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Loren Booda
May26-04, 11:29 PM
There exist shapes of particular materials that self-propagate in vacuum due to the Casimir effect. Such an object would use vacuum polarization to accelerate relative to other, quasi-inertial objects. Does this absolute motion disagree with relativity, or might it relate to the blackbody background?

techwonder
May27-04, 09:49 AM
What materials and shapes would that be?

Loren Booda
May27-04, 10:51 AM
I guess asymmetric, atomic-sized conductors.

russ_watters
May27-04, 11:49 AM
There exist[s]...

I guess.... Well hold on - there is a big difference between "there exists" and "I guess." Has anyone ever demonstrated this?

It sounds suspiciously like a misunderstanding of pressure/buoyancy to me...

europium
May27-04, 03:33 PM
It happens. It is due to zero point energy between two conductors at a certain distance and of a certain size. At certain distances ZPE somehow 'takes over' and attraction occurs. Also known as vacuum energy it is what is thought to be making space expand. Do google for zero point / vacuum energy

K_

Loren Booda
May27-04, 07:02 PM
Consider the empty vacuum. Place within it a spherically asymmetric conductor (an ovoid, say) of atomic dimensions. The vacuum polarization upon the object's quantum-scale surface biases the overall Casimir force as significantly noninertial with respect to averaged vacuum fluctuations, in possible disagreement with relativity. When compared to a similar object, mutual gravitation diminishes greatly with distance as opposed to the original scalar Casimir effect, which balances out cosmological spacetime curvature.

Can the Casimir effect concur with relativity in this manner?

russ_watters
May27-04, 09:38 PM
It is due to zero point energy between two conductors... Yes, I know about the attraction due to ZPE - but that's symmetrical and not what we're talking about here. Consider the empty vacuum. Place within it a spherically asymmetric conductor (an ovoid, say) of atomic dimensions. The vacuum polarization upon the object's quantum-scale surface biases the overall Casimir force as significantly noninertial with respect to averaged vacuum fluctuations, in possible disagreement with relativity. When compared to a similar object, mutual gravitation diminishes greatly with distance as opposed to the original scalar Casimir effect, which balances out cosmological spacetime curvature. But has this actually been done?

Loren Booda
May27-04, 10:36 PM
To my knowledge, only as a Gedanken experiment. (Those Casimir calculations, even seemingly simple ones, are intractable.)

techwonder
May28-04, 07:15 AM
Could you post us a link to that gedanken experiment, please?

russ_watters
May28-04, 09:00 AM
Could you post us a link to that gedanken experiment, please? "Gedanken" is German for "thought." This is the problem with thought experiments: they are only meaningful if you understand the science behind them - its not just a matter of what your intuition says should happen.

Looren Booda, I don't see any reason why vacuum energy would behave any differently than pressure on irregularly shaped objects. A common misconception brought out in 1st semester fluid mechanics courses is whether pressure is different on different sides of an irregularly shaped object (ie, can you have a net force on the object): It isn't.

A similar misconception is concentration of pressure. If you take a tall, wide vessel or hydraulic cylinder, can you concentrate the pressure at the bottom by funneling it into a small tube (at the same height as the bottom of the vessel)? Answer: no.

Loren Booda
May28-04, 11:05 AM
The question as I see it is, is there a suitably shaped and sized conductor which being near the quantum level undergoes a disequilibrium of forces not due to classical mechanics, but to its irregular constructive/destructive interference of quantum fluctuations, thus possibly contradicting relativity.

The thought experiment is my own.

Loren Booda
May28-04, 11:08 AM
The question as I see it is, is there a suitably shaped and sized conductor which being near the quantum level undergoes an inertial disequilibrium of forces not due to classical mechanics, but to its irregular constructive/destructive interference of quantum fluctuations, thus possibly contradicting relativity.

The thought experiment is my own.

Loren Booda
May28-04, 11:09 AM
The question as I see it is, is there a suitably shaped and sized conductor which being near the quantum level undergoes an inertial disequilibrium by forces not due to classical mechanics, but to its irregular constructive/destructive interference of quantum fluctuations, thus possibly contradicting relativity.

The thought experiment is my own.

TeV
May28-04, 11:41 AM
Consider the empty vacuum. Place within it a spherically asymmetric conductor (an ovoid, say) of atomic dimensions. The vacuum polarization upon the object's quantum-scale surface biases the overall Casimir force as significantly noninertial... Here's the error in the line of thought I guess.

russ_watters
May28-04, 01:04 PM
The question as I see it is, is there a suitably shaped and sized conductor which being near the quantum level undergoes an inertial disequilibrium by forces not due to classical mechanics, but to its irregular constructive/destructive interference of quantum fluctuations, thus possibly contradicting relativity. I understand, but... The thought experiment is my own. Well, fine - my thoughts are different from yours. Are we at an impasse? I don't think so.

A thought experiment, if it hasn't actually ever been performed in reality should conform to the logic and constraints of existing theory, not just personal intuition (or wishful thinking?). Existing theory suggests such a shape does not exist.

This is an eye-opener to me. This may be the root cause of a lot of the problems we have with thought experiments on this board. It may simply be that people are assuming they can have whatever outcome they want since the experiment exists only in their head. Not so.

Loren Booda
May29-04, 01:59 AM
Let me put my original premise this way: can the Heisenberg uncertainty principle disagree with Einstein's principle of equivalence, i. e., can a noninertial frame for a quantum object arise from local vacuum fluctuation action alone?

Blackforest
May29-04, 03:04 AM
Concerning a mental experiment (Gedanken), I invit you to read mine on this forum: Physics = only math? I just suggest that fluctuations (for example EM) occur exactly in the same mathematical space than Laws of the GR are defined and valid because there is only one world... It is for me a good reason why, with work and patience, we should be able to find a connection between Quantum Theory and GR in this world. Blackforest

Olias
May29-04, 03:27 AM
Let me put my original premise this way: can the Heisenberg uncertainty principle disagree with Einstein's principle of equivalence, i. e., can a noninertial frame for a quantum object arise from local vacuum fluctuation action alone?

The HUP is gauged as a Local Effect, if one gets pretty close to a particle during observation (assuming observation is 'Locating' the Quantities that define a particle!), then you forsake one measurable quantity against the other.

You know that a Particles momentum is not in the same vicinity of its position if 'YOU'(detector) are Relative to either!

The simple fact of the matter is YOU cannot be in Two places at any instant, which is the factor needed to measure with a high degree of accuracy a particles two most previlent features, the features which determine its existence.

Now the question you pose above needs further investigation if one make this statement: If you could be in two locations at any instant, are you Relative to yourself?..how could your Acceleration be determined if you stand on Earth, and at the same instance be at a Blackhole Horizon of a far off distant Galactic formation just after the Big-Bang!

Think about it :rolleyes:

Think about the dimensionality of curvature, and the dimensionality of non-curvature SpaceTimes?..the route of information needed to Locate any 3-D object is 'NOT' the same for a Flat 2-D field.

3-Dimensional objects are by defination located with a Boundary, they have definate paramiters which give them real spacetime definations.

2-Dimensional Fields are by defination 'Everywhere', Boundary free!

A 3-Dimensional object can sit within a 2-Dimensional Field, if another 3-Dimensional object exists in the Same field, then they can be referenced.

The problem is that a 2-Dimensional Field 'CANNOT' exist within a 3-Dimensional Object. This needs a perceptional journey to get around the obvious paradoxes, but like I said a 2-D field extends without Boundaries, it is infinite, so cannot be constrained by a Finite 3-D object.

The simplistic value of this is contained within SR and GR, a lesson in EPR was used to show the QM community, E-P-R failed to convince them :smile:

I'm editing this post because of the obvious content of Lorens Question, so lets see if we can advance a little further?

Question: Can 3-D energy appear out of an infinite 2-D field? and is there a comparable action for a 2-D field appearing out of a 3-D object?

TeV
May29-04, 03:28 AM
Let me put my original premise this way: can the Heisenberg uncertainty principle disagree with Einstein's principle of equivalence, i. e., can a noninertial frame for a quantum object arise from local vacuum fluctuation action alone?I don't see in what way HUP can disagree with the equivalence principle of GR.Seeking for the effects arising from QM,that would reveal incompletness of QM, Einstein himself imagined a serie of thought experiments.Once he came to Bohr in triumph showing him thought experiment he considered to be in disagreement with his theory.Einstein couldn't find a flaw.But next day,Bohr find the flaw using the very same GR equations (!),showing there was no inconsistencies.Einstein was shocked.Afterwards he admited he didn't know Bohr knew the core of GR so well.

Loren Booda
May29-04, 01:16 PM
OliasQuestion: Can 3-D energy appear out of an infinite 2-D field? and is there a comparable action for a 2-D field appearing out of a 3-D object? There are quantum gravity models that seemingly can only be solved in two spatial dimensions.

J. A. Wheeler says "the-one dimensional boundary of the two-dimensional boundary of a three-dimensional space is zero."

Olias
May29-04, 01:41 PM
Olias There are quantum gravity models that seemingly can only be solved in two spatial dimensions.

J. A. Wheeler says "the-one dimensional boundary of the two-dimensional boundary of a three-dimensional space is zero."

This going to get philosophical, but tell Wheeler I said a Two Dimensional 'anything' has no boundery!..actually Einstein's Field equations makes this plain!

As I said quite plain in my post?..now look at the Casimir Effect based on this fact, the energy makes it way from the fabric of 'Quantum' structure internal Space, and flows around the dimensional objects used in experimentation.

Electro-Magnetic Fields that extend along a 2-Dimensional Plain of certain Space(flat-space), naturally contract when a 3-D piece of matter appears , this is because of Curvature Caused by the 3-D matter. The same E-M Field naturally Expands when there is no SOLID-MATTER of substance, it by defination Expands to Infinite.

Feynman and Wheeler(who worked with Einstein) discussed this and developed QED between them, but it was Feynman who realized that the 2-D E-M field is reminicent of a Single Electron, and made a statement to this fact, Electrons that are everywhere, to the extent of saying there is but a single Electron that travels backwards and forwards in Time.

The 2-D field is that Electron in a sense, you find it where-ever Boundery conditions connect 3-Dimensional space with 2-Dimensional Fields!

The Space between Galaxies are the structure of E-M Vacuum Points, each component Electro/Magnetic are in Unison along the Field, when one seperates the products, then one gets Singular, Mono Dimensional Points, these do not extent anywhere but inversely, they are Singularities, and thereby are Dimensionally detached from each other, it is debatable if a 'single dimensional point' can Expand to encompass all other Dimensional Structures, dont want to expand on this just yet, but Witten called it a Bubble Of Nothing, and I have dealt with this on another forum, so I wont expand on this for the moment :biggrin:

E-M Vacuum forms a continous Line, it is the Fabric of Flat Space, it is not the Fabric of Spacetime, Curved Space.

Again a 2-D field Naturally Contracts, producing a clear Flat Space Metric in Expansion models, 3-D space-time-Curvature Naturally Expands, its dimensionallity allows Photon Emissions, which is Energy Expansion, offsetting Energy Contraction in Cosmological models.

The 2-D fields contract, its the direction of Contraction >-< which produce Grip around anything that pops into existence, such as Galaxies. The Scale factor between a Contracting E-M-V and an Expanding 3-D energy of Matter is the total sum of space and Spacetimes throughout the Universe, the Extra dimensional Constructs are just that, extra and Man-made.

Creator
May29-04, 02:37 PM
There exist shapes of particular materials that self-propagate in vacuum due to the Casimir effect. Such an object would use vacuum polarization to accelerate relative to other, quasi-inertial objects. Does this absolute motion disagree with relativity, ...

Interesting question. And clearly vacuum polarization has the potential to accelerate an object (not necessarily based on the shape, but on high enough differential surface charge).
However, I think this is not an example of 'absolute motion' since, if I'm not mistaken, the vacuum fluctuations are Lorentz invariant.

Creator :wink:

Loren Booda
May30-04, 07:57 PM
CreatorHowever, I think this is not an example of 'absolute motion' since, if I'm not mistaken, the vacuum fluctuations are Lorentz invariant.

Thanks for your as usual thoughtful and definitive response. You encourage me to persist with physics, although my grasp of it has had to readjust over the years.

DW
Jun5-04, 10:43 AM
There exist shapes of particular materials that self-propagate in vacuum due to the Casimir effect. Such an object would use vacuum polarization to accelerate relative to other, quasi-inertial objects. Does this absolute motion disagree with relativity, or might it relate to the blackbody background?

Actually the prediction of the self propogation is from general relativity. see
section 1 of chapter 12
http://www.geocities.com/zcphysicsms/chap12.htm#BM12_1
and section 4 of chapter 12
http://www.geocities.com/zcphysicsms/chap12.htm#BM12_4

Loren Booda
Jun5-04, 02:37 PM
DW,

You have succeded where we others have failed. Is that "metric engineering" possible with spaceship co-moving accelerative masses, or fixed masses near the point of departure?

DW
Jun6-04, 09:48 AM
DW,

You have succeded where we others have failed. Is that "metric engineering" possible with spaceship co-moving accelerative masses, or fixed masses near the point of departure?

Yes, it can carry the matter responsible for the acceleration, or more accurately that matter would accelerate and frame drag the surrounding spacetime along with the rest of the ship with it.

Loren Booda
Jun6-04, 11:28 AM
What is a possible configuration for such matter?

DW
Jun6-04, 12:14 PM
What is a possible configuration for such matter?

For a very weak effect simply Casimir plates accross from some matter of positive energy and pressure would work. I know the stress energy properties of matter that produce the effect, but not what matter and fields would contain the stresses required to produce the effect on a large scale.