Permeability of free space question

Click For Summary
SUMMARY

The discussion centers on the relationship between the permeability of free space (μ₀ = 4π x 10⁻⁷ H/m) and vacuum energy density, particularly in the context of the Casimir effect. Paul Titze questions whether μ₀ is affected by the lower energy density between Casimir plates, suggesting that reduced vacuum fluctuations could lead to a lower effective permeability in that region. Uncle Al advises Paul to consider permittivity instead of permeability, indicating a potential misunderstanding of the concepts involved. The conversation highlights the complexities of quantum vacuum properties and their implications in theoretical physics.

PREREQUISITES
  • Understanding of electromagnetic theory, specifically permeability and permittivity.
  • Familiarity with the Casimir effect and its implications in quantum physics.
  • Knowledge of vacuum energy density and its role in quantum field theory.
  • Basic mathematical skills to engage with theoretical physics papers.
NEXT STEPS
  • Research the Casimir effect and its influence on vacuum properties.
  • Study the relationship between vacuum permeability and vacuum energy density.
  • Examine the concept of vacuum birefringence and its implications in quantum mechanics.
  • Review relevant academic papers on the Scharnhorst effect and its experimental challenges.
USEFUL FOR

Physicists, researchers in quantum mechanics, and students studying electromagnetic theory who are interested in the properties of vacuum and their implications in theoretical physics.

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?
Thanks for your time.

Cheers, Paul Titze.
http://wizlab.com/marine
 
Astronomy news on Phys.org
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?
> Thanks for your time.
>
> Cheers, Paul Titze.
> http://wizlab.com/marine[/color]

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

Similar threads

  • · Replies 10 ·
Replies
10
Views
6K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
4
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 25 ·
Replies
25
Views
3K
  • · Replies 31 ·
2
Replies
31
Views
7K
  • · Replies 9 ·
Replies
9
Views
40K