RE: 3 Coil System Speed of acoustic waves in electrons (fwd)

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---------- Forwarded message ----------
Date: Mon, 25 Jun 2007 10:12:28 +0100
From: Colin Dancer <colind@xxxxxxxxxxxxxx>
To: 'Tesla list' <tesla@xxxxxxxxxx>
Subject: RE: 3 Coil System      Speed of acoustic waves in electrons (fwd)

Hi Dave,

Can I ask what kind of longitudinal waves you talking about?  Plasma waves
in the sea of Fermi electrons in the metal?  

This is a well studied area, and while you can get Plasmons (see wikipedia),
these are high frequency in nature up in the terahertz plus region.  

Large scale, bulk resonance of the electrons in metals
_related_to_the_bulk_speed_of_sound_in_that_metal_ is not something which
theory predicts or has been observed in any of the many millions of
experiments people have done on antennas.  Even if people were approaching
the problem with a closed mind I think you're kidding yourself if you think
such an effect would have gone unnoticed.  

The fundamental reason why it just isn't going to happen as you suggest is
that any mechanical style vibrations in the bulk of the metal are tied into
the motion of the positively charged atomic nuclei (which carry most of the
mass).  The free electrons are so light in mass (compared to the strength of
the electrostatic field between them and the nuclei), that their density
exactly tracks the motion of the nuclei giving you zero charge separation. 

The only exception to this is if the material is piezoelectric.  In this
case there is a large scale anisotropy in the way the electrons are placed
in the material which is fixed into the bulk of the material by the
different nature of the individual atoms.  You then can observe
electroacoustic coupling, but this can only happen because the material is
an insulator.  Once the electrons are free to more around (a conductor) the
electro-acoustic coupling disappears. 

Finally, your data doesn't match the observed speed of sound in metals,
which is ~5.1km/s for Al & ~3.6km/s for Cu

I don't mean to be negative, but when you say that you're picking up
resonance on the pipes are you absolutely sure you've eliminated other
possible reasons for your detector showing a peak? 

I can also say with first hand experience, that for most magnifiers the
product of the inductance of the third coil and the top load is the critical
factor in tuning, and the tertiary coil is definitely not equivalent to a
metal pipe of the same dimensions.

Colin.


---------- Forwarded message ----------
Date: Sat, 23 Jun 2007 22:12:12 -0500
From: David Thomson <dwt@xxxxxxxxxxxx>
To: 'Tesla list' <tesla@xxxxxxxxxx>
Subject: RE: 3 Coil System      Speed of acoustic waves in electrons

Hi Bart,

I did a rough test tonight.  The measurements are in the ballbark.

The setup was a frequency generator and Bert Hickman's double led resonance
detector.  The lead from the resonance detector went to a brass plate, which
I stood a free standing section of metal pipe on.

I have two pieces of metal pipe, one is a 47.25" length of 1.125" diameter
copper, the other is a 48" length of 1.0" diameter aluminum.

With the pipe on a free standing stand, its ends were about 24" from the
floor and ceiling and about three feet from the nearest object in the room.


Using the equation for acoustic waves in a completely open or completely
closed resonator, the speed of the acoustic wave in the copper pipe was
about 4.452 x 10^-3c.  That is, it was about 4.452/1000 of the speed of
light; in the ballpark of what I predicted.

The equation is F = c / 2L, which worked out as:

556kHz * 2 * 47.25in = 4.452 x 10^-3c

The aluminum value was:

571kHz * 2 * 48in = 4.644 x 10^-3c

It is possible the aluminum has a higher acoustic speed than does copper.
However, the error of the double led resonance detector could be about 10%
either way as it did not tune very sharp in this setup.  I'm sure that by
encasing the copper tube in oil the reading would be much sharper and more
accurate.  Of course, this also indicates that exposed pipe is not the best
way to go due to electron and photon losses.

The pipe wall is about .035" in thickness.  If a wound coil were made to the
same dimensions of the copper pipe, and using the wall thickness as the wire
diameter, it would calculate to 1961kHz.  However, back calculating from the
pipe frequency of 556kHz, the pipe would have an effect thickness of .010".
This could be a problem for the theory I'm working on unless there is a skin
effect.

The math is close enough that it warrants further and more accurate
research.  I think I'm well on the path to quantifying longitudinal waves in
a three coil setup.  The math is far easier than I thought it would be.

Dave