Antenna gain question
Hi Richard
Thank you for your answer.
You are quite right Richard, this is the great postulate of Bohr, but
from:
physics.indiana.edu/~sg/p641/chap2.ps
I have extracted this paragraph (rememember that I did study from books
in spanish, so I had to search the web to find a suitable english
references.)
"...Some physicists of the time did not at first believe in
Rutherford's model
of the atom because, classically, such a model is unstable. The
argument is as
follows: Electrons in orbits around a nucleus undergo acceleration. But
accelerating charged particles emit electromagnetic radiation, losing
energy. Therefore,
electrons orbiting a nucleus should lose energy and spiral into
nucleus.
Then in 1913 Bohr solved the problem by simply postulating that
electrons
move around the nucleus in certain stationary orbits without emitting
radiation.
According to Bohr¡s model electrons emit radiation as photons only
when making
a transition from one stationary orbit with a higher energy to another
stationary
orbit with a lower energy."
Bohr's postulate would not invalidate the postulate of the classic
electromagnetism that a accelerated charge irradiates energy in
classical conditions. Their postulate refers to an electron in an
atomic orbital, a typical quantum situation, the electrons in a
circular wire would be being part of a classic macroscopic system, (I
think).
In such a case, would not emit energy, according to that pointed out in
the cited Indiana's university text ?
I can think a more elaborated example of Direct Current to avoid
derived issues of the electronic movement in a complicated crystalline
structu An electron (or current of electrons) inside a magnetic
field in the vacuum, just as in a cyclotron...
Would it be rightfully an Direct Current?.
Does it fulfill the postulates of the classic physics?
Does it irradiate electromagnetic energy?
For these reasons, I think that DC irradiates electromagnetic energy (a
very, very, very little quantity, of course. This ponderings rises in
my mind from a friend's question about an eternal current in a
superconductor ring.
What do you think about?
Thank you very much for your corrections to my translations...
Miguel Ghezzi (LU 6ETJ)
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Hola Richard.
Gracias por tu respuesta.
Tienes razon Richard, ese es el gran postulado de Bohr, pero de:
physics.indiana.edu/~sg/p641/chap2.ps
Extraje este parrafo (recuerda que yo estudie de libros en espaniol de
manera que tuve que buscar en la web para encontrar referencias
adecuadas en ingles).
[Original english text not translated...]
El postulado de Bohr no invalidaría los postulados del
electromagnetismo clasico que una carga acelereada irradia energia en
condiciones clasicas. su postulado se refiere a un electron en un
orbital atomico, una típica situacion cuantica. Los electrones en un
conductor circular estarían formando parte de un sistema macroscopico
clasico, creo.
En tal caso, no emitirian energia de acuerdo a lo senialado en el texto
de la Universidad de Indiana citado?
Puedo pensar en un ejemplo mas elaborado de corriente continua para
evitar las cuestiones derivadas del movimiento electronico en una
complicada estructura cristalina: Un electron (o corriente de
electrones) dentro de un campo magnetico en el vacio, como en un
ciclotron.
Sería legitimamente una corriente conínua?
Cumple con los postulados de la fisica clasica?
Irradia energia electromagnetica?
Por estas razones creo que una CC irradia energia electromagnetica (una
muy, muy, muy pequenia cantidad, por supuesto). Estas cavilaciones
surgen en mi mente a partir de la pregunta de un amigo acerca de una
corriente eterna en un anillo superconductor.
Que piensas?
Miguel Ghezzi (LU 6ETJ)
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