Does quantum tunnelling affect the magnitude of the Casimir Effect?

[Eukonidor]

While reading something recently that mentioned the Casimir Effect, it occurred to me that the plates used in an experiment to measure the force between them would be close enough to allow quantum tunnelling if the plates were transparent, which led me to wonder whether (and how much) the force would be affected if a beam of light were sent through at an angle which would prevent transmission across the gap by any means other than tunnelling.

I'm fully aware that the beam of light being reflected would also impart a minute force, and that would be reduced by the amount of light which tunneled through, but would there be a discrepancy?

Don't know if such a thing would have any use or not, but it would be an interesting data point nonetheless.

 

[Vanadium 50]

occurred to me that the plates used in an experiment to measure the force between them would be close enough to allow quantum tunnelling if the plates were transparent

If the plates were transparent, wouldn't the light just shine on through?

 

[pines-demon]

While reading something recently that mentioned the Casimir Effect, it occurred to me that the plates used in an experiment to measure the force between them would be close enough to allow quantum tunnelling if the plates were transparent, which led me to wonder whether (and how much) the force would be affected if a beam of light were sent through at an angle which would prevent transmission across the gap by any means other than tunnelling.

I'm fully aware that the beam of light being reflected would also impart a minute force, and that would be reduced by the amount of light which tunneled through, but would there be a discrepancy?

Don't know if such a thing would have any use or not, but it would be an interesting data point nonetheless.

I am not an expert but you can calculate the Casimir force for a given material not just perfect mirrors

 

[PeterDonis]

While reading something

What? Please give a specific reference.

 

[hutchphd]

What? Please give a specific reference.

Amen to that.

Isn't the Casimir effect for flat conductors? (you have a transparent conductor?????). My understanding is that it is that they are analogous to "Van dar Waals surface forces" induced on each of two conducting plates by dipolar fluctuations in space between.

 

[Eukonidor]

What? Please give a specific reference.

I don't see why I would need a specific reference, since it was merely the fact that the text mentioned the Casimir Effect, not anything in particular in the article itself. I just happened to be in a frame of mind where that mention got me thinking about it, and how the plates would be close enough together that tunneling could occur, and that the probability curve for the photon in that space is non-zero but decreasing over distance. In fact, I don't remember what article it was, because it became irrelevant to me as soon as my speculation took over.

 

[Eukonidor]

If the plates were transparent, wouldn't the light just shine on through?

The light striking the surface undergoes reflection at the interface between two materials of different refractive index. At high angles, that reflection is only partial - some reflects and some passes through, but at some critically shallow angle, determined by the difference in the refractive indices, that reflection becomes total, and all the incident light is reflected.

 

[Eukonidor]

Amen to that.

Isn't the Casimir effect for flat conductors? (you have a transparent conductor?????). My understanding is that it is that they are analogous to "Van dar Waals surface forces" induced on each of two conducting plates by dipolar fluctuations in space between.

Some conductors have low enough opacity that in thin films, they can be transparent. You can see this in some cars, where the heating element for the windshield or rear window is a solid sheet, rather than the wire grid that most vehicles have on their rear windows.

I'm not particularly well-informed on the Casimir Effect in depth, so I'm going to have to go with Wikipedia here, but it looks like what you're mentioning is known as the Casimir-Polder force:
https://en.wikipedia.org/wiki/Casimir_effect

 

[hutchphd]

I don't see why I would need a specific referenc

You also don't seem to understand the specifics of the process. We cannot discuss the vagaries in your brain. This is why a specific example is de rigueur for this type of discussion. Saves time and effort for the teacher. Consider it a courtesy if you wish. Capisce?

 

[Eukonidor]

I am not an expert but you can calculate the Casimir force for a given material not just perfect mirrors

While I don't know how, I do know you can calculate it, and that it's actually something that is only known for conductors and dielectrics currently, not mirrors, but I was thinking of how the nearness of the second plate would allow the wavefunction of the light that SHOULD be completely reflected to include a probability of each photon being transmitted rather than reflected, and whether that would alter the actual value of the force measured.

 

[Eukonidor]

You also don't seem to understand the specifics of the process. We cannot discuss the vagaries in your brain. This is why a specific example is de rigueur for this type of discussion. Saves time and effort for the teacher. Consider it a courtesy if you wish. Capisce?

Well, I don't know what to tell you. You're obviously not the type of person who can see a single word and be sent off into a completely different train of thought, unrelated to the previous thinking save for the existence of that single word, which is what happened to me.

Since my thinking was totally unrelated to what I had been reading, save for the words "Casimir Effect", I tried to explain the setup of what I was thinking as well as I could. If there are specific details that I have not included, OTHER THAN what I was reading beforehand, I will try to explain, but I DO NOT remember what I was reading, and it is actually totally irrelevant to my question, save that is contained the phrase "Casimir Effect".

 

[pines-demon]

While I don't know how, I do know you can calculate it, and that it's actually something that is only known for conductors and dielectrics currently, not mirrors, but I was thinking of how the nearness of the second plate would allow the wavefunction of the light that SHOULD be completely reflected to include a probability of each photon being transmitted rather than reflected, and whether that would alter the actual value of the force measured.

By mirrors I was imagining ideal materials. Both transmission and reflection coefficients are involved in the specific material calculation, it does play a role.

I don't see why I would need a specific reference,

That is not how PF works...

 

[Eukonidor]

By mirrors I was imagining ideal materials. Both transmission and reflection coefficients are involved in the specific material calculation, it does play a role.

OK, I think we're having a communication problem here. The Casimir Force is not related directly to the transmission and reflection of light. I was combining two different effects in my question, and wondering if they could affect each other.

 

[pines-demon]

OK, I think we're having a communication problem here. The Casimir Force is not related directly to the transmission and reflection of light. I was combining two different effects in my question, and wondering if they could affect each other.

You are right, I think I misread your set up. Why do you care if the plates are shined upon or not? At worst, that would just make everything more difficult to measure.

Edit: also the Casimir force does depend on transmission and reflection of light.

 

[PeterDonis]

I don't see why I would need a specific reference

PF rules say you should always provide a specific reference when asked for one.

it was merely the fact that the text mentioned the Casimir Effect

You don't need to reference some random article that you won't tell us the source of to justify asking a question about the Casimir Effect. Just ask it. Referencing an unnamed source invites the thought that you are making use of something in that unnamed source, which is probably not a valid reference and is probably saying something that is misleading you. If that's not the case, the best way to prevent people from thinking that it is is not to mention unnamed sources at all.

 

[PeterDonis]

my thinking was totally unrelated to what I had been reading

Which begs the question, why did you even mention what you were reading?

 

[PeterDonis]

The light striking the surface undergoes reflection at the interface between two materials of different refractive index. At high angles, that reflection is only partial - some reflects and some passes through, but at some critically shallow angle, determined by the difference in the refractive indices, that reflection becomes total, and all the incident light is reflected.

All of this is a classical analysis, but this is the QM forum, and your question involves two quantum effects, tunneling and the Casimir effect. That means you can't rely on a classical analysis of the reflection/transmission process. In quantum electrodynamics, there is no such thing as a definite "angle" at which light strikes a surface.

 

[Eukonidor]

All of this is a classical analysis, but this is the QM forum, and your question involves two quantum effects, tunneling and the Casimir effect. That means you can't rely on a classical analysis of the reflection/transmission process. In quantum electrodynamics, there is no such thing as a definite "angle" at which light strikes a surface.

Vanadium 50 apparently didn't understand the effect I was describing in the OP, so I was explaining it to him.

Obviously tunneling is going to occur to some extent at all angles, until the barrier created by the angle of incidence becomes too great for tunneling to occur, based on the distance to the second material, but my setup was described with the intent to force all transmission to be from tunneling only, removing any influence of transmission by classical means.

 

[Eukonidor]

Which begs the question, why did you even mention what you were reading?

Because I didn't think of it when I was titrating alkalinity values at work, and I certainly didn't see the phrase "Casimir Effect" on one of our work orders. I was reading something. It's purely used as a reference to my actions prior to the thought, not something that I was trying to understand in the article, nor trying to extrapolate from the article.

 

[PeterDonis]

Vanadium 50 apparently didn't understand the effect I was describing in the OP, so I was explaining it to him.

You may have been trying to, but as I said, a classical analysis can't be relied on in this discussion, since you are asking about quantum effects.

Obviously tunneling is going to occur to some extent at all angles

You're missing the point: if we are doing a quantum analysis, which we have to because you are asking about quantum effects, there is no such thing as the angle at which the light hits the surface. So your statement here, and in fact all the rest of your post, is meaningless.

 

[PeterDonis]

It's purely used as a reference to my actions prior to the thought, not something that I was trying to understand in the article, nor trying to extrapolate from the article.

And in that case, it's better not to mention it at all. Please bear that in mind for future reference.

 

[Vanadium 50]

If you write "Casimir Effect" in the thread's title, you shouldn't be surprised that people infer that you want to talk about the Casimir Effect.

I have no idea of what sort of setup you have in mind with your "lights shining on plates" idea. If you want to discuss it, you need to be much clearer about what you have in mind. Equations might help.