"K1TTT" wrote
...
On Jan 3, 5:41 pm, "Szczepan Bialek" wrote:

In space is the rare plasma + dust.
S*

sure, and in the rare plasma of most of space omega-p goes to zero so
the remaining waves are pure electromagnetic. you can only support
those other wave types in a dense plasma as in the lower levels of the
solar atmosphere or in a confined plasma in a laboratory. you might
as well take the basic Maxwell's equations and claim they don't work
on the Earth's surface because air has a different dielectric constant
that in space... while this is true, the results are rarely measurably
different than free space.

In plasma are electrons and ions. Like in metals.

Tesla known that: http://www.tfcbooks.com/tesla/1929-09-22.htm

":Up to 1896, however, I did not succeed in obtaining a positive
experimental proof of the existence of such a medium. But in that year I
brought out a new form of vacuum tube capable of being charged to any
desired potential, and operated it with effective pressures of about
4,000,000 volts. I produced cathodic and other rays of transcending
intensity. The effects, according to my view, were due to minute particles
of matter carrying enormous electrical charges, which, for want of a better
name, I designated as matter not further decomposable. Subsequently those
particles were called electrons."

You are still before the electron time:

""When Dr. Heinrich Hertz undertook his experiments from 1887 to 1889 his
object was to demonstrate a theory postulating a medium filling all space,
called the ether, which was structureless, of inconceivable tenuity and yet
solid and possessed of rigidity incomparably greater than that of the
hardest steel. He obtained certain results and the whole world acclaimed
them as an experimental verification of that cherished theory. But in
reality what he observed tended to prove just its fallacy".

But you are fine. Nothing wrong.
S*