Re: NASA Tether (was SA's latest issue)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-uswest-dot-net>" <evp-at-pacbell-dot-net>

> The NASA tether experiment is a true "currents thru conductors circuit" as
> compared to Hertzian waves (electromagnetic radiation) thru dielectrics. The
> emf is generated by moving a wire thru a magnetic field. The interesting
> part is how the electrical energy transfer at each end of the tether to
> ionosphere is accomplished. NASA does it with an electron gun and sphere.
> High voltages are necessary because of the high resistances.

	Yep, understand and agree.  Key word is high resistance.  See below.

> Tesla coilers
> perform a similar experiment every time they test their coils for sparks
> from the secondary. The secondary coil is the tether with an emf induced by
> a primary coil. The spark is the current thru the surrounding atmosphere to
> ground instead of the ionosphere.

	Absolutely true.  The ionosphere is too far away to be involved in any
way.  Perhaps a lower height is 50 km or so, and don't remember Tesla
proposing anything with an order of magnitude of that high.  Do you?

> 
> I believe the capacitance between the ionosphere and ground is a minor
> factor in Tesla's "wireless" system because Hertzian waves are not involved.
> Note that wireless does not mean conductorless. 

	Sorry, but I am not referring to Hertzian waves at all, and I am
discussing conduction a la Tesla.  Consider the transmission between two
points via a spherical transmission line.  In that case the series
resistance of the line (ionosphere) and the shunt capacitance to ground
are critical parameters and that they would provide so much attenuation
that he could never achieve significant efficiency, no matter what he
said.

Tesla said that he had
> worked out the details but did not divulge what he had in mind. However,

	If he had, and IF it worked, none of this discussion would be taking
place.  He didn't divulge, we can only imagine what he had in mind, and
no one seems to have achieved any of his goals.  One possible
explanation (not the only one) is that his scheme is badly flawed. 

we
> can get a hint of what he was thinking by understanding the fact that the
> world's lightning system uses currents in the ionosphere, ground, and
> atmosphere. Very high voltages, high resistances, 

	High resistances and high shunt capacitance mean high losses for any
attempted AC transmission.

> and low currents are
> involved. 

	The average current flowing from lightning is of the order of several
hundred amps, summed over the entire surface of the earth, and the
voltage difference is of the order of 400 kV.  If I haven't slipped a
decimal point, that's only 400 megawatts per thousand amps.

> Apparently Tesla finally concluded that the system's overall
> efficiency was too low in spite of the fact that the ionosphere efficiency
> was high.
> 
> I do not agree that Tesla had "feet of clay". On the contrary, Tesla had a
> clear understanding of what was necessary for his "wireless" system.
> However, he had great difficulty in getting people to understand the
> differences between electrical energy transfer by currents thru conductors
> compared to Hertzian waves thru the media. This confusion still exists
> today.

	Regardless of the understanding or the theory, final results are what
count and there aren't any!  As far as the difference between radiation
and conduction, as one goes up in frequency there is no clear boundary
and I challenge anyone to show that current EM theory can't explain
everything the good gentleman proposed.

	Absolutely have no intention of disparaging the man, who was certainly
a true pioneer and outstanding genius.  Furthermore, he could explain
things beautifully when he chose to do so.  My personal opinion is that
he went off the deep end on the power transmission subject and that is
the real reason why we don't see such wireless power transmission
schems.  There are many other difficulties with what he proposed which
he doesn't mention or seem to have considered, but enough of this
diatribe.

Ed