Then there's a Section titled
"Galactic Dimensioned Birkeland Currents"
.. Sounds promising … might get to the bottom of how he concludes there is such a thing, in the first place:
Quote:
Extrapolating the size and strength of magnetospheric currents to interstellar space leads to the suggestion that confined current flows in interstellar clouds assists in their formation (Alven, 1981).
As a natural extension of the size hierarchy in cosmic plasmas, the existence of galactic dimensioned Birkeland currents or filaments was hypothesized (Alven and Falthammar, 1963, Peratt, 1986).
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.. a 'slam dunk' here .. if Alven hypothesised this then it must be so !.. he continues …
Quote:
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A galactic field of the order B = 1e-9 to 1e-10 T associated with a galactic dimension of 10e20 to 10e21 m suggests the galactic current to be of the order I = 10e17 to 10e19 A.
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This field strength, (1e-9 T = 1e-5 G), is four (?) orders of magnitude
greater than was measured in the paper from our "Primordial Intergalactic Magnetic Fields" thread the other day which said the measured field strength was 1e-9
G (which is 1e-13
T, check me here … I think that's right).
Quote:
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In the galactic dimensioned Birkeland current model, the width of a typical filament may be taken to be 35kpc (approx 10e21), separated from neighbouring filaments by a similar distance. Since current filaments in laboratory plasmas generally have a width/length ratio in the range 10e-3 to 10e-5, a typical 35kpc wide filament may have an overall length between 35 Mpc and 3.5Gpc with an average length of 350 Mpc. The circuit of course, is closed over this distance (Peratt, 1990).
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Man .. his initial assumption is out by four (?) orders of magnitude .. so the rest is also …
I've almost finished with this thread …
Cheers