Re: Charged spinning disks

On May 27, 5:11 am, "Sue..." <suzysewns...@xxxxxxxxxxxx> wrote:
On May 26, 9:55 pm, RP <no_mail_no_s...@xxxxxxxxx> wrote:



On May 26, 7:44 am, "Sue..." <suzysewns...@xxxxxxxxxxxx> wrote:

On May 26, 8:10 am, RP <no_mail_no_s...@xxxxxxxxx> wrote:

On May 26, 12:00 am, "Sue..." <suzysewns...@xxxxxxxxxxxx> wrote:

On May 25, 9:46 pm, RP <no_mail_no_s...@xxxxxxxxx> wrote:

You are assuming gravity and inertia are fundamental.

I'm am assuming quite the contrary. You might have picked up on that
had you read in a previous post where I said that gravity is an
electromagnetic effect, and that it is emergent frommicroscopic laws
of eletromagnetism. And elsewhere where I suggested, or rather quoted
Weber as suggesing, that mass is also an electromagnetic effect..
Recently I found a paper by Assis dedicated to this subject.

http://www.ifi.unicamp.br/~assis/
Electromagnetic-Phenomena-V6-p29-35(...

Here is the dual gauge I mentioned earlier.

Page 34 << According to
Mach’s principle the usual kinetic energy mv 2 /2 of
any particle arises from its gravitational interaction
with the distant bodies in the cosmos, [12, 25–29].
The quantitative results presented in this paper yield-
ing Li2 /2 = N meff v 2 /2 indicate that also the mag-
netic energy arises from an electrodynamic interac-
tion of the mobile electrons with the stationary posi-
tive ions of the lattice. >>

http://www.ifi.unicamp.br/~assis/
Electromagnetic-Phenomena-V6-p29-35(...







This is what I was attempting to address in the original post. Will
the inertia of the excess charge on the disk increase as a result of
the disk's rotation.

I don't think it will. even with Weber's electrodyanmics because
he included an induced dipole mechanism... ' tho it is hard to
identify in his paper.  Assis makes it clearer in his papers.

And then you responed with a reference to the
complimentary charge that had to have been produced in charging the
disk.  Here Assis shows, as I attempted to explain, that it depends
upon the geometry of the system.   If the disk is isolated in space
far removed from any other bodies, then what would be the source of
such an "effect" increase in the rotational inertial mass?  

Mach's principle does not posit that you can get far enough
"out in space" so inertia will stop working, does it ?

Note that
the charge itself is in motion wrt other charges on the same disk. Wrt
any point charge on the disks all other point charges are in motion
wrt it, thus there is also in this case Weber's PE between them, and
we should expect there to be a self induction on this disk as well--
when it is brought up to speed, and when it its rotation winds down to
a stop, this PE has to be exchanged to and then from the system.  

Something sounds a little bootstrappy about that. The potentials
developed within the disk material might help rip it apart but
I don't think we can credit them with with storing the angular
momentum that brought the disk up to speed.

Has any one ever spun up a one or two atom thick disk?
That might be in the realm of today's nanofabrication.

This
is why I asked Eric whether it might be easier to just say that the
inertial mass of the charges increases due to their relative motion..

I don't that is valid for a rigid body.  If I on my horsey reach
across the hub of a carousel and give your horsey a push
I have some doubt we can increase the carousel's rotational
speed that way.
That same force *could* aid in ripping the carousel apart.

Here Assis has addressed this issue in full, but in the case of the
spinning disk, this has to be an actual rather than an apparent
increase in mass, else angular momentum will not have been conserved.
I think. :)

The apparent increase in mass wrt the so-called fixed-stars
is quite real.   The auto scrap yards are brimming with proof.

<< we can account for the ever decreasing acceleration
of a particle subject to a constant force [see Eq. (1542)]
by supposing that the inertial mass of the particle increases
with its velocity according to the rule (1546). Henceforth,
$m_0$ is termed the rest mass, and $m$ the inertial mass.http://farside.ph.utexas.edu/teaching/em/lectures/node126.html

I never took that to apply to a rigid body and will need
a bit more convincing if you think it does.

I don't know if an additional rotational drag will appear or not on
the charged disk. The question is of central importance however to
Weber's model and to the nature of relativity, that is, whether
rotation is relative or absolute.  

You are not alone. Some interesting experiments are ongoing
to better determine rotating and mesoscopic effects.

http://en.wikipedia.org/wiki/Martin_Tajmar

Semiclassical Gravity and Mesoscopic Physicshttp://arxiv.org/abs/gr-qc/9511077

On the interaction of mesoscopic quantum systems with gravityhttp://arxiv..org/abs/gr-qc/0408010

My fundamental electromagnetic
equation utilizes the relative "tangential" speed of the charges wrt
each other, and thus the charged spinning disk would be the ideal test
of the validity of that equation.

Purcell ?

Why not superposition of charges?
<< In electromagnetism, Maxwell's equations can be written
by means of multiple integrals to calculate the total
magnetic and electric fields. In the following example,
the electric field produced by a distribution of charges is
obtained by a triple integral of a vector function: >>http://en.wikipedia..org/wiki/Multiple_integral#Some_practical_applica...http://farside.ph.utexas.edu/teaching/em/lectures/node50.htmlhttp://espg.sr.unh.edu/ism/what1.htmlhttp://en.wikipedia.org/wiki/Free_space

Putting *time* (or velocity) in conservative
expressions messes with energy symmetry.





According to my equation the Coulomb
point charges on the disk would experience an enhancment of the net E
field in the radial direction.  A current would flow toward the outer
edge of the disk until equilibrium is achieved, which would be the
point in time when the angular velocity of the disk assumed a constant
value.  Interestingly this is also predicted by Purcell's model. The
equations are actually identical for this case, while only the
premises differ.  Purcell assumes length contraction of lines of
charge laid along concentric circles on the disk, I do not. I assume
only that the relative motion between the charges produces the force
and no change in charge density is required to produce this result.
One could assume that the charge of an electron is no more constant
than its mass, i.e, that both increase wrt another electron that is
motion wrt the first.  It isn't important how the equation is
interpreted, but only whether it is empirically consistent.  I see in
this system the possibility of a direct test of the equation, although
it would necessarily validate Purcell's theory as well, and thus
wouldn't be able to distinguish between the two theories.  It would
however be valuable information.

I think the radiation yield of Smith-Purcell ~undulators~ has
already invalidated Purcell's theory.  It was much lower
than predicted so wigglers, combs and gratings are now the
preferred method for enhancing radiation of a moving charge.

Pythagoras is still easier to teach than triple integrals
so Purcell's method should be secure for at least
three more generations.

"Science progresses one funeral at a time."
--Max Planck



I guess I'm done with the discussion for now. I'll have to actually do
some math before I have anything else to add to the discussion.  I was
hoping that Assis or one of the other leaders of the Weber crusade
would have already worked through this problem, but I've come up empty
handed.

It was fruitful for me.  I didn't realise that Weber included
induced dipoles in his theory in my previous study.  I didn't
even know to look for it at the time. It is probably discussed
in some of Assis paper if we knew which one. Assis does
publish a paper about van der Waal's and gravity.

AFAIK there isn't any elegant maths that is easy to apply.
Brute force with a smidgin of Fourier seems to be the
choice in molecular dynamics.

http://www.research.ibm.com/grape/grape_ewald.htm

The Origin of Gravity
Authors: C. P. Kouropouloshttp://arxiv.org/abs/physics/0107015http://arxiv.org/abs/physics/0107015v1

Sue

This is all an interesting new twist to the theory for me. Before the
spinning charged disk gedanken I had not taken any of these ideas
seriously. Apparently, judging from the links you provided, there
exists a population of physicists who take these ideas very seriously.
The latter link above appears to be based in Weberian Electrodynamics
and Absorber theory. Unfortunately I'm only able to understand about
a third of what he says. :) I have a suspicion though, that
relativity is even stranger than Einstein's version of it. If charges
have much more influence over the metric than masses do (in Einstein's
theory), then relativistic effects are actually much more pronounced
in reality than provided for by GR. A neutral spinning disk leads to
the same problem of angular momentum conservation, given that two
geometrically identical disks of vastly different mass are made to
spin by exerting counter torques upon one another, then the angular
momentums of the two will not sum to zero as predicted by Newton. In
this case we use relativistic momentum and the equation is balanced.
But if the effect is more pronounced on charged disks, then we would
have to conclude that the mass energy relationship derived by Einstein
is only a special case for neutral ponderable bodies (atoms), and that
perhaps it represents only the upper limit on energy obtainable from a
given mass, whereas much smaller proportions of E to m can also be
obtained, the lower limit being zero, that is, a very small measure of
energy can correspond to a very large relativistic mass increase. This
seems to be the case in the Assis derivation involving self
induction. But I'm wondering how all of this might effect the
equivalence principle. Is relativistic mass increase equivalent to a
gravitational mass increase? This should be testable.
















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