"W5DXP" napisal w wiadomosci
...
On Friday, July 20, 2012 1:41:11 PM UTC-5, Szczepan Bialek wrote:
In physics is only one field.
Strange - the extremely well respected physics book, "Principles of
Optics" written by Born and Wolf talks about the E-field and H-field -
Section 1.4.1 "The general electromagnetic plane wave, page 23, 4th
edition.
I wrote: "That fields and the gravity are only in the textbooks (as e
sperate
chapters).
They are also in engineering."
Heaviside and Pointing assumed: "In this case very near the wire, and within
it, the lines of magnetic force are circles round the axis of the wire. The
lines of electric force are along the wire,"
So they had the result: "The whole of the energy then enters in through the
external surface of the wire, and by the general theorem the amount entering
in must just account for the heat developed owing to the resistance, since
if the current is steady there is no other alteration of energy. It is,
perhaps, worth while to show independently in this case that the energy
moving in, in accordance with the general law, will just account for the
heat developed." From:
http://en.wikisource.org/wiki/On_the...gnetic_F ield
Is it true now?
"the lines of magnetic force are circles round the axis of the wire" is the
Biot-Savart law.
In physics no magnetic monopoles and no the lines of magnetic force.
If you read the whole article you see that Pointing was full of doubts.
Heavisde was en engineer and Pointing was a teacher:
"Poynting and the Nobel prizewinner J. J. Thomson co-authored a multi-volume
undergraduate physics textbook, which was in print for about 50 years and
was in widespread use during the first third of the 20th century.[5]
Poynting wrote most of it.[6]"
It is not easy to explain physics to children and engineers.
I am not a teacher and a textbook writer.
But I know that the electrons are. Heaviside and Pointing did not that when
they wrote EM.
S*