.
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!