How do deterministic Bohmian/Pilot Wave Theories Handle These?

[Dmitry67]

Can you tell me just one thing: Do you really want to understand BI better, or do you just want to provoke people who disagree with you? I will not answer any of your further questions until you answer this one.

Frankly, I am here, in this thread because I am puzzled (and I try to understand the reasons) why people can prefer such interpretation. So I am trying to understand BM better - but ont the psycological, not mathematical level.

There are theories which can look strange, weird, contre-intuitive but they are BEAUTIFUL. Thru these theories I feel the reflection of God. I see the beauty.

Correct me if I am wrong, but BI is just a sequence of ad-hoc attempts to catch up with an understanding of reality. Even these artificial attempts might be successful, they created more and more artificial things making it less and less beautiful.

Bohmians had made their theory relativistic by the ugly price of adding a preferred frame. Now as I said to ilja - it is not possible to define a common preferred frame in the curved space, for example, a common frame for the inner and outer part of the black hole. I had had confirmed it, because in his GLET there is no such thing as collapse.

But I am sure that BM will be able to accommodate the black holes by making more and more artificial assumtions. But what is a whole point? Pure/MWI (and even CI) QM is able to work on the edge of the semi-classical approach to gravity (Hawking, Unruh) while BM is in denial of both effects because these effects are inconsistent with BM.

You can say that both effects are not confirmed experimentally. I agree, but at least they are predicted. What is a prediciton power of BM except that it had recently accommodated SR and is trying to tackle some GR things?

Finally, the single histrory deterministic theory suffers from the laplace determinism, so me writing this post is pre-coded in the initial conditions during the big bang. I see such determinism as a loss, not as a victory.

Could you explain, what aspects of BM are so attractive for you?

P.S.
I ahd noticed an interesting thing, looks like our discussion about BM and Virtual particles are the same. Without these 'particles' added to wavefunctions these wavefunctions are not real enough for you, and it leads to some strange classification of what is real and what is not.

 

[Demystifier]

Could you explain, what aspects of BM are so attractive for you?

No, I could not. I have tried many times to explain that to you, but you still ask me the same question. So there is no point in trying to do that again. In the following, I will only point to some of your misconceptions.

 

[Demystifier]

1. So what happens when electrons exchange virtual photons in QFT?

As I already said many times, electrons do not exchange virtual photons.

 

[QMessiah]

Demystifier: I dno about Dmitry67 and doubt he really cares or knows too much about QM.

I've always gone with STFU and calculate.

As for interpretations:

Copenhagen = insanity and definitely wrong
Many Worlds = uncertain, all I know is that it can't arrive at Born's Rule and therefore can't be considered coherent yet.

I've always felt Bohmian sounded reasonable, however never dwelled deeper into it.

If your saying that the universe is fundamnetally indeterministic and past and future exist (eternalism) I have a hard time swallowing that as a realist interpretation.
Am I missinterpreting your statements or is this what Bohmian mechanics claim?

 

[Dmitry67]

BTW there are some good news.

So, relativistic BM is indistinguishable (experimentally) from other iterpretations of QM.
But, BM predicts that there is a preferred frame.
The situation changes in curved space, check here:

http://en.wikipedia.org/wiki/Parameterized_post-Newtonian_formalism

There are special parameters:

The meaning of these is that α1 , α2 and α3 measure the extent of preferred frame effects

And these values of these parameters are experimentally verifiable.

 

[ueit]

1. There are no postulates.
If you still want something, then I can give it in a negative form: you don't need to make any extra assumptions (collapses, particles) to explain the reality. Just pure QM.

So, give me the postulates that define what you name "pure QM".

2. Check my previous post: classical reality is explained ia QD, and a choice of basic depends on the observer

What do you mean by "observer" (I want a definition of "observer" only in terms of the postulates of "pure QM")

3. Do other interpretation give a definition for what "human" is? :) it is an interesting question, but shouldn't it be a part, say, of a biology rather then QM?

Yes, in BM you could define a human based on a certain particle distribution (a human is, after all a collection of molecules of a certain type).

Observer does not play any special role in MWI. Nor the "measurement devices". They are treated the same as all other systems - microscopic or macroscopic. There is no boundary between QM and classical world. World is quantum on all scales, and our classical view is just an illusion.

Well, then define what a "system" is using only the postulates of "pure QM"

 

[Demystifier]

Again, do you consider a photon emitted from the sun and absorbed by our eye are real or virtual? Let's make it simpler. A photon is emitted during de-excitation of an atom and is absorbed by another atom. Was this photon real or not?

It is real.

As I tried to explain earlier, the only consistent way we currently have to define a particle as "real" is off at infinity.

I disagree. The unitary evolution of the physical state can be calculated for any time. This state is physical (and hence "real") at any time.

Again, here by random, because you want a realism theory, you have to mean unknown but definite value. This is different than truly random.

I did not mean truly random. I meant effectively random, because we do not know how "God" chooses initial conditions.

I must be frank here. I feel this is teetering on Metaphysics/philosophy and not actually physics. This proposes much additional structure that doesn't even sound testible.

I don't know any physical theory that does not contain something untestable. For example, can you measure the wave function of standard QM?

Things will become even more convoluted if you actually manage to derive the lamb shift and the magnetic moment of the electron (it would be hard to take your "new QFT" seriously without at least showing how such calculations could be done in principle and showing the correct results should follow ... for relativistic quantum mechanics gets the wrong result, it took field theory to get the rest, so such calculations really demonstrate that final step from non-relativistic quantum -> relativistic quantum -> quantum field theory).

In few days, I will upload a paper on arXiv showing how BI can be made consistent with QFT.

 

[Demystifier]

If your saying that the universe is fundamnetally indeterministic and past and future exist (eternalism) I have a hard time swallowing that as a realist interpretation.
Am I missinterpreting your statements or is this what Bohmian mechanics claim?

Good news:
BM is not fundamentally indeterministic. It only appears indeterministic because we do not know the actual initial conditions.

Bad news:
Yes, I am saying that past and future exist (eternalism). If it is hard to swallow, maybe this can help:
http://fqxi.org/data/essay-contest-files/Nikolic_FQXi_time.pdf

 

[DrChinese]

Since my paper is close to finishing, I can tell you that the sentence above is not so far from the Bohmian picture. More will become clear soon, when I upload the paper on arXiv.
For now, let me only tell you two things:
1. In BM, everything is determined by the initial conditions, but the initial conditions themselves are essentially random.
2. To have nonlocality and relativity at the same time, the concept of an "initial" condition should be radically revised. A part of it can be in the past, while another part of it can be in the future. [See http://xxx.lanl.gov/abs/0811.1905 .] Consequently, the initial condition may appear as something that occurs randomly during the evolution of the universe.

Thanks. Still following along, please don't mind my questions. This is very interesting, and I am glad you are tackling some difficult issues in your work.

 

[Count Iblis]

Many Worlds = uncertain, all I know is that it can't arrive at Born's Rule and therefore can't be considered coherent yet.

In the MWI, you can replace Born's rule by the weaker rule that says that if the wavefunction is an eigenstate of an observable, then measuring that observable will yield the corresponding eigenvalue.

 

[Demystifier]

Thanks. Still following along, please don't mind my questions. This is very interesting, and I am glad you are tackling some difficult issues in your work.

I like your constructive questions very much. They help me to sharpen my own understanding of it as well.

 

[isabelle]

Demystifier, it is interesting to have someone on this forum who (based on my quick reads of some of your papers) is an expert on the Bohmian interpretation of quantum mechanics.

As an undergrad I read Holland's "Quantum Theory of Motion", and besides introducing me to advanced classical mechanics, I also found the idea to be appealing at the time. When I studied Bell's theorem and Aspect's experiments a few months later my enthusiasm for BI waned, and when I learned QFT I formed my personal interpretation around quantum fields, rather then particles.
When you do publish your results on Bohmian field theory I will read them, and perhaps they will rekindle my interest.

Anyway, now my research mostly involves statistical field theory and my outlook towards physical theories is that they are only models of reality. It's like Euler said: we can never know the true nature of things, but sometimes a certain fictive hypothesis may suffice to explain many phenomena. This position differs from logical positivism, or CI, which says we cannot know the true nature of things and so any attempt to do so is a waste of time. Anyway, from this point of view Bohmian mechanics replaces a linear theory that is exactly integrable in some important cases with a highly nonlinear theory that seems to be intractable. If all of our models are merely "fictive hypothesis" then it does not make sense to replace a tractable model with an intractable one which gives the same results. In stat mech the goal is not to write down a theory that purports to describe the way things are, but to write down a theory that can in some sense be solved but still captures some interesting physics.

Anyway, good luck to you on your Bohmian QFT.

 

[Demystifier]

and when I learned QFT I formed my personal interpretation around quantum fields, rather then particles.

But all measurable predictions of QFT eventually reduce to predictions on particles, don't they? For example, fermionic fields are not even observables. Fermionic particles, on the other hand, are observables. Thus, it should not seem unreasonable to assume that QFT is actually a theory of particles.

Anyway, from this point of view Bohmian mechanics replaces a linear theory that is exactly integrable in some important cases with a highly nonlinear theory that seems to be intractable. If all of our models are merely "fictive hypothesis" then it does not make sense to replace a tractable model with an intractable one which gives the same results.

Sometimes it is even simpler to solve things with the Bohmian approach:
Phys. Rev. Lett. 82, 5190 - 5193 (1999)
http://prola.aps.org/abstract/PRL/v82/i26/p5190_1

 

[Ilja]

There are theories which can look strange, weird, contre-intuitive but they are BEAUTIFUL. Thru these theories I feel the reflection of God. I see the beauty.

Correct me if I am wrong, but BI is just a sequence of ad-hoc attempts to catch up with an understanding of reality.

I certainly disagree. The guiding equation is a very beautiful one, it is part of Hamilton-Jacobi theory, which is a very beautiful classical theory, and which appears in the classical limit if we use pilot wave theory.

And it gives also, independently, the continuity equation.

These are two independent beautiful justifications for one and the same equation. That's not something one can made up, that's a sufficiently strong hint that the guiding equation is correct.

Bohmians had made their theory relativistic by the ugly price of adding a preferred frame. Now as I said to ilja - it is not possible to define a common preferred frame in the curved space, for example, a common frame for the inner and outer part of the black hole. I had had confirmed it, because in his GLET there is no such thing as collapse.

But I am sure that BM will be able to accommodate the black holes by making more and more artificial assumtions.

What do you mean with "accomodating black holes"? In GLET there is such a thing as a gravitational collapse, it simply stops immediately before horizon formation. The result will, from observational point of view, not differ from GR black holes.

And the price is ugly for you. I have postulated the existence of a preferred frame for completely different reason before even learning pilot wave theory. And my ether model of the SM (http://ilja-schmelzer.de/clm" ) gives all
observed particles of the SM and allows to compute the SM gauge action. I can wait now
until some competing theory presents something comparable.

But what is a whole point? Pure/MWI (and even CI) QM is able to work on the edge of the semi-classical approach to gravity (Hawking, Unruh) while BM is in denial of both effects because these effects are inconsistent with BM.

I don't see why semiclassical gravity is in any way inconsistent with BM.

You can say that both effects are not confirmed experimentally. I agree, but at least they are predicted. What is a prediciton power of BM except that it had recently accommodated SR and is trying to tackle some GR things?

The predictive power of pilot wave theory is that of QM. These are identical. That's sufficiently large predictive power.

Finally, the single histrory deterministic theory suffers from the laplace determinism, so me writing this post is pre-coded in the initial conditions during the big bang. I see such determinism as a loss, not as a victory.

I don't care about determinism. Some stochastic variants (Nelson) have some beautiful aspects, they give the Bohmian quantum potential in a quite natural way.

Could you explain, what aspects of BM are so attractive for you?

First of all, it has a preferred frame. (This is, of course, my personal position, I understand that you don't share it).

I have not cared much in the past about foundations, shut up and calculate was fine for me, so I'm not a dogmatic. But once we have found some realistic interpretation in the sense used by EPR and Bell, there is no reason to give up this notion of realism, thus, the only viable (for me) competitors are realistic ones. Relativistic symmetry I have rejected earlier for different independent reasons.

Realistic collapse theories are obviously made up and ugly. But pilot wave theory has, with the guiding equation, a remarkable and beautiful completion of quantum theory.

 

[Ilja]

BTW there are some good news.

So, relativistic BM is indistinguishable (experimentally) from other iterpretations of QM.
But, BM predicts that there is a preferred frame.
The situation changes in curved space, check here:

http://en.wikipedia.org/wiki/Parameterized_post-Newtonian_formalism

There are special parameters:

And these values of these parameters are experimentally verifiable.

The situation doesn't change. These parameters measure some possible effects of a preferred frame. For a theory where the preferred frame is hidden, they have the same values as for GR.

 

[Ilja]

Good news:
BM is not fundamentally indeterministic. It only appears indeterministic because we do not know the actual initial conditions.

Bad news:
Yes, I am saying that past and future exist (eternalism). If it is hard to swallow, maybe this can help:
http://fqxi.org/data/essay-contest-files/Nikolic_FQXi_time.pdf

But you should not take this as the common opinion of all pilot wave supporters. Pilot wave theory is a theory which is compatible with presentism (only presence exists).

 

[Dmitry67]

Ilja, well, our understanding of beauty is quite different. I have to admit, I am shocked by the fact that preffered frame for you is a beauty - not an uglyness.

But anyway... talking about your GLET,
did you see this:
http://en.wikipedia.org/wiki/Parameterized_post-Newtonian_formalism

Looks like it does not take a long time to check if your GLET is compatible with an experimental data...

 

[Dmitry67]

The situation doesn't change. These parameters measure some possible effects of a preferred frame. For a theory where the preferred frame is hidden, they have the same values as for GR.

But they are not hidden in GLET, because, as I understand, GLET gives different predictions then SR
For example, in SR if I jump ito BH I am torn apart by the tidal forces, but there is no surface
In your theiry you hit the surface

 

[Ilja]

So Bohmian Mechanics require:

1. TRUE indeterminism/randomness at the fundamental level?
2. 10 000x The speed of light which inreturns means: a block universe/eternalism?


This is less realist than positivism =\

Pilot wave theory certainly does not require that. It is deterministic itself. A block universe is not necessary too. A simple preferred frame does the job.

There are independent arguments in favour of a preferred frame, for example my model of the standard model particles http://ilja.schmelzer.ce/clm" .

 

[Ilja]

There are ways to turn discussions of foundational issues into experimental tests (such as Bell's inequalities). Speaking of which, I thought that some papers by the nobel laureate Tony Leggett combined with experiments, ruled out nonlocal-realism as well.

Not non-local realism (these tests are irrelevant for the non-local realistic pilot wave theories as well as other theories with preferred frame), but a particular extravagant version of non-local realism. I'm not sure anybody has seriously proposed a theory of the type rejected by Leggett.

You may be able to hobble together a theory equivalent to quantum mechanics in that it predicts the same values for all experiments, but to do so you would have to abandon much of what we learned about the deepest symmetries of physics. To cling onto one a priori expectation you have, you'd end up replacing real physics with adhoc results. Sure, Lorentz Ether Theory predicts the same results as Special Relativy for electrodynamics .. but do all those ad-hoc statements really amount to a better, or even useful, theory ... can you even call it an "interpretation" of a theory if you replace all the beauty and guts with something else to fit your a priori expectation? There is a reason LET and the Bohm interpretation haven't led to new predictions and advancement of physics. In my opinion they are a waste of time.

The reason is a simple one: Much more people working in other directions, and a de facto taboo on ether theory.

But what is comparable in the domain of explanation of the properties of the standard model of particle physics with my model http://ilja-schmelzer.de/clm" ? Can anybody else compute the fermionic content, the SM gauge group and its action of fermions from simple first principles applied to a simple model? I can.

By the way, my generalization of the Lorentz ether to gravity is comparable even in beauty with GR. In particular, it has a useful application for two beautiful constructions which have been independently invented to simplify GR: harmonic coordinates and the ADM decomposition.

 

[Ilja]

But they are not hidden in GLET, because, as I understand, GLET gives different predictions then SR
For example, in SR if I jump ito BH I am torn apart by the tidal forces, but there is no surface
In your theiry you hit the surface

There are some additional terms, which lead to different predictions, but, surprise, purely formal the theory has also a Minkowski symmetry (that of the vacuum solution, for appropriate signs of my cosmological constants). So the different predictions are not about preferred frames.

Then, the additional terms are mainly cosmological in nature. They do not depend on derivatives of the metric, like Einsteins cosmological term. They become large only in cosmological situations and in situations where the harmonic coordinates otherwise would become infinite. For PPN, I would suggest that the relevant parameters are simply too small to be observable.

The remarkable thing is, of course, that however small they are, the surface remains, and the big bang singularity cannot happen too.

 

[Ilja]

Ilja, well, our understanding of beauty is quite different. I have to admit, I am shocked by the fact that preffered frame for you is a beauty - not an uglyness.

The beauty of the preferred frame was simply a joke. I understand very well that more symmetric things are more beautiful, and, whenever I have a variant with relativistic symmetry, nothing otherwise worse with it, I certainly prefer it.

But one thing is the preference for symmetry, another thing that the situation with realism, the violation of Bell's inequality, and pilot wave theory give very strong support for a preferred frame - and that preferred frame I had postulated even earlier for completely different reasons. It is quite clear that one likes to see that the own ideas obtain independent strong support.

 

[Dmitry67]

So what happens if I jump into a black hole, or, how you call it, a frozen star?
Or, what happens to an observer staying on the surface of a 'frozen star'?

Being indistinguishable from SR requires that observer in your GLET witness all effects, predicted by SR: ergosphere, blue sheet at the Cachy horizon, and even watching the naked Kerr ring - in all its beauty.

 

[Ilja]

So what happens if I jump into a black hole, or, how you call it, a frozen star?
Or, what happens to an observer staying on the surface of a 'frozen star'?

Being indistinguishable from SR requires that observer in your GLET witness all effects, predicted by SR: ergosphere, blue sheet at the Cachy horizon, and even watching the naked Kerr ring - in all its beauty.

The observer will hit the surface and certainly not survive this. The temperature of the surface itself, in the relativistic frame, will be very hot, because it is heated by infalling matter. But, as far as I understand, not hot enough to be visible from outside.

 

[rjbeery]

DrChinese: I've got you thinking eh? After reading the OP and a bit of thought, here are the answers coming from my gut:

PRESUMING quantum retrocausality and requiring an absorber for each emitted particle...

A) Recall that no space is empty, but filled with waves (making no distinction between EM and wavefunctions here) coming from every direction. Suppose constructive interference is not relegated to a single system's wavefunction, but under certain (extremely rare) circumstances the wavefunctions of multiple systems could interfere to create the appropriate absorbers for the respective emitted particles of each system. This would provide a deterministic mechanism for virtual particles.

B) Under these presumptions particle decay could simply be described as a (deterministic) probability function of the emitter "encountering" the appropriate absorber via the Poisson distribution. The longer the half-life, the rarer the appropriate absorber.

These presumptions would also (stated from pop-sci level of knowledge of black holes) explain black hole radiation while preserving information: allow particle X to pass the horizon. Now, a created particle/antiparticle pair (X*, Y) straddling the horizon could only occur if there was the appropriate absorber within the horizon; in this case, Y would also fall into the black hole, headed for X. X* escapes, while X and Y annihilate, thereby both preserving information and obeying the no-cloning principle.

 

[DrChinese]

DrChinese: I've got you thinking eh? After reading the OP and a bit of thought, here are the answers coming from my gut:

PRESUMING quantum retrocausality and requiring an absorber for each emitted particle...

A) Recall that no space is empty, but filled with waves (making no distinction between EM and wavefunctions here) coming from every direction. Suppose constructive interference is not relegated to a single system's wavefunction, but under certain (extremely rare) circumstances the wavefunctions of multiple systems could interfere to create the appropriate absorbers for the respective emitted particles of each system. This would provide a deterministic mechanism for virtual particles.

B) Under these presumptions particle decay could simply be described as a (deterministic) probability function of the emitter "encountering" the appropriate absorber via the Poisson distribution. The longer the half-life, the rarer the appropriate absorber.

These presumptions would also (stated from pop-sci level of knowledge of black holes) explain black hole radiation while preserving information: allow particle X to pass the horizon. Now, a created particle/antiparticle pair (X*, Y) straddling the horizon could only occur if there was the appropriate absorber within the horizon; in this case, Y would also fall into the black hole, headed for X. X* escapes, while X and Y annihilate, thereby both preserving information and obeying the no-cloning principle.

Yes, it is pretty interesting that the probability waves are the main thing that act as if they are "real" at all times... until there is a wave function collapse and one of the possibilities are selected. So it would be natural to presume that just like in an ocean, waves from different particles can overlap and then there is either constructive or destructive interference. In this model, the "virtual" particles would somehow represent suitable wave crests to use an analogy. The problem as I see it is that implies that there are more wave crests near large objects as compared to empty space - assuming that the wave strength diminishes with distance - and there is nothing to indicate that this is the case. But who knows, maybe there are effects which are different in open space versus near Earth, where most experiments are done. (I believe that it has been ruled out that dark matter is ZPE.)

And also interesting: where are the hidden variables? In Bohmian interpretations, they reside non-locally. In MWI, they are in other worlds (being a little loose here). In Retro-causal interpretations, in the future. But they all have similar ideas in terms of supplying the missing ingredients that we hope would "complete" QM. Assuming, of course, that it is possible to complete QM, which many doubt - and I can understand that position too.

So one of the reasons I am interested in Demystifier's work - and that of others in BM - is to understand how it applies to some of the other phenomena in the quantum world. So if I ask him about radioactive decay - how is that "caused" in BM - then the same question would also apply in retro-causal (time symmetric) interpretations. There must be an advanced wave and a retarded wave for the W boson as well. And of course, the standard model is still silent on this - which also is sensible given the current state of experiments.

 

[Count Iblis]

Does BM allow one to in principle manipulate the probabilities that standard quantum mechanics predicts? BM is deterministic and an observers consist of particles, so why not?

 

[Dmitry67]

The observer will hit the surface

Good. In GR this does NOT happen
So, your GLET and GR give DIFFERENT predictions for some experiments, do we agree?
Why not then put it into the formalism and check if it fits the experimental data?

 

[rjbeery]

probability waves are the main thing that act as if they are "real" at all times... until there is a wave function collapse and one of the possibilities are selected.

It seems that this language is an artifact of CI. There is no "until"; each particle has a discrete path at all times. A pilot wave is directly equivalent (in my mind, but I may be wrong) to pure retroaction, which is the framework within which I provided my answer.

The problem as I see it is that implies that there are more wave crests near large objects as compared to empty space

Because the waves are retrocausal, distance to a potential absorber may be disregarded. In other words, your objection is only as detectable as the Universe is transparent. Something just occurred to me - this model would imply that Hawking radiation would not originate from the horizon at all, but would rather spontaneously occur all over the Universe.

where are the hidden variables?

The hidden variables exist in the future presuming that pilot wave theory and pure quantum retrocausality are equivalent. If they are not, then I am defending the wrong interpretation!

 

[rjbeery]

DrChinese: Rereading post number 126, it is clear that you are drawing a distinction between retrocausal theories and BM so it is possible that I am in fact defending the wrong interpretation as framed by your question. It is my position that BM and retrocausal interpretations are equivalent; I guess I would like to add to your questioning and ask any BM advocates to explain the difference between the following two pictures:

Under retrocausality:

[FONT="Fixedsys"]
t=1: Ex~~~~~ A
t=2: E x~~~~ A
t=3: E  x~~~ A
t=4: E   x~~ A
t=5: E    x~ A
t=6: E     x A

Under non-retrocausal pilot wave theory:

[FONT="Fixedsys"]
t=1: Ex~     A
t=2: E x~    A
t=3: E  x~   A
t=4: E   x~  A
t=5: E    x~ A
t=6: E     x A

Where E is the emitter, x is the particle, ~ is the (pilot)wave function, A is the absorber and of course t is the time progression. Does ~ precede x in the time dimension or not? I have have difficulties with either answer unless I presume retrocausality...

 

[DrChinese]

DrChinese: Rereading post number 126, it is clear that you are drawing a distinction between retrocausal theories and BM so it is possible that I am in fact defending the wrong interpretation as framed by your question. It is my position that BM and retrocausal interpretations are equivalent; I guess I would like to add to your questioning and ask any BM advocates to explain the difference between the following two pictures:

Under retrocausality:

[FONT="Fixedsys"]
t=1: Ex~~~~~ A
t=2: E x~~~~ A
t=3: E  x~~~ A
t=4: E   x~~ A
t=5: E    x~ A
t=6: E     x A

Under non-retrocausal pilot wave theory:

[FONT="Fixedsys"]
t=1: Ex~     A
t=2: E x~    A
t=3: E  x~   A
t=4: E   x~  A
t=5: E    x~ A
t=6: E     x A

Where E is the emitter, x is the particle, ~ is the (pilot)wave function, A is the absorber and of course t is the time progression. Does ~ precede x in the time dimension or not? I have have difficulties with either answer unless I presume retrocausality...

It was Demystifier who was mentioning the there might be a component of the Bohmian interpretation which relates to the future, and I believe we will get a chance to hear more about that soon. So I wasn't going to push in that area as he will tell us about it when he is ready.

If I were strictly guessing, I might imagine that non-local influences would look, in a lot of ways, as if it were arriving from the future.

A follow-up question, for Demystifier or other BM knowledgeable person: The guidance equation is a function of the configuration of the system, Q(t) = (Q1(t), · · · ,QN(t)). What is not clear is whether particle Qn's influence decreases with distance (sorta like an inverse square effect), or not. Anything anyone could add on that?

 

[Ilja]

Good. In GR this does NOT happen
So, your GLET and GR give DIFFERENT predictions for some experiments, do we agree?
Why not then put it into the formalism and check if it fits the experimental data?

We do agree that the predictions are different for some experiments. But the parameter Y of my theory has to be extremely small to allow for an early stage of the universe, so I'm very sure that it will not give observable effects in the PPN. I agree that one should write down this and get some numbers, but my priorities have been (and are yet) different, simply because I'm sure that PPN will lead to some observable differences. And, as I have already mentioned, the effects will not be those responsible for preferred frame effects.

 

[Dmitry67]

Ilja, thank youfor clarification.
(even for me it is very hard to believe that there are no observable effects when there is an obvious difference for the BH. There are some data on the strong gravitational fields, like tight binary pulsars slowdown et cetera)

 

[p764rds]

1) Certainly the retro-causal action would solve the notoriously difficult NP Complete algorithm problem.
If collisions of particles etc are to be determined rather than 'just happen' there needs to be a solution to
calculate where and when. Even a computer has massive NP problems with that (nearly as bad as super determinism). Retro causality would be great to have.

2) BM: "A simple preferred frame does the job" - I'll go for an informational one if we are allowed to start having those!

 

[Ilja]

Ilja, thank youfor clarification.
(even for me it is very hard to believe that there are no observable effects when there is an obvious difference for the BH. There are some data on the strong gravitational fields, like tight binary pulsars slowdown et cetera)

Simply there are two free parameters X, Y, and if they approach zero we obtain exactly the Einstein equations. Thus, making them sufficiently small is sufficient to get the Einstein equations (but not GR) with any required accuracy.

It is harder to understand why there nonetheless remain differences. But these differences are connected with infinities: The big bang singularity and infinite redshift (even if the last is not considered by standard GR as something infinite).

 

[Dmitry67]

What is a minimum value of X and Y to prevent the collapse?

 

[Ilja]

What is a minimum value of X and Y to prevent the collapse?

X is arbitrary, non-zero, Y should be > 0 to prevent collapse. Any value >0 does it.

There is a very small maximum for Y, because else the dense states of the early universe we observe would be impossible.

 

[Dmitry67]

Hm, so do you believe that in fact Y is >0, Y=0 or you don't know?
The reason why I asking is that if Y=0 and your theory becomes equialent to SR,
then a preferred 'timelike' frame becomes spacelike inside the black hole,
and normal particles will behave like tachions inside the horizon relative to that frame.

It is possible that as that frame is undetectable, then it is remains undetectable in your BM theory even under such extreme conditions. But it this case it is quite interesting and beautiful. Spacelike preferred frames... Did you think about it?

 

[Ilja]

Hm, so do you believe that in fact Y is >0, Y=0 or you don't know?
The reason why I asking is that if Y=0 and your theory becomes equialent to SR,
then a preferred 'timelike' frame becomes spacelike inside the black hole,
and normal particles will behave like tachions inside the horizon relative to that frame.

It is possible that as that frame is undetectable, then it is remains undetectable in your BM theory even under such extreme conditions. But it this case it is quite interesting and beautiful. Spacelike preferred frames... Did you think about it?

I believe that Y>0 but extremely small.

But even for Y<=0 the situation is not as you describe. The complete physical part (according to this version of the theory) is then only a part of the complete GR solution. Absolute time reaches infinity at a part which looks unproblematic from GR point of view.

The interpretation is quite unproblematic: The collapsing star becomes frozen. Nothing moves there. The infalling observer will never experience the moment of proper time after his freezing.

 

[Dmitry67]

Your position is inconsistent.

You claim that Y is small and hence there GLET give an identical results for almost all experiments. And yet, you say that there is a dramatic difference for the strong fields: no collapse in your theory vs collapse.

If there is no collapse your theory should produce different results for the strong gravity fields: http://en.wikipedia.org/wiki/Tests_of_general_relativity#Strong_field_tests

 

[Dmitry67]

The interpretation is quite unproblematic: The collapsing star becomes frozen. Nothing moves there. The infalling observer will never experience the moment of proper time after his freezing.

If falling observer's time is slowed down in the same ratio as the star, then for that observer star won't look frozen. So what would he see?

 

[Count Iblis]

If falling observer's time is slowed down in the same ratio as the star, then for that observer star won't look frozen. So what would he see?

See here:

http://arxiv.org/abs/gr-qc/0609024

 

[Dmitry67]

Count Iblis, it is about GR
Ilja's GLET is different :)

 

[Dmitry67]

P.S.
But the article was quite interesting.
I was thinking that at least with non-rotating BH everything was clear :)

 

[Demystifier]

I understand very well that more symmetric things are more beautiful, and, whenever I have a variant with relativistic symmetry, nothing otherwise worse with it, I certainly prefer it.

So, do you find something worse with http://xxx.lanl.gov/abs/0811.1905 ?

 

[Demystifier]

It was Demystifier who was mentioning the there might be a component of the Bohmian interpretation which relates to the future, and I believe we will get a chance to hear more about that soon.

Actually, you can see about that in my older paper too:
http://xxx.lanl.gov/abs/0811.1905

A follow-up question, for Demystifier or other BM knowledgeable person: The guidance equation is a function of the configuration of the system, Q(t) = (Q1(t), · · · ,QN(t)). What is not clear is whether particle Qn's influence decreases with distance (sorta like an inverse square effect), or not. Anything anyone could add on that?

No, it doesn't decrease with distance. But the average influence decreases with the number of environment degrees of freedom that destroy coherence, which, in turn, may (or may not) decrease with distance.

 

[Demystifier]

Thanks, Demystifier. Please don't rush on your work, though of course I am interested in seeing more on the subject. :)

Here it is:
http://xxx.lanl.gov/abs/0904.2287

 

[DrChinese]

Here it is:
http://xxx.lanl.gov/abs/0904.2287

I will have some questions as soon as I can digest this... very impressive on first glance!

 

[Halcyon-on]

Here it is:
http://xxx.lanl.gov/abs/0904.2287

In this paper a quantum many particle state depends on a many spacetime positions vector and the coordinate degeneracy of the quantum state originates the quantum behaviors of QFT. This approach is very reminescent of another deterministic theory publicated about a mouth ago: http://arxiv.org/pdf/0903.3680 . In this case the degeneracy of the single particle coordinates comes from the de Broglie assumption of periodicity, which is exact for free fields. A deep relationship between pilot wave or Bohmian interpretation and the de Broglie approach to QM from these interesting papers.

 

[strangerep]

Here it is:
http://xxx.lanl.gov/abs/0904.2287

Hi Demystifier,

I just had a look through this paper. In section B you attempt to
set up an inf-dim space relying on a measure of the form:
<br /> Dx ~:=~ \prod_{n=1}^\infty \; d^4x_n<br />
(I'm just paraphrasing your equations 28,30,31, etc.)

If I've understood what you're trying to do (forgive me if I've
got it wrong), you're taking the ordinary Lebesgue measure dx
on a 1-particle configuration space, then the corresponding Lebesgue
measure on a N-dimensional product of these spaces (which is fine
so far), and then assuming that this remains valid for N\to\infty.
However, it's a theorem that a non-trivial Lebesgue measure on an
inf-dim space of this kind does not exist. See, e.g.,

http://en.wikipedia.org/wiki/There_is_no_infinite-dimensional_Lebesgue_measure

The essence of the proof is that if we demand the measure be translation-invariant,
(roughly, that dx = d(x+c) for c constant), then the measure is trivial (zero).

Exactly the same problem occurs in path integrals, forcing people to adopt
Wiener (Gaussian) measure instead, which is not translation-invariant.
(This issue is also related to the stuff currently being discussed over in the
other thread about "unbounded operators".)