Re: Wireless Transmission

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: robert heidlebaugh <rheidlebaugh@xxxxxxxxxxxxxx>

Steve Conner. I liked what you said, but let me state a slight conflict.
Ground waves do exist on the surface and within the earth. The phase of
these waves differ from air waves by 90o That is a east west air antenna
will propigate north south within the earth. It is common to beleave that
radio waves only propigate within the earth at low frequency , below 65 Khz,
but experiments prove 30 Mhz can be used to communicate within the earth.
    Since we live on or above the surface very little research has been done
with sub-terra  wave propigation so little data is available on the subject.
       Robert   H
.

--


> From: "Tesla list" <tesla@xxxxxxxxxx>
> Date: Fri, 14 Jan 2005 16:57:30 -0700
> To: tesla@xxxxxxxxxx
> Subject: RE: Wireless Transmission
> Resent-From: tesla@xxxxxxxxxx
> Resent-Date: Fri, 14 Jan 2005 17:18:22 -0700 (MST)
>
> Original poster: "Steve Conner" <steve.conner@xxxxxxxxxxx>
>
>> In the end, I think established and
>> resistant science beat Tesla down unjustly and the kinder pigeons he sat
>> feeding were more worthy company
>
> Well I'm not so sure. I have spent a lot of time reading the Colorado
> Springs notes and any other material written by Tesla I could find. The
> impression I got was that he was right out on the very edge of science at
> the time and speculating away like crazy. He simply wrote down every thing
> that crossed his mind. His lab notes were not meant for public consumption.
>
> A lot of this stuff, like the non-Hertzian waves, sounds very compelling. I
> am ashamed to admit I nearly built one of those caduceus coil things myself
> :-o But I now believe the whole thing is a myth and in fact Tesla just
> didn't understand how energy really is propagated by EM waves. (Probably
> nobody did in 1899.)
>
> I have had fun reading the CSN and trying to understand how he was thinking
> at the time. As far as I can tell he thought the ground current from his
> magnifier was driving the earth and ringing the whole globe like a big
> spherical electrode. All the energy was transmitted through the ground while
> the topload just acted as a "counterweight" or charge reservoir to let the
> drive work.
>
> He didn't seem to have a conception of what we now know as displacement
> current. I ought to explain this further. Displacement current is the dD/dt
> in Maxwell's curl B= J + dD/dt. In intuitive terms this equation says that a
> current creates a loop of magnetic field around itself, and a time-varying
> electric field creates a loop of magnetic field just like a current does,
> even if there is no conductor present for any "ordinary" current to flow in.
>
> This strange "current" that flows in thin air really exists. It explains how
> radio waves propagate and why you can get RF burns from touching grounded
> objects while running your Tesla coil. And also why your electric guitar
> stops buzzing when you pick it up. Anyway. The modern model says that the
> displacement current from the topload returns to ground and cancels out the
> ground current. The current "lands" in a patch around the coil that is
> called the "near field" or "reactive field" and practically no ground
> current or radiation leaves this zone. Any EM that makes it out of the near
> field propagates just as radio waves do, because it _is_ radio waves.
>
> I have never seen any experiment done by anyone with a Tesla coil that would
> deny this modern explanation. The near field was probably several miles
> across with Tesla's big transmitter and I suppose he radiated a fair amount
> of power in the far field too, with that huge antenna mast.
>
>
> Steve C.
>
>