Quote:
Originally Posted by CraigS
See, in my newly educated mode, (credits to Don Scott) .. 
There is some credible, theoretical plasma physics basis behind his filament statement. (Dark mode Birkeland, filaments).
The problem is producing the evidence that one this big could ever exist, as Carl rightly points out.
How it powers itself is directly related to the density of the plasma and the power dissipation, as it travels thru space. At the moment in my 'education', it looks to me like a perpetual motion machine. It seems that once a Birkeland filament exists, it can never stop !
Cheers |
Problem is this, Craig....anything masking the Birkeland currents will cause them to collapse. You're effectively blocking the current flow. If you hide them from view (at all wavelengths), you're stopping any emissions from the plasma in which the Birkeland currents exist. Essentially, you're neutralising the plasma. Neutralise the plasma in any way, shape or form and it becomes nothing more than a cloud of gas.
This dark mode is a furphy. Essentially an engineering term for a bias current generated in a semiconductor detector or circuit without the input of an external source of energy, e.g. light, charge etc. In astrophotography parlance, it's the current that is generated in a CCD when no light is falling on the detector...hence the term "dark". It's called the bias and when taking your piccies, you have to account for it as it will increase the noise present in your piccies. This is a reasonably good explanation of what it is....
Dark Current (Dark Mode).
It has nothing to do with astrophysics.
There is a feedback mechanism in plasmas where a z-pinch can gain net energy from the plasma in the pinch (via elastic collisions and induction), but it still requires an input from somewhere to sustain it for any indefinite period. Otherwise, as you said, it becomes a perpetual motion machine.