Re: Electromagnetic field

On Feb 27, 7:11 pm, Harry <harry0...@xxxxxxx> wrote:
Well, a lot information thanks!....

I like to bring your attention to this interesting article that
triggered me to ask a more general question:

                              "A Capacitor Paradox":

                   http://www.hep.princeton.edu/~mcdonald/examples/twocaps.pdf

Here's my question:  How can one find the electromagnetic field that
is *radiated* from a
single electron moving in a circular path?  (far field ;  1/r )

Tom's Wiki pictures look correct for an induction loop.


What about the near field?

Should the near field contain both a Coulomb field ( E ;   1/r^3  )
and reactive fields ( E and H ;  1/r^2 )?


"Near and Far field"
http://www.sm.luth.se/~urban/master/Theory/3.html


If it keeps radiating forever, where does the infinite engergy come
from?  ( like in an atom )

Atoms don't radiate much because of their symmetry.
http://www.uwosh.edu/faculty_staff/gutow/Quantum/Nice%20Atomic%20Orbital%20Pictures.html
They do when you knock them off balance.

"Damped Oscillation"
http://www.iop.org/activity/education/Teaching_Resources/Teaching%20Advanced%20Physics/Vibrations%20and%20Waves/Images%20300/img_tb_4437.gif

Anything asymtotic takes forever to reach zero.

Not sure why you mention a *single* electron.

The "Capacitor paradox" is just a single turn loop antenna.
The antenna details of transforming the impedance of free space
hidden by simply stating an effective value of 30 ohms
in the circuit.




I don't know which of the above references has all the answers.


So pick a problem that includes the answers. :o)

"How an antenna launches its input power into
radiation: the pattern of the Poynting vector at
and near an antenna" --J.D. Jackson
http://repositories.cdlib.org/lbnl/LBNL-57623/
http://arxiv.org/abs/physics/0506053


Thank you all for the help!

Not sure it is helpful. Wear safety glasses and
remove all innocent adults a safe distance before
applying power.

Sue...


-- Harry

.

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