Electrical Discharges

[D_Archer]

Electrical Discharges:
https://mysite.du.edu/~jcalvert/phys/dischg.htm

I am reading this now and there a lot of clues of how these discharges can work in space on asteroids, planets etc. It well written and easy to understand.

Regards,
Daniel

[paladin17]

Yeah, this is a nice one, thanks. Seems pretty simple.
Although I think a good handbook on plasma physics basics would also be nice (don't ask me about where to find one, because I have little idea about it).

Just popped into my mind: maybe some sort of "school on plasma physics" under a Thunderbolts patronage would be nice.

[D_Archer]

Yeah, this is a nice one, thanks. Seems pretty simple.
Although I think a good handbook on plasma physics basics would also be nice (don't ask me about where to find one, because I have little idea about it).

Just popped into my mind: maybe some sort of "school on plasma physics" under a Thunderbolts patronage would be nice.

Well, the article mentions that 'plasma physics' is not every useful if you want to know about electrical discharges.

This is because plasma physics* is more concerned with fusion (*mainstream plasma physics departments etc).

So yes, some sort of EU Plasma physics school would be nice.

Regards,
Daniel

[D_Archer]

Fact: Electrical discharges produce light.

This is to me their top characteristic.

Would this mean that all light producing events are actually always electrical discharges?

The emission of light is one of the principal characteristics of discharges. Light of a definite frequency is emitted when an excited atom falls to a lower energy level. If there is an electric dipole transition moment, then the transition is called allowed, and occurs in about 10-8 s if nothing intervenes. The collision frequency is about 1011 per second at atmospheric pressure, so usually the excitation energy is lost in a collision before it can be radiated. At 1 mmHg, however, the collision frequency is comparable to the radiation lifetime, and radiation is a possibility. Radiation is always a competetion between de-excitation processes. If the dipole transition moment is forced to be zero by symmetry considerations, then radiation may occur by other means, such as magnetic dipole or quadrupole radiation, but the radiative lifetime for these is much longer, so they are not seen even at 1 mmHg pressure. These are forbidden transitions. They are not really forbidden, just improbable. At higher pressures, excited atoms are continually affected by collisions, which broaden the lines emitted. At still higher pressures, the atom states are smeared out, and the radiation begins to assume the characteristics of black-body thermal radiation

Regards,
Daniel

[paladin17]

Fact: Electrical discharges produce light.

This is to me their top characteristic.

Would this mean that all light producing events are actually always electrical discharges?

No, I don't think so.
First of all, there is incandescence. Then there is a bunch of other phenomena like chemiluminescence or sonoluminescence that also do not require an electric current or net charge flow of any other sort.

[seasmith]

D_Archer wrote:

“Fact: Electrical discharges produce light.

“This is to me their top characteristic.

Would this mean that all light producing events are actually always electrical discharges?”

Paladin 17
“”No, I don't think so.
First of all, there is incandescence. Then there is a bunch of other phenomena like chemiluminescence or sonoluminescence that also do not require an electric current or net charge flow of any other sort.””

But then again, they are all “dis-charging”, yes?
That is as opposed to ‘charging’; which process describes the various impulses that initiated each of the above given examples.

Light doesn’t flow, it radiates, but it is an essentially Electric transmission, no ?
~

[paladin17]

Paladin 17
“”No, I don't think so.
First of all, there is incandescence. Then there is a bunch of other phenomena like chemiluminescence or sonoluminescence that also do not require an electric current or net charge flow of any other sort.””

But then again, they are all “dis-charging”, yes?
That is as opposed to ‘charging’; which process describes the various impulses that initiated each of the above given examples.

Light doesn’t flow, it radiates, but it is an essentially Electric transmission, no ?
~

Well, that looks more like a problem of linguistics than the problem of physics.
But still you're right in some point: particle physics (namely, quantum electrodynamics) considers photons as being the quantae of electromagnetic interaction or electromagnetic field itself. So the propagation of photons through space means the propagation of a sort of a "distortion" in this field. For example, we get the emission of photons when the charged particle is being accelerated. This acceleration causes the distortion in the field , and that's where the photons appear - they start propagating outwards, "informing" other charged particles about the changes that were made by this acceleration of the initial particle.
I don't talk very scientific here, but it looks kind of like that.

[seasmith]

~

Paladin17 wrote:

particle physics (namely, quantum electrodynamics) considers photons as being the quantae of electromagnetic interaction or electromagnetic field itself.

I think you've mentioned elsewhere that you are a student of QCD, Quantum ChromoDynamics.
Does that model distinguish between electric 'charging' and 'discharging' ?




http://www.researchgate.net/publication ... nvironment

[paladin17]

~

Paladin17 wrote:

particle physics (namely, quantum electrodynamics) considers photons as being the quantae of electromagnetic interaction or electromagnetic field itself.

I think you've mentioned elsewhere that you are a student of QCD, Quantum ChromoDynamics.
Does that model distinguish between electric 'charging' and 'discharging' ?




http://www.researchgate.net/publication ... nvironment

Yeah, you're right.
But QCD studies the so-called strong interaction, not the electromagnetic interaction (here we have the mentioned QED, quantum electrodynamics). Strong interaction is what (presumably) keeps the nucleons and other hadrons intact (these particles are thought to be made of quarks), and in its residual form also keeps the atomic nuclei together. The "charge" that is being used in QCD is called color. Not a very smart name, and really doesn't bear much physical sense, but it is what it is. The quarks of course also have the electric charge (-1/3 or +2/3 of the electron charge), but that is almost irrelevant, because the strong interaction is much stronger (thus the name) - at least at these distances (we're talking about 10^(-15) meters here).
In principle the accelerated quark should also emit gluons (quantae of the strong field), creating an analogue of the electromagnetic radiation. And these gluons then give birth to cascades of new gluons and quarks, which then combine into hadrons. This is what observed at the particle accelerators or colliders in the form of so-called hadronic jets. There is a difference between e/m and strong fields, however: the second one is non-Abelian. In simple terms this means that one gluon can produce two new gluons (of quarks) just by itself. Photons cannot do that, - a photon can only produce electron-positron pair, not two other photons.
I'm not sure if that answers your question, but roughly speaking, there is a clear analogy here, though the subjects of study are somewhat different.