Charles, my comments and questions follow these marks: >>.
postby CharlesChandler » Sat Apr 13, 2013 12:30 pm [on TB forum]
_It's easy to see that the Universe is full of filaments, especially in stellar nurseries.
>> In the papers I read online, mentioned below, I think they said the .3 ly or .3 pc galactic filaments predominate throughout the galaxy, or at least wherever HI is found, but not in nebulae, which are more globular, rather than linear. Nebulae seem to have smaller filaments, but I wonder if the larger filaments also consist of smaller filaments.<<
_Here are some papers that Lloyd located on the topic.
_Please post links to other papers if you know of any, especially those with the low-level data showing the physical characteristics of filaments.
_Carlqvist, P., 1988: Cosmic electric currents and the generalized Bennett relation. Astrophysics and Space Science, 144 (1-2): 73-84
_Verschuur, G.L., 1995: Interstellar Neutral Hydrogen Filaments at High Galactic Latitudes and the Bennett Pinch. Astrophysics and Space Science, 227 (1-2): 187-198
_Peretto, N. et al., 2012: The Pipe Nebula as seen with Herschel: Formation of filamentary structures by large-scale compression?
_One interpretation, as discussed in the typical width for interstellar filaments? http://www.thunderbolts.info/forum/phpBB3/viewtopic.php?f=3~, thread and elsewhere, is that stars are forming in these filaments due to the magnetic pinch effect. (Elaboration on that interpretation should be done on that thread.)
>> It seems like you're splitting hairs and unnecessarily giving the impression of disagreeing with EU, when to me it seems like your filamentation theory is still an electric process with magnetic pinching that help maintain each filament shape.<<
_But there's another interpretation, which is the subject of this thread.
_For book-keeping purposes, I "think" that the first time I presented this was on the ...Where does the juice come from? thread http://www.thunderbolts.info/forum/phpBB3/viewtopic.php?f=3~.
_Anyway, what I'm saying here is substantially similar, but I did new diagrams to better illustrate it, and this thread is just for this idea.
_It's possible that the observed currents, and their related magnetic fields, are not causes, but rather effects, of the accretion.
>> I think the cause of accretion is more likely to be cascading currents. The motion of one electron with respect to the surrounding matter is a current. This motion helps to ionize the matter slightly, which helps create the negative charged dust grain and the Debye sheath. The first dust grain would be a single atom. Atoms then become molecules, which become larger molecules, each with electron clouds and Debye sheaths. Each electron motion would be a tiny electric discharge, but with increasing size. Discharges move electrons to dust grains. Dust grains then assemble into larger dust grains and those into meteors.<<
>> I guess carbon and oxygen would be needed to make meteors. Plenty of hydrogen already exists. One TB forum member, with a username something like Quantauniverse, has a website where he posted info about carbon nanotubes etc found in space via spectroscopy. He usually posted messages with links on the EU board.<<
_If "something" causes the accretion, the movement of the plasma toward the centroids will look like an electric current with an associated magnetic field, because the matter is ionized, and thus it constitutes moving electric charges, which is the definition of an electric current, and which will generate a magnetic field.
_But that doesn't mean that the current was the prime mover, nor that the magnetic field is forcing the accretion.
>> It seems to assist the filamentation.<<
_Something else might have caused the movement. So what is the nature of that "something" that pulls the matter together?
_We all know that it isn't gravity, which can account for only 1/5 to 1/20 of the force necessary.
>> Have you explained that estimate somewhere? If so, could you provide a link to it? Or, if not, could you explain how you make that estimate?<<
_The principle contention is that the force is electrostatic, in the "like-likes-like" configuration.
>> I think people might prefer hearing it called Feynman's configuration or something.<<
_In a dusty plasma, the dust grains pick up a negative charge, due to the higher mobility of the electrons.
_Thus more electrons impact the dust grain than +ions, and electrons are absorbed into the electron cloud of the dust grain, while the surrounding gas becomes ionized by the loss of electrons, forming what is known as a Debye sheath.
_The dust grain and its Debye sheath, taken together, are net neutral, and normally, we'd think that they would not interact electrically with their environments.
_Well, they don't interact much. But if we're looking for something that is 5 times greater than the near-infinitesimal force of gravity, it doesn't have to be much.
_Fact of the matter is that there is a net force between net-neutral systems — it's called the "like-likes-like" force (as Richard Feynman called it).
>> How about calling it the Feynman force?<<
_In a cluster of these things, the negative dust grains repel each other, while being attracted to the Debye sheaths.
_In between dust grains, the Debye sheaths overlap, increasing the attraction.
_So while the dust grains repel each other, they are attracted to their shared +ion clouds.
_Now we just have to remember that the electric force obeys  the inverse square law.
_This means that the attraction to the shared +ion clouds is greater than the repulsion between the like-charged dust grains, because the +ion clouds are closer.
_This means that there is a net attraction "between likes", hence the paradoxical "like-likes-like" force.
_And since the attraction is between every dust grain and each of its neighbors, this isn't going to just pull one dust grain toward one other dust grain.
_Rather, it's a net body force on the entire dusty plasma, pulling it all together.
_But also notice that there is a lot of repulsion in that configuration, between like charged dust grains, and like charged +ion clouds.
_Now look what happens if the spherical dusty plasma is stretched into a filament.
_There is no repulsion anywhere in this configuration! All of the electric lines of force close on the nearest neighbor, which is oppositely charged.
_So it's all attraction and no repulsion.
>> If those positive and negative charges were protons and electrons, instead of dust grains and Debye sheaths, the electrons would join the protons as hydrogen atoms. Kanarev seems to have determined pretty well how close the electron is to the proton in hydrogen atoms. It's on the TB forum in my NPA thread. I can find it. I wonder if individual protons and electrons in space would tend to line up in filaments and then form hydrogen atoms which would remain in the same filaments. Or would they prefer to form H2? If hydrogen atoms don't form filaments or chains, I wonder if carbon would. Oxygen would tend to form H2O, which seems likely to form into chains, since it's a dipole. Kanarev says the electric and magnetic fields of protons and electrons in hydrogen atoms cause the electron to be attracted, but then repelled by the other field, which results in the electron reaching only a certain distance from the proton, hovering there with their poles aligned, I think. Nearby atoms should be attracted to each other in chains, I think.<<
_I conclude from this that the net attractive force in this configuration is much greater, and thus the chances of accretion are much greater.
>> Isn't it easy to calculate how strong the force would be between atoms and molecules of various sizes? What would dust grains most likely consist of?<<
_So then we just have to look for things that would encourage filaments to form, and then the rest happens automatically.
_I'm thinking that a nearby supernova doesn't "compress" a dusty plasma into a star, but rather, stirs things up a bit, and in the stirring, filaments get stretched into existence.
_Once formed, they'll snap together.
_In other words, it would be like grabbing a balloon and stretching it into a filament.
_Eventually, the balloon bursts, and then the rubber is pulled violently toward the poor little fingers that stretched it into a filament.
>> Do you mean a dust grain in a Debye sheath is like a balloon and collisions with photons or fast electrons from one direction cause the balloon to stretch out? If moving normal to a dust grain balloon a plane of photons or fast electrons collides head-on with it, would the pressure be strongest at the normal (perpendicular) circumference, or at the center? My impression is that it would be greatest at the center, so, instead of stretching the balloon out, it would compress the balloon like a pancake.<<
_I'm currently working out the implications of this.
_In 3D, stretching a spherical dusty plasma into a filament won't instantaneously create a single-file filament.
_Rather, the first form of accretion is toward the axis of the filament, as it stretches thinner & thinner.
_I'm thinking that this "thinning filament accretion" is where stars get their first chance of forming.
_With radial inflow toward the axis along the filament, conflicting magnetic fields will result in a spiraling inflow, and the fields will resolve into an axial field, parallel to the axis of the filament.
_This agrees with the data, and suggests that the "currents" are not Birkeland currents spinning around an external magnetic field, but rather, they are collapsing charged particles that form their own magnetic field.
>> What data does it agree with? Do you mean the data that says magnetic fields are parallel to filament axes, instead of normal to it? If so, where's that data?<<
_This explains how zig-zag filaments could have zig-zag axial magnetic fields.
_A Birkeland current running through an external magnetic field would have all of the filaments aligned to the external magnetic field — they wouldn't zig-zag.
>> Where are there zig-zag filaments? I've only heard of filaments being supposedly fractal or like Lichtenberg figures, where I think branching tends to occur at 90 or 60 degree angles.<<
_Also, if stars are forming simply by the accretion of a dusty plasma that got stretched, stars will form like beads on a string, and the string itself will never snap together end-to-end.
_The beads-on-a-string configuration is common, and this appears to be a plausible explanation.
_Here are the papers mentioning the significance of turbulence in triggering the formation of filaments:
_André, Ph., et al., 2010: From filamentary clouds to prestellar cores to the stellar IMF: Initial highlights from the Herschel Gould belt survey, A&A, 518, L102
_Arzoumanian, D., et al., 2011: Characterising interstellar filaments with Herschel in IC 5146, A&A, 529, L6