A general comment: it's pretty clear that you and pln2bz have different perspectives on what the "Plasma/Electric Universe" approach/worldview/whatever is, sometimes these appear in direct conflict.
I don't see anything wrong with it. Perhaps, we disagree on some things. Or maybe, he makes a mistake and I correct him; or maybe, I make a mistake and he corrects me. In fact, there are mutually contradictory hypotheses on a number of things in Plasma Universe. So what? This is normal. Let's not obsess on particular individuals, but rather keep the overall picture in mind.
Leo
P.S. Don't read too much into what I choose to comment on and what I don't. Often, it's as simple as not having time.
Of late, leokorhas been applying the standard EU spiel more closely to Peratt's stuff, appealing to authority (see his response to your post, among others), and trying to lend credibility to Thornhill and Scott by blurring the distintions between the "Electric Universe" (of Thornhill/Scott) and plasma cosmologies in general by saying "Plasma Cosmology". This has rubbed off on pln2bz, who thinks the only obstacle to the proof and mainstream acceptance of EU is the lack of a sufficiently good argument.
The way I see it, Thornhill, Scott, and the Thunderbolts group in general put admirable effort into popularizing Plasma Universe. Would you hold a popular science book on, say, Big Bang, to the same rigorous standards as required for publication in peer-review journals? I think not.
In addition, they cover more subjects that have been hitherto covered by published articles on Plasma Universe. Given that peer-reviewed journals have not yet been saturated by the latter, I don't find it unreasonable to pursue qualitative speculation on relevant issues. If anything, these stimulate a new, fresh outlook and may, in time, lead to actual publications, in full rigor. Do not belittle them.
Care to explain - quantitatively - the dozens of detailed observations of weak and strong gravitational lensing of rich clusters of galaxies?
Links to articles on those observations, please. You probably would do it faster than if I go looking.
Care to explain - quantitatively - Zwicky's 1930s detailed observations on the radial velocity distribution of the Coma galaxy clusters (since repeated, for hundreds of other clusters)?
Care to explain - quantitatively - the observed trend in the average density of the universe, as the scale over which that density is measured increases?
Don't care, and don't see why I ought to. Plasma Universe makes no prediction on this matter. From its point of view, it could be anything, including the observed.
Care to explain - quantitatively - why the night sky is dark (except, of course, in Manhattan)?
Heh. This may be a paradox from the point of view of certain cosmological theories. But Plasma Universe expects a non-uniform distribution, based on the fundamental property of plasma to form current sheets and plasma filaments. No numbers on this, simply because Plasma Universe calls for no particular pattern, nor for a particular age of the Universe to accomplish it.
Different theories have different experimenta crucis.
Translation: pln2bz has read that a few (less than ten) people who seem to have affiliation with a plasma physics lab are "arguing for the Electric Universe concepts".
I dare say there are more than ten published in a single issue of IEEE Transactions on Plasma Science alone.
Fact: to the extent that the rich variety of theories, models, hypotheses, etc that comprises mainstream science is inconsistent with "EU", then said EU has been tested, repeatedly... and has failed every test.
Name one. So far, the main strategy of dealing with Plasma Universe by the mainstream astrophysics has been to ignore it. I would much like to see evidence to the contrary, in the form of articles and tests that purportedly falsify it.
Science is not about consensus; it doesn't work by judging lots of ideas. It works by having ways to know when you've found wrong ideas, which is called reductionism. Science doesn't have to "discuss" (have a dialog about) your Electric Universe hypotheses. Such a discussion will not advance human knowledge, but will serve only to placate the proponents of such a theory (hah! not likely) and distract people from exploring more promising and fruitful paths of scientific inquiry.
If there were indeed more promising paths, I would have agreed. Unfortunately, the current state of knowledge about space, especially beyond the solar system, leaves much to be desired. Most of the mainstream astrophysical theories are so heavily covered with ad-hoc patches that can hardly see the lining. Being surprised with every new observation and inventing yet another ad-hoc explanation every time is NOT a normal course of science. In such cases, it is time to reconsider the assumptions behind the original theory, in the first place. And why not? What reason, other than financial, is not to?
Many S- and SB- type galaxies are ejecting axial particle streams in directions where no galaxies are there to "cooperate", even on ONE pole, let alone both(!) poles simultaneously. If this were an electromagnetic phenomenon, we would not see this type of thing without bending electromagnetism to the breaking point.
There do no have to be any other galaxies over very large distances in the jet's direction. Firstly, we don't know the geometry of current filaments and where they lead. We do know that most of galaxies have their rotation axes close to parallel to the plane of the nearest large-scale structure ("wall"), but there is nothing to require the current filaments to be straight. Secondly, there is no upper limit to the filament's length. According to Peratt's galaxy formation model, galaxies form along the filaments where double layers form. And the distance between double layers along the same current filaments can be arbitrarily large. Recall that double layers is where most of the voltage differential is contained; outside of them, electric field is very weak. It may, in fact, be so weak that the filaments may lose pinch to such effect as to merge back into a current sheet.
Quoting the abstract: "Intense geomagnetic storms are usually caused by the CME-magnetosphere interaction. Up to now there are only very few in situ measurements with respect to the details of interactions of CME with the front shock and magnetosphere. In this paper we report such a fortuitous observation made by Cluster four spacecraft. At 16:35 UT on Nov. 4, 2001 LASCO/SOHO observed an Earth-direction halo CME. Associated with the CME were a front shock and a magnetic cloud, which caused an intense magnetic storm with $DstI could keep citing articles ad nauseum; there are too many to list here. Just a couple on double layers in cometary tails (very much akin to the Earth's magnetotail); the last article quoted above is also relevant.
Pardon for the garbled text. Some characters haven't been well received by the slashdot.org software. Anyhow, there should be a paragraph break before "I could keep citing articles ad nauseum; there are too many to list here. Just a couple on double layers in cometary tails (very much akin to the Earth's magnetotail); the last article quoted above is also relevant." For the abstract, follow the link.
I have not performed any experiments on exploding double layers. Acutally, I am not aware of any having been done at all. The idea of exploding DLs by Alfven was to describe the substorm process in the Earth's magnetotail.
To be sure, double layers explode not only in the magnetotail. Alfven himself observed it en vivo, for example, when he was invited to investigate certain large-scale accidents at the Swedish power company. Moreover, double layers are heavily involved in the process deceptively called "magnetic" reconnection.
However, this tenet is not usable any more, because this double layer has not been found to exist in the Earth's magnetotail.
Really? Not found to exist? Please point me to the sources for your statement. In the meantime, allow me to remind the readers of the most elementary properties of plasma. Double layers always form at the boundaries between plasma regions of different physical conditions. As an example, consider the stable double layer in the magnetopause. They even form under the conditions of relativistic Weibel instability; in lab, point a relativistic electron-positron or electron-ion beam at a slightly magnetized plasma; in space, a gamma ray burst will do:
Double layers also form in current-carrying plasmas; in general, wherever there exists a voltage differential in plasma. Their formation leads to and/or is result of various plasma instabilities. Therefore, among other things, double layers are very common in multi-ion-species plasmas (typical in space). The cross-field current instability, that plays such an important part in the current disruption model, is one; see, for example:
Quoting the abstract: "Intense geomagnetic storms are usually caused by the CME-magnetosphere interaction. Up to now there are only very few in situ measurements with respect to the details of interactions of CME with the front shock and magnetosphere. In this paper we report such a fortuitous observation made by Cluster four spacecraft. At 16:35 UT on Nov. 4, 2001 LASCO/SOHO observed an Earth-direction halo CME. Associated with the CME were a front shock and a magnetic cloud, which caused an intense magnetic storm with $DstI could keep citing articles ad nauseum; there are too many to list here. Jus
How about this: "Bright Spiral Galaxy M81 from Hubble" (http://antwrp.gsfc.nasa.gov/apod/ap070529.html) - note the asymmetric arms, the large central bulge;
Ah, I'm surprised to see you call on unquantified illustrations, but that's OK. I'm more concerned with where you got the idea that assymetry would falsify Peratt's model, nor why would so do a large central bulge. Do you in all seriousness suppose that Peratt's model relies on perfectly parallel plasma filaments with identical cross-section, plasma and current density, and their chemical composition? If you have a source that shows this in rigorous detail, perhaps you would be so kind as to provide an attribution?
As it happens, Peratt's own articles bear witness that symmetry is not essential. Indeed, many of his examples are not symmetric. Moreover, and in response to your next statement:
or this "One-Armed Spiral Galaxy NGC 4725" (http://antwrp.gsfc.nasa.gov/apod/ap050901.html)?
allow me to quote Peratt from A. L. Peratt. Evolution of the Plasma Universe II. The Formation of Systems of Galaxies. IEEE Transactions on Plasma Science, PS-14, 6 (1986); the quote stars at the bottom of page 768 and continues at the top of page 770:
Whether a normal spiral (S) or a barred spiral (BS) galaxy forms out of the plasma interaction depends primarily on the profile or cross section of the current-carrying filaments, its density distribution, and strength of the azimuthal magnetic fields. Bars form when the interacting plasma regions are sharply divided in plasma density, while normal spirals tend to form when the interacting plasma supporting the current-conducting filaments is more homogeneous overall.
If you want more detail as to why and what plasma experiments/models show it, the normal course of action would be to write Peratt and ask a question, as scientist to scientist. If you disagree and have a substantiated argument to that effect, feel free to publish it (or at least, present it here). If you can refer us to such article already published, by all means, do so.
As to the one-armed galaxy, I wonder if a bar would still form if the current density in one of the filaments is too low to trigger star formation. That would be another good question to ask Peratt, which I will do and will communicate his answer, if you're prepared to wait.
For starters, the MOND folk (Milgrom, Sanders, McGaugh, etc) would no doubt take strong exception to the "without recourse to [...] dark matter" part (http://www.astro.umd.edu/~ssm/mond/).
Oh, are you trying to shame me into not listening to another alternative model? I'm glad you pay attention to it, but I happen to disagree with that one, too. In any case, we were discussing something else.
Next, even in 1986, the observed "shape" of Double Radio Sources associated with Active Galactic Nuclei (DRAGNs) was inconsistent with the Peratt's model; today, with considerably more, much higher resolution, across many more EM wavebands observations, Peratt's model clearly fails both "shape" and "stability" criteria (an example: http://www.cv.nrao.edu/~abridle/dragnparts.htm).
How is it inconsistent? In what terms? What parameters don't match, and in which example? If in general, I'm more than interested to see a better exposition. The linked webpage would hardly qualify.
Finally, we now have independent estimates of the radial distribution of mass in galaxies, from analyses of gravitational lensing, something not available to any significant extent in 1986.
Are you saying, then, that you have data showing that galaxies don't, after all, rotate nearly as solid bodies? If so, there is no need for dark matter. Publish it; that would be a sensation.
There is no hard and fast definition of Plasma Universe. There are, however, some characteristic elements in the approach. One of them is the application of the principle of scalability of plasma to modeling large-scale space phenomena in plasma lab. Another is equal emphasis on the (pardon for imprecise wording) "electric side" of the electromagnetic phenomena (electric currents, double layers, etc.) as opposed to the typical emphasis in astrophysics on supposedly purely magnetic phenomena ("frozen" magnetic fields, and the like).
Alfven has always emphasized that electric currents in space must be given the same importance as magnetic fields. He is also famous for stating, time and time again, that ideal magnetohydrodynamics is unphysical and is little more than a simple limit of a much more complicated theory, primarily intended for pedagogical purposes. All of this can be found in his articles. See, for example, Alfven's "Double Layers and Circuits in Astrophysics," published in the First Special Issue on Plasma Universe of IEEE Transactions in Plasma Science (1986).
That said, you must also keep in mind that not every scientist politicizes the distinction. Moreover, plasma physics is a much larger field than astrophysics, but only a small portion of plasma physicists work with space plasmas. Others may not even be aware of how many (not all) astrophysicists treat plasma (some still think that plasma is a kind of gas; which is like saying that fluid is a kind of solid, or worse, for plasma is VERY different indeed). Volwerk's thesis is pure physics; but given that he works in Alfven's Lab, I would be much surprised if he hasn't heard of Plasma Universe, nor of how it relates to double layers.
You know, just because something with both "astrophysics" and "double layers" is published in a peer-reviewed journal, it doesn't make it outside of Plasma Universe. Plenty is published on Plasma Universe, including but not limited to seven special issues of IEEE Trans. Plasma Sci. But then, you may define Plasma Universe as what is NOT published. Then you'll be always right--by virtue of your definition. Or you could always ask Peratt. I mean it without sarcasm.
There are two methods of producing magnetism: 1) by current and 2) by aligning particles with non-zero magnetic moments (quantum spin) within a substance.
I don't suppose you would claim that those particles stay still inside permanent magnets, do you? Granted, the microscopic current argument can be applied to cosmic plasmas, too. But only in the framework of ideal magnetohydrodynamic, which actually does not apply to cosmic plasmas. Ideal plasmas do not form double layers, and cosmic plasmas do. Ideal plasmas do not possess collisionless resistivity, and cosmic plasmas do. Etc. etc. etc.
It's similar hubris for self-labeled "plasma physicists" (and even the occasional *actual* plasma physicist) to claim that a superficial resemblance of a few plasma effects they've seen in their work or models they've done on computers supersede the observations (of which they are largely unaware) of astronomers, cosmologists, astrophysicists, geophysicists, meteorologists, and planetary scientists, and moreover the theories developed in those fields that are consistent with the phenomena said "plasma physicists" misinterpret, misunderstand, or just don't know about.
What makes you think they are superficial? Perhaps because YOU don't know much about them? There is a solid basis behind the principle of scalability of plasma. If you know of even one observation that doesn't square with Peratt's model of galaxies, by all means, let us know. For Peratt's model, see:
To this day, Peratt's model remains the only one that explains the shape and stability of galaxies, and does it without recourse to such ad-hoc devices as dark matter.
Actually, I wouldn't be that vindictive. Alfven waves have been known for decades; they arise in many different scenarios. But it is also well known that, unlike say magnetosonic waves, Alfven waves cannot be generated by mechanical or gravitational means. It is also known that Alfven waves are intimately related to double layers. So, in fact, the suggested theory implicitly acknowledges that there is more to the so-called "magnetic" reconnection than pure magnetism.
And it should come as no surprise to SD readers that lab experiments have been done on "exploding double layers"! Indeed, here is a PhD thesis on just this topic (the author did this at no less an august lab than the Alfvén Lab, at the Royal Institute of Technology in Stockholm Sweden): http://adsabs.harvard.edu/abs/1993JPhD...26.1192V. Now that may be a little difficult to get one's hands on, and it is now nearly 15 years' old, so how about something more recent and accessible? Like "TOPICAL REVIEW: A review of recent laboratory double layer experiments" perhaps (http://adsabs.harvard.edu/abs/2007PSST...16....1C)?
Of course, research has been done on exploding double layers! How nice of you to quote work from the other side of the divide. Or did you think that Plasma/Electric Universe is to be defined as what has NOT been published?
Not quite; see http://slashdot.org/comments.pl?sid=426528&cid=22279668. Admittedly, however, the original statement, if enthusiastic, is also imprecise. That doesn't mean that the Plasma Universe point of view is necessarily in the wrong.
Not at all. I don't have time to respond to every nitty-bitty thread, so here's the gist of it. The supposed "debunking" creates a strawman, modeling cosmic bodies as isolated "pith-ball" charges in vacuum. It ignores the collective effects of many individual charges in the solar wind plasma that, on the relevant scale, can be assumed to be nearly continuous. It forms a double layer plasma sheath around a cosmic body (normally, in the magnetopause) that screens that cosmic body's charge from the outside. Most of the voltage differential occurs within such plasma sheath (also called Langmuir sheath). This very property of plasma gave it its name. Thus, provided the plasma sheaths don't intersect, there is no electrostatic interaction between individual cosmic bodies.
"And shame on everybody for just going along with the idea that Maxwell's Equations are meaningless in space. When you see a magnetic field, your first question should always be, "Where's the current?" To assume that it is not present even when you can see the magnetic field is just mind-boggling!" BUSTED http://slashdot.org/comments.pl?sid=426528&cid=22181096;
This is so old. The supposed "debunking" merely refers to the ideal magnetohydrodynamics. But if ideal gas can more or less be used to approximate a real gas, real plasmas behave very differently from the ideal plasma. In the ideal plasma limit, magnetic fields are indeed "frozen" into plasma. But that limit is unphysical, which is the gist of Alfven's objections to using it in an undiscriminating manner in astrophysics. Ideal plasma doesn't form double layers; it also knows no collisionless resistivity phenomena, which are known to occur in real plasmas.
That said, what does it have to do with comets? I suggest you stop diverting the readers' attention from the actual subject by trying to discredit Plasma/Electric Universe in general, by either demolishing strawmen or by picking on on occasional imprecise statement by this or that supporter.
No, it doesn't. I looked it up once before in an argument with an electric universe guy and I'm too lazy to do it again, but you can find the velocity of the solar wind as measured by SOHO and also by Voyager with a quick Google. I found an average value for Earth's neighborhood as well. Guess what? Fastest at SOHO, slower at Earth, slowest as measured by the Voyagers. That is, the solar wind slows down as it "passes the planets." The solar wind DOES accelerate within a few radii of the sun's surface but it certainly does not accelerate farther out.
You're comparing apples with oranges. Measurements in the immediate neiborhood of any planet will show a very different behavior than at the same distance from the Sun with no planet in the way. Admittedly, the statement you have responded to should have been phrased less ambiguously, in terms of orbital distance.
While it is true that the solar wind does not accelerate, it doesn't slow down either, until very very far out, probably due to the proximity of the heliopause. That slowdown is qualitatively consistent both with the hypothesis of a slowdown due to ionization of interstellar neutrals with the subsequent ion pickup, and with the Plasma Universe hypothesis of the heliopause having the structure of an electrostatic double layer. Note that neither camp has been ready to give a quantitative prediction--we don't even know where the heliopause begins.
The relative constancy of the solar wind in between is consistent with the Plasma Universe hypothesis of the area between the solar corona and the heliopause representing a positive column of a plasma discharge. Since most of the voltage differential occurs inside the double layers--one at the solar photosphere and another at the heliopause--the electric field inside the positive column is very weak. It likely keeps the solar wind from decelerating (the poster you have responded to has been rash to claim absolute acceleration).
For more rigorous comparative data on the solar wind velocity, see:
Notably, there is a 1.3 year periodicity to the solar wind averages. The velocity distribution at 1 AU is still very volatile, with the standard deviation of approximately 100 km/s, whereas the standard deviation decreases to 25 km/s at 15 AU. This means that the solar wind becomes closer to constant further on. At 40 AU, decrease of merely 30 km/s has been observed.
You seem to think that as long as something (finally!) becomes accepted by the mainstream, then it ceases to be a part of Plasma Universe. Not so. Do you remember Alfven vs. Chapman debate? How many years did it last? Chapman was already dead, and Alfven already a Novel laureate by the time space probes discovered Birkeland currents in the 70s, which settled it.
Plasma Universe is not a theory. It doesn't constitute a single model based on a set of hypotheses. It's an approach, with a distinct methodology and subject emphasis. Plasma Universe may, and indeed does, contain theories on the same subject that contradict each other. It is not a monolith. Methodologically, Plasma Universe is characterized by the following.
(1) General: Consistent application of plasma physics to space phenomena. Particular: Strong emphasis on the role of the electromagnetic force, so often neglected by the mainstream astrophysicists. It is conjectured that it may play a far more important part than does the gravity. Note that Plasma Universe is not limited to a specific set of people. Rather, it's defined by the subject and the approach.
(2) General: The principle of scalability of plasma, meaning that the basic properties of plasma are the same everywhere, at any scale. Particular: Extrapolation of laboratory and near-space experiments, as well as computer simulations based on those, to space phenomena long ago and far away, justified by the principle of scalability. Note that this principle is not an arbitrary assumption but a result of many years of observations, from the microscopic scale up to the planetary scale--as many degrees of magnitude of difference as between the planetary scale and the cluster scale.
(3) General: Preference is given to the "actualistic" approach, as defined by Alfven in opposition to the "prophetic" approach. The former starts in the here-and-now and works its way outward and back in time. The latter proposes a very detailed knowledge about the origin of the universe and works its way in the opposite directions. Particular: As a result, Plasma Universe is stronger in the near-space science, as evidenced even by the now-wide acceptance of the Alfven-Birkeland theory of auroras. But it is fuzzier in the department of cosmology (not to say that the greater detail of the Big Bang theory necessarily means that it's correct). For more on this dichotomy, see the Alfven's paper where he introduces it:
(4) Normally, I wouldn't have to say it, since experiment is a necessary part of scientific method--remove experiment, and you've got no science (and I mean it). But seeing the prevalence of purely theoretical approach in the mainstream astrophysics, I want to emphasize that Plasma Universe places a heavy emphasis on experiment. No matter who's the author of a theory--even Alfven himself--even a couple of contrary experiments may be grounds for reconsidering the theory's hypotheses. Plasma Universe does not construct no epicycles. No does it care how beautiful a theory is. As someone once said, the greatest tragedy of science is the slaying of a beautiful theory by an ugly fact.
Finally, I'd like to emphasize that "mainstream astrophysics" is far from being the same as "mainstream science." Plasma physicists are generally on the side of Plasma Universe. It is supported by IEEE (the largest scientific institution on the planet), the Los Alamos National Laboratory, and elements of NASA. LANL has an entire website devoted to Plasma Universe (http://public.lanl.gov/alp/plasma/TheUniverse.html). IEEE Transactions on Plasma Science links to it from its main page (http://www.ieeetps.org/). More importantly, IEEE Trans. Plasma Sci. has already devoted seven Special Issues to Plasma Universe, the latest one in August 2007. Here's the editorial:
Slashdot Mirror
I don't see anything wrong with it. Perhaps, we disagree on some things. Or maybe, he makes a mistake and I correct him; or maybe, I make a mistake and he corrects me. In fact, there are mutually contradictory hypotheses on a number of things in Plasma Universe. So what? This is normal. Let's not obsess on particular individuals, but rather keep the overall picture in mind.
Leo
P.S. Don't read too much into what I choose to comment on and what I don't. Often, it's as simple as not having time.
The way I see it, Thornhill, Scott, and the Thunderbolts group in general put admirable effort into popularizing Plasma Universe. Would you hold a popular science book on, say, Big Bang, to the same rigorous standards as required for publication in peer-review journals? I think not.
In addition, they cover more subjects that have been hitherto covered by published articles on Plasma Universe. Given that peer-reviewed journals have not yet been saturated by the latter, I don't find it unreasonable to pursue qualitative speculation on relevant issues. If anything, these stimulate a new, fresh outlook and may, in time, lead to actual publications, in full rigor. Do not belittle them.
Leo
Moreover, intergalactic filaments are not unknown: NGC 1410/1409: Intergalactic Pipeline.
Leo
Links to articles on those observations, please. You probably would do it faster than if I go looking.
A.L. Peratt. Evolution of the Plasma Universe: II. The Formation of Systems of Galaxies. IEEE Transactions on Plasma Science PS-14, 6 (1986).
Particularly, Fig. 14 on page 771 with the attendant discussion.
For the classical Rayleigh-Jeans part of the curve, see:
W. Peter, A.L. Peratt. Synchrotron Radiation Spectrum for Galactic-Sized Plasma Filaments. IEEE Transactions on Plasma Science PS-18, 1 (1990)
Particularly, the discussion of thermalization of synchrotron radiation below plasma frequency.
Don't care, and don't see why I ought to. Plasma Universe makes no prediction on this matter. From its point of view, it could be anything, including the observed.
Heh. This may be a paradox from the point of view of certain cosmological theories. But Plasma Universe expects a non-uniform distribution, based on the fundamental property of plasma to form current sheets and plasma filaments. No numbers on this, simply because Plasma Universe calls for no particular pattern, nor for a particular age of the Universe to accomplish it.
Different theories have different experimenta crucis.
Leo
I dare say there are more than ten published in a single issue of IEEE Transactions on Plasma Science alone.
Name one. So far, the main strategy of dealing with Plasma Universe by the mainstream astrophysics has been to ignore it. I would much like to see evidence to the contrary, in the form of articles and tests that purportedly falsify it.
Leo
If there were indeed more promising paths, I would have agreed. Unfortunately, the current state of knowledge about space, especially beyond the solar system, leaves much to be desired. Most of the mainstream astrophysical theories are so heavily covered with ad-hoc patches that can hardly see the lining. Being surprised with every new observation and inventing yet another ad-hoc explanation every time is NOT a normal course of science. In such cases, it is time to reconsider the assumptions behind the original theory, in the first place. And why not? What reason, other than financial, is not to?
Leo
There do no have to be any other galaxies over very large distances in the jet's direction. Firstly, we don't know the geometry of current filaments and where they lead. We do know that most of galaxies have their rotation axes close to parallel to the plane of the nearest large-scale structure ("wall"), but there is nothing to require the current filaments to be straight. Secondly, there is no upper limit to the filament's length. According to Peratt's galaxy formation model, galaxies form along the filaments where double layers form. And the distance between double layers along the same current filaments can be arbitrarily large. Recall that double layers is where most of the voltage differential is contained; outside of them, electric field is very weak. It may, in fact, be so weak that the filaments may lose pinch to such effect as to merge back into a current sheet.
Leo
Pardon for the garbled text. Some characters haven't been well received by the slashdot.org software. Anyhow, there should be a paragraph break before "I could keep citing articles ad nauseum; there are too many to list here. Just a couple on double layers in cometary tails (very much akin to the Earth's magnetotail); the last article quoted above is also relevant." For the abstract, follow the link.
Leo
To be sure, double layers explode not only in the magnetotail. Alfven himself observed it en vivo, for example, when he was invited to investigate certain large-scale accidents at the Swedish power company. Moreover, double layers are heavily involved in the process deceptively called "magnetic" reconnection.
J.F. Drake. Collisionless Magnetic Reconnection.
Really? Not found to exist? Please point me to the sources for your statement. In the meantime, allow me to remind the readers of the most elementary properties of plasma. Double layers always form at the boundaries between plasma regions of different physical conditions. As an example, consider the stable double layer in the magnetopause. They even form under the conditions of relativistic Weibel instability; in lab, point a relativistic electron-positron or electron-ion beam at a slightly magnetized plasma; in space, a gamma ray burst will do:
Milosavljevic M., et. al. Steady-State Electrostatic Layers from Weibel Instability in Relativistic Collisionless Shocks. Astrophys. J. 637 (2006)
Double layers also form in current-carrying plasmas; in general, wherever there exists a voltage differential in plasma. Their formation leads to and/or is result of various plasma instabilities. Therefore, among other things, double layers are very common in multi-ion-species plasmas (typical in space). The cross-field current instability, that plays such an important part in the current disruption model, is one; see, for example:
G. Zimbardo, et. al. Magnetic turbulence and particle dynamics in the Earth's magnetotail. Annales Geophysicae 21 (2003)
R. L. Stenzel, et. al. Double layer formation during current sheet disruptions in a reconnection experiment. Geophysical Research Letter 9 (1982)
J. E. Borovsky. Double layers do accelerate particles in the auroral zone. Physical Review Letters 69, 7 (1992)
Reddy R.V., Lakhina G.S. Ion acoustic double layers and solitons in auroral plasma. Planetary and Space Science 39, 10 (1991)
El-Taibany, W. F.; Sabry, R. Dust-acoustic solitary waves and double layers in a magnetized dusty plasma with nonthermal ions and dust charge variation. Physics of Plasmas 12, 8 (2005)
Xiao C., et. al. Cluster Observation of Wave Excitation in the Magnetopause Caused by Interplanetary Shocks. 2006 Western Pacific Geophysics Meeting
Quoting the abstract: "Intense geomagnetic storms are usually caused by the CME-magnetosphere interaction. Up to now there are only very few in situ measurements with respect to the details of interactions of CME with the front shock and magnetosphere. In this paper we report such a fortuitous observation made by Cluster four spacecraft. At 16:35 UT on Nov. 4, 2001 LASCO/SOHO observed an Earth-direction halo CME. Associated with the CME were a front shock and a magnetic cloud, which caused an intense magnetic storm with $DstI could keep citing articles ad nauseum; there are too many to list here. Jus
Ah, I'm surprised to see you call on unquantified illustrations, but that's OK. I'm more concerned with where you got the idea that assymetry would falsify Peratt's model, nor why would so do a large central bulge. Do you in all seriousness suppose that Peratt's model relies on perfectly parallel plasma filaments with identical cross-section, plasma and current density, and their chemical composition? If you have a source that shows this in rigorous detail, perhaps you would be so kind as to provide an attribution?
As it happens, Peratt's own articles bear witness that symmetry is not essential. Indeed, many of his examples are not symmetric. Moreover, and in response to your next statement:
allow me to quote Peratt from A. L. Peratt. Evolution of the Plasma Universe II. The Formation of Systems of Galaxies. IEEE Transactions on Plasma Science, PS-14, 6 (1986); the quote stars at the bottom of page 768 and continues at the top of page 770:
If you want more detail as to why and what plasma experiments/models show it, the normal course of action would be to write Peratt and ask a question, as scientist to scientist. If you disagree and have a substantiated argument to that effect, feel free to publish it (or at least, present it here). If you can refer us to such article already published, by all means, do so.
As to the one-armed galaxy, I wonder if a bar would still form if the current density in one of the filaments is too low to trigger star formation. That would be another good question to ask Peratt, which I will do and will communicate his answer, if you're prepared to wait.
Oh, are you trying to shame me into not listening to another alternative model? I'm glad you pay attention to it, but I happen to disagree with that one, too. In any case, we were discussing something else.
How is it inconsistent? In what terms? What parameters don't match, and in which example? If in general, I'm more than interested to see a better exposition. The linked webpage would hardly qualify.
Are you saying, then, that you have data showing that galaxies don't, after all, rotate nearly as solid bodies? If so, there is no need for dark matter. Publish it; that would be a sensation.
There is no hard and fast definition of Plasma Universe. There are, however, some characteristic elements in the approach. One of them is the application of the principle of scalability of plasma to modeling large-scale space phenomena in plasma lab. Another is equal emphasis on the (pardon for imprecise wording) "electric side" of the electromagnetic phenomena (electric currents, double layers, etc.) as opposed to the typical emphasis in astrophysics on supposedly purely magnetic phenomena ("frozen" magnetic fields, and the like).
Alfven has always emphasized that electric currents in space must be given the same importance as magnetic fields. He is also famous for stating, time and time again, that ideal magnetohydrodynamics is unphysical and is little more than a simple limit of a much more complicated theory, primarily intended for pedagogical purposes. All of this can be found in his articles. See, for example, Alfven's "Double Layers and Circuits in Astrophysics," published in the First Special Issue on Plasma Universe of IEEE Transactions in Plasma Science (1986).
That said, you must also keep in mind that not every scientist politicizes the distinction. Moreover, plasma physics is a much larger field than astrophysics, but only a small portion of plasma physicists work with space plasmas. Others may not even be aware of how many (not all) astrophysicists treat plasma (some still think that plasma is a kind of gas; which is like saying that fluid is a kind of solid, or worse, for plasma is VERY different indeed). Volwerk's thesis is pure physics; but given that he works in Alfven's Lab, I would be much surprised if he hasn't heard of Plasma Universe, nor of how it relates to double layers.
You know, just because something with both "astrophysics" and "double layers" is published in a peer-reviewed journal, it doesn't make it outside of Plasma Universe. Plenty is published on Plasma Universe, including but not limited to seven special issues of IEEE Trans. Plasma Sci. But then, you may define Plasma Universe as what is NOT published. Then you'll be always right--by virtue of your definition. Or you could always ask Peratt. I mean it without sarcasm.
Leo
I don't suppose you would claim that those particles stay still inside permanent magnets, do you? Granted, the microscopic current argument can be applied to cosmic plasmas, too. But only in the framework of ideal magnetohydrodynamic, which actually does not apply to cosmic plasmas. Ideal plasmas do not form double layers, and cosmic plasmas do. Ideal plasmas do not possess collisionless resistivity, and cosmic plasmas do. Etc. etc. etc.
Leo
What makes you think they are superficial? Perhaps because YOU don't know much about them? There is a solid basis behind the principle of scalability of plasma. If you know of even one observation that doesn't square with Peratt's model of galaxies, by all means, let us know. For Peratt's model, see:
A. L. Peratt. Evolution of the Plasma Universe I. Double Radio Galaxies, Quasars, and Extragalactic Jets. IEEE Transactions in Plasma Science, PS-14, 6 (1986)
A. L. Peratt. Evolution of the Plasma Universe II. The Formation of Systems of Galaxies. IEEE Transactions on Plasma Science, PS-14, 6 (1986)
To this day, Peratt's model remains the only one that explains the shape and stability of galaxies, and does it without recourse to such ad-hoc devices as dark matter.
Leo
Leo
Of course, research has been done on exploding double layers! How nice of you to quote work from the other side of the divide. Or did you think that Plasma/Electric Universe is to be defined as what has NOT been published?
Leo
Not quite; see http://slashdot.org/comments.pl?sid=426528&cid=22279668. Admittedly, however, the original statement, if enthusiastic, is also imprecise. That doesn't mean that the Plasma Universe point of view is necessarily in the wrong.
Not at all. I don't have time to respond to every nitty-bitty thread, so here's the gist of it. The supposed "debunking" creates a strawman, modeling cosmic bodies as isolated "pith-ball" charges in vacuum. It ignores the collective effects of many individual charges in the solar wind plasma that, on the relevant scale, can be assumed to be nearly continuous. It forms a double layer plasma sheath around a cosmic body (normally, in the magnetopause) that screens that cosmic body's charge from the outside. Most of the voltage differential occurs within such plasma sheath (also called Langmuir sheath). This very property of plasma gave it its name. Thus, provided the plasma sheaths don't intersect, there is no electrostatic interaction between individual cosmic bodies.This is so old. The supposed "debunking" merely refers to the ideal magnetohydrodynamics. But if ideal gas can more or less be used to approximate a real gas, real plasmas behave very differently from the ideal plasma. In the ideal plasma limit, magnetic fields are indeed "frozen" into plasma. But that limit is unphysical, which is the gist of Alfven's objections to using it in an undiscriminating manner in astrophysics. Ideal plasma doesn't form double layers; it also knows no collisionless resistivity phenomena, which are known to occur in real plasmas.
That said, what does it have to do with comets? I suggest you stop diverting the readers' attention from the actual subject by trying to discredit Plasma/Electric Universe in general, by either demolishing strawmen or by picking on on occasional imprecise statement by this or that supporter.
Leo
You're comparing apples with oranges. Measurements in the immediate neiborhood of any planet will show a very different behavior than at the same distance from the Sun with no planet in the way. Admittedly, the statement you have responded to should have been phrased less ambiguously, in terms of orbital distance.
While it is true that the solar wind does not accelerate, it doesn't slow down either, until very very far out, probably due to the proximity of the heliopause. That slowdown is qualitatively consistent both with the hypothesis of a slowdown due to ionization of interstellar neutrals with the subsequent ion pickup, and with the Plasma Universe hypothesis of the heliopause having the structure of an electrostatic double layer. Note that neither camp has been ready to give a quantitative prediction--we don't even know where the heliopause begins.
The relative constancy of the solar wind in between is consistent with the Plasma Universe hypothesis of the area between the solar corona and the heliopause representing a positive column of a plasma discharge. Since most of the voltage differential occurs inside the double layers--one at the solar photosphere and another at the heliopause--the electric field inside the positive column is very weak. It likely keeps the solar wind from decelerating (the poster you have responded to has been rash to claim absolute acceleration).
For more rigorous comparative data on the solar wind velocity, see:
H.R. Collard, et. al. Radial variation of the solar wind speed between 1 and 15 AU. J. Geophys. Res. 87:A4 (1982)
J. D. Richardson. Solar wind processes. Physics of Space Plasma (1995)
Notably, there is a 1.3 year periodicity to the solar wind averages. The velocity distribution at 1 AU is still very volatile, with the standard deviation of approximately 100 km/s, whereas the standard deviation decreases to 25 km/s at 15 AU. This means that the solar wind becomes closer to constant further on. At 40 AU, decrease of merely 30 km/s has been observed.
Leo
Plasma Universe is not a theory. It doesn't constitute a single model based on a set of hypotheses. It's an approach, with a distinct methodology and subject emphasis. Plasma Universe may, and indeed does, contain theories on the same subject that contradict each other. It is not a monolith. Methodologically, Plasma Universe is characterized by the following.
(1) General: Consistent application of plasma physics to space phenomena. Particular: Strong emphasis on the role of the electromagnetic force, so often neglected by the mainstream astrophysicists. It is conjectured that it may play a far more important part than does the gravity. Note that Plasma Universe is not limited to a specific set of people. Rather, it's defined by the subject and the approach.
(2) General: The principle of scalability of plasma, meaning that the basic properties of plasma are the same everywhere, at any scale. Particular: Extrapolation of laboratory and near-space experiments, as well as computer simulations based on those, to space phenomena long ago and far away, justified by the principle of scalability. Note that this principle is not an arbitrary assumption but a result of many years of observations, from the microscopic scale up to the planetary scale--as many degrees of magnitude of difference as between the planetary scale and the cluster scale.
(3) General: Preference is given to the "actualistic" approach, as defined by Alfven in opposition to the "prophetic" approach. The former starts in the here-and-now and works its way outward and back in time. The latter proposes a very detailed knowledge about the origin of the universe and works its way in the opposite directions. Particular: As a result, Plasma Universe is stronger in the near-space science, as evidenced even by the now-wide acceptance of the Alfven-Birkeland theory of auroras. But it is fuzzier in the department of cosmology (not to say that the greater detail of the Big Bang theory necessarily means that it's correct). For more on this dichotomy, see the Alfven's paper where he introduces it:
http://plasmascience.net/tpu/downloads/CosmologyAlfven.pdf
(4) Normally, I wouldn't have to say it, since experiment is a necessary part of scientific method--remove experiment, and you've got no science (and I mean it). But seeing the prevalence of purely theoretical approach in the mainstream astrophysics, I want to emphasize that Plasma Universe places a heavy emphasis on experiment. No matter who's the author of a theory--even Alfven himself--even a couple of contrary experiments may be grounds for reconsidering the theory's hypotheses. Plasma Universe does not construct no epicycles. No does it care how beautiful a theory is. As someone once said, the greatest tragedy of science is the slaying of a beautiful theory by an ugly fact.
Finally, I'd like to emphasize that "mainstream astrophysics" is far from being the same as "mainstream science." Plasma physicists are generally on the side of Plasma Universe. It is supported by IEEE (the largest scientific institution on the planet), the Los Alamos National Laboratory, and elements of NASA. LANL has an entire website devoted to Plasma Universe (http://public.lanl.gov/alp/plasma/TheUniverse.html). IEEE Transactions on Plasma Science links to it from its main page (http://www.ieeetps.org/). More importantly, IEEE Trans. Plasma Sci. has already devoted seven Special Issues to Plasma Universe, the latest one in August 2007. Here's the editorial: