On 11/10/2014 6:00 PM, Wimpie wrote:
El 10-11-14 19:39, escribió:
wrote:
snip
Jim, I would encourage you to dive into rotating magnetic dipole
radiation.
You mean like in a pulsar?
To be more precise, I mean the radiation with same frequency as pulsar
rotation, of course only present when there is a net magnetic dipole
moment. I am not pointing to the pulsed RF radiation.
I want to be clear on this. You are saying that a rotating magnetic
dipole *does* create EM waves just the same as any antenna? The only
difference between a Pulsar and a handheld magnet is one of scale?
For practical electromechanical systems (even in practial vacuo) it is
negligible as (c0)^5 is in the denominator and (2*pi*rev/s)^4 is in
the numerator, but that doesn't mean it isn't present from a
theoretical point of view.
Again, not talking about any "electromechanical system", just a permanet
magnet spining.
That just spinning magnet produces dB/dt, hence an E-field (not
conservative).
Superposition of two quadrature magnetic oscillating dipoles (small loop
antnenas) gives a rotating magnetic dipole field. Such a quadrature
setup can be exchanged by a rotating permanent magnet.
Also implied is the macro level, i.e. a magnet one can hold in one's
hand and velocities well below any relativisitc effects.
I considered non-relativistic velocities only.
I'm not interested in Jim's hand waving. Either a magnet can or can't
generate EM waves. If a big one does it, then a little one does it too.
--
Rick