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From your post
So if i am getting it right the hypothetical Warm Dark Matter in the papers you provided is playing the role of solid constraining walls ...Right ?The slim threads are apparently held together, at least in the centre of our own galaxy, by a magnetic field possessing both azimuthal and poloidal components. Electron acceleration (to relativistic energies) in these structures yields and electrodynamic picture of electron currents driven along magnetic field lines and synchrotron emitting linear filaments approximately 1 lt yr wide.
Let me rephrase ~
So the residual emission of radiation emitted by a single filament is possibly absorbed by the ISM who is a weakly ionized plasma.
Last edited by Don J; 2012-Apr-17 at 03:56 AM. Reason: adding a link
The source for that is given, in the P&P paper, as three papers, dated 1985, 1987, and 1988.
Perhaps a more relevant paper might be this 2003 one, by F. Yusef-Zadeh, one of the co-authors of the 1985 and 1987 papers*: The Origin of the Galactic Center Nonthermal Radio Filaments: Young Stellar Clusters. Here's the abstract:
Or this 2006 one, by Belmont and Tagger: A Viscous Heating Mechanism for the Hot Plasma in the Galactic Center Region. Here's the abstract:Originally Posted by Yusef-Zadeh
Note that these filaments are completely different from the giant, ~350 Mpc long Birkeland currents (or filaments) that the rest of the P&P 1990 paper is about.Originally Posted by Belmont and Tagger
They are also different from the Verschuur filaments (as far as I can tell).
As far as I know, neither Peratt nor Verschuur (nor Peter) has claimed that the Pelican, the Snake, and other galactic centre filaments (yes, some filaments have names!) are Birkeland currents.
* the other co-author - M. Morris - also has some more recent, highly relevant, papers
As far as I know, no one - not Peratt, not Peter, not Verschuur, no one - has attempted to explain the Snake, the Pelican, and the other galactic centre filaments in terms of a "Benneth pinch"*.
If you know of any such attempts - as in, papers published in relevant peer-reviewed journals (or relevant conference papers) - by all means please post the details.
Indeed.No need for dark matter acting as a solid constraining walls,
These are galactic centre filaments, and as the two papers I cited demonstrate, the astronomical observations can be explained quite well by means of physical processes other than Bennett pinches or CDM (and those were only two papers; I quickly found well over a hundred relevant papers).
* I think you meant to write "Bennett pinch"
I will also try to find if Peratt have something about that .
If so why so much papers about them ...is it because no one in the mainstream is in agreement about a physical mechanism explaining these filaments ?
provided in your two papers in term of prediction , behaviour ,magnetic power spectrum , energy and shape of these filaments predicted before they were observed ?
However, as of now, it seems you have provided no evidence to support your claim.
Evidence, as is quantitative, objective, independently verifiable evidence.
I take it, from this, that you have not, yet, read the two papers?.... BTW is there any quantitative evidence
provided in your two papers in term of prediction , behaviour ,magnetic power spectrum , energy and shape of these filaments predicted before they were observed ?
Nor have you read the ones each cites?
More generally, I infer that you may have a, um, strange idea of the nature of astrophysics ...
Remember than I was asking for prediction and calculation made before the observation of these filaments .Something like "we have predicted
that the super massive black hole at the center of the galaxie will produce the formation of these filaments here the year of that prediction"
I am beginning to read the first paper now I am at page 4
English is not my first language so it will take me some time to go through it. (back later with some comments when i will have some free time to continue my reading)
You mean the papers provided by Shaula...
Very summarely.... because of the reference to Cold Dark Matter i knew what it was about.However I did not know there was also a Warm Dark Matter... What is the difference betwen them ? I hope that the answer is not because Dark Matter is Cold in winter and WARM in summer!!!
I will let this un-commented ....for the moment!More generally, I infer that you may have a, um, strange idea of the nature of astrophysics ...
Last edited by Don J; 2012-Apr-17 at 01:52 AM.
at 7 from page 4
I was right to assume (post 160) that there is no concencus in the mainstream about the origin or about a mechanism explaining the formation of these filaments .....
I just checked quicly your second paper to verify what is their proposal ....hmm! which one have the right solution ?
I will continue my reading of your first paper later when i have some free time....stay tuned !
Maybe not finally, until you tell me which one of your two Mainstream papers have the right solution or that you can find a mainstream paper to which there is a consensus among the mainstream crowd.
Last edited by Don J; 2012-Apr-17 at 04:04 AM. Reason: Typos
Now, maybe the plasma universe describes the two observations with just one model. I'd be more than happy to hear or read how the plasma universe can exactly explain the the two different thermal emissions on the galactic ridge (Belmont and Tagger), while still explaining the individual non-thermal filaments(F. Yusef-Zadeh). Since these papers go back three and a half to nine years, certainly, the plasma universe people have been able to provide the quantitative explanations to at least the levels in both papers. Can you point me to those?
I'd really be interested in you pointing to some plasma universe paper showing how the molecular clouds, identified in the Belmont and Tagger paper, would affect those ~350 Mpc long Birkeland currents (or filaments) or even the Verschuur filaments. Or what value, exactly, either the Birkeland Currents or the Verschuur Fillaments get for either a magnetic field or current with the cloud velocities found in the paper? Can you point to something in the plasma universe papers? For that matter, can you point to something in the plasma universe papers that even acknowledges the clouds and their velocities? How about the expected global geometry of the Birkeland Currents or Verschuur Fillaments?
I fully understand that the plasma universe may make different predictions or have different interpretations of the observations, than appear in these papers. So, can you point out, in some plasma universe publication or paper, how they explain, say, the non-thermal spectrum, or if they accept it, how they explain how it's produced, numerically? Or, if they don't accept those observations as molecular clouds, what they think those observations indicate. Or, again, if they don't accept the observations as molecular clouds, what exactly is the observation indicating velocity for those clouds.
Don, you claim no consensus? All of the papers use the same basic model. The differences are in the parameters used. The models are compared against observation and refined. They all use the same basic forces but vary the dark matter mixes. You are quoting ONE person over and over again. Are you surprised that there seems to be more 'consensus' on your side of the fence? And this sudden change to ask for papers written before filaments were observed? Why so? I'd go with the models and theory that best match what we see rather than the oldest ones. And PU does not match up to observations.
WDM acts like glass tube walls? No, and I have no idea where you would get this idea from. It acts more like a gas on huge scales.
If the radiation from these filaments is absorbed by the ISM why do we see it from other structures? We see synchrotron emission from loads of sources, ans cyclotron from plenty too. But not these magic filaments. So in your quest to get rid of dark matter you now need this magic plasma to emit magic photons which vanish en route to us.
The papers I gave were the result of a quick search for some reading material for you. Not exhaustive. The point of them was that the mainstream explains what we see quite nicely. Filaments are one part of it but not the be all and end all of it. The models we have use the same basic forces but differ in the mix of dark matter and approximations used for computational efficiency. They aim to reproduce, to a fairly high accuracy, ALL of what we see. Plasma universe ideas don't even come close. The few predictions they have made? Galactic morphology - Fail. Origin of the CMBR - Fail. Large scale distribution of gas - Fail. In fact the only near success they have had is "Plasma often ends up in filaments and there are filaments in the universe - look there is one!" I am not falling off my chair in amazement.
I notice that in their paper there is a full chapter using Alfven calculus applied to viscous plasma does that sound a bell ?
The 2 two different thermal emissions on the galactic ridge are produced by 2 energetic plasma source.
Last edited by Don J; 2012-Apr-17 at 07:33 AM. Reason: typos
On another note, what are "random walks" as expressed below (http://arxiv.org/pdf/astro-ph/0511365.pdf: An excursion set model of the cosmic web: The abundance of sheets, filaments and halos)?
To embed this collapse model in the excursion set approach requires study of three-dimensional random walks crossing a barrier...
Is that your rebuttal BTW? "You have tunable parameters"? Because I have seen no evidence that things like plasma density, current density and so on were predicted from scratch in any of the papers you have presented. Please do link to the paper where he derives the plasma parameters without reference to any observations, then validates them against observations.
Plasma universe stuff is not mainstream because it fails the tests applied to it. It requires layer after layer of convoluted reasoning to do something the standard models do far more accurately and easily with maybe two parameters to tune - dark matter amounts and energy distributions.
This is not turning out to be a very productive debate. You are now trying to fling mud at the mainstream, presumably to imply that it has as many flaws as the plasma universe idea. Well, sorry but it does not. It does a fairly good job at describing what we see. PU does not. It solves a wide range of observational puzzles with one mechanism, PU does not. It has been modelled and tested over and over to refine its accuracy. PU has not. It has attracted lots of researchers to work on it by virtue of its predictive and explicative power. PU has not.
In reply to Tensor and Shaula....
The thing you forget is that experiments and observations made with plasma were able to explain the cause of electromagnetic phenomena in space -at a time to which the mainstream astronony have not even a clue about them- which were later proven to be right...and recuperated by the mainstream .
See that little history about the establishment astronomy dispute against Birkeland the pionner of plasma cosmology who was later proven to be right....
Birkeland and the electromagnetic cosmology.
Followed by Alfven who at a time when mainstream astronomie was only at the visual stage of observation.Alfven predicted that when the Universe will be scanned at the electromagnetic level the picture and comprehension of it will be far different that what the mainstream thing it is based only with visual observation. In other word Alfven have contributed to the understanding of the Universe based on his work with plasma.Again this was recuperated by the Mainstream .
So you have no evidence and not arguments beyond a vague appeal to an imagined precedent?
Both scientists were right about some things and wrong about others. Thing is where they were right was generally in areas where there was no strong evidence available at the time - but also no contradictory evidence. Peratt is nowhere near this. He has some ideas which are falsified by observations. There is simply no way around this. Either his ideas are wrong of else everything else we know about the way electrons interact with magnetic fields is wrong. I am not going to argue that the scientific community of perfect, filled with little angels. It is not. But this is not an issue here because the ideas as presented are not right. It is not the case that there is no evidence for, it is the case that there is evidence against. Astronomy has come a long way and is far more than just visual analysis now.
I am not reading those links. I refuse to drive more traffic to the site. I have already waded through two badly written papers filled with lookey-likey, awful misleading analogies and hand waving. No more. You are not countering any points made, you are just repeating non-scientific arguments and plastering up links. This is Science and Technology, not Vague Appeals To Emotion and Argument By Obfuscation
Various links, that don't have quantitative support.
Complaints about mainstream theory.
Claims that mainstream theory has free parameters, when EU/PU also has free parameters.
Whining that various EU/PU researchers didn't or don't have adequate funding.
Complaints that the mainstream has some sort of funding that addresses all of the researchers financial concerns, in addition claiming that these researchers have no other concerns except to do theoretical astrophysics.
And links to a website that promotes EU/PU ideas.
Yeah, that will convince a lot of people.
As a remember the prediction of the CMB was put forward by Fred Hoyle a steady state theorician with a value betwen 7K or 10 K....That idea was recuperated by the mainstream but not for the same reasons with a prediction of 20K to 50K.The final result was 2,7K . Hmm!
Another surprise for the mainstream was when they discovered than 90 % of matter was missing in the Universe for matching their gravitational model ...
Oh! and what about the expansion of the Universe which also came as a surprise for the mainstream model...
Thus the need for patches added to the model like Dark Matter which came in flavor Cold and Warm to which you can play with the mixes at will and the need for a new kind of energy called Dark Energy.....
And returning to the subject about the filaments ....How do you explain that even with an army of mainstream theorician physisists there is still no agreement betwen them about their existence or a physical mechanism ?
There is at least 17 attempts by the mainstream to try to find an explanation and no consencus (1)....If i was to apply Occam Razor law the simpler explanation is the better and when the observation math experiment made with plasma for the formation of filaments aka Bennett Pinch
as mechanism ...plasma cosmology prediction and physical mechanism match observation.
(1)no consencus in the mainstream ...
at 7 from page 4
Proof that there is no concencus in the mainstream about the origin or about a mechanism explaining the formation of these filaments ....
As I said, you are genuinely surprised that there is apparent consensus when all your citations are from one man?
I am not wading back through Peratt's papers. This thread is filled with counter points to his ideas (lack of cyclotron, CMB polarisation, galactic morphology, CMB spectrum......).
Incidentally - the non consensus bit is about the source of the filaments, not their formation mechanism. The formation physics is broadly agreed upon. What they are looking for is the strength of the field and the source of the electrons.
And frankly when did this become a thread about how united the mainstream was? Even if there were a million variants of the mainstream model it would not make the plasma universe ideas any more right or attractive.
You have switched to several classic ATM stances as Tensor has pointed out:
1) There are these perceived problems with the mainstream as a whole so my idea must be right
2) They are all ganging up on the idea - vote Underdog today!
3) Hah, but here is one line in one paper that kind of supports what I think so I must be right
4) Your detailed models have problems replicating the fine details of observations, whereas my handwaving doesn't
Still waiting for your Plasma universe model with NO tunable parameters.
Let's get back to Hoyle, in his review of Gamow's book, Hoyle notes that "...[the Big Bang model] would lead to a temperature of the radiation at present maintained throughout the whole of space much greater than McKellar's determination for some regions within the Galaxy." So, Hoyle knew of Mckellar's measurement. Oh, the that value of 7-10K, Hoyle calculated that ((actually, it was 11K) as many others did) from data in the appendix of Gamow's book. Gamow used slightly different values than those published values, which gave him the value of 50k. I also notice you didn't bother mentioning Alpher and Herman's 1949 paper, which got values of 1K and 5K, depending on the parameters used. And, before you jump up yelling about free parameters, what they are talking about here are the various error bars on the parameters in 1949, which in some cases were larger than they are today.
So, lets see, Hoyle didn't make a independent prediction, he used Gamow's values, Gamow tweaked his own values prior to Hoyle and got the 50K. Alpher and Herman got 1-5K, depending on parameters, and two different observers (Mckellar and Dicke) had observations that pretty much match (again, within error bars of parameters used) the current value. Wow, you haven't got any of it right!
Now, Alpher and Herman re-estimated their calculations to 28K, but Gamow dropped his to 7K in the early 50s. Why would that happen, several reasons. The calculations depend on several things. One, the (as it was then called) Hubble Constant, and the assumption of where the Earth's location was(this would either make the CMB isotropic, or not). Alpher and Herman re-did their calculations using a new Hubble constant, this was found to be wrong later in the 1950s, and Gamow made a different assumption as to the location of the Earth. Either way, the changing numbers are understandable.
Gee, I notice you missed this one:
Why do you keep avoiding the answers?Originally Posted by Tensor