr. McComas seems most intrigued by. And from what I can gather, it was not predicted by any of the models involved from the project. You throw in a ‘ribbon’ of ENA’s and you have now more questions from the team, than answers.
Or is it the best way to continue more funding dollars to be filtered toward NASA? This particular mission has roughly cost $130 mn dollars . I mention this because as far as I can tell, this mission only supports previous experiments and theories from the scientific community. Mind you with good pictures and graphs. But still, sound science, based upon earlier peer reviewed articles.
The scientific articles and the teams presentation of their findings left me wondering if they know more than they are letting on and is it because of funding or fear of scrutiny. Only time will tell.
david alan (12:33:08) :
you have now more questions from the team, than answers.
And that is just as it should be. The more we know, the more [and better] questions we can ask. Progress is answering those new questions, which in turn leads to still more questions, and so on. Questions is what it is all about.
@ur momisugly Dr. Leif Svalgaard:
Dr. Svalgaard presents Evans’ statement:
“Mathematical deductions — engineering is fine where the physical properties have been quantified and the quantification has been verified by empirical observation & measurement.”
And:
Dr. Svalgaard responds: “The equations [Maxwell’s and Newton’s] have been verified by observations and therefore one can perform mathematical deductions and calculations from them. The equations are just a shorthand for the overwhelming experimental evidence behind them.”
The fallacy of Dr. Svalgaard’s response is twofold, one, “the equations have been verified by observations”, but the resulting observations demonstrate the opposite conclusion, electric current causes magnetic fields, from what Dr. Svalgaard would have have the reader believe, and, two, “the overwhelming experimental evidence” was conducted, here, on Earth’s surface, not in space.
Therefore, Dr. Svalgaard’s hypothesis (it’s not a theory because no experiments have been conducted) contradicts the known experimental results, and, further, his hypothesis has never been tested in the conditions (space) he has postulated.
It’s nonsense to state an opposite result from known experimental results, and to declare this as verified (or really there is no need to verify) when the hypothesis has never even been tested in the conditions claimed for the hypothesis’ validity.
And Dr. Svalgaard makes this nonsensical statement under a cloud of controversy. Vasylifinas paper states:
“…it all depends on what approach to describing plasmas one has adopted and what one’s views are in the ongoing controversy on whether the magnetic field and the plasma flow or the electric current and the electric field are to be treated as the primary variable.”
Dr. Svalgaard responds: “There is no controversy…”, rather, just “sloppy use of concepts”, and, “people that do not understand the issue…”
Funny, Vasylifinas, obviously thought there was a controversy, or he wouldn’t have mentioned it (every word and idea is considered in a paper like this), and there would be no reason for the paper in the first place.
This puts Dr. Svalgaard in a difficult position: On the one hand, he supports the conclusion of Vaylifinas, but on the hand, dismisses Vasylifinas considered statement of the “ongoing contraversy”.
Well, perhaps, Varylifinas was guilty of “sloppy use of concepts” in his choice of the word, “controversy”, but that doesn’t speak highly for the rest of the conclusions in the paper, now does it?
Or more likely Dr. Svalgaard couldn’t admit there was “ongoing controversy” because that would undermine his determined effort to present a united front in the astrophysical fraternity on the subject when, in fact, none existed.
Dr. Svalgaard states: “This is the difference between real science and EU [which has no equations and therefore does not allow calculations to be experimentally tested]”
The above statement is misleading:
Actually, the quantification of electromagnetism in space is proceeding apace with every additional in situ satellite probe experiment that observes & measures the electric charges, electric fields and electric current and magnetic fields. And how do we know NASA is doing that?
Take NASA at it’s own word, that’s how:
“Electric charges, electric fields and electric current are critical to the study of the structure of the Sun, solar wind and the magnetosphere of the Earth. Moreover, electric current causes magnetic fields (see Electromagnetism) that are important to understanding dynamic characteristics of the Sun and how the Sun interacts with the Earth.”
http://stargazers.gsfc.nasa.gov/resources/electricity.htm
Until advanced in situ satellite probes were regularly sent into space, it was next to impossible to detect and measure electric fields and electric currents in space plasma and a significant element in the astronomical community didn’t particularly welcome the idea of electricity in space because they espoused a mechanical model based on “hot gas”, “kinetics”, and “pressure”, much as Dr. Svalgaard has done in this thread.
But NASA already recognizes space is electrified. Even if Dr. Svalgaard and others in a minority are determined to maintain the primacy of their mechanical model. The horse is already out the barn door, so to speak. The quantitization of electromagnetism in space and the understanding of its structures and processes will continue and mathematical equations & calculations will flow from that. Suggesting EU isn’t real science is nothing more than an ugly smear unworthy of scientists of goodwill.
(Dr. Svalgaard’s hostile comment emanates from professional rivalry, EU proponents have been theorizing the solar system’s electromagnetism for decades, led by the eminent Hannes Alfven, 1970 Nobel Prize winner in physics, father of Plasma Cosmology, but also an outsider to the astrophysical community, which is an insular community.)
Dr. Svalgaard presents the statement: “NASA provides this explanation for their solar system website.”
And Dr. Svalgaard states: “Their [NASA] website states specifically: ‘The dynamic interaction of the plasma and magnetic field produces electrical fields and currents in the North and South polar regions.'”
It’s important to place statements in proper context, so, here, is the full statement from the NASA site:
“As the magnetosphere snaps back toward the Earth, it introduces more energetic plasma closer to the Earth. The dynamic interaction of the plasma and magnetic field produces electrical fields and currents in the North and South polar regions. The electrical fields accelerate charged particles down into the atmosphere. Movement of the charged particles of the plasma becomes very complicated near to the Earth.
http://stargazers.gsfc.nasa.gov/resources/earth_magnetosphere.htm
NASA isn’t making a global statement that magnetic fields cause electric currents, however, apparently Dr. Svalgaard wants to give the reader that impression. Rather, NASA is referring to a specific region of space in the Earth’s magnetosphere where the electric currents, already present in the solar wind’s plasma, in the helio current sheet, cause and direct electrical currents to flow specifically into “North and South polar regions” of the Earth’s atmosphere.
I suggest Dr. Svalgaard presented his truncated version to promote his preferred ideas and opinion.
But what does NASA have to say about it?
“The interplanetary magnetic field is formed by currents of plasma within the Sun and within the solar wind.”
http://stargazers.gsfc.nasa.gov/resources/earth_magnetosphere.htm
“Magnetic fields are produced by electric currents. These currents are generated within the Sun by the flow of the Sun’s hot, ionized gases. We observe a variety of flows on the Sun’s surface and within its interior. Nearly all of these flows may contribute in one way or another to the production of the Sun’s magnetic field.”
http://solarscience.msfc.nasa.gov/dynamo.shtml
And. of course, readers already have seen where NASA states: “Electric charges, electric fields and electric current are critical to the study of the structure of the Sun, solar wind and the magnetosphere of the Earth.”
This seems to be inconvenient to Dr. Svalgaard’s primarily mechanical model.
James F. Evans (16:18:27) :
“Magnetic fields are produced by electric currents. These currents are generated within the Sun by the flow of the Sun’s hot, ionized gases. We observe a variety of flows on the Sun’s surface and within its interior. Nearly all of these flows may contribute in one way or another to the production of the Sun’s magnetic field.”
You still don’t get it [that’s OK, I didn’t think you would].
What NASA is describing here is how a dynamo works. The currents are generated by the flow of plasma in the existing magnetic field inside the Sun. Whenever you move a conductor in a magnetic field, an electrical current is generated. The magnetic field from the current generated from the existing magnetic field amplifies that magnetic field, and in this way strong magnetic fields [e.g. in sunspots] are built up. Let me re-iterate Vasiliunas’s conclusions [which are unassailable, expect by people that do not know physics]:
(1) a given plasma bulk flow produces an electric field,
(2) a given electric field does not produce a plasma bulk
flow.
This is not really difficult to grasp. Even Wikipedia has it correct: “The dynamo uses rotating coils of wire and magnetic fields to convert mechanical rotation into a pulsing direct electric current through Faraday’s law.”
It doesn’t surprise me that Dr. Svalgaard would maintain his position in the face of direct and unequivocal statements from NASA that electric currents cause magnetic fields. It’s there in black and white for everybody to see.
His arguments have been examined and shot down, every one.
Afterall, his reputation is on the line.
But the facts and evidence speak for themselves — facts are stubborn things.
But let’s briefly review:
Charged particles when not in motion do not produce a magnetic field.
Only motion of charged paricles produces magnetic fields.
The electromotive force, which is 39 orders of magnitude stronger than gravity will induce charged particle motion without the presence of a magnetic field, yes, once the current of charged particles starts flowing (electric current) due to that electromotive force, a magnetic field will emanate from the charged particles in motion. But the magnetic field does not “start the ball rolling”, rather, it’s the electromotive force.
Yes, I understand Dr. Svalgaard can’t continence this…
Afterall, his reputation is on the line…
I don’t know what to think about this debate between Leif and James. I mean no disrespect to either of you, but has the scientific community drawn a concensus as to which science is more accurate. I guess my question is this: Does magnetic field lines in the heliosphere give rise to electromagnetism as a result of kinetic interactions or does kinetic interactions between interstellar and solar gases create electromagnetic field lines?
I’m just asking because I think that is the difference (in my own understanding) between both of yours hypothesis’.
I wonder if this NASA IBEX joint mission, in mapping the heliosphere, gives any clearer picture to this debate.
That’s all for now.
James F. Evans (17:46:42) :
The electromotive force…
Clearly, you do not know what the emf is.
It is the work expended to produce a potential difference, which is generated by separating positive and negative charges. The potential difference can then drive a current if there is a conductor between the separated charges, thereby draining the difference [battery goes flat].
Anyway, I have tried to teach you some science, but you have proven to be a slow learner [I guess not everybody is above average].
david alan (18:56:18) :
Does magnetic field lines in the heliosphere give rise to electromagnetism as a result of kinetic interactions or does kinetic interactions between interstellar and solar gases create electromagnetic field lines?
precision of words are important. A plasma [solar wind] moving across magnetic field lines, creates an electric field [and thus current]. In the solar wind itself, the magnetic field moves with the plasma, so no ‘cross’ movement and thus no electric field. If the solar wind blows past a magnetic Earth, an electric current will be created around the Earth. The important thing is that there is a magnetic field always everywhere in the cosmos, so any movement of a plasma [or conductor] will create electric fields and associated currents. All this is well-understood by any physicist and engineer [for that matter] and is the basis for countless devices in our ordinary life, where a dynamo run in reverse becomes an electric motor.
Leif Svalgaard (20:16:00): {The important thing is that there is a magnetic field always everywhere in the cosmos, so any movement of a plasma [or conductor] will create electric fields and associated currents.}
Precision of words are important indeed. Thank you for your clarification Dr. Svalgaard. I think a light went on in my head.
@ur momisugly david alan:
An important question when considering how much weight to give to one opinion or anoher in a debate is how they deal with obvious points, pieces of evidence, and facts presented by the other side. Do they grasp the issues raised when challenged or do they tend to ignore them and deflect off onto other issues? Do they rely on their “authority”…well…because they are an “authority” like the scientists on the AGW side of the Global Warming debate, or do they effectively meet the evidence presented by the other side in goodfaith and where appropriate even acknowledge points raised by the other side?
Take for instance, here, NASA’s multiple statements that electric current causes magnetic fields. Also, the experimental results that demonstrate electric currents cause magnetic fields. And the lack of experiments to back up Dr. Svalgaard’s claims.
Did Dr. Svalgaard directly grasp the nettle on those issues?
Or did he tend to move on hoping something else might stick?
Take this NASA statement I presented:
“Magnetic fields are produced by electric currents. These currents are generated within the Sun by the flow of the Sun’s hot, ionized gases. We observe a variety of flows on the Sun’s surface and within its interior. Nearly all of these flows may contribute in one way or another to the production of the Sun’s magnetic field.”
Again, note the explicit and direct statement at the top of the paragraph: “Magnetic fields are produced by electric currents.”
And look at the last sentence in the passage: “Nearly all of these [plasma] flows may contribute in one way or another to the production of the Sun’s magnetic field.”
Nothing in NASA’s statement even remotely suggests a “[pre-]existing magnetic field” that causes the plasma to flow, on the contrary NASA explicitly states the opposite, that the electric currents cause magnetic fields to form.
Twice Dr. Svalgaard mentions an “existing magnetic field” in his explanation without any support for this proposition in direct contradiction of NASA’s statement.
This is an example of somebody expecting you to take their “say so” simply because they “say so”, not because of any rational or supporting scientific evidence. This is right out the playbook of the AGW scientists.
David presents the statement: ” {The important thing is that there is a magnetic field always everywhere in the cosmos, so any movement of a plasma [or conductor] will create electric fields and associated currents.}”
Yes, there are magnetic fields all over the Universe, but they are due to the flow of charged particles, electric currents all over the Universe.
It is the flows of plasma that generate the magnetic fields.
Dr. Svalgaard states: “Whenever you move a conductor in a magnetic field, an electrical current is generated.”
This is true, magnetic fields will induce electric currents, that is why I previously stated in this thread that electric current and magnetic fields are two sides of the same coin and why it’s called electro-magnetism.
Dr. Svalgaard goes back to the Vasiliunas paper: “Let me re-iterate Vasiliunas’s conclusions [which are unassailable, except by people that do not know physics]:
(1) a given plasma bulk flow produces an electric field,
(2) a given electric field does not produce a plasma bulk
flow. ”
Vasiliunas acknowledges that plasma flows produce an electric field (electric fields cause acceleration of charged particles, motion of charged particles, so electric fields cause electric current), what Vasiliunas doesn’t address is that charged particles not in motion will have an electric field, this “potential drop” or voltage is the electromotive force that will cause an electric current without a magnetic field being present. Magnetic fields do not start the process, electric fields do. But magnetic fields will contribute to the process in that an electric current is a self-reinforcing process, also known as positive feedback loop.
Vasiliunas is taking a plasma condition at two seperate times, so, yes, a bulk flow of plasma will produce an electric field, but it doesn’t follow that a given electric field be responsible for the ending bulk flow of plasma. That occurs through time and motion which produce the self-reinforcing build up of electric currents and magnetic fields because they are two sides of the same coin and are mutually reinforcing.
At the end of the day, it is clear that at the start of the day, plasma motion was caused by the electromotive force due to the presence of the electric field, not the magnetic field.
“Vasiliunas’s conclusions…are unassailable”???
I’d say Vasiliuna’s conclusions are refuted.
Dr. Svalgaard wrote: “The dynamo uses rotating coils of wire and magnetic fields to convert mechanical rotation into a pulsing direct electric current through Faraday’s law.”
Yes, this is another example of magnetism”s ability to cause secondary electrical currents. But the primary causation is the charged particle motion of the electrons or their “spin” inside the bar magnet or in the electromagnet; this causes the magnetic field which then in turn when moved will generate a secondary electric current.
The above is a good example of the “two sides of the same coin” idea of electromagnetism.
Dr. Svalgaard states: “Clearly, you [Evans] do not know what the emf is.
It is the work expended to produce a potential difference, which is generated by separating positive and negative charges.”
99% of the visible Universe is made up of plasma, charged particles in the state of ‘charge seperation’, so, electromotive force is the force that attracts positive and negative charges together or repels same charged particles apart. But since 99% of the Universe is plasma, the majority of the physical encounters are ones of electromotive force of attaction across a voltage potential drop or repulsion, not the work to seperate neutral atoms.
Let’s consider the word, “electro-magnet”, take a hint from word construction, but for the “electro”, an electromagnet would not be a magnet at all, take away the “electro” and it’s not a magnet.
Such as it is true for “electro-“magnets here on Earth, so it is also true for magnetic fields in space. This fulfills the idea that physical laws are constant throughout the Universe. That is why Science refers to these physical relationships as physical laws.
On the other hand, Dr. Svalgaard wants to invoke special laws of physics for special places without scientific evidence to support it. There is no support in Science for this kind of flawed reasoning, but Dr. Svalgaard is not approaching it from a sciencific perspective, but from faith in his own opinions inspite of the scientific evidence — This approach is more akin to religion than science.
And men can be fervent in their desire to see that their ideas are right. This trait of Human Nature for self-justification is one that Science must always guard against.
And we have seen this repeatedly in the AGW debate. Dr. Svalgaard, sadly, is caught in this spider’s web of self-delusion.
James F. Evans (10:44:44) :
And men can be fervent in their desire to see that their ideas are right.
Might explain your tenacity
And we have seen this repeatedly in the AGW debate. Dr. Svalgaard, sadly, is caught in this spider’s web of self-delusion.
In David’s head a light-bulb went off. In yours, darkness still reigns supreme.
99% of the visible Universe is made up of plasma, charged particles in the state of ‘charge separation’
Another little point [as we must take small steps in order not to loses you] for you to grasp: in a cosmic plasma, the charges are not separated, but thoroughly mixed. The slightest separation will result in the very mobile electrons [1 Volt accelerates an electron to more than a million miles per hour] finding their positive partners virtually instantly. Result: there is no charge separation.
@ur momisugly Dr. Svalgaard:
[D]avid has a right to his own opinion as do you, but you’re grasping at straws to use his statement as vindication for your opinion.
Look at david’s statement: “Precision of words are important indeed. Thank you for your clarification Dr. Svalgaard. I think a light went on in my head.”
I agree precision of words are important. Definitions are critical in physics, and, more important still is the consistent use of definitions.
But the statement david attributes to you: “{The important thing is that there is a magnetic field always everywhere in the cosmos, so any movement of a plasma [or conductor] will create electric fields and associated currents.}”
Is only “one side” of the two sides of the coin of electromagnetism.
Dr. Svalgaard, you have stated by fiat (without supporting experimental results) that magnetic fields are the primary variable (magnetic fields cause electric currents) by resorting to an admitted “thought experiment” which without experimental verification is nothing but a hypothesis.
Dr. Svalgaard states: “…in a cosmic plasma, the charges are not separated, but thoroughly mixed.”
Actually, they are in a state of ‘quasi-neutrality’, which is a state of ‘charge seperation’.
What do i mean by that?
Plasma by definition is physical matter where at least one electron is seperated from the nucleus, which results in free electrons and positive ions (more than one electron can be seperated from the nucleus), or, in other words, charged particles. Yes, these can be “thoughly mixed”, but they still retain their electromagnetic properties as charged particles. The charged particles react to the electromotive force and are conducive of electric current.
Dr. Svalgaard, you seem to forget your basic lessons: Langmuir won 1932 Nobel Prize in chemistry for his work with charged particles. Langmuir is the one who coined the term “Plasma”, and the reason he named it “Plasma” is because it had qualities that were like living tissue, blood plasma, it was self-organizing. Langmuir’s work demonstrated that plasma doesn’t “short out” into neutral atoms as you claim.
Rather, this self-organizing quality of charged particles is why space plasma, as Hannes Alfven, 1970 Nobel Prize winner in physics, noted in his later years, tends to be cellular and connected in circuits.
Dr. Svalgaard claims: “The slightest separation will result in the very mobile electrons [1 Volt accelerates an electron to more than a million miles per hour] finding their positive partners virtually instantly. Result: there is no charge separation.”
This claim is false.
If such was the case, then instead of 99% of the visible matter in the Universe being plasma, only a very small percentage would be plasma, charged particles. But since the compostion of the visible Universe is 99% plasma, it stands in mute testimony against you.
This claim is straight out of the 1960’s, and is so demonstratably false, it is unworthy of you. But such is your fervid desire to protect your ideas that you are willing to make this antquated statement.
Your fellow physicists will look at this statement and know you have gone over the edge.
Leif Svalgaard (11:20:54) :
The slightest separation will result in the very mobile electrons [1 Volt accelerates an electron to more than a million miles per hour] finding their positive partners virtually instantly. Result: there is no charge separation.
Now, you can get a charge separation [and hence an electric field and a current] by letting the plasma flow into a magnetic field. The magnetic field deflects positive charges one way and negative charges the other way and thus creates a charge separation and an electric current. To maintain the current, you need to keep pushing the [neutral] plasma across the magnetic field. As I have said now a zillion times, this is the fundamental physical process [verified by countless experiments] that drives energy release in the cosmos [flares, aurorae, etc].
NASA is planning to launch a series of spacecraft [MMS Mission] in 2014 to study this process. Here is how James Burch and James Drake [American Scientist, volume 97, number 5, sept-Oct, 2009] describe the mission background: “The twisting and turning of material in the core of the Earth, near the surface of the Sun, and in galaxies across the universe, amplifies magnetic fields in a process known as the dynamo [c.f. what I said earlier about the magnetic field being present first]. […] given that magnetic fields and their associated energy exists throughout the universe, it is not surprising that this energy is occasionally released, typically in the form of magnetically driven explosions [as I have pointed out several times]. Storms in the near-Earth space environment and flares in the corona of our Sun and other stars are examples of eplosions driven by the release of magnetic energy. […] A large fraction of the magnetic energy from solar flares is released as very high-energy particles […] As the Earth’s own magnetic fields are buffeted by storms from the Sun, large numbers of energetic particles are injected into the Earth’s radiation belts [as I have pointed out]. […] We now know that the mechanism for the fast release of magnetic energy requires that oppositely pointing magnetic fields be torn apart and reattached to the neighbors in a process called magnetic reconnection. […] The past decade and a half has witnessed noteworthy advances in our understanding, but a breakthrough requires a highly sophisticated space experiment, the NASA Magnetospheric Multiscale Mission scheduled for launch in 2014. […] Dungey’s magnetic reconnection idea had moved from questionable [although confirmed by Fairfield & Arnold and Svalgaard & Mansurov] to highly controversial (owing to the inability at the time to make actual observations) to universally accepted as the main driver of space storms around the Earth. […] The question of whether reconnection triggers the storm was answered in 2008 by the five-spacecraft NASA THEMIS mission which showed conclusively that reconnection is in fact the trigger mechanism. […] Could it be that the same type of reconnection that powers the Earth’s magnetosphere is responsible for energetic phenomena throughout the universe? Of course, our Sun is stong evidence in favor of this possibility […] The study of the dynamics measured with NASA’s TRACE and Japan’s Hinode satellites has dispelled any doubt about the central role of magnetic reconnection in producing explosive phenomena in the solar corona. […] Similarly, throughout the universe explosive phenomena are observed. […] In general, astrophysicists consider reconnection as a possible mechanism for any phenomenon exhibiting plasma heating, particle acceleration, magnetic field collapse or topology changes. […] In 1984 Galleev and Sagdeev proposed that the intense layers of electric currents produced during magnetic reconnection generate turbulent electric field fluctuations. […] The swirling electric field vortices generated in reconnection are similar to the gusty vortices of wind developing during the passage of a strong weather front. […] Another confirmation that the reconnection rate is determined by ion-scale dynamics, such as the magnetic field component predicted by Hall reconnection which has now been confirmed in the laboratory as well as in space.[…]”