Re: Particle Visualization



Monitek wrote:
> "PD" <TheDraperFamily@xxxxxxxxx> wrote in message
> news:1118959156.273773.83420@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> >
> >
> > Monitek wrote:
> >> "PD" <TheDraperFamily@xxxxxxxxx> wrote in message
> >> news:1118522689.968198.238280@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> >> >
> >> >
> >> > Monitek wrote:
> >> >> "PD" <TheDraperFamily@xxxxxxxxx> wrote in message
> > [snip]
> >> >> >
> >> >> > There are several reasons why this cannot be the case.
> >> >> > Let's start with where the supposed vacuum polarization charges go.
> >> >> > Do
> >> >> > they actually make it to the capacitor plates?
> >> >> > If no, then this would result in a dielectric effect, exactly as in
> >> >> > a
> >> >> > real material, with a measurable dielectric constant > 1. I don't
> >> >> > believe that has been measured.
> >> >> > If yes, then some of the charge delivered in the leads would be that
> >> >> > pulled from the vacuum, as well as that pulled from the battery.
> >> >> > That
> >> >> > is, there would be more *excess* charge than accountable from the
> >> >> > source.
> >> >> >
> >> >>
> >> >> Vacuum dielectric constant is defined as 1. The polarised vacuum is
> >> >> polarised by the energy of the charge on the plates of the capacitor.
> >> >> There
> >> >> is no net current flow between the plates via the battery. As the
> >> >> vacuum
> >> >> polarisation takes place there is an effective current flow due to
> >> >> charge
> >> >> separation until the charge reaches equilibrium then the "current
> >> >> flow "
> >> >> stops and the electric field is established and is maintained via the
> >> >> vacuum
> >> >> polarisation.
> >> >
> >> > You didn't answer the question. Is the charge in the gap delivered to
> >> > the plates or no?
> >> An electron does not flow from the negatively charged plate to the
> >> positive
> >> plate. The dielectric polarises ie lines its charge up in the direction
> >> of
> >> the potential gradient. The negative polarisation adjacent to the
> >> positive
> >> plate causes the electrons to move from the plate by the fact that like
> >> charges repel. This leaves a net positive charge on the positive plate.
> >> Similarly when EMR passes a capacitor the plates are polarised by the
> >> state
> >> of vacuum polarisation which is created by the EMR wave.
> >>
> >> > (If not, WHY NOT?)
> >>
> >> Why if an electron crossed the gap between the plates it would be a
> >> conductor not a capacitor an ideal example of which has infinite
> >> resistance.
> >
> > You've defined the displacement as being a *real* current with charge
> > flow. I would suggest that any material where there is a current in the
> > presence of an electric field is a conductor. The usual algebraic
> > formulation of this looks something like this: J = (sigma)*E, where J
> > is the current density, E is the electric field, and (sigma) is the
> > conductivity. You say J is nonzero when E is nonzero, which demands
> > that (sigma) is nonzero. The resistivity is the reciprocal of (sigma).
> > So if you have infinite resistance, what must the conductivity be? If
> > you have nonzero conductivity, how can the resistance be infinite?
> >
> > But algebra aside, let's look at a region of space immediately adjacent
> > to a plate. You say there is charge separation in that region of space
> > *right next* to the plate. What on earth keeps the charge from
> > depositing on the plate. The vacuum gap is nothing like a material
> > dielectric, where there is a surface to the dielectric material beyond
> > which the dielectric's charges cannot move.
> >
>
> First of all I have not said there is charge flow in between the plates of a
> capacitor I have said there is charge movement. The charge movement I
> envisage is that of electron positron pairs in the vacuum separating, but
> not separating as far as would be required for pair creation. Partially
> separated pairs will have partial charge and partial mass. Imagine a
> capacitor with the plates horizontal, the upper plate being negative and the
> lower plate being positive. The partially separated electron positron pairs
> whilst they are moving are equivalent to a current flow. In this case the
> partially separated electron moving upwards would be regarded as a
> conventional current flow downwards, this would produce a clockwise magnetic
> field arround the axis of movement. Similarly, the positron moving
> downwards, creates a clockwise magnetic field round the positron axis of
> movement. The magnetic fields from both particles are additive. A magnetic
> field associated with the charging of a capacitor has been measured by
> Röntgen I am suggesting that this field is a result of movement of charge in
> the dielectric medium.
>
> Capacitors only function due to the dielectric properties of the space
> between the plates.

That is incorrect. Capacitance is *defined* as the constant, which
depends on structure and material only, that is the ratio of the charge
to potential difference, mathematically defined as Q = C*V. A single
conductor can have a capacitance (where in this case, the potential at
infinitely far away is set to some constant value). The point is,
capacitance between two conductors is too narrow a definition.

>When there is no ponderable matter between the plates of
> a capacitor and the capacitor still functions then the inevitable conclusion
> is that the apparently empty space in between the plates is a dielectric
> medium capable of polarisation. I suggest that the magnetic field is due to
> the charge movement during vacuum polarisation and further say that as the
> magnetic field associated with such movement is real then the particles
> being moved are real.
>
> The reason why the charge does not jump onto the plates is two fold.
> Firstly, the e-p pairs are only partially separated, have only partial
> charge and can not therefore substitute for an electron in the conducting
> plate surface.

You're going to have to quantitatively define "partial separation" and
"partial charge" for me. That is, take a charge dipole pair, and in
terms of their raw charges and their raw spatial separation, define a
parameter that indicates the partiality of the effective separation or
the effective charge. It should be clear from your definition at what
point the "partial" becomes "complete".

> Secondly, the charged particles are paired inthe same way as
> an insulated dielectric material made from ponderable matter would be.

The difference is that in ponderable media, there is a "surface
tension" effect that keeps charges from leaving the surface of the
medium. In vacuum, of course, there would be no such effect.

> Interestingly pair separation does not occur if a capacitor with a vacuum as
> a dielectric because when the plate voltage exceeds a critical value a
> "vacuum arc" breaks out when the Work Function of the metal electrode
> surfaces is exceeded.
>
>
>
> >>
> >> >>
> >> >> > Secondly, there would be simple tests to determine whether charge
> >> >> > moves
> >> >> > in the gap. A phosphorescent screen placed near one plate would
> >> >> > register hits from passing charges. I'm pretty sure this has NOT
> >> >> > been
> >> >> > observed.
> >> >> >
> >> >>
> >> >>
> >> >>
> >> >> I have some zinc sulphide powder handy will that do? I will have to
> >> >> get
> >> >> the
> >> >> van der graph out though.
> >> >
> >> > You can do the research on what's required for a phosphorescent screen.
> >> > Got an old computer monitor? (Legal notice: you could kill yourself
> >> > here if you don't know what you're doing.)
> >> >
> >>
> >> I think the material used for video screens only fluoresces as having a
> >> sustained afterglow would be a nuisance.
> >
> > Yes, either a fluorescent or a phosphorescent screeen will work.
> >
> >>
> >> >> Is that a fact that only charged particles cause materials to
> >> >> phosphoresce?
> >> >
> >> > Well, pretty much so, but it's irrelevant. If you don't see anything on
> >> > the screen, then you know for sure you don't have charge flowing
> >> > through the phosphorescent screen, because moving charges will cause
> >> > phosphorescence.
> >> >
> >>
> >> Pretty much so is too vague, I really would like a yes/no on this one,
> >> because other than using such screens I have never had occasion to
> >> condider
> >> what they do and why they do it. So is it a fact that only charged
> >> particles
> >> can cause a phosphorescent material to glow?
> >
> > Photons, if they are high enough energy, can kick out electrons from
> > the surface of the screen and cause the electron to leave a spot on the
> > screen, but that's a 2nd-order effect. The point here is that moving
> > electrons WOULD be detected. I'm not expecting you to see spots and
> > then having to worry that they are due to something else. I don't
> > expect you to see spots from ANYTHING in the gap, let alone moving
> > charges.
> >
>
> Well, I see afterglow from my phophorescent screen when the screen is
> exposed to infrared radiation, I think you will agree that at those
> frequencies the effect is not due to a photoelectric effect.

I'm not sure I'm getting your point. If you put a fluorescent or
phosphorescent screen in your capacitor gap and see nothing, what does
that tell you?

>
> >>
> >> >> Might have to wait until the rotating magnet investigation is
> >> >> completed.
> >> >> I
> >> >> have the holder made to fix the magnet in a drill. Would you be happy
> >> >> with a
> >> >> ceramic disc capacitor as a probe to save me making one?
> >> >
> >> > Recall that you needed to change the gap so that you can get more than
> >> > one data point and fit the results to eliminate the pickup in the
> >> > twisted pair.
> >> >
> >> >>
> >> >>
> >> >> As far as the effect has not been seen all tha means is the charge
> >> >> separation is below the minimum for the effect.
> >> >
> >> > And your model should predict what that is. After all, you claim you
> >> > have a measurable and *real* displacent current, and so you can say
> >> > that you know exactly how much charge has been moved from one side of
> >> > the gap to the other. Therefore you know how many vacuum electron and
> >> > positrons have moved that distance and then you can determine whether
> >> > that is above or below threshold for seeing it.
> >> >
> >>
> >> First of all I do not know if the effect of phosphorescence has been
> >> observed between capacitor plates or not. I dont know whether it can be
> >> seen
> >
> > Why wouldn't it be seen? Do the test. Better yet, choose an electron
> > detector of your choice and put that in the gap.
> >
> >> even if I am right about pair separation being responsible for carrying
> >> the
> >> electric field. I am looking into it. From the size of the displacement
> >> current one can determine the equivalent electron flow and thats about
> >> it.
> >>
> >> Secondly, thats not quite what I said. I said that the displacement
> >> current
> >> can be measured and has been measured by measuring the magnetic field
> >> associated with it - they are synonymous. If you are measuring a real
> >> current then real charges are moving to create it. A galvo does not
> >> respond
> >> to an imaginary current.
> >
> > And a galvo is not measuring the magnetic field.
> >
> >> I personally have not measured the displacement
> >> current.
> >
> > Then I suggest you should!
>
> >>
> >> As for e-p separation, I wish it was as easy as that. I have determined
> >> an
> >> approximate figure for the separation distance v charge value of e-p
> >> pairs.
> >> However, as you know from Maxwells equations that the potential is the
> >> sum
> >> of all the individual charges and is so in this case. The difference
> >> being
> >> the value of the charge is a variable and the number of pairs
> >> contributing
> >> to the charge is unknown. One can make a guess and say that pair
> >> separation
> >> would be the limit of charge carrying capability after that the vacuum
> >> creates pairs and the capacitor becomes a conductor.
> >
> > Then your model is stuck. At least you could have a free paramater for
> > one and calculate the other in terms of it.
> >
> Hmm. The model is not stuck, the maths are on hold until I can figure out a
> reliable way round the impass. Maybe one could start with Avogadros number
> but I can see no logical reason why that would be related.

Neither can I, as that would apply to ponderable media only, where
there is a known, finite supply of charge.

>
> >>
> >> >>
> >> >> >>
> >> >> >>
> >> >> >> > Summarizing, if you'll look again at Maxwell's equations, you'll
> >> >> >> > see
> >> >> >> > that there is a possible source of an electric field that is NOT
> >> >> >> > due
> >> >> >> > to
> >> >> >> > any physical electric charge (the field lines do not terminate at
> >> >> >> > any
> >> >> >> > charges), and there is a possible source of a magnetic field that
> >> >> >> > is
> >> >> >> > NOT due to any physical electric current.
> >> >> >
> >> >> > Have you looked at Maxwell's equations?
> >> >> >
> >> >>
> >> >> Yes they contain a term for the displacement current.
> >> >
> >> > They contain a term dE/dt and dB/dt.
> >> >
> >> > http://hyperphysics.phy-astr.gsu.edu/hbase/electric/maxeq.html#c3
> >> >
>
> Look in the 4th block down on above site. D is the displacement current. The
> displacement current is equivalent to the field strength x the dielectric
> constant, thus the displacement current is built into Maxwells equations (or
> were they Heavyside's)

No. D is not the displacement current. D is the electric displacement.
My apologies on behalf of the physics community about the confusing
terminology. The electric displacement is a rescaled electric *field*,
where the rescaling factor is epsilon. The displacement current density
is what is normally associated with the term dD/dt in Ampere's law,
which as you can see, is proportional to dE/dt as advertised.

>
>
> >> >> The displacement
> >> >> current is due to charge movement during vacuum polarisation. When the
> >> >> electric field is established the charges stop moving and the magnetic
> >> >> effect ceases. If the equations require a displacement current then
> >> >> the
> >> >> displacement current is real, the charge movement is also real.
> >> >>
> >> >> >> >
> >> >> >> > [snip]
> >> >> >> >
> >> >> >> > PD
> >> >> >> >
> >> >> >>
> >> >>
> >>
> >>
>
> Regards,
> Monitek (Arden Barker)

.

Relevant Pages

  • Re: Electrostatic Induction
    ... As an experiement I recently made a flat plate capacitor ... There is no exchange of energy as the pen's static charge decayed ...
    (sci.physics.electromag)
  • Re: Electric force and charge
    ... Now 'electron' decides to start moving to the +100V plate. ... How does Mr electron 'know' where the positive plate is? ... Here, at this point vizicks has no answers, it is content with the *field*. ... the question of 'what is charge' is a very good one. ...
    (sci.physics)
  • Re: Particle Visualization
    ... >> An electron does not flow from the negatively charged plate to the ... The dielectric polarises ie lines its charge up in the direction ... Interestingly pair separation does not occur if a capacitor with a vacuum as ...
    (sci.physics.particle)
  • Re: Electrostatic Levitation
    ... >>> If this is the case wouldn't a free electron in a vacuum be levitated upward ... >>> Also it seems that any object which could maintain a negative charge of 0.1 ... capacitors hold *no* net charge. ... fields surrounding such a capacitor. ...
    (sci.physics)
  • Re: Brain FRY Problem # 3.1
    ... the capacitance or surface charge. ... and E.D with the liquid. ... parallel plate problem, a little calculus for the coax problem. ... along the length of the capacitor. ...
    (sci.physics)