Zero point fluctuations and the Casimir effect

[Chuck Norris]

I have recently read about the zero point fluctuations of quantum vacuum and the effect that it has on Casimir plates. However, I don't understand what type of fundamental particle ''carries'' the zero point waves? and also how and why can those particles exit in quantum vacuum (space in its ground state without energy in any form).?

[swansont]

Any particle/antiparticle pair can do this. The vacuum does not have zero energy, it has [math]\frac{1}{2}\hbar\omega_n[/math] for each mode. However, this is generally ignored, since you can't tap into it. What is important is the difference in energy between states, and in most cases the zero-point terms all cancel out. Edited September 9, 2009 by swansont
fix error

[ajb]

The original calculation involves just fluctuations in the electromagnetic field. Particles other than photons contribute, but they are very much suppressed.

 

In more generality, it is known that any boson will produce an attractive force and any fermion repulsive one. Curiously, this means in supersymmetric theories the contributions cancel and there is no Casimir effect. T

[Bob_for_short]

The Casimir effect can be understood as a kind of Van der Waals force which is more physical than "vacuum fluctuation" in a "free" space.

 

In fact, it is an interaction of neutralized charges at a distance. The charges are never free from the quantized EMF. I would say, the quantized EMF is a property of each charge. Thus the (neutralized) charge potential interaction at long distances is an interaction of compound systems, just like atom-atomic interaction at long distances (Van der Waals or so).

 

Look at an atom (of Hydrogen, for example). The electron is bound to a nucleus. We can speak of electron fluctuations in the whole space but it is not possible without an atom. The vacuum here is just the atomic ground state. The same is valid for the quantized EMF - its "fluctuations" are not possible without a charge so no virtual particles are present in an empty space without a charge.

[Ranjha]

MMMMM does 0 Kelvin make any sense to any of you? Van der waals won't work because it's still based on Newtonian physics. You'll need Wave functions to actually quantify the quantum vaccum space. Think of it like looking at a hole in the ground, you know it's a hole because you see the ground on the edges of the hole. You'll have to use Schdronger's Wave mech. to know the "quantum ground" to see the "quantum hole" which would be vaccum. And it can't be a "particle" since "photon, boson, or whatever else you want to call it" are based on "wave/particle" concept. I think it's a very good question but we need revised quantum theory to go further. Perhaps a blend of wave mech., probablity and something I'm not very fond of "Strings".

[Bob_for_short]

Zero Kelvin makes perfectly sense for all of us but you.

[Ranjha]

hahaha...apparently sarcasm is not a norm here!

[Chuck Norris]

Sorry the intended question was a bit vague. What I was hoping to get the answer to was this: Due to zero point fluctuations a force is 'supplied' on the Casmir plates. Every force has a force carrier (I think) what is the force carrier in this situation?

[Bob_for_short]

>what is the force carrier in this situation?

 

It is the same as in case of two neutral atoms at long distances, nothing else.

[froarty]

"Due to zero point fluctuations a force is 'supplied' "

 

The restriction of long wavelength fluctuations could be relativistic instead of the simple "up-conversion" of wavelengths suggested by present theory. I am suggesting the same longer wavelengths appear up-converted from our perspective outside the cavity due to space-time twisting on the time axis inside the cavity.

see animation

Edited September 23, 2009 by froarty
formatting

[elas]

Extract from: http://en.wikipedia.org/wiki/Casimir_effect

Because the strength of the force falls off rapidly with distance, it is only measurable when the distance between the objects is extremely small. On a submicrometre scale, this force becomes so strong that it becomes the dominant force between uncharged conductors. In fact, at separations of 10 nm—about 100 times the typical size of an atom—the Casimir effect produces the equivalent of 1 atmosphere of pressure (101.3 kPa), the precise value depending on surface geometry and other factors.[7]

 

Atmospheric pressure is a product of the Gravitational force and particles. Casimir force comes into significant play when the G force between two neutral plates is equal to or greater than the G force creating the atmospheric pressure causing the particle/wave structure between the plates to be polarised as shown in the Wikipedia wave diagram. The atmospheric field between the plates is then separate to the external atmospheric field.

The external waves are not restricted to the plane shown in the wikipedia diagram; it would however be difficult, if not impossible; to conduct the experiment in any other plane than the one shown.

Edited September 23, 2009 by elas

[froarty]

Yes a gravitational difference is created by a Casimir cavity where the plates are braced apart. the cavity restricts vacuum fluctuations vs outside the cavity creating a boundary. Italian researchers Di Fiore et all in a 2002 paper "Vacuum fluctuation force on a rigid Casimir cavity in a gravitational field" proposed the possibility of verifying the equivalence principle for the zero-point energy of quantum electrodynamics, by evaluating the force, produced by vacuum fluctuations, acting on a rigid Casimir cavity in a weak gravitational field. Their calculations show a resulting force has opposite direction with respect to the gravitational acceleration, their calculations indicates an equivalent acceleration of only 10 E^-14 N. This appears inconsequential but the spatial confinement inside the cavity may allow heat energy to contribute to accelerating gas atoms on this vector. My personal thought is that this force could be the energy source behind excess heat when atomic hydrogen is diffused into rigid catalysts that have casimir geometry like Rayney nickel or possibly Pd - The geometry may resist high velocity formation of diatomic compounds.

[swansont]

Extract from: http://en.wikipedia.org/wiki/Casimir_effect

Because the strength of the force falls off rapidly with distance, it is only measurable when the distance between the objects is extremely small. On a submicrometre scale, this force becomes so strong that it becomes the dominant force between uncharged conductors. In fact, at separations of 10 nm—about 100 times the typical size of an atom—the Casimir effect produces the equivalent of 1 atmosphere of pressure (101.3 kPa), the precise value depending on surface geometry and other factors.[7]

 

Atmospheric pressure is a product of the Gravitational force and particles. Casimir force comes into significant play when the G force between two neutral plates is equal to or greater than the G force creating the atmospheric pressure causing the particle/wave structure between the plates to be polarised as shown in the Wikipedia wave diagram. The atmospheric field between the plates is then separate to the external atmospheric field.

 

You didn't properly bold the statement.

the equivalent of 1 atmosphere of pressure (101.3 kPa)

 

i.e. "1 atmosphere" is the magnitude of the pressure of the Casimir force under those conditions; this is merely a convenient reference — these experiments are done under vacuum, so the atmospheric pressure is reduced by a factor of perhaps a billion. There is no "atmospheric field" to worry about

 

———

 

froarty, you already have a thread on this, please do not hijack other discussions

 

Other thread is here. Some posts have been moved

Edited September 25, 2009 by swansont
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[elas]

You didn't properly bold the statement.

the equivalent of 1 atmosphere of pressure (101.3 kPa)

i.e. "1 atmosphere" is the magnitude of the pressure of the Casimir force under those conditions; this is merely a convenient reference — these experiments are done under vacuum, so the atmospheric pressure is reduced by a factor of perhaps a billion. There is no "atmospheric field" to worry about

 

Surely, 'under vacuum' means a reduction in charged particles, it does not alter gravitational force, gravitons, photons or virtual particles hence the differences are proportional, with gravity playing a larger role due to the abscence of the more powerful charged particles. It is even possible that the gravitons carry some of the observed waves along with other neutral particles; for example:

How many neutrinos are flooding through the experiment?

 

All neutral and virtual particles entering the gap between the plates are subject to a change in the orientation of the local gravity field and that movement is observed as an increase in temperature.

 

Vacuum decreases the charge structure only to be replaced by an increase in the flow of the neutral structure.

 

froarty quotes experiments using gas atoms where the change in gravitational orientation would cause a change in electron orbit oreintation hence a temporary increase in temperature.

[swansont]

Surely, 'under vacuum' means a reduction in charged particles, it does not alter gravitational force, gravitons, photons or virtual particles hence the differences are proportional, with gravity playing a larger role due to the abscence of the more powerful charged particles. It is even possible that the gravitons carry some of the observed waves along with other neutral particles; for example:

How many neutrinos are flooding through the experiment?

 

All neutral and virtual particles entering the gap between the plates are subject to a change in the orientation of the local gravity field and that movement is observed as an increase in temperature.

 

Vacuum decreases the charge structure only to be replaced by an increase in the flow of the neutral structure.

 

froarty quotes experiments using gas atoms where the change in gravitational orientation would cause a change in electron orbit oreintation hence a temporary increase in temperature.

 

The Casimir force does not depend on interactions with particles in the atmosphere. It also does not depend on neutrinos, since it's an electromagnetic phenomenon.

[elas]

The Casimir force does not depend on interactions with particles in the atmosphere. It also does not depend on neutrinos, since it's an electromagnetic phenomenon.

 

It is true to say that the prediction theory used to match theory with the observed Casimir force is Quantum Electrodynamics but, the experiment itself is done in completely neutral conditions with no applied electromagnetic field.

 

Force theories are related to density, applying vacuum force removes 'charged' particles and replaces the 'charged' particles with 'neutral' particles; the 'neutral' force then exists and interacts at a higher density (i.e.QE) level.

 

All so-called fundamental forces (and therefore the theories applied to them), are dependent on the existance of a (particle) force carrier. That is to mean, as proposed by Newton, that the universe is corpuscular in nature.

Edited September 26, 2009 by elas

[Severian]

I still don't understand the Casimir effect. Can someone please run through a proof for me?

[froarty]

my own simple animation and a link to wikipedia that has a good description.

- I have followed some of your previous threads circa 05 but arrived on the scene too late.

Regards

Fran

[Severian]

my own simple animation and a link to wikipedia that has a good description.

- I have followed some of your previous threads circa 05 but arrived on the scene too late.

Regards

Fran

 

The Wiki article seems very flawed to me. The Casimir effect is supposed to be a vacuum effect, but their derivation starts with standing waves.

[froarty]

My math is weak and I don't want to hijack this thread so I have posted a reply to your 2005 related thread here . It may be possible to discuss "fast" hydrogen (relativistic) in a new thread outside of pseudoscience -it has all the advantages of the hydrino without the fractional state controversy.

Fran

[elas]

The Wiki article seems very flawed to me. The Casimir effect is supposed to be a vacuum effect, but their derivation starts with standing waves.

 

Take a look at:

 

http://www.windows.ucar.edu/spaceweather/info_mag_fields.html

 

Observe that between N and S the variation in charge particle density is a static variation, hence a static observation derived from moving particles. if the high density were central, the observer would record an apparent static wave.

 

In a partial vacuum field the Vacuum Zero Point is always at the field centre therefore the variation in density accross the field creates a density wave.

 

Where the movement of charged or neutral particles through a charged or neutral field is a regulated steady flow, the variation in density is observed as a static line or wave.

 

When the neutral (gravitational) force between two plates is stronger than the external gravitational force, the (apparent static) wave lies accross the gap.

[swansont]

The Wiki article seems very flawed to me. The Casimir effect is supposed to be a vacuum effect, but their derivation starts with standing waves.

 

With an occupation number of zero for each mode. You only have standing-mode solutions available to you once you put conductors in the problem. The Casimir force is the result of the zero-point energy of the solution, which is the solution for the vacuum.

[Bob_for_short]

With an occupation number of zero for each mode. You only have standing-mode solutions available to you once you put conductors in the problem. The Casimir force is the result of the zero-point energy of the solution, which is the solution for the vacuum.

 

If we calculate only vacuum, zero point energy of the quantized electromagnetic field, then the plates, disconnected from this fild have nothing to do with it, why should they attract or interact?

 

Therefore it is charge interaction effect that includes the quanitzed electromagnetic filed, attached to each charge. Such an interaction exists not only for conductors but for any material so it is not due to "boundary conditions".

 

As I said, there is an atom-atomic interaction at long distances in which the QEMF contributes. Even in an isolated atom there is the Lamb shift which is due to taking into account the coupling to QEMF (an additional QM charge smearing).

Edited September 28, 2009 by Bob_for_short

[froarty]

If we calculate only vacuum, zero point energy of the quantized electromagnetic field, then the plates, disconnected from this fild have nothing to do, why should they attract or interact?

 

So it is charge interaction effect that includes the quanitzed electromagnetic filed, attached to each charge. Such an interaction exists not only for conductors but for any material so it is not due to "boundary conditions".

 

As I said, there is atom-atomic interaction at long distances in which the QEMF contributes. Even in an isolated atom there is the Lamb shift which is due to taking into account the coupling to QEMF (an additional QM charge smearing).

 

Bob, I think you are coming to the same argument I had with Thomas Prevenslik. Thomas contends there is no exploitable difference to produce the Casimir force. Nature saw to it that the thermal kT energy in the gap is promptly conserved by higher energy QED induced EM radiation that at VUV levels by the photoelectric effect charges the plates and produces an attractive electrostatic force. but this not the neutal force Casimir was thinking of in 1948. He agree the hydrogen atom will be affected by the closeness of plates because of the QED induced EM radiation that excites its quantum states, but this is not caused by the vacuum energy (sic ZPE) proposed by Black Light Power and Cal Physics.He feels ZPE is a hoax and that Planck should have dismissed the ZPE as unphysical upon his derivation because it allowed energy to diverge at high frequency, but did not. Thomas feels that physics for over 100 years has been misdirected into believing you can get something for nothing.[/i]

 

I don't disagree with his thermal perspective in that it could be equivalent but I do disagree with the assumption that we are getting something for nothing and think the paper by DiFiore et all regarding the Casimir cavity having a gravitational equivalence may represent the energy source allowing both interpretations to be valid. here is my take on it.

[swansont]

If we calculate only vacuum, zero point energy of the quantized electromagnetic field, then the plates, disconnected from this fild have nothing to do with it, why should they attract or interact?

 

The conductors modify the boundary conditions for the electric field.