Permeability of free space question

1. Jun 9, 2007

captpaul101@hotmail.com

Hi everyone,

Been doing some reading on permeability lately... My question is would
the permeability of free space (u0) be related in any way to the
vacuum
energy density or would it remain the same regardless (4PIx10-7)?

For eg would u0 be lower inside the space between the Casimir plates
where the energy density is lower then outside the plates or the
same?

Cheers, Paul Titze.
http://wizlab.com/marine

2. Jun 9, 2007

Uncle Al

captpaul101@hotmail.com wrote:
>
> Hi everyone,
>
> Been doing some reading on permeability lately... My question is would
> the permeability of free space (u0) be related in any way to the
> vacuum
> energy density or would it remain the same regardless (4PIx10-7)?
>
> For eg would u0 be lower inside the space between the Casimir plates
> where the energy density is lower then outside the plates or the
> same?
>
> Cheers, Paul Titze.
> http://wizlab.com/marine

http://arXiv.org/abs/gr-qc/0107091
http://arXiv.org/abs/quant-ph/0010055
Phys. Lett. B236 354 (1990)
Phys. Lett. B250 133 (1990)
J Phys A26 2037 (1993)
Scharnhorst effect

It has never been demonstrated - propagation normal to the surfaces
makes for a short experiment!

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2

3. Jun 12, 2007

captpaul101@hotmail.com

Looking up the definition, permeability is the degree of magnetization
of a material that
responds linearly to an applied magnetic field.

So the permeability of free space (uo = 4PIx10^-7) is the degree of
magnetizaton of free space
that responds linearly? to an applied magnetic field. Magnetization
being a measure of the
magnetic dipole density.

This is why one observes vacuum birefringence for eg as this polarizes
the dipoles in the quantum
vacuum when one applies a strong enough magnetic field. If the vacuum
fluctuations are created as
particle/antiparticle pairs (which act as magnetic dipoles?) and since
the vacuum energy density
is lower between the Casimir plates this would mean that these vacuum
fluctuations are partly
suppressed (less particle/antiparticle pairs) between the plates. If
the magnetic dipole density
is less between the plates then the permeability of the Casimir vacuum
should be less then that
compared to free space? u(Casimir) < u0 ?

These are only simple arguments, better go through the maths first...
are there any papers out
there that specifically touch on this subject? Can't seem to find much
on arXiv... What I'm really
interested to know is if there is a relation between vacuum
permeability and vacuum energy density...

Cheers, Paul Titze.
http://wizlab.com/marine

4. Jun 12, 2007

Voltage

Paul, perhaps you should look at permittivity rather than permeability.