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I Generalization of Lorentz ether

  1. Apr 12, 2016 #1
    <<Moderators note:
    Discussion split from: https://www.physicsforums.com/threads/motivation-for-the-introduction-of-spacetime.866669/>>

    You think the violation of Bell's inequality is not a serious challenge?

    You have to give up realism as well as causality if you want to defend the spacetime. An interpretation where we are, unfortunately, unable to measure with clocks and rulers which events happen at the same time, but this "same time" nonetheless exists, and "spacetime" fundamentally splits into space and time, can be realistic as well as causal.

    In fact, I cannot imagine a more serious challenge of whatever belief - if I would have to give up realism and causality to defend this belief.
     
    Last edited by a moderator: Apr 14, 2016
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  3. Apr 12, 2016 #2

    PeterDonis

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    Not with respect to the classical theory of relativity, which is what I understood the OP to be asking about. It might be when we take quantum mechanics into account, although our current best theory of quantum mechanics, quantum field theory, still uses the underlying spacetime structure we are talking about. See below.

    I'm not sure I agree. In QFT, the requirement of causality is that field operators at spacelike separated events commute. That requirement does not imply that the Bell inequalities must be satisfied. So QFT can account for violations of the Bell inequalities while still having spacetime and causality. I don't think "realism" is a precise enough term to add anything here.
     
  4. Apr 12, 2016 #3
    Ok, the OP may have made his question in a classical context. But if there are serious challenges outside the classical domain, it would be misleading to hide them making explicit claims that you are not aware of any serious scientific challenges. This would be fine only if you would have added "in the classical domain".

    Yes. But this is a serious weaking of the notion of causality. It is essentially about correlations, not about causality. Fundamental principles of causality, like Reichenbach's principle of common cause, have to be given up. But to give it up is a serious damage to the scientific method itself. You know, this is the principle which forces scientists to search for causal explanations of observed correlations.

    And the EPR principle of reality - more is not necessary from realism to prove the Bell inequalities - is precise enough. And obvious enough to understand that giving it up is a quite serious thing. What could be a meaningful meaning of realism if the EPR criterion does not hold?
     
  5. Apr 12, 2016 #4

    PeterDonis

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    Until somebody constructs a physical theory that (a) doesn't use a 4-dimensional spacetime continuum as a fundamental construct, and (b) matches experiments, there isn't a serious scientific challenge. There might be various philosophical challenges (see below), but that's not the same thing.

    Furthermore, any such model will still have to explain why a 4-dimensional spacetime continuum model works so well in the domain in which it's verified to work. Such an explanation will end up invoking the same considerations that have already been mentioned in this thread.

    What you mean is, it's a notion of causality that doesn't conform to your opinions about what a notion of causality should be. Whether or not I agree with those opinions is beside the point. Any discussion along those lines is philosophy, not physics, and is off topic here.

    Similar remarks apply to your comments about the scientific method and the EPR principle of reality.
     
  6. Apr 12, 2016 #5

    Dale

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    I disagree completely. Modern QFT is also compatible with special relativity and therefore not a challenge to the idea of spacetime either. The limitation "in the classical domain" does seem to specify the context of the OP, but is not required for PeterDonis' statements to be correct.

    There are tentative theories in which spacetime may be an emergent phenomenon or something else, but there is no evidence supporting them at present and even if there were it would be more of an explanation of spacetime than a challenge to spacetime.

    I think your characterization is wrong and the tone is rather inflammatory.
     
  7. Apr 13, 2016 #6
    No, to construct such a theory is not problematic at all, such theories exist and are published.
    Schmelzer, I.: A Condensed Matter Interpretation of SM Fermions and Gauge Fields, Found. Phys. vol. 39, 1, p. 73-107 (2009), arXiv:0908.0591
    Schmelzer, I.: A generalization of the Lorentz ether to gravity with general-relativistic limit, Advances in Applied Clifford Algebras 22, 1 (2012), p. 203-242, arXiv:gr-qc/0205035
    No. The second paper contains a derivation of the Einstein Equivalence Principle which in no way invokes your considerations.
    Ok, once you think it is forbidden to discuss Reichenbach's common cause principle and EPR-realism and their role in science in a discussion about physics, I have to live with this.
     
  8. Apr 13, 2016 #7

    Dale

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    I wonder if this theory is even still viable in light of recent GW observations of a black hole merger? Also, fundamentally since it has more free parameters than GR, it is more complicated than GR and unlikely to be more than a mathematical curiosity unless it correctly predicts experimental results that disagree with GR.

    I think you should probably try to work through it and publish a bit more on it, particularly in more reputable journals. It seems a little premature to be promoting it until then.
     
    Last edited: Apr 13, 2016
  9. Apr 14, 2016 #8
    I would not expect any serious differences. The GWs, as far as they are observable, are the same. I cannot afford for myself any complex numerical computations to check this, but the differences appear anyway only very close to the black hole horizon, and, anyway, only for [itex]\Upsilon>0[/itex].
    The curiosity has no quantization problem at all. We know how to quantize a condensed matter theory. The non-renormalizability remains, of course, but is not problematic at all, because for a continuous condensed matter theory it is natural to be an effective theory only. All the other GR quantization problems simply vanish into nothing. This is, of course, nothing.
    I'm already sure that whatever I do more, it will be ignored anyway.

    Seen the first paper? Which explains the SM in a quite simple way? Such a result would be the dream of string theory, but they have no hope to reach something similar. A derivation of the SM gauge group and all fermions from simple first principles and a surprisingly simple model. More reputable journals? Foundations of Physics not enough reputation? Sorry, but more reputable journals do not even peer-review papers about theories with the e-word. Once this paper has been simply ignored, I have given up the hope that any publication of any result about an ether theory will change anything. I probably have to wait until string theory is completely dead and people are really looking for something new.

    The theory of gravity is already necessary to support this ether model for the SM. Because, else, it can be ignored with the excuse that it is incompatible with gravity. It isn't, as shown by this theory of gravity. By the way, the main formulas of the theory of gravity are also in the appendix of the Foundations Physics paper.
     
  10. Apr 14, 2016 #9

    PeterDonis

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    Do these theories make any testable predictions that are different from the standard theories?
     
  11. Apr 14, 2016 #10
    The first paper explains the Standard Model of particle physics. Explanation is, essentially, a post-diction, a prediction about what we already know, from observation, but have no explanation for.

    The Standard Model simply postulates a lot of fields. The theory predicts, starting from a sufficiently simple model, and sufficiently simple principles, the fermion and gauge fields of the SM. So, if it would have been proposed earlier, it would have predicted three generations of fermions, three colors of quarks and so on.

    Which is already much much more than what string theory dreams of.

    The theory of gravity predicts that the universe has to have trivial topology, and has to be flat (the flat universe is the only homogeneous one).

    I hope you will apply similar criteria to my theories in comparison with string theory as well as LQG and other fundamental proposals (except, of course, for the criterion "it is mainstream").
     
  12. Apr 14, 2016 #11

    PeterDonis

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    Ok, but it doesn't make any new testable predictions, correct? For example, it doesn't predict new particles the way supersymmetric extensions of the SM do, correct? It just predicts the same observations that the SM predicts?

    I assume by "trivial" you mean ##R^4##? Absolutely, or just on cosmological scales? I.e., does this theory also predict that there are no actual black holes, only apparent ones? ("Apparent" meaning "something that looks locally like a horizon and region inside it, but is compatible with global ##R^4## topology".) If so, that would be a (possibly) testable prediction that's different from at least some current models (but this is an area where there isn't an "established" theory, because we don't have an established theory of quantum gravity).

    I assume you mean spatially flat?

    Remember that PF is for discussion of already established science, not for trying to discover new science, which is what you are doing. We do have the Beyond the Standard Model forum, where the rules are a bit different because no theory beyond the SM can be said to be "established" at this point. We generally try to limit discussion of string theory, LQG, etc. to that forum for that very reason.
     
  13. Apr 14, 2016 #12
    There are some additional scalar fields. Massive, with unknown but large masses, so some CDM candidates. There are also the gauge degrees of freedom, which can in some sense play the role of the Higgs.
    Absolutely.
    Correct. There is a critical parameter, [itex]\Upsilon[/itex], and for [itex]\Upsilon>0[/itex] we have stable gravastars with a size slightly greater than horizon size. For large enough [itex]\Upsilon>0[/itex] this would lead to observable differences, but [itex]\Upsilon[/itex] would have to be extremely small for another difference, namely a big bounce instead of a big bang, to be compatible with what is known about the big bang.

    For [itex]\Upsilon<0[/itex] there would be nothing but a little more dark matter, so the modification of GR would be insignificant for anything observable. One could never reach the region inside a black hole nonetheless - this is because "proper time" is only interpreted as distorted clock time, not as real time, and the infalling observer would be simply frozen.
    Of course.
    I have not started a thread about this, recognizing very well that PF is open only to those parts of speculative science which are sociologically established by a lot of grants and so on, without caring about the real results.

    I have only answered a false claim, which I have rejected with a reference to published papers. Here was the relevant claim:
    And I think once the theory is published in a peer-reviewed journal, and simply ignored instead of being questioned, the fact of the existence of such a theory is part of established science, not? So I think my response was appropriate and on-topic.

    If it would be ok to start a thread about my theories this would be fine.

    As I have already said, I have already accepted that for the evaluation of the value of such theories it is irrelevant what has been really reached by the particular directions, what counts are published papers, received grants and other sociological points. This makes sense today, where the young scientist is extremely insecure and has to care most about the question where he gets the next grant after the end of the actual one, instead of caring which approach will win in the long run because it is better. The long run does not matter if the young scientist works, in this long run, as a taxi driver.

    Nonetheless, even in such a situation it may be helpful to distribute some information about the existence of these results. So that, similar to Bohmian mechanics, it will not be completely forgotten, but at least one guy (for Bohmian mechanics, this was Bell) will know about it. And in some future the situation may become different, who knows.
     
  14. Apr 14, 2016 #13

    PeterDonis

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    Um, you are aware that my statement applies equally well to string theory and LQG, are you not? "Established" in this context doesn't just mean "published"--it means "verified by experiment". That means the theory has to make some prediction that other theories do not make, and that prediction has to be verified. Your theory does appear to make some predictions that other theories don't make (for example, gravastars instead of black holes); but those predictions can't be tested either way with our current observational abilities. That's why, as I said, we try to put discussions of string theory, LQG, etc. into the BTSM forum, and when those theories get mentioned in other forums, we try to be explicit that they're speculative, not confirmed, at this point.

    Since, as you say, your work has been published in peer-reviewed journals, you could at least suggest it as an acceptable reference. The question would be, on what basis would you start a thread? Just saying "here are my theories, explain to me why they're wrong" wouldn't be sufficient--any more than a similar post based on string theory or LQG would. Even "here are some papers, does anyone see any issues with them?" wouldn't really be sufficient, because, as I said, PF is not for discovering new science.

    PF isn't for this either. Your papers are posted on arxiv. You can always have your own blog.
     
  15. Apr 14, 2016 #14

    PeterDonis

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    I'm not sure I understand. The theory still uses the underlying manifold ##R^4##, and still defines a metric on that manifold with a (1, 3) signature. The metric is technically not "fundamental", since it's constructed from other entities, but it's there, and its existence, AFAICT, is crucial to the derivation of the EEP. This derivation doesn't explicitly mention the considerations discussed earlier in this thread, but it certainly relies on them implicitly since they are equivalent to having a metric with a (1, 3) signature.
     
  16. Apr 14, 2016 #15
    What is crucial for a derivation is what one has to assume. The metric itself is not fundamental, and it is also not assumed.

    In fact, the main points of the derivation do not even mention the metric. We have classical Noether conservation laws, because of translational symmetries. This gives an energy-momentum tensor. This tensor is identified with the gravitational field - which is roughly the definition of the gravitational field. All other fields are called matter fields. The Noether connection between translational symmetry and conservation law has, in the formalism, the form that the conservation laws are the equations for the preferred coordinates. Then comes the action equals reaction symmetry, and the point that by construction of the gravitational field, the equations for the preferred coordinates depend only on the gravitational field, not on matter fields. Which gives that the equations for matter fields do not depend on the preferred coordinates. Which is the EEP.

    I see here no role for a metric, even less with signature (1,3). That the gravitational field is described by such a metric is the consequence of some additional assumptions. But this is in no way connected to the EEP. The EEP proof would go through even if the gravitational field - the energy-momentum tensor - would be described differently.
     
  17. Apr 14, 2016 #16

    PeterDonis

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    Your proof that the EEP holds depends on your proof (corollary 1 in section 8) that "internal observers" can describe all their experiments and observations as if they were in a local solution of what you call "GRCF". In other words, you're depending on the fact that the solution can be described the way GR would describe it, using a metric with a (1, 3) signature.
     
  18. Apr 14, 2016 #17
    It would be nice if this would be really the case.
    Very simple, on the same reasons people start threads in BTSM about whatever, for whatever justification. If string theory and LQG papers which have no empirical relevance at all can be posted there, why not starting a thread with much more closer relation to the SM and to GR?

    I'm not sure if all the other threads of BTSM have any base at all in the forum rules. I would not wonder if not - a quite common mechanism to have rigorous rules which nobody fulfills, but if any outsider comes and violates them too, he will be punished, while the established mainstream guys go unpunished.

    So I would hope (recognizing that this hope is quite naive, or, more accurate, rhetorical) that you can explain why the BTSM forum is not simply empty, and this justification would give, I think, also a justification for me to present my theory there.

    So, ok, this particular proof relies on this. What is behind, as discussed in app. D., does not have to rely on this.
     
  19. Apr 14, 2016 #18

    Dale

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    If the observable results are the same then the theory with fewer free parameters is scientifically preferable. But since the computation hasn't been published it is still a bit speculative to make that claim on PF.

    Their most recent impact factor is 1.03. At least it is not less than 1, but yes there is substantial room for improvement.

    So then why did you put that word in there? That seems like a really bad choice on your part.

    You believe that you have an absolutely revolutionary theory that is rejected, not based on any flaws of the theory, but on a simple word choice. So why didn't you choose a different word and reap the professional rewards of your theory?

    If your theory is as truly revolutionary as you believe then someone will take it and present it without that word, and then this paper will just serve as a citation in the new paper.
     
  20. Apr 14, 2016 #19

    PeterDonis

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    People start threads in BTSM (or threads that get moved there) because they have questions about string theory or LQG or some other theory that goes beyond the current Standard Model (which in this context includes GR). If someone saw your paper on arxiv or in a journal and had a question about it, that forum is where the post would properly go.

    People aren't supposed to start threads in BTSM, or anywhere else, just to say "I just posted this paper on arxiv, please look at it". If you find threads of that sort, you are welcome to report them so the moderators can deal with them.

    Again, if you see a thread in BTSM, or anywhere, that you think violates the rules, the proper response is to report it so the moderators can take appropriate action.

    I'll take a look at Appendix D.
     
  21. Apr 14, 2016 #20

    PeterDonis

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    I don't see a prediction of three generations of fermions (e.g., electron, muon, tauon, and their corresponding neutrinos and quarks) in the paper. I see a derivation of the gauge group SU(3) x SU(2) x U(1), but the SM contains three copies of this group (at least for the fermions), one for each generation, not just one. Of course you could construct a model with three copies of your underlying lattice, but why must it be three?
     
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