Re: Non-Radiative Evanescent Waves are back in the news... (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 11 Jun 2007 17:45:40 -0500
From: Scott Stephens <scottxs@xxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Non-Radiative Evanescent Waves are back in the news... (fwd)

Tesla list wrote:
> From: William Beaty <billb@xxxxxxxxxx
> "Evanescent fields" is a slight distortion.  Those authors are using terms
> from wave mechanics to describe an air-core RF transformer.
>   
I see wikipedia (http://en.wikipedia.org/wiki/Evanescent) has a great
little paragraph on this.
> You're aware that evanescent fields in optics are no different than the e-
> and b-fields surrounding a capacitor or inductor?  They're the nearfield
> part of EM, the non-radiating part.
In optics, photons can "tunnel" across small gaps in waveguide
boundaries. It the field the field of the photon, or atom in the
waveguide matter, or vacuum polarization? Perhaps its more accurate to
say that the fields determine the probability of detected a photon, or
an atom for that matter (pun unintended). Or again, in making a
distinction between fields and particles.

My "crank" reflex is triggered by the term "evanescent", having read
some papers on super-luminal propagation through waveguides above
cutoff. I remember the controversy about superluminal transmission and
group and phase velocities in waveguides.

I should probably be more generous in attributing ignorance rather than
malice to young researchers that think they've discovered hyper-light
radios or wireless power transmission. One thing about Tesla's era was
miraculous inventions of his, Marconi and Edison, et. were modernizing
the world. Today we take nuclear power, computers and spacecraft for
granted, and those older of us think there's nothing new under the sun,
except death & taxes.

Scott