Talk:Dusty plasma

The terms of the equation need to be defined.

Should "q/m ~ √G" be "q/m ≈ √G"?

I hope "vxB" doesn't mean "v × B". — Omegatron 02:57, 8 December 2005 (UTC)

Thanks for that, all fixed. --Iantresman 08:15, 8 December 2005 (UTC)

Inappropriate

I must say that I don't like the fact that the book "Physics of the Plasma Universe" which is chiefly concerned with the pseudoscience of "the electric universe" is used as a reference here.--Deglr6328 23:23, 4 February 2006 (UTC)

Physics of the Plasma Universe has NOTHING to do with the Electric Universe theory, and is published by a reputable publisher (1992, Springer-Verlag). If you can find (a) just ONE sentence in the book which suggests pseudoscience, (b) any mentions of the "Electric Universe" (c) any error in the section on dusty plasmas, then I'll remove the reference. Have you read it? --Iantresman 01:03, 5 February 2006 (UTC)

"electric universe" "plasma universe" "plasma cosmology", it's all the same nuttyness.--Deglr6328 01:57, 5 February 2006 (UTC)

I concur. Reference removed. It's not a particularly good or relevant reference anyways. Nonsuch 03:40, 7 April 2006 (UTC)

I restored the citation. This is the actual book where some of the informatin for the article came from, and is in accordance with Wiki policy. What you personally think about plasma cosmology, is irrelevent to the discussion on dusty plasmas. --Iantresman 07:35, 7 April 2006 (UTC)

The reference was deleted again, with no comment. I've restored it. Just to illustrate that it is a valid and relevant reference, take a look at recent citations of it in the peer-reviewed literature (from NASA ADS), one of which is from 2007 --Togr 10:27, 19 July 2007 (UTC)

I looked at these and I should point out that the references are generally for plasma cosmology and not dusty plasmas. --Nondistinguished 15:51, 23 July 2007 (UTC)

Reference restoration

I would like to restore this deleted reference as the verifiable reliable secondary source for the section on Dynamics, and offer the following rationa le, unless there are verifiable reasons not to:

1. I contributed much of the section on Dynamics.[1] I used as my source, page 325 of the reference.[2] It is the source, making it both good and relevant.
2. I can not find any support for the description of the book by the other editors. I checked two peer reviewed reviews, witch have not a hint of the concerns of other editors.:
   * A 1993 review of the book [3] in the peer reviewed, scientific journal Astrophysics and Space Science describes it as "educational reading for any astrophysicist".
   * A 1994 review [4] of the book in the scientific journal Space Science Reviews, mentions the "useful appendix [..] on dusty and grain plasma"
3. The book has just been republished by the academic publishing company, Springer in 2012.[5]
4. I also checked whether the book is being used by textbooks as a reference, and found it in a range of books including "Soft X-Rays and Extreme Ultraviolet Radiation" (2007)[6], "Plasma Physics: Confinement, Transport and Collective Effect" (2005)[7], "An Introduction to Plasma Astrophysics and Magnetohydrodynamics"[8]
5. The book itself alleviates some of the editors' concerns. It's introduction notes that "Some of the interesting topics in contemporary astrophysics such as discordant redshifts and other cosmological issues are not discussed here" (preface, page v).
6. In conclusion, I find no evidence supporting the other editors' concerns, and none was offered. All indications are that this is a standard text book that verifies the information in the article.

Iantresman (talk) 14:31, 5 November 2012 (UTC)

No, it's not a reliable source to be linking as it's clearly fringe. IRWolfie- (talk) 13:54, 6 November 2012 (UTC)

Thanks for your reply. If it is "clearly fringe", can you offer a couple of sources that suggests this, as this does not seem to be reflected in any of the sources I provided. The more I look, the more I find it referenced throughout the standard mainstream literature, eg. in the scientific journal, Physics of Plasmas,[9] the peer-reviewed scientific journal Solar Physics,[10] the scientific journal Physics Letters,[11] and just this year, Applied Physics,[12]. I don't understand why all these publication would be using an unreliable source? --Iantresman (talk) 15:22, 6 November 2012 (UTC)

I have further checked with Coalition for Plasma Science, "a group of institutions, organizations, and companies" whose aims are to promote plasma science, with a long list of reputable members, whose education material includes a publication on Space Plasmas, and its Suggested Reading include Physics of the Plasma Universe. --Iantresman (talk) 15:49, 6 November 2012 (UTC)

You googled for matches of the book and a group, that has an article, written by Peratt, that has the book as a reference is all you got? Also that something is in peer reviewed papers does not mean it is not a fringe viewpoint. Conformal cyclic cosmology is also a fringe viewpoint for example. We don't present fringe viewpoints as though they were mainstream. We also have WP:ONEWAY mentions only. IRWolfie- (talk) 20:14, 7 November 2012 (UTC)

In addition to the article used by the Coalition for Plasma Science (who must consider Peratt a respectable reliable source), I also cited 4 peer-reviewed articles, to go with the 2 peer-reviewed articles I mentioned last time, plus the two text books, plus the two reviews (by peer-reviewed publications), plus the republication of the book by Springer. They all seem to contradict your conclusion. I don't know why you mentioned Conformal cyclic cosmology as it is not mentioned in the article, so it does not seem relevant. WP:ONEWAY does not seem to be relevant here either, the dynamics of dusty plasmas is not fringe. I repeat my suggestion. If the book is "clearly fringe", can you please offer a couple of sources that suggests this, so that other editors can review them. Iantresman (talk) 22:36, 7 November 2012 (UTC)

What do you think 4 articles using the book shows? It shows nothing for our consideration here. The Plasma universe is a fringe viewpoint and it will not be getting space in this non-fringe article per WP:ONEWAY. IRWolfie- (talk) 16:31, 8 November 2012 (UTC)

You included a link to an article on cosmology. If you recall, I noted that the the book includes nothing on cosmology. Published this year by a reputable scientific publisher, the 6 peer-reviewed articles and 2 textbooks demonstrates that the source (irrespective of whether it maybe fringe) is a reliable source for the information in the article. There are many more peer-reviewed citations to the book, including those in: the Journal of Experimental and Theoretical Physics,[13] Physical Review A,[14] Physical Review D,[15] Physical Review E,[16] Plasma Physics Reports,[17] Advances in Space Research,[18] European journal of physics,[19] and many more.

I am quite concerned that (a) we take information from the book but refuse to provide due credit (b) that peer-reviewed articles, academic books, and an industry organisations, all seem to contradict your conclusion (c) you have still not provided a verifiable source so that other editors can review your concerns. --Iantresman (talk) 17:27, 8 November 2012 (UTC)

You are not using a good indicator. Cold fusion has a few papers published in journals every year, and even the occasional book, but it's still fringe. --Enric Naval (talk) 17:53, 8 November 2012 (UTC)

I see this as clearly within the "fringe universe" regardless of if said universe is made of plasma or exaggeration. History2007 (talk) 18:00, 8 November 2012 (UTC)

@Iantresman, no doubt you will support removing "Physics of the plasma universe" from Plasma universe. IRWolfie- (talk) 18:49, 8 November 2012 (UTC)

@Enric Naval: I also don't think we are comparing like with like. Cold fusion is not generally accepted. Plasma astrophysics is pretty standard. As a comparison, we would need to find (a) a non-critical textbook on cold fusion that is either in print, or has been republished by a reputable scientific publisher in the last couple of years (I couldn't find any) (b) the same book is reviewed positively about the science (c) the book is use as a positive reliable source in peer-reviewed articles.

@History2007: You've also said "clearly", so I would welcome your sources, so that other editors can assess them.

@IRWolfie: I will be happy to discuss the book in the appropriate place. I am still looking forward to reviewing the source of your concern.

As far as I can tell from all the sources, the book satisfies WP:IRS as a reliable, published source, that is used extensively as a citation. --Iantresman (talk) 19:44, 8 November 2012 (UTC)

Plasma cosmology can't be "pretty standard" when it's part of Non-standard cosmology..... Anyways, here you have Nuclear Energy Encyclopedia: Science, Technology, and Applications John Wiley & Sons 2011 and other publications by cold fusion supporter Krivit, and Edmund Storms' The Science Of Low Energy Nuclear Reaction 2007 World Scientific. Even Beaudette, Charles G. (2002), Excess Heat & Why Cold Fusion Research Prevailed, Beaudette's self-published book got recommendations in a few mainstream sources.

I see no reason to restrict the search to books published in the last couple of years, looks to me like an arbitrarily high requirement that would leave out valid comparisons. --Enric Naval (talk) 14:42, 9 November 2012 (UTC)

I agree that "plasma cosmology can't be 'pretty standard'". As you will note in my point #5 above, and elsewhere in this thread, the quote I provided shows that the book has nothing to do with cosmology.

  I'm not sure what point you are making concerning the books, I'm having problems finding reviews about them, academic textbooks that reference them, and peer-reviewed journals that cite them, from any decade.

I am making no arbitrarily high demands, just following WP:IRS. All the mainstream sources I have found seem to contradict the concerns of editors. --Iantresman (talk) 15:37, 9 November 2012 (UTC)

Just to nail this down:

"Yet the instances are numerous, rather than rare, in which none of these exceptions apply and nevertheless prominent, successful scientists hitherto respected by their peers make claims that provoke a high degree of disdain or contempt for those same peers (...) And Hannes Alfvén was awarded the Nobel Prize in 1970 for work on space plasma, yet according to a later article in Science, 'many regard his cosmological ideas as belonging to the fringe, and researchers who study his cosmology say they get no public support.'" Fatal Attractions: The Troubles With Science by Henry H. Bauer pp. 103-104

I am looking at the summary and content index, and it seems to be coherent with the definition in Plasma cosmology " Its central idea is that the dynamics of ionized gases (or plasmas) plays a decisive role in the physics of the universe at scales larger than the Solar system." And the author is Anthony_Peratt_(physicist), who has written about plasma cosmology. And the book has applications of plasma theories to galaxies, which also fits the definition of plasma cosmology. Thus, I understand that this book uses Alfvén's ideas, and that its topic is plasma cosmology, under the alternative name of "plasma universe". P.D.: Heck, years ago Peratt published a paper titled Plasma Cosmology. --Enric Naval (talk) 16:13, 9 November 2012 (UTC)

Thank you for that, you've obviously put in some good research there, and provided some good sources we can work with. There is no doubt that some consider Plasma Cosmology fringe, and I did not disagree with you earlier. But it is important to note (per your quote) that Alfvén also won the Nobel Prize for some of his work on astrophysical plasmas which is now mainstream.

  Now we start to go astray a bit. It is no surprise that some of the content of Physics of the Plasma Universe has similarities to Alfvén's work and Plasma Cosmology. For example, Alfvén explains that his basic research in plasma physics, such as magnetohydrodynamics (MHD), are also a fundamental part of Plasma Cosmology, and indeed, MHD is also covered by the book in section 2.4.

  So how can we find out that the book is not about Alfvén's Plasma Cosmology? (1) the book tells us in the introduction "cosmological issues are not discussed here" (preface, page v). (2) We can double check the first point, because keywords such as "ambiplasma", "symmetric cosmology", "Oscar Klein", "metagalaxy" are not mentioned in the book (3) None of the sources I have already provided suggest that the book includes contentious material.

  So, there is no dispute, and no surprise that the book includes some of Alfvén ideas, (after all, he has been described as the "the father of modern space plasma physics"[20]) and there may indeed be content that is in common with Plasma Cosmology, but the book states it does not include anything on cosmology, and none of the textbooks, book reviews, or peer-reviewed citations, suggest that there is sufficiently contentious material to make the book unreliable. On the contrary, the reviews give the book praise, and the textbooks and peer-reviewed citations use the book a verifiable reliable source. --Iantresman (talk) 18:08, 9 November 2012 (UTC)

You've even cited the book in support of text at plasma cosmology. IRWolfie- (talk) 19:24, 9 November 2012 (UTC)

No, seriously, I'm looking at the content index and one of the chapters is called "Scaling laws" and it's linked to a page called Plasma scaling which cites Alfvén and talks of plasmas at scales larger than the Solar System (meh, it even uses the same image as our Plasma Cosmology article....). Another chapter is called "Birkeland Currents in Cosmic Plasma", with a link to Birkeland current, in the chapter "Cosmic Birkeland currents" it talks about "many structures in the universe exhibiting filamentation", for the size of the effect it cites Peratt's book. I understand this is directly related to the theories of plasma cosmology, with the filaments that supposedly created spiral galaxies? I understand also that there are parts that are clearly not about cosmology, like "The Bennett Pinch". But, seriously, I would rather use a book that doesn't delve into fringe topics in several chapters. And from an author who is not throughly criticized in the randi forums for not correcting flaws in his theories and publishing in low-impact journals.... [21]. One who doesn't call himself indirectly a "plasma dissident", see Anthony L. Peratt, 'Dean of the Plasma Dissidents', The World & I, May 1988, pp. 190-197. One who doesn't sign open letters about how he doesn't get funding fo his alternative theory[22]. I mean, really, how are we supposed to distinguish which parts are affected by fringe theories and which aren't? As IRWolfie points out, there are other books on dusty plasma that don't have these problems lots to pick from. I don't see why we should insist i n using problematic books when there are non-problematic books available. --Enric Naval (talk) 21:47, 9 November 2012 (UTC)

To add to that, I suggest googling the Bennett Pinch with Plasma Cosmology. THe bennet pinch appears to also be invoked in plasma cosmology [23]. IRWolfie- (talk) 21:56, 9 November 2012 (UTC)

Dusty plasma is also part of plasma cosmology, since it's used to explain the formation of galaxies from galactic dust plasma. And Peratt's specialty in cosmology is the formation of galaxies..... Is that appendix about "mainstream" dusty plasma at solar system level, or about the "fringe" one at galactic level? --Enric Naval (talk) 13:16, 10 November 2012 (UTC)

@Iantresman: Don't you feel lonely here? History2007 (talk) 21:41, 8 November 2012 (UTC)

I have lots of verifiable sources keeping me and my source, company ;=) but thank you for asking. Congratulations on reaching 70,000+ edits, and I agree with your Russian roulette view of scientific content. --Iantresman (talk) 22:25, 8 November 2012 (UTC)

You are essentially performing a classic wikilawyer. You are setting the requirements arbitrarily high, that another source must have dismissed your specific source. Drop the stick. IRWolfie- (talk) 23:39, 8 November 2012 (UTC)

I refer you to the Wikilawyer section "Misuse of the term": "Because reasoned arguments in a debate necessarily include both elements of fact and references to principles, disputants who lack such an argument sometimes try to undermine arguments they can not otherwise overcome by just tossing out the naked accusation that their fact and principle marshaling opponent is a wiki-lawyer.".

  I am not requiring you to provide sources that dismiss mine, we may have sources that support opposing views. I am requesting an independent verifiable reliable source (ie. a fact) that supports your concerns, a basic requirement to identifying a reliable source. I could have claimed that the book was a reliable source, and we could have argued it ad infinitum. Instead, I provided evidence that the book is published by a respectable scientific publisher, provided two positive book reviews, and at least a dozen peer-reviewed citations to the book, and an industry organisation, all of which suggests that the book is a reliable source. The only suggestion that the book is not a reliable source, are the opinions of a couple of editors. We could argue ad infinitum, or you could offer a couple of sources so that any editor can assess and review your concerns.

  Editors are fallible. One editor has already mis-associated the 1992 edition of the book with the "electric universe" one version of which did not appear until 6 years later in 1998[24] and another version over a decade later in 2007.[25] A simple source supporting the association would have circumvented the mistake. Likewise, you have suggested that the book is "advocating plasma cosmology"[26], and I have provided a source from the book, that you can check yourself, indicating that it does not (my point #5 above). All you have to do is provide a couple sources that lets other editors check for themselves. --Iantresman (talk) 00:34, 9 November 2012 (UTC)

There are many perfectly good Plasma books you could have used for this article. You have choosen this book for it's very obvious connection to plasma universe, rather than the many other very ordinary books. You are asking for a source to say that a specific book of a pretty obscure fringe theory is itself fringe? Please, plasma cosmology and the "plasma universe" is so fringe now there is next to no mainstream response. I'm rather curious about it's claims to notability. IRWolfie- (talk) 00:47, 9 November 2012 (UTC)

I already used other citations such as adding those for Mendis and Hill,[27] and the citation to Merlino.[28] The fact is that the section on dynamics was sourced to Physics of the Plasma Universe, as I demonstrated in my very first point #1 above, which I used because the mainstream scientific literature readily used it too, and it had a section devoted to the topic in question. I am asking for a source, that says anything negative about the book, from which we can infer that it is not reliable as you suggested. All the sources I have provided seem to contradict your characterisation. For example, you have mentioned "plasma cosmology" now for the third time, and as I have previously shown with a quote, (my point #5, above), the quote seems to contradict this characterisation.

  As you are a man of science, I am sure you would be the first to extol the virtues of independent sources to review facts. If you refer to the section on reliable sources in WP:FRINGE you will find that the book meets WP:IRS in every way. My research suggests that the book is satisfactory. I would be more than happy for you to replace the citation with another relevant book, it's just that my other books on plasma did not have a section on the dynamics of dusty plasmas. --Iantresman (talk) 09:48, 9 November 2012 (UTC)

From google books, there are several books dedicated to dusty plasmas e.g [29][30]. I see you are still wikilawyering by asking for a source to say your source is unreliable. IRWolfie- (talk) 10:12, 9 November 2012 (UTC)

Thank you for the links to the two books on dusty plasmas, I am aware of many, but do not have access to them. The second book seems to have nothing on the dynamics of dusty plasma. If you wish to add a citation, all you have to do is find the appropriate page that is relevant to the article section on the dynamics of dusty plasmas, and cite it.

  My sources seem to contradict your description of the book as "not a reliable source". My source seems to contradict your suggestion that the book is an "advocating plasma cosmology". I don't think it is unreasonable then, to have some independent reliable published sources, in order to review your conclusion, per WP:IRS.

  Have you looked through a copy of Physics of the Plasma Universe? --Iantresman (talk) 11:59, 9 November 2012 (UTC)

• I've taken this to Wikipedia:Arbitration/Requests/Enforcement since this push comes so soon after the topic ban removal, IRWolfie- (talk) 19:51, 9 November 2012 (UTC)

Anthony Peratt is a reputable scientist who held senior posts in the DOE and at Los Alamos. He is an expert in plasma and he's written a text book on the subject. Iantresman has argued there is nothing about the scientifically non-mainstream theory of plasma cosmology in this text book. I can't see that IRWolfie~ has countered that argument anywhere above, which would be simple to do by simply citing an instance. Instead his argument is that Iantresman is wikilawyering by "asking for a source to say [Iantresman's] source is unreliable". It is not Iantresman who is wikilawyering. It is disturbing to see here a vendetta being carried out on a reputable scientist. Examples: "The Plasma universe is a fringe viewpoint and it will not be getting space in this non-fringe article per WP:ONEWAY. IRWolfie-" (the point about this discussion was that Iantresman was arguing that the text book wasn't about plasma cosmology, but IRWolfie~ wishes to silence Peratt for his heresy in supporting plasma cosmology); "I don't see why we should insist i n using problematic books [Peratt's] when there are non-problematic books available. --Enric Naval" (the point being that the book is non- problematic, but Peratt is problematic to people such as IRWolfie~ and Enric Naval). Aarghdvaark (talk) 12:56, 11 November 2012 (UTC)

I see you changed another article to try and suit your argument here: [31]. Content you yourself initially wrote: [32]. Iantresman was taken to arbitration enforcement and has been given a topic ban due to his actions here. IRWolfie- (talk) 17:22, 11 November 2012 (UTC)

Iantresman made a bit of cherrypicking when he quoted the Astrophysics and space science's book review. The reviewer is not aware that "plasma universe" = "plasma cosmology", he amusingly believes that "plasma universe" = "all plasma in the universe". And he is not aware of the importance in this cosmology of double layers, Debye length and Diocotron instability. And he is not aware that the target readership are plasma cosmologists, who want to read mostly about topics important to this cosmology. This makes for a mildly amusing quote:

"However, the very extensive occurrence of plasmas means that the title "Physics of the Plasma Universe" is somewhat ambitious; a full coverage of all the topics covered by this theme is impossible, and there is inevitably considerable selection by the author. At times this selection appears surprising; for example, double layers are extensively treated, but I find no mention of magnetic reconnection. (...) I am unclear of the target readership (...) even to understand Chapter 1, the reader must be familiar with concepts like plasma frequency and Debye length, and the so-called Diocotron instability (a term with which I was not familiar, and not mentioned in many standard plasma texts) is introduced briefly as a "fundamental" concept at this early stage."

--Enric Naval (talk) 16:04, 14 November 2012 (UTC)

I quoted a few paragraphs of the book in Talk:Anthony_Peratt#Book_.22Physics_of_the_Plasma_Universe.22. Can you take a look and say if they are based in plasma cosmology theories? --Enric Naval (talk) 18:53, 16 November 2012 (UTC)

"Appendix C. Dusty and Grain Plasmas. (...) The transition of plasma into stars involves the formation of dusty plasma, the sedimentation of the dust into grains, the formation of stellesimals, and then the collapse into a stellar state (Alfvén and Arrhenius 1976, Alfvén and Carlqvist 1978)." p. 325 This is the plasma cosmology theory posited by Alfvén, that stars are formed via electromagnetic forces in plasma, instead of via gravitational collapse and Jeans instability. At the end of the appendix, he claims that "If the grain plasma is in the presence of a strong magnetic field, the Jeans mass may be radically altered (...).".

So, appendix C cites plasma cosmology right in its first page, and it ends with an argument for plasma cosmology. I googled "stellesimals" and it's a term that only appears in plasma cosmology. --Enric Naval (talk) 14:06, 17 November 2012 (UTC)

Physics of the Plasma Universe is a fringe source. Waleswatcher (talk) 17:43, 24 November 2012 (UTC)

Rename to "complex plasma"?

The research community in this field decided on the term "complex plasma" to replace "dusty plasma" a few years back. Perhaps this article should be moved? --Togr 17:26, 16 July 2007 (UTC)

• This page title seems to suggest that complex plasmas encompass dusty plasma, colloidal Plasma, and Plasma Crystals? --Iantresman 18:20, 16 July 2007 (UTC)

It sure looks that way, but that was not the way I understood the terms. I'll ask my (dusty|complex) plasma expert sources to comment (citing the meeting source if I can find it) and get back to you --Togr 18:34, 16 July 2007 (UTC)

Ok, here is what my friend wrote in the introduction to his PhD thesis on complex (dusty) plasmas:

Complex plasmas is a new name of the field better known as dusty plasmas, and was officially adopted at the IV European workshop on dusty and colloidal plasmas, in Costa da Caparica, Portugal, June 3--5, 2000. Although the old term (dusty plasma) is more descriptive of the physical media at hand—"a plasma with dust in it"—we will for the introductory parts of this thesis try to stick to the new term (complex plasma), reflecting the current trend among researchers in the field. The origin of the term complex plasmas is an analogy to the field of complex fluids, which is the field of condensed matter involving colloidal suspension, as well as similar media containing small particles. Another name—colloidal plasmas—is also often encountered, but this name is used for collision-dominated plasmas under laboratory environments typical for the plasma chambers used in industrial processes.

Brattli, A.: Complex plasmas in planetary rings, the Earth's mesopause, and laboratory experiments. Dissertation for the degree of Dr. Scient., University of Tromsø, May 2001

Hope that helps --Togr 10:06, 17 July 2007 (UTC)

Complex Plasma is a wide field dealing with plasmas that are complex. To be more precise, it includes dusty plasmas as well as - for example - reactive plasmas or plasmas with a lot of plasma chemistry going on. Thus - from this (newer) definitiopn - a dusty plasma is a complex plasma, but a complex plasma is not necessarily a dusty one. By the way: There is also a difference between a plasma with dust and a dusty plasma. If the dust is strongly coupled due to coulomb interaction, it shows collective behavior and can, thus, be seen as an additional plasma component. Then the term dusty plasma is correct. In case of dust in a plasma, there is just dust in the plasma, which may be charged but that's it (like in comet tails, saturn rings and interstellar dust clouds). --134.245.68.53 (talk) 12:28, 2 November 2010 (UTC)

Hello! Anyybody still watching this article?

Concerning the discussion about dusty/complex plasma: The term 'dusty plasma' came first, then there was an attempt to switch to 'complex plasma' for the controlled laboratory experiments. A short quote from this article: G.E. Morfill and A. V. Ivlev, Complex plasmas: An interdisciplinary research field, Rev. Mod. Phys., 2009, vol. 81, p. 1353: "Complex plasmas are composed of a weakly ionized gas and charged microparticles. The name was originally chosen in analogy to “complex liquids,” which defines the class of soft matter systems that exist in the liquid form. The important point (which incidentally also marks the difference with respect to most naturally occurring dusty plasmas) is that the microparticles are the dominant component as regards energy and momentum transport so that these systems can be “engineered” as practically single-species media. Naturally the detailed physics of interaction between the components determines the “material” properties of complex plasmas— they are thermodynamically open non-Hamiltonian systems and can exist in gaseous, liquid, and solid forms." So, the person above me wrote switched things around. In fact, dusty plasmas include complex plasmas, but not the other way around. I think we should keep the article named Dusty Plasma. (Sternenstaub (talk) 04:36, 30 September 2012 (UTC))

First paragraph

Concerning these sentences: Dust particles may be charged and the plasma and particles behave as a plasma,[1][2] following electromagnetic laws for particles up to about 10 nm (or 100 nm if large charges are present). Dust particles may form larger particles resulting in "grain plasmas".

I think there is a lot that's easy to misunderstand in this paragraph, or that's outright wrong:

• the dust particles are always charged in a dusty plasma
• the particles do not behave as a plasma, they only behave as a solid, liquid or gas. The plasma of course always behaves as a plasma
• the interaction between the dust particles always follows 'electromagnetic laws', as they are always charged. Even much larger particles than 100 nm interact via a screened Coulomb potential.
• The nanometer-sized particles often agglomerate to form larger particles, yes. The term 'grain plasma' is extremely uncommon (Google finds only 3,540 results, the first of which is Wikipedia). Plasmas containing microparticles are also called dusty or complex plasmas.

I'd suggest replacing the quoted paragraph with this: The dust particles are charged, for instance by collecting particles from the surrounding plasma or by charging via ultraviolet light. The dust particles can thus interact with each other via the electromagnetic force. The dust particles can also stick together and grow in size. If the electromagnetic interaction between the dust particles is of the same strength as the gravitational interaction, the system is called "grain plasmas". Dusty plasmas in which the dust is the dominant component regarding energy and momentum transport are called "complex plasma", in analogy to complex liquids. Complex plasmas are often studied in specifically designed laboratory experiments. (Sternenstaub (talk) 04:58, 30 September 2012 (UTC))

I think I was considering that since the dust was charged to -10 < Q < +1V, negatively due to electrons, positively due to the photoelectric effect, and consequently this could have included the case of where Q=0. I guess by definition, if the dust becomes uncharged, then it no longer becomes a dusty plasma?

I got the impression that the dust may behave as a plasma. Solids, liquids and gases do not respond to EM forces, and the degree of coupling to the background plasma would determine whether the dust behaves as a plasma. Mendis and Rosenberg describe two regimes which they call "dust-in-plasma" and a true "dust-plasma",[33] and I assume that in the latter, the collective behavior of the dust is plasma-like?

I'd also be delighted if you would look over my "Reference restoration" comments above.

--Iantresman (talk) 15:32, 5 November 2012 (UTC)

As an independent observer with a science background, I did look at your comments there, and commented in less than a delighted form. Sorry, it is fringe. History2007 (talk) 18:02, 8 November 2012 (UTC)

Dusty plasma dynamic reference

Thank you for finding a reference to the section on dynamics.[34] I wonder whether you could provide a page number, so that editors can more easily review it, and check that the equations and conclusion in the article have been accurately represented. --Iantresman (talk) 13:32, 10 November 2012 (UTC)

Added, with other reference. IRWolfie- (talk) 14:30, 10 November 2012 (UTC)

The source introduction to dusty plasmas also covers it quite nicely, I will expand based on that. IRWolfie- (talk) 14:57, 10 November 2012 (UTC)

Thanks for that. I'm unable to view the pages in the first source, but the second one looks OK. As you say, the section may need expanding/modifying based on the source contents. --Iantresman (talk) 18:08, 10 November 2012 (UTC)

I've found a fairly recent, but quite nice text to expand the article from (see the dynamics section). I think this is nicer to work from that the others, so I've removed them. I might re-use them when it becomes necessary. IRWolfie- (talk) 18:59, 10 November 2012 (UTC)

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Vandalism

This article has been vandalized. John G Hasler (talk) 01:00, 29 November 2020 (UTC)