On 10 May, 18:09, "Frank's"
wrote:
I am aware that the impedance of a particular
atmosphere is 377 ohms but that is certainly not a ratio.

From:http://whatis.techtarget.com/definit...845268,00.html

Frank, you got my attention when you pointed to the above link.
I read it a few times and 377 ohms was refered to as Zo. I can't find
any reference
that states Zo is a ratio. Did you intend to point to another link
that specifically points
to Zo is a ratio? Surely you are not following in the steps of others
where anything can be written
right or wrong as long as it creats an augument or distress? You
disapoint me!
Some in this group are already thinking it is legal for a ratio to
have units assigned
because of the inference that the link say's it's so which is an
untruth and
you are perpetuating the spread of untruths. This is similar to
another untruth
that is being perpetuated with respect to photons just because one
person
it be so stated. It is getting to the point that if you read it on the
net don't believe it

unless it can be verified.

I think you are confusing a posting by Cecil. Anyway, quoting
from "Engineering Electromagnetics" by Nathan Ida, 2nd ed. p 743:
"....the reference field is E (an arbitrary choice used in
electromagnetics as a convention). Thus we define the ratio between
Ex(z) and Hy(z) as eta = Ex(z)/Ey(z) = ...... sqrt(mu/epsilon) [ohms]
This quantity is an impedance because the electric field intensity is
given in [V/m] and the magnetic field intensity is given in [A/m].
The quantity eta is called the intrinsic impedance or wave impedance
of the material.....".

Frank

O.K. I will go with the majority and bedamned to those who oppose us.
I now know what the new or modern mathematics is all about and
called for by educationists. I suppose the next generation will be
completely at home with these new conventions unlike the mixture
that we presently have. Shame that they didn't introduce modern math
some 50 years ago which would have shortened this thread by 90%.
Regards
Art