Wireless power transmission (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 18 Jun 2007 21:37:08 -0500
From: David Thomson <dwt@xxxxxxxxxxxx>
To: 'Tesla list' <tesla@xxxxxxxxxx>
Subject: Wireless power transmission

Hi Colin,

> I agree you can get "longitudinal"/compression/sound waves in 
> a plasma (a highly ionized gas).

Yes, we see this on the surface of the Sun.  Scientists can "see" sunspots
on the other side of the Sun by tracking longitudinal waves in the plasma.

> However, this is absolutely _not_ a phenomena you can observe 
> in normal breathable air, because:
> 
> * the density of ions in air is normally very low, typical no 
> more than a few thousand per cubic centimetre
> 
> * the mean free path (the distance an atom/ion/molecule 
> travels before a
> collision) for air at sea level is approx 0.1um.

In normal air, you would be correct.  But in the case of air next to a
wireless power generator, the ion concentration is rather high.  One of the
by-products of a Tesla coil of any type is the production of ions near the
top load.  If you leave the Tesla coil operating for a period of time, it
will fill a space with ions. 

Thus the ion density normally increases near a wireless power transmitter.  

> To get plasma waves in normal pressure air requires near 
> total ionization of the medium (think nuclear fireball or a 
> huge electric arc).

We don't need plasma waves.  All we need is an electrostatic field.  Each
ion will repel every other ion, building up a stiffness in the electrostatic
field.  The stiffness of the electrostatic field can be acoustically
modulated, just as can a wooden reed or a metal bar.  The efficiency of the
wireless power generator will depend partially upon the stiffness of the
surrounding electrostatic field.

> Even if you do manage to build a device 
> to do this to large volumes of air, I recon I'll stick to my 
> wires for energy transmission rather than roasting everyone 
> on the planet.

A stiff ambient electrostatic field occurs naturally in plastic wrap
factories, near waterfalls, just prior to lightning storms, on dry cold
days, and when you pull your clothes out of the dryer.  Nobody gets roasted
in these situations.  The electrostatic field when you take your clothes out
of the dryer will likely be many times stronger than the electrostatic field
needed to transfer small amounts of power across rooms.

I do agree, however, that large scale use of the wireless system Tesla
envisioned is likely to be dangerous to the planet.  Not necessarily because
of heat, but because it will divert the natural flow of Earth's electrical
ground currents, disorient insects and animals, and possibly alter weather
patterns.  There is a lot of technology we can do, but probably ought not
do.  That also goes for some technology we already have in use.

But as experimenters, we should thoroughly investigate each technology and
understand its effects.  Only with proper testing can we determine the
benefits and perils.

I'm positive I have the proper understanding of wireless power transmission
figured out.  Now I just have to finish building a working model, and also
figure out how to combine electromagnetic theory with acoustics in order to
quantify it properly.  There are other interesting things that can be done
with wireless power transmission technology, btw.  I could careless about
sending a few watts of power to my cellphone.  It's the other things you can
do with this that is most interesting.

Dave