Re: Tesla Coil RF Transmitter

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Dan" <DUllfig@xxxxxxxxxxxxx>

Paul:

Ok, interesting paper. But I have one criticism: I think you give 
resonance far too little importance. Let me give you an analogy, and 
see if I can make myself clear.

Suppose you have a flexible beam, solidly held at it's mid point. If 
you grab one end with your hand, and slowly move one half of the beam 
back and forth, you will be hard pressed to even detect the slightest 
motion at the other half of the beam. But if you shake one half of 
the beam at it's resonant frequency, and the other half has the same 
resonant frequency, the amplitude of the motion will be nearly 
identical on both halves, even though nothing is physically shaking 
the other end.

Let us not forget, Tesla did not even contemplate world power 
transmission, until he measured standing waves produced by lightning 
strikes. Standing waves would mean the EM pulse produced by the 
lightning strike is being reflected back to the source without much 
attenuation. This would also mean the EM pulse travels all over the 
globe before returning. Tesla didn't need the "shaking" in the earth 
to be particularly strong, he just needed it to travel all over the 
globe. The only way you can do that is by tuning to the resonant 
frequency of the earth.

So I go back to my prior question: Do lightning strikes actually 
produce standing waves or not ?!

Now, before you start saying that my analogy is faulty, because I am 
physically grabbing the beam, and in the case of currents we are 
dealing with electric fields, let me remind you that at an atomic 
level we never really "grab" anything, the atoms of your hand never 
come in contact with the atoms of the beam :)

Dan

----- Original Message -----
From: <mailto:tesla@xxxxxxxxxx>Tesla list
To: <mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx
Sent: Monday, September 19, 2005 5:29 PM
Subject: Re: Tesla Coil RF Transmitter

Original poster: Paul Nicholson 
<<mailto:paul@xxxxxxxxxxxxxxxxxxx>paul@xxxxxxxxxxxxxxxxxxx>

Dan (DUllfig) wrote:

 > ...everyone keeps talking about near and far field effects, EM,
 > electrostatics, etc. But in a cable, power is transmitted quite
 > effectively by a current, without the need of any other effect.

That's the bit you've got wrong.   The power isn't carried by
the current, but by the EM field associated with the current.
The wire serves to guide the field to where you want it.

 > no one has actually DISPROVEN that currents cannot
 > be conducted through the earth.

True, because currents can and are conducted through the earth.

The issue is that Tesla thought currents would flow through the
earth without being impelled to do so by the EM field from the
transmitter, which we know is wrong.

I made some notes on this a while back,

  <http://www.abelian.demon.co.uk/tesla-notes/030802.html>http://www.abelian.demon.co.uk/tesla-notes/030802.html

 > There is a lot of talk of why we THINK it cannot be done,

We know how currents, fields, and charges behave, with about the
same degree of certainty as we 'know' the earth is roughly a sphere.
So if someone says they THINK the earth is flat, we don't rush out
enthusiastically to test their hypothesis.  Instead, we just remind
them of the evidence for a non-flat earth and leave the ball in
their court.

 > Don't forget that all throughout history there have been things
 > that we "knew couldn't be done" until we tried them :)

Ah, you're thinking only of those ideas that actually worked.
If you count those against the vastly greater number of wild ideas
that didn't pan out, you find the odds of any particular idea
turning out a success are pretty slim.   So the argument that
'other long shots have worked, therefore this one is worth
trying' doesn't carry much weight.
--
Paul Nicholson
--