On Aug 14, 2007, at 3:55 AM, Michel Jullian wrote:
What you are still missing Horace is that the two plates, provided
they are closer together than their lateral extent, act as their
own Faraday cage so their surface charges really only depend on
their difference of potential, irrespective of their potential
relative to nearby external objects including the external Faraday
cage (whose use is desirable anyway as previously discussed).
What you are missing Michel is the discussion that started this whole
thing, the original discussion about the massive morphological
effects of small electrostatic fields *parallel to the plates* in the
Szpak cell experiments. It was a mysterious effect. I hypothesized
these morphological surface effects were due to changes in ion
concentration and electron fugacity, and from the amazingly small E
fields that must have remained at the electrodes from the 6 kV
applied across the cell. I suggested that such a small change in
fields could be affecting cold fusion experiments all over the world
due to differing atmospheric conditions at differing times and
places. Let's be more specific (below).
This follows as I said from Gauss's law (also mentioned by John,
appropriately). I sent you a link earlier, here it is again:
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/gaulaw.html
Here is the important figure with regards to our discussion.
V1 V2
(Ground)=(++HV--)===I I==============(Ground)
I I
V3 I GGGIGGG
I===(+LV-)=====I G GgG G
.....I..............I...G GgG G.............................
I I G GgG G
I I XG GgG G
+ ==oXG GgG Go
+ oXG GgG Go
+ oXG GgG Go
+ oXG GgG Go
+ oXG GgG Go
+ oXG GgG Go
+ XG GgG G
+ G GgG G
+ GGGGGGG
GGGGGGG
Key:
=I - Rubber HV insulated test lead
(--HV) - High voltage low current DC power supply
(LV) - Floating low voltage electrolysis DC power supply
G - Surface of thick strong electrolyte-proof insulator
+ - Electrolysis anode, slightly less negative than
cathode wire.
X - CR-39 slab
g - Ground potential electrode for the high voltage field.
o - Cathode wire cross section
.. - Electrolyte level
Figure 1 - High electron fugacity experiment
Your position is the electron fugacity in the cathode supplied by V1
is dependent only on the potential difference V1-V2, and not the
absolute potential of the cathode coil as I defined absolute
potential. Your position is any potential can be added to both V1
and V2 and the electron fugacity in the cathode will be the same -
especially on the surface opposed to the anode plate.
My position is that the fugacity of the cathode supplied by V1 will
differ depending on the absolute potential of that cathode as I
defined absolute potential. In other words, an electron deficit in
the cathode produces low electron fugacity. You say not. This is our
central issue and central disagreement. Other issues are academic.
The fugacity of the electrons is critical because it affects the
quantum state of some of the population.
I further say you can not apply the difference idea without limits
because a conductor stripped of conduction band electrons can not
have high electron fugacity. A sufficiently negative plate (using
potential within the gauge I defined) can not have high electron
surface fugacity regardless how positive the plate adjacent to it may
be. That is an extreme case, but it demonstrates the fact you can
not pedantically apply the principles you suggest out of context,
especially the principle:
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/pplate.html#c2
which is based on *incremental* charge changes on the plate surfaces.
I also say Gauss's law has limited relevance with regards to electron
fugacity in this case, and to your position, because it ignores the
effects of any external field on the electrode within the envelope,
and also because you've ignored the effects on the cathode coil (or
plate if need be) other than the surface area opposed to the HV
anode. It also was the objective to have potential (not field
measurement) be useful for design and measurement of experimental
values.
excerpt:"It is an important tool since it permits the assessment of
the amount of enclosed charge by mapping the field on a surface
outside the charge distribution."
Once you will have come to terms with this powerful law and its
implication which I already mentioned(*) that a conductor's surface
charge density is uniquely determined by the field right above that
surface, then this controversy will be solved, at last :-)
Michel
(*) I first mentioned Gauss's law/theorem a few days ago, you may
remember I applied it to a judiciously chosen small box,
And I asked you "what box" to which you did not reply, unless I
missed it. I did not see a definition of the box.
I suggest you dig that post out (search for "Gauss"). In my
derivation I had forgotten a permittivity factor I realize, sorry
about that, surface charge density sigma is in fact permittivity
epsilon (or epsilon0 if dielectric is vacuum or air) times the
field strength E (=delta_V/d in the case of two parallel plates),
and its sign is determined by the field direction (negative if the
field is towards the plate, which is the case for the most negative
of the two plates). Capacitor equations follow from the above, see:
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/pplate.html#c2
(note again that the capacitor charge equation q=C*Delta_V alone
should have sufficed
That Q is merely an *incremental* Q, not an absolute charge on the
plate surface.
to convince you, surely you realize that what you have been
preaching at length contradicts this simple elementary equation,
isn't this a bit foolish?)
Needling will not change the facts, whatever they may be. 8^)
Horace Heffner
http://www.mtaonline.net/~hheffner/
