Question: what are seismic properties of plasma?

[King David]

Anybody have resources on this?

[D_Archer]

What do you mean exactly?

If you ask about the Plasma Sun you could look to helioseismology, but be aware the standard science is laden with assumptions (wrt the composition of the Sun etc).

Regards,
Daniel

[King David]

What do you mean exactly?

If you ask about the Plasma Sun you could look to helioseismology, but be aware the standard science is laden with assumptions (wrt the composition of the Sun etc).

Regards,
Daniel

Actually what I mean is what are the acoustic properties? Are there compressional waves through it?

[seasmith]

~
King David,

Yes, but they are not the classical P waves, such as observed in fluids like water. The ES and EM properties of the 'ionized' medium must be taken in to account.

Generically speaking, the shockwave characteristics of a Plasma are a function of pressure/temperature, ~densities and the variable electrical properties of the plasmic constituents.

For a very large, spheroid resonant chamber like a sun (even given the simplistic parameters listed above), the acoustic/seismic properties are, given the current state of the science, impossible to define.

D_Archer's admonition is spot on .

In plasma physics, an ion acoustic wave is one type of longitudinal oscillation of the ions and electrons in a plasma, much like acoustic waves traveling in neutral gas. However, because the waves propagate through positively charged ions, ion acoustic waves can interact with their electromagnetic fields, as well as simple collisions. In plasmas, ion acoustic waves are frequently referred to as acoustic waves or even just sound waves. They commonly govern the evolution of mass density, for instance due to pressure gradients, on time scales longer than the frequency corresponding to the relevant length scale. Ion acoustic waves can occur in an unmagnetized plasma or in a magnetized plasma parallel to the magnetic field. For a single ion species plasma and in the long wavelength limit, the waves are dispersionless (\omega=v_sk) with a speed given by (see derivation below)

v_s = \sqrt{\frac{\gamma_{e}ZK_{B}T_e+\gamma_{i}K_{B}T_i}{M}}
where K_{B} is Boltzmann's constant, M is the mass of the ion, Z is its charge, T_e is the temperature of the electrons and T_i is the temperature of the ions. Normally γe is taken to be unity, on the grounds that the thermal conductivity of electrons is large enough to keep them isothermal on the time scale of ion acoustic waves, and γi is taken to be 3, corresponding to one-dimensional motion. In collisionless plasmas, the electrons are often much hotter than the ions, in which case the second term in the numerator can be ignored.

wikibla.bla

[King David]

~
King David,

Yes, but they are not the classical P waves, such as observed in fluids like water. The ES and EM properties of the 'ionized' medium must be taken in to account.

Generically speaking, the shockwave characteristics of a Plasma are a function of pressure/temperature, ~densities and the variable electrical properties of the plasmic constituents.

For a very large, spheroid resonant chamber like a sun (even given the simplistic parameters listed above), the acoustic/seismic properties are, given the current state of the science, impossible to define.

D_Archer's admonition is spot on .

In plasma physics, an ion acoustic wave is one type of longitudinal oscillation of the ions and electrons in a plasma, much like acoustic waves traveling in neutral gas. However, because the waves propagate through positively charged ions, ion acoustic waves can interact with their electromagnetic fields, as well as simple collisions. In plasmas, ion acoustic waves are frequently referred to as acoustic waves or even just sound waves. They commonly govern the evolution of mass density, for instance due to pressure gradients, on time scales longer than the frequency corresponding to the relevant length scale. Ion acoustic waves can occur in an unmagnetized plasma or in a magnetized plasma parallel to the magnetic field. For a single ion species plasma and in the long wavelength limit, the waves are dispersionless (\omega=v_sk) with a speed given by (see derivation below)

v_s = \sqrt{\frac{\gamma_{e}ZK_{B}T_e+\gamma_{i}K_{B}T_i}{M}}
where K_{B} is Boltzmann's constant, M is the mass of the ion, Z is its charge, T_e is the temperature of the electrons and T_i is the temperature of the ions. Normally γe is taken to be unity, on the grounds that the thermal conductivity of electrons is large enough to keep them isothermal on the time scale of ion acoustic waves, and γi is taken to be 3, corresponding to one-dimensional motion. In collisionless plasmas, the electrons are often much hotter than the ions, in which case the second term in the numerator can be ignored.

wikibla.bla

That is far out man, I had no idea.

[kiwi]

Boltzmann's constant

Is dead and buried? ..... If invalid. what is the consequence of its use in the formula its attached to?

[seasmith]

kiwi wrote:

Boltzmann's constant

Is dead and buried? ....

..??

[seasmith]

~

kiwi » Fri Nov 27, 2015 4:35 am

Boltzmann's constant
Is dead and buried? ..... If invalid. what is the consequence of its use in the formula its attached to?

Kiwi, Were you maybe thinking of Kirchhoff's Law, a la Robitaille,
or has Boltzmann's kicked the bucket as well ?

cheers


https://en.wikipedia.org/wiki/Boltzmann_constant

[kiwi]

Hi Seasmith

Yes

He claims Boltzman constant along with of course Planck who extended Kirchoff.. and Stefan's Law thought to hold true across all phases of matter ( not even in solids as he explains , and particulary cannot be assiged to the Gaseous state, where the emissivity in reality drops with the fourth power of the Temp).... I actually had the opportunity to ask him a few days back ... my question actually being ... "If the constants of Planck/ Boltzman etc are now thought invalid through the correction given by you re Universality, does that make those constants inadmissable in any and all calculations they are used in"? .... he said it was quite complicated and that there are situations where they are performing functions involving their use in determining ratio's and other parameter related applications ..... but he did name four of Plancks that he said have no physical meaning any more.. Planck width, length, and I think Mass ... and one other that escapes me right now,... I should probably get it claified as I wouldnt like to misquote him .....

thanks for the reply, tricky stuff to get your head around isnt it

[seasmith]

Kiwi,
Thank you for that input from Dr Robitaille.

Agreed, and it’s gotten much more complicated in the hundred+ years since Boltzmann had his eureka moment. The so-called “constant” was ok as a ‘transforming factor’ between macro and micro characteristics of a non-ionized so-called “ideal gas”,
using a purely statistical approach.

Since then, “micro” has devolved into the gooey mass called Quantum Physics; which is often just a wonky euphemism for things too tiny and rarified to observe or understand. This trend has brought into use heuristic contraptions like electronvolts, Landau damping and electron temperatures. These are all used as heuristic devices for mathematical treatments of Charge,
an entity not understood.
Classical Boltzmann/Plank was fine for (absorbent) Black Body temperature estimations, but Not for highly complex Radiant Bodies, like a sun.
That is all I was trying to convey to the OP of this thread, [and as with Chandler, Svalgaard, etc. in some other earlier threads].

Going off on a slight tangent here,
if a sun is composed of a (minimum), generally acceptable, 4-5 resonant spheroidal components: ie core(s), radiative/tachocline/convective zones, chromosphere and photosphere ~{plus 3 or 4 exo-zones prevailing from corona out to helio-pause};
And given the EM/ES/thermal pressures, flows & turbulence resulting from those forces, any scientific “helio-seismology” is way beyond the capabilities of the instrumentation available today,
imo.

[Michael Mozina]

Anybody have resources on this?

http://sun.stanford.edu/~sasha/sasha.html