Steven;
Yes. Its certainly confusing from the outset. Very tiny amounts of plasma mixed in with ionised gas is a pretty weak argument for the claim that 99%, (by volume), of the universe is made from plasma (a claim made early on).
So, can the presence of this 1% of plasma be detected ?
Quote:
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The vast regions of nearly neutral hydrogen (HI regions) found in the Galaxy and other galaxies are weakly ionized plasmas. These regions extend across the entire width of the galaxy and are sometimes found between interacting galaxies. They are detected by the 21 cm radiation they emit.
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Carl mentioned to me that: 'the 21 cm line line is not due to some plasma state of the gas, it's caused by the spin flip of the electron in the hydrogen atom'.
So, it seems that even Peratt's method of detecting plasma is not one for detecting plasma properties at all.
He then goes on to mix up the presence of magnetic fields with it all. The implication being that magnetic fields are caused by either; large moving plasmas or; by moving intrinsic magnetic fields interacting with the 'weakly' ionised gases (having 1% plasma). I find it very difficult to work out whether he's using the presence magnetic fields as evidence for the volumes of plasma, or not.
Cheers