Zero point fluctuations and the Casimir effect

[Bob_for_short]

The conductors modify the boundary conditions for the electric field.

 

They modify because of interaction. The filed itself does not exist, don't you see?

[froarty]

They modify because of interaction. The filed itself does not exist, don't you see?

I can quote swansort here because it is the same situation...

And it can't be that the descriptions are different ways of looking at the same thing, much like phenomena that have both a classical and quantum description?

It doesn't matter if you look at it from thermal perspective or believe vacuum fluctuations are able to move plates, the results are the same. Both theories propose a change in frequency ( VUV for thermal vs vacuum flux for Casimir) inside a Casimir cavity that results in the observer seeing more shorter wavelengths of interest. I think Naudts suggestion of a relativistic solution represents a 3rd option that is compatible with both perspectives. The relativistic solution suggests All wavelengths appear up converted because space time itself warps in the cavity. This would make everything look faster from our perspective outside and sidesteps the controversey regarding fractional states.

Edited September 28, 2009 by froarty
grammar

[swansont]

They modify because of interaction. The filed itself does not exist, don't you see?

 

Well, the whole point of the experiment is that the zero point energy is real. The [math]\frac{1}{2}\hbar\omega[/math] has some physical meaning. The fluctuation interpretation is (AFAICT) that sometimes there's a photon there, and sometimes not.

[Bob_for_short]

Well, the whole point of the experiment is that the zero point energy is real. The [math]\frac{1}{2}\hbar\omega[/math] has some physical meaning. The fluctuation interpretation is (AFAICT) that sometimes there's a photon there, and sometimes not.

 

About fluctuations, I can tell that in an atom there is always an electron coupled to a nucleus. The natural variables are the center of inertia (CI) and relative coordinates. The total wave function of such a compound system is a product of a CI plane wave and an atomic wave functions: Ψ = exp(-iPR/ћ)⋅ψ(r). The atomic ground state can be considered as the vacuum (no excitations).

 

The same is valid for quantum oscillators and charges - they come together and represent zero-mode oscillations in compound systems. An electron with its quantum oscillators (I call it an "electronium") can be described quantum mechanically in full analogy with an atom: as a product of the CI and relative motion wave functions (the oscillators). So there is no photons in the ground state of such compound system.

 

Charge is smeared quantum mechanically in compound systems, for example, in atoms there are negative and positive charge clouds of different sizes around the atomic CI (described with atomic form-factors). Similarly in the electronium the electron charge is smeared but no photons exist in the ground states. Real photons are excited states of electronium.

[swansont]

We're talking about the vacuum, meaning no atoms. Solve the 2-D "particle in a box" for EM radiation with perfect conductors at the edge.

 

AFAICT, your electronium model is nonstandard. Please restrict discussion of it to Speculations.

[Bob_for_short]

We're talking about the vacuum, meaning no atoms. Solve the 2-D "particle in a box" for EM radiation with perfect conductors at the edge.

 

"In vacuum" and "in a box" are different things. Perfect conductors mean a strong interaction with walls, so you cannot get rid of charges. My electronium is as natural as your box with perfect conductors.

 

The sense of electromagnetic field is to get into the dynamic equations for charges as an external field. An external field has its own source. For example, the waves in a box are proper to this box. Same for electronium.

 

Separation of electron and of quantized EMF does not mean they are non-interacting, independent systems but subsystems of one compound system belonging to separated variables, like R and r in a two-body system. Then no questions arise about Casimir, Lamb, and other effects.

[insane_alien]

in a cacuum and in a box are different yes, but they are not mutually exclusive.

[Bob_for_short]

in a cacuum and in a box are different yes, but they are not mutually exclusive.

 

How one can excite the quantized electromagnetic filed oscillators? How photons are produced? By acting on a charge, pushing a charge. So the charge is like a particle in a couple of two-particle system bound with an elastic spring:

 

External force =>OwwwwwwwwwwO,

 

and the oscillator describes the relative motion of the couple (a quasi-particle with a reduced mass).

 

So, the quatized EMF is always "coupled" to charges, they come together - it follows from the exact equations of QED. Electronium or a real charge is name of it - it contains both the charge and the quantized EMF.

 

Interaction of plates affected with the quantized EMF is an interaction of real charges of plates at long distances. When electrically neutralized plates still interact due to presence of the quantized EMF in real charges.

 

Even when non-neutralized (electron and proton in Hydrogen, for example), the quantized EMF gives corrections to the potential energy anyway - the Lamb shift.

[froarty]

 

Even when non-neutralized (electron and proton in Hydrogen, for example), the quantized EMF gives corrections to the potential energy anyway - the Lamb shift.

 

Sounds familiar...Haisch replied to my theory (back when I was still trying to use the term relativistic hydrino -an oxymoron) which to paraphrase he said, the process in the Haisch-Moddel paten(http://www.calphysics.org/Patent.html) does not claim to create "hydrinos." We propose a shift in electron orbitals of atoms in a Casimir cavity which they propose to call a Casimir-Lamb shift. Upon emergence from the cavity they believe the atoms revert to their normal state and that are no stable sub-Bohr states, but they propose that in the process energy may be released from the quantum vacuum.

[swansont]

"In vacuum" and "in a box" are different things. Perfect conductors mean a strong interaction with walls, so you cannot get rid of charges.

 

The box gives you boundary conditions, the interior is a vacuum. Solve the equation, and the cavity QED effects are there.

[Bob_for_short]

The box gives you boundary conditions, the interior is a vacuum. Solve the equation, and the cavity QED effects are there.

 

The boundary conditions with perfect conductors are only possible due to strong coupling the quantized EMF with lots of free electrons (free in your case).

 

It is sufficient to replace the box wall with a non-metallic material and you will obtain a "black body" cavity - with a continuous EMF spectrum. The interieur vacuum remains a vacuum.

[swansont]

The boundary conditions with perfect conductors are only possible due to strong coupling the quantized EMF with lots of free electrons (free in your case).

 

It is sufficient to replace the box wall with a non-metallic material and you will obtain a "black body" cavity - with a continuous EMF spectrum. The interieur vacuum remains a vacuum.

 

I don't see your point. We're discussing the Casimir effect here, which (by definition) requires a boundary that is a conductor. Solving the particle-in-a-box for those boundary conditions is exactly what the problem description is.

[Bob_for_short]

I don't see your point. We're discussing the Casimir effect here, which (by definition) requires a boundary that is a conductor. Solving the particle-in-a-box for those boundary conditions is exactly what the problem description is.

 

The point is simple: the Casimir effect is an interaction of (neurtalized) real charges of plates. This interaction exists whatever material is used.

Edited September 29, 2009 by Bob_for_short

[swansont]

The point is simple: the Casimir effect is an interaction of (neurtalized) real charges of plates. This interaction exists whatever material is used.

 

The interaction isn't the same if the material isn't a conductor, but then that modifies the boundary conditions.

 

One can view the interaction as the mirror effect of charges. That does not negate the fact that one can also predict/explain it as a ramification of the modification of the zero-point energy spectrum.

[Bob_for_short]

If you do not believe me, read this: http://arxiv.org/abs/hep-th/0503158

Edited October 5, 2009 by Bob_for_short

[swansont]

The paper's main objection seems to be about the "reality" of the zero-point fluctuations, rather than the validity of that method. It confirms what I said in my previous post: there is more than one way of deriving it.

[Bob_for_short]

The paper's main objection seems to be about the "reality" of the zero-point fluctuations, rather than the validity of that method. It confirms what I said in my previous post: there is more than one way of deriving it.

 

So why to insist on a misleading one?

[froarty]

Jaffee concludes only that here is no evidence to prove the reality. He does put the big picture together nicely regarding Lifshitz and the fine structure constant. I am a little lost regarding the attention to the fields in close proximity or high v/c. I won't pretend to know how close the plates can get before the local fields break down due to the fine structure constant. My point is the force is dominated by the stationary plates and no matter how high the H1 V/C becomes the effect is too distributed and small to matter - rather it is driven by the changing fields established by the changing topography of the plates when the atoms diffuse through them

[Peron]

Are the virtual particles of Quantum electrodynamics related to the Casimir force?

[froarty]

Are the virtual particles of Quantum electrodynamics related to the Casimir force?

I have considered this question also, according to wikipedia if the virtual particle lasts long enough to actually be measured then it is not really a virtual particle, Yet vacuum fluctuations / virtual particles are said to "up convert" from longer wavelengths to shorter wavelengths as Casimir force increases and then you have papers proposing that lower frequency virtual photons below 2 THZ are more gravitationally active... so are virtual photons measurable but virtual particles not? This leads me to ask if the vacuum fluctuations are actually the underlying fabric of space or just happen to be a group of frequencies that better reflect property changes to this fabric? I believe the "up conversion" of vacuum flux is relativistic based on work by Naudts and Bourgoin which means space time gets curved and all pertubations painted on this fabric will also appear curved (up converted) not just the narrow frequency bad under consideration. This includes the entire electromagnetic spectrum and the orbital wavelengths of atoms diffused inbetween the plates. This is a relativistic interpretation but still begs the question "are these vacuum fluctuations the medium or just another, smaller more represenative resident of the medium?"

Regards

Fran

Edited October 22, 2009 by froarty
grammar

[swansont]

Are the virtual particles of Quantum electrodynamics related to the Casimir force?

 

That's one explanation of it.

[Peron]

That's one explanation of it.

 

But no direct way to know if the vacuum energy is actually made of virtual particles or some sort of elementary energy.

[Peron]

What I was asking was that, we don't really know if it's made of virtual particles. It could be something else.

[insane_alien]

it could be, yes, but itis pointless to speculate without further evidence. virtual particles doesn't require the introduction of new unknown entities and it doesn't violate any physical laws.

 

it fits, we just aren't sure(>95% confidence) as experimentation is difficult.

 

basically in order to say its something different you'd need to supply direct experimental evidence(as with anything).

[swansont]

But no direct way to know if the vacuum energy is actually made of virtual particles or some sort of elementary energy.

 

This gets a little into the previous discussion — it depends on what model you are using. If you are using the QED model which involves virtual particles, then it's due to virtual particles. If you have another valid model using whatever this elemental energy is, then it would be due to that.