Something new under the sun

[sol invictus]

.
Thank you for pointing out the silly error, whch has now been corrected. I am sorry that the responses and corrections do not happen has fast we might like, but we don't always have the luxury of time, but under 7 hours from notification to correction, isn't bad.

I wasn't asking why you haven't corrected it. I was asking how it got there in the first place, and whether the predictions of PC agree with it or not. You never answered, and you still haven't.

According to Zeuzzz that was written by none other than Perrat, and as I said earlier I simply don't see how any physicist working on that problem could possibly make such a mistake.

Have the predictions of PC now suddenly shifted to accommodate the new language?

EDIT - yes, I see they have. Currently it says

Perrat's spirals had qualitatively flat rotation curves

I don't know what "qualitatively flat" means, but according to Ian it means not like a rigid disk. Yesterday it said

The simulation produces a flat rotation curve (ie the galaxy appears to rotate as a solid disk), but no hypothetical invisible dark matter is needed, as required by the convention model of galaxy formation.

Which is it, Ian? Or have the simulations all been re-done in the last few hours and magically produced different results?

 

[Zeuzzz]

I wasn't asking why you haven't corrected it. I was asking how it got there in the first place, and whether the predictions of PC agree with it or not. You never answered, and you still haven't.

According to Zeuzzz that was written by none other than Perrat, and as I said earlier I simply don't see how any physicist working on that problem could possibly make such a mistake.

for christs sake sol, if you didn't have me on ignore you would see that you misinterpretted this from the beginning, Peratt has changed nothing from his model, and dedicates a whole section to rotation curves. If you had read his paper (which i absolutely guarantee you have not even bothered to) you would know this. Ian admitted the small wording mistake on his site, and corrected it, what more do you want? How do you expect to get answers to your questions if you put everyone who disagrees with you on ignore?

I think that Peratt is well aware of what a flat rotation curve is, and what was produced in his simulation. He designates and entire section of his paper (section VII) to the rotation curves, and he has graphs of the rotation curve properties of the galaxies in question.

 

[Zeuzzz]

I've been lurking for quite a while, carefully collecting material to continue the study I hinted at in the Thunderbolts JREF thread

Hi DeiRenDopa. I did wonder where you had gone, and so while your here, may i ask what are the puroposes of this study? why are you conducting it? just curious.

 

[Zeuzzz]

Zeuzzz, did you read Verschuur's ApJ paper? If so, did you understand it? Did you also read the v1 on the arXiv preprint server, and compare it with the v2 that subsequently got published? How about the comments of Richard Lieu in the Cosmocoffee discussion forum on it (Lieu is Verschuur's endorser, for this paper)?

Thankyou, i will have a look at this when i have the time. I'll be honest, I wasn't even aware of this relatively new area of Gerrits work until earlier today, but it seems interesting and I'll have a look at it over the next few days.

My point here is that while Verschuur (and Lieu) would very much like to be able to show that the CMB, in its WMAP form, contains some otherwise unmodelled foreground, many years of trying have (so far) failed. This most certainly does NOT mean that there is no unmodelled foreground in the WMAP CMB (processed) data!

Seems like the issue is far from resolved. We'll just have to wait and see

 

[Dancing David]

.
If you feel I have misrepresented, then I apologise, it is not intentional.

Oh yeah, then where are his quotes and why do you deliberately leave out the part about the charge and velocity of the particles?

Sure , whatever.

I have provided numerous references so you can double check

i did and you were WRONG

so why not quote Alfven directly in context.

, such as the reference to the equation on gravitoelectrodynamics, where clearly the requirements of charge (implicit for a plasma), and velocity with respect to a magnetic field determine whether gravity or electromagnetic forces dominate.

Oh right, and then you JUST INGNORE it and MISREPRESENT what Alfven said repeatedly, and you don't actually quote him very often, just wave at the papers.

Why have you consistantly ignored the charge and velocity in YOUR STATEMENTS Ian, do not act like it is there in what you said , I have the quotes below. You LEFT IT OUT!

I have also provided Alfvén's comparison of electromagnetic forces to gravity here, again so you can double check what was actually written, compared to my description.

I have also acknowledged my bad use of the phrase "gravitational collapse". So I am happy to be corrected. If I don't provide references, or hide them, then I think you'd have a fair point.

You continue to make the same errors as well, plasmas don't collapse because they are plasmas, and you won't admit to your leaving out the crucial part of Alfvens quote, you didn't aknoledge it at all, until I pointed it out!

You do hide your references in that :you wave your hand at the paper but refuse to quote the actual citation from the paper.

Well here goes, not that it will dissuade you in the least.

http://www.internationalskeptics.com/forums/showpost.php?p=3506124&postcount=198

I think you're not far wrong. The magnetic field in a plasma cloud may stop gravitational collapse. This was investigated by Per Carlqvist in 1988, resulting in the eponymous Carlqvist Relation, peer reviewed in (ref, full text). As Carlqvist and Hannes Alfvén mention in another paper, the magnetic field may either counteract, or aid the contraction of cloud resulting in a pinch.

So hand waving and no direct citation and the third reference in your link is the one to the paper where you misinterpret Alfven's statement.


http://www.internationalskeptics.com/forums/showpost.php?p=3506550&postcount=210

I don't think I did. I noted that Carlqvist's and Alfvén's paper said that magnetic fields may counteract gravitation collapse of a plasma cloud. I refer you to:

II.4. Do Magnetic Fields Aid or Counteract a Compression? (p.498) in "Interstellar clouds and the formation of stars" Astrophysics and Space Science, vol. 55, no. 2, May 1978, p. 487-509.
Now, it may be that while magnetic fields counteract gravitational collapse, they may not be able to prevent it; once grain sizes increase, gravity certainly plays the dominant role. But magnetic plasmas whose particle size is less than grains, electromagnetic forces dominate. Period. (See Gravitoelectrodynamics)

And so here you are engaging in handwaving again and then telling the mistaken story of 'grain size', all without any citation of Alfven or any one.

http://www.internationalskeptics.com/forums/showpost.php?p=3507110&postcount=213

I stand corrected. It just occurred to me that you are referring to "Gravitational Collapse" of a massive body, whereas I was discussing the collapse, gravitationally, of a plasma cloud (a non-massive body).

And here you make the same mistake, saying that a plasma will not be effected by gravity , for whatever uncited and supported reason.



http://www.internationalskeptics.com/forums/showpost.php?p=3519839&postcount=322

It may depend on the density (and hence size) of such mass, and the time-scale.

The man who coined the word "plasmoid" and first investigated them, Winston H. Bostick, noted with respect to the plasma in the spiral arms of galaxies, that ".. Chandrasekhar and Fermi have shown that a magnetic field of 10-6 gauss in the arms is necessary to prevent the complete
gravitational collapse of the ionized hydrogen present in the arms."

With respect to plasmoids specifically, ".. the plasma being supported against the central gravitational field by the magnetic field. [..] gravitational energy is
transformed into magnetic energy".

Reference: Bostick, Winston H., "Possible Hydromagnetic Simulation of Cosmical Phenomena in the Laboratory.", Cosmical Gas Dynamics, Proceedings from IAU Symposium no. 8.

And here you are again making the mistaken statement upon the density and size of the mass.

Still violate GR much, Ian?


http://www.internationalskeptics.com/forums/showpost.php?p=3532479&postcount=538

...
Because all space plasmas are magnetized, and the weak local magnetic field overwhelms gravitational forces at a distance. For example, the smaller-scale interplanetary medium (a plasma) although it is populated with the Sun, planets and asteroids, is influenced more by the interplanetary magnetic field than gravity, resulting in the largest structure in the Solar System, the heliospheric current sheet.

so there you are again, no citation or evidence, saying that somehow a plasma in the interstellar medium does not undergo collapse.

http://www.internationalskeptics.com/forums/showpost.php?p=3539218&postcount=694

That you can obtain by plugging in some values in to Gravitoelectrodynamics equations. For charged particles smaller than grains, electromagnetic forces dominate. Larger than grains, gravity dominates.

Hannes Alfvén compares the two forces on a charged particles in a partially ionized plasma, and finds electromagnetic forces are dominant by a factor of 10,000,000. See "Electromagnetic force, Comparison with the gravitational force: In a partially ionized plasma". Basic plasma physics.

Here you are handwaving, you don't actually cite the quote of Alfven's, now do you. And again you are misinterpreting what he said.

http://www.internationalskeptics.com/forums/showpost.php?p=3539756&postcount=719

If it is dense enough, and charged neutral, then maybe.

But, just take a look at any nebula, or perhaps M87's "jet" which extends 5000 light-year (big enough?). Gravity clearly does not dominate, but works together with electromagnetic forces.

So here again you are mistakenly suggesting density as a factor that would prevent gravitational collapse.


http://www.internationalskeptics.com/forums/showpost.php?p=3541165&postcount=765

You need a point mass of higher density, eg. a particle larger than grain before gravity becomes significant. With a cloud of low-density plasma, electromagnetism dominates.

Where is the centre of gravity of the plasma making up the intergalactic medium? No doubt at the centre of the Universe.

And here you are mentioning grain size again!


http://www.internationalskeptics.com/forums/showpost.php?p=3541236&postcount=768

Many things sound like nonsense until they are understood properly. As I said in a previous post:

Hannes Alfvén compares the two forces on a charged particles in a partially ionized plasma, and finds electromagnetic forces are dominant by a factor of 10,000,000. See "Electromagnetic force, Comparison with the gravitational force: In a partially ionized plasma". Basic plasma physics.

Gravitoelectrodynamics provides the equations of motion for small particles and grains where electromagnetic forces dominate. For larger grains, gravity dominates.

More handwaving and lack of actual quotations. Are you really MISREPRESENTING what Alfven said?

http://www.internationalskeptics.com/forums/showpost.php?p=3542674&postcount=800

No one is ruling out the effects of gravity, but electromagnetic forces are significant too, and dominate while charged particles smaller than grains are present. See:

Interstellar clouds and the formation of stars, Alfven, H.; Carlqvist, P., Astrophysics and Space Science, vol. 55, no. 2, May 1978, p. 487-509. (Online in full)

And again, no direct quote and the grain thing again!

http://www.internationalskeptics.com/forums/showpost.php?p=3543131&postcount=818

Agreed. An sometimes electromagnetism dominates, as it does in jets, the interplanetary medium, the interstellar medium, and the intergalactic medium.

No citations just this bold assertion that somehow this is magically happening.

http://www.internationalskeptics.com/forums/showpost.php?p=3543190&postcount=821

There is no contradiction. The motion of charged particles smaller than a grain is dominated by electromagnetic forces.

Gravity does sometimes dominate, as it does with the planets.

And again with the grain thing!

So here there are:
-four references to grain size, without any explanation of why this would matter.
-three references to plasma not being effected by gravity just because it is plasma
-at least five references to somebody like Alfven saying something in a paper but then you don’t actually cite a quotation
-two references, uncited and unquoted where Alfven says that EM forces dominate at some ration
-four references to density effecting gravitational collapse.

So there it is Ian, you make these statement repeatedly and as though they were true, you have cited that plasmas don’t undergo gravitational collapse and that density and grain size have some effect on something not collapsing. But you don’t say why and pretend to cite some authority but you don’t actually quote the authority many times.

Now here is the deal, you have a web site do you not and I assume that the stuff you say here is similar to what you say there?

This is reprehensible, you make claims based upon something you say that Alfven said, but you don’t actually quote him.

1. So you have a choice, go back and find the quotations that Alfven made in their context and support your citations of his authority.
2. Admit that you have been making claims about Alfven without any basis for making those claims.
3. Find sources that support the grain size and density thing.
4. Admit that you have misrepresented and misinterpreted what Alfven said.


Time to choose!

 

[iantresman]

I wasn't asking why you haven't corrected it. I was asking how it got there in the first place, and whether the predictions of PC agree with it or not. You never answered, and you still haven't. [..]

Which is it, Ian? Or have the simulations all been re-done in the last few hours and magically produced different results?

.
The mistake was mine. Since it has now been removed, you can conclude that plasma cosmology does not, and has never, agreed with it.

Of course you could easily have checked this yourself, by simply reading some of the papers on the subject.

 

[Dancing David]

Hi Zeuzz, have anything that involves the actual computation of the EM forces that some PC people keep claiming cause visible motions that are observable.

I notice that you still haven't done that, you are able to cite all these great papers and web sites. yet you can't find something we can put to the observational test?

Do i really have to go witha whole galaxy because I am very certain that it will give such an outraheous answer that you will accuse me of fraud.

So what shall it be Zuezz, fair is fair. You choose the obejct that you feel has motion that can not be explained or should not be explained by gravity plus dark matter.

You choose the obejct that has motion that is not predicted by gravity minus dar matter, and then we will take the difference and multiply it by the mass of the object, negotiate a charge and we will have a computational prediction of the EM force that some people like you have been saying move things around.

So why haven't you taken me up on this?

Are you now accepting that gravity and dark matter are sifficient an explanation?
Why not tell me an object that is accelerated by EM forces that is not allegedly subject to the influence of dark matter?

I am waiting.

You coose the object, then we negotiate the charge.

Why no answer?

 

[ben m]

OK, maybe I'm beginning to understand plasma cosmology. Depending on the day and the interlocutor, it's either:

• #1) Ordinary, totally non-crackpot astrophysical plasmas, on scales from Earth-ish scales to Galactic scales. Y'know, the type that is already studied at universities everywhere, except that if you call it "Plasma Cosmology" instead of "astrophysical plasmas" you win special iconoclast points. But there's really nothing iconoclastic about it, except that some reason you throw out magnetic reconnection and talk a lot about Birkeland currents.
• #2) Extremely nonstandard astrophysics, in which you claim ... well, various things having to do with invoking a Galactic plasma force making the rotation curve (of stars, gas, plasma?) flat (or rigid, or multivalued?), making redshifts wrong, faking the CMB via foreground effects, and so on.
• #3) Utter crankery, wherein the Sun and the Earth are powered high-energy electrons from the Pioneer 10 RTG , which even the PC aficionados are quick to disavow.

Any general conceptual question about #2 gets the reply, "Well, it works in #1." Any question about #3 gets the reply, "Stop calling us stupid, this is serious peer-reviewed stuff, look at #1." Any detailed question about #2 either (a) gets ignored, (b) gets confused with Categgory #1 stuff, or (c) is shown to disagree catastrophically with plasma cosmology, in which case it's quietly shunted into category #3. "Why are you still asking about stellar rotation curves? That's electric sun nonsense."

So in the end, we're left with (#1) fairly standard mainstream "gastrophysics", (#3) indefensible crackpot loonery, and, in the middle, (#2) supposedly-interesting, paradigm-challenging astrophysical predictions that no one can explain or calculate.

It's like going to the Apple Store, where they show you (#1) a wide variety of DVI-VGA adapters and USB chargers, (#3) a toy radiometer labeled "New Prepetual Motiun Mashine: Energy For The Future" and finally (#2) a revolutionary portable music player called the iPod. When you ask for more details about the iPod, you find that salesman can't quite turn it on, don't know what the circular dial does, and responds to all questions about storage, battery life, etc., by mumbling and bragging about the USB charger. And occasionally he hints that maybe it's supposed to be powered by the radiometer, but retracts it if you point it out.

Seriously, PC folks. PC's rotation curves are like the iPod above---it's your only possibly interesting product. You're supposed to be the sales clerk. Learn your friggin' product. If it doesn't have a hard drive, a battery, or a well-thought-out force law, I'm not going to buy it no matter how nice the VGA adapter is.

 

[Reality Check]

And someone please quote my above post so mattus can see all the plasma cosmology publications in mainstream journals, because at the moment he is trying to argue with someone he has on ignore

Zeuzzz: Totally new law of the universe: The number of papers published on a area of science establishes the truth of that area of science!
Plasma "cosmology" has "hundreds" (at least 50 and maybe as much as 200).
Big Bang cosmology has 1000s (querying the ADS database for 'big bang cosmology' gives 4918 results).
Guess who wins!

 

[BeAChooser]

If PC does indeed predict that the rotation curves of galaxies will be similar to solid disks, it is ruled out by experiment.

And if mainstream theory requires "open magnetic field lines", is it too ruled out?

 

[sol invictus]

• #1) Ordinary, totally non-crackpot astrophysical plasmas, on scales from Earth-ish scales to Galactic scales. Y'know, the type that is already studied at universities everywhere, except that if you call it "Plasma Cosmology" instead of "astrophysical plasmas" you win special iconoclast points. But there's really nothing iconoclastic about it, except that some reason you throw out magnetic reconnection and talk a lot about Birkeland currents.
• #2) Extremely nonstandard astrophysics, in which you claim ... well, various things having to do with invoking a Galactic plasma force making the rotation curve (of stars, gas, plasma?) flat (or rigid, or multivalued?), making redshifts wrong, faking the CMB via foreground effects, and so on.
• #3) Utter crankery, wherein the Sun and the Earth are powered high-energy electrons from the Pioneer 10 RTG , which even the PC aficionados are quick to disavow.

Any general conceptual question about #2 gets the reply, "Well, it works in #1." Any question about #3 gets the reply, "Stop calling us stupid, this is serious peer-reviewed stuff, look at #1."

Very good.

And that's exactly why I was trying to get one specific prediction or phenomenon which "PC" explains differently than the mainstream - to distinguish 1) from 2). But there are no such predictions or phenomena, so it didn't work.

You know, the most charitable interpretation of these crank's motives is that they simply fell in love with plasma physics at some point. If that's it, let me offer a word of advice: learn enough physics to distinguish between 1) and 2), or at least 1) and 3), and stop making your favorite subfield look so bad. Plasmas are cool, everyone likes them, everyone that studies astrophysics studies them too, and they play very important roles a lot of the time.

But the sun is not an anode, plasma physics does not explain rotation curves, and gravity is by far the most important force on large scales. Deal with that and move on.

 

[BeAChooser]

I find it hard to believe that a real physicist could make such an elementary mistake. This is the central fact on a subject he has written several papers about.

Sol, I am puzzled how "real" physicists could make such an elementary mistake as to keep referring to "breaking", "open" and "reconnecting" magnetic field lines since "open" field lines are strickly prohibited by Maxwell's laws (unless you want to claim the universe if full of monopoles). This has long been a central fact when the mainstream discusses magnetic reconnection in the context of explaining black hole jets, various solar observations and other space phenomena. It's "really hard to believe".

 

[ben m]

And if mainstream theory requires "open magnetic field lines", is it too ruled out?

It doesn't require open field lines in the sense you're talking about. Period. The word "open field line" is sometimes used casually when the speaker means "a line that that reconnects somewhere outside our region of interest" or sloppily in saying "magnetic reconnection involves breaking and reattaching field lines" when the speaker means "... crossing and reattaching field lines."

May I use you as an illustration of the importance of careful language in physics? "I once argued with a guy who read about 'open field lines' on the web somewhere, and got stuck for years believing that astrophysicists didn't know Maxwell's equations. Don't let this happen to one of your students!"

 

[ben m]

Sol, I am puzzled how "real" physicists could make such an elementary mistake as to keep referring to "breaking", "open" and "reconnecting"

Our only mistake was to forget how long a dedicated troll can cling to a simple misstatement.

 

[BeAChooser]

On one hand, what's to explain? These research groups just put 1,000,000 particles in a simulated box, made them all attract one another with F= ma = F = Gmm/r^2, and the result is filaments. This is not a fancy new result; it's the only way that these equations work, and it's been around for decades.

Really? And you say there is only one way these equations work and that way has been around for decades? Then why do they call the standard model the Lambda-CDM model? CDM stands for "cold dark matter", right? The reason I ask is that in order to make that million particle computer calculation produce filaments, the researchers had to ASSUME the dark particles were "warm dark matter". So if there was only one way the equations could work and they were around decades ago, why isn't the mainstream model called the Lambda-WMD model?

 

[Reality Check]

Hi BeAChooser and iantresman, Zeuzzz may have missed my post about the inclusion of gravity in Peratt's model and the comparison of the stills of the simulation of a spiral galaxy to the optical photos of a spiral galaxy.
Maybe you can answer?

 

[ben m]

Really? And you say there is only one way these equations work and that way has been around for decades? Then why do they call the standard model the Lambda-CDM model? CDM stands for "cold dark matter", right? The reason I ask is that in order to make that million particle computer calculation produce filaments, the researchers had to ASSUME the dark particles were "warm dark matter". So if there was only one way the equations could work and they were around decades ago, why isn't the mainstream model called the Lambda-WMD model?

Does this have something to do with PC? Is it going to lead to an explanation of PC rotation curves? No? I thought not. You're just trolling.

Anyway, you're flat wrong; where'd you dig that up? Filaments appear in all N-body gravity calculations, whether the matter is cold, warm, or simply baryons. (Hotter dark matter hypotheses predict that the filaments are broad and/or erased early; that (among other reasons) why the hot dark matter hypothesis was rejected. The WDM is less-strongly rejected for other reasons.)

I furthermore reject the hypothesis that taking you off ignore might be worthwhile. Never mind.

 

[iantresman]

Oh yeah, then where are his quotes and why do you deliberately leave out the part about the charge and velocity of the particles?

.
Plasmas consist of charged particles by definition. Anyone interested in quantifying electromagnetic and gravitational forces can check the details with the references I have provided. Here's a direct quote from Hannes Alfvén and Carl-Gunne Fälthammer on the general importance of electromagnetism compared to gravity on plasma:

"The basic reason why electromagnetic phenomena are so important in cosmical physics is that there exist celestial magnetic fields which affect the motion of charged particles in space. Under certain conditions electromagnetic forces are much stronger than gravitation. In order to illustrate this, let us suppose that a particle moves at the earth's solar distance R_E ((the position vector being R_E) with the earth's orbital velocity v. If the particle is a neutral hydrogen atom, it is acted upon only by the solar gravitation (the effect of a magnetic field upon a possible atomic magnetic moment being negligible). If M is the solar and m, the atomic mass, and γ is the constant of gravitation, this force is f = -γMm R_E/R_E³. If the atom becomes singly ionized, the ion as well as the electron (charge e = ± 4.8 x 10^-10 e.s.u.) is subject to the force f_m = e(v/c) x B from an interplanetary magnetic field which near the earth's orbit is B. The strength of the interplanetary magnetic field is of the order of 10^-4 gauss, which gives f_m/f ≈ 10⁷. This illustrates the enormous importance of interplanetary and interstellar magnetic fields, compared to gravitation, as long as the matter is ionized." -- Hannes Alfvén and Carl-Gunne Fälthammar, Cosmic Electrodynamics (1963) "Chapter 1 General Survey", Oxford University Press.​

On gravito-electrodynamics, Alfvén and D.A. Mendis write:

While larger bodies in the Saturnian magnetosphere (e.g., boulders, satellites, etc.) are overwhelmingly influenced by gravitational forces, the electrons and ions are overwhelmingly influenced by electromagnetic forces. While Newtonian mechanics describes the motion of the former, electrodynamics describes the motion of the latter. In the case of the fine charged dust present in the Saturnian magnetosphere, the gravitational and electromagnetic forces can become comparable, at least to within an order of magnitude. In that case neither Newtonian mechanics nor electrodynamics is adequate for studying the motion of such grains; what is required is a combination of the two, namely, “gravito-electrodynamics.” -- "Plasma effects in the formation, evolution and present configuration of the Saturnian ring system, Alfven, H.; Mendis, D. A., Symposium on the Giant Planets and Their Satellites, Ottawa, Canada, May 16-June 2, 1982"​

They do give examples of various criteria, noting the importance of grain size, potential, and angular velocity.

 

[The Man]

I am still waiting for anyone to answer this question.

How do EU theorists determine interstellar and intergalactic distances?

Now, I am not interested in how they do not gauge distance or whatever problems may be perceived with current astronomical distancing. I am only asking how such distances are determined by EU theorists.

Without some measure of astronomical distances, correct or not, there is no theory but only conjecture.

 

[Dancing David]

Sol, I am puzzled how "real" physicists could make such an elementary mistake as to keep referring to "breaking", "open" and "reconnecting" magnetic field lines since "open" field lines are strickly prohibited by Maxwell's laws (unless you want to claim the universe if full of monopoles). This has long been a central fact when the mainstream discusses magnetic reconnection in the context of explaining black hole jets, various solar observations and other space phenomena. It's "really hard to believe".

Yeah, it is hard to beleive, especially since there is no one who ever made claim that the flat rotation curve of galaxies came from thier formative years as plasma and then it just gnomishly carried on for billions of years...
Now that would be hard to believe!