PF's policy on Lorentz Ether Theory and Block Universe - Comments

[Dale]

DaleSpam submitted a new PF Insights post

PF's policy on Lorentz Ether Theory and Block Universe

Continue reading the Original PF Insights Post.

 

[jedishrfu]

Nice insight!

 

[eltodesukane]

"Often a single theory is compatible with many different philosophical interpretations. There is no possible way to resolve a dispute between different philosophical interpretations through appeal to experiment because all of them make the same predictions for all experiments. The choice between philosophical interpretations is therefore entirely a matter of personal philosophical preference."
In that case, philosophical interpretations are unnecessary, superfluous, irrelevant.

 

[Demystifier]

There is little or no debate among professional physicists about these issues (as opposed to e.g. interpretations of quantum mechanics)

Certainly much less than interpretations of QM, but how much exactly? Let us see
http://lanl.arxiv.org/find/gr-qc/1/ti:+aether/0/1/0/all/0/1 (aether = 78)
http://lanl.arxiv.org/find/gr-qc/1/ti:+AND+block+universe/0/1/0/all/0/1 (block universe = 3)

 

[harrylin]

This is not a "new" contribution, but for this thread I will repeat my earlier comment:
Excellent summary!

As that post was in fact the culmination of debates on this forum that started with a push to promote "block universe" as "truth", for interested newcomers it will be helpful if some links to the wealth of available information in the PF archives is added at the bottom of that post. That will prevent unnecessary questions about where explanations about those interpretations can be found.

 

[harrylin]

"Often a single theory is compatible with many different philosophical interpretations. There is no possible way to resolve a dispute between different philosophical interpretations through appeal to experiment because all of them make the same predictions for all experiments. The choice between philosophical interpretations is therefore entirely a matter of personal philosophical preference."
In that case, philosophical interpretations are unnecessary, superfluous, irrelevant.

Mostly interpretations happen automatically in our brains: if not wittingly, then unwittingly. As a result, often an interpretation is erroneously promoted as part of the theory. To avoid such error, it is useful to be aware of these.

 

[Demystifier]

Mostly interpretations happen automatically in our brains: if not wittingly, then unwittingly. As a result, often an interpretation is erroneously promoted as part of the theory. To avoid such error, it is useful to be aware of these.

I agree. But one cannot become aware of these if one bans discussions about interpretations.

 

[harrylin]

I agree. But one cannot become aware of these if one bans discussions about interpretations.

There is another way; see my first reply here

 

[stevendaryl]

"Often a single theory is compatible with many different philosophical interpretations. There is no possible way to resolve a dispute between different philosophical interpretations through appeal to experiment because all of them make the same predictions for all experiments. The choice between philosophical interpretations is therefore entirely a matter of personal philosophical preference."
In that case, philosophical interpretations are unnecessary, superfluous, irrelevant.

I think that conclusion is a little bit of an exaggeration. A theory (in the operational sense of a mathematical way of generating testable predictions from observable initial conditions) might have multiple interpretations that are indistinguishable from within that theory. However, every theory that we have is tentative and incomplete--we expect that one day, our current theories will be replaced by new theories. The expectation, of course, is that new theories will have older theories as limiting cases, in the way that Newtonian physics can be seen as a kind of limit of special relativity, approximately valid in the case where all objects are traveling at nonrelativistic speeds. Even though interpretations might be irrelevant to a current theory, different interpretations of a theory can suggest different ways to extend that theory. To get back to Lorentz aether theory: it's indistinguishable from SR. However, one could imagine extending LET to a new theory LET', that is inconsistent with SR, but would still reproduce the predictions of SR in limiting cases.

I'm not actually very hopeful that such a thing will happen in the case of LET, but I do believe that it is doing a disservice to physicists to say absolutely that they should never think about interpretations, because thinking about them could very well be the way to develop future theories.

 

[stevendaryl]

I'm not actually very hopeful that such a thing will happen in the case of LET, but I do believe that it is doing a disservice to physicists to say absolutely that they should never think about interpretations, because thinking about them could very well be the way to develop future theories.

On the other hand, the charter for Physics Forums declares that it is for discussing existing theories, rather than developing new ones, so maybe my argument is not so relevant here.

 

[Dale]

it will be helpful if some links to the wealth of available information in the PF archives is added at the bottom of that post.

That is a good idea. Most of those threads end in a closure and/or a ban. If you remember one that didn't end like that then it might be a good one to point to.

 

[Dale]

Certainly much less than interpretations of QM, but how much exactly? Let us see
http://lanl.arxiv.org/find/gr-qc/1/ti:+aether/0/1/0/all/0/1 (aether = 78)

Note that the vast majority of those never made it through peer review in a reputable journal.

 

[atyy]

However, every theory that we have is tentative and incomplete--we expect that one day, our current theories will be replaced by new theories.

That is an interpretation!

Of course, it's the correct one.

 

[atyy]

Note that the vast majority of those never made it through peer review in a reputable journal.

Hmmm, randomly clicking on them, it seems many did. Did you count?

Edit: Also some like http://lanl.arxiv.org/abs/0801.0516 which don't have a journal listed have been published in peer-reviewed journals http://link.springer.com/article/10.1007/s10714-008-0648-y.

 

[Dale]

Of the first ten I saw only two that even made it out of arXiv somewhere.

 

[atyy]

Of the first ten I saw only two that even made it out of arXiv somewhere.

If you took the first ten most recent, they would have had less time to have been peer-reviewed. Also, some of them are almost certainly correct despite not being peer-reviewed, eg. http://lanl.arxiv.org/abs/1404.7689 is not peer-reviewed, but is commented on in a way by http://lanl.arxiv.org/abs/1405.6351 that makes me think it is probably correct, because of Ted Jacobson's general reputation.

But let me count.

 

[Dale]

Even if all of the remaining ones went to peer reviewed journals, that would only be a total of 70 since arXiv started. In a field that publishes as much as theoretical physics does, that certainly qualifies as "little or no debate". It is a small sideshow at best.

 

[atyy]

I saw your post #17, but here is the count anyway.

Not published in peer-reviewed journal
http://lanl.arxiv.org/abs/1508.00276
http://lanl.arxiv.org/abs/1507.06618
http://lanl.arxiv.org/abs/1412.2778
http://lanl.arxiv.org/abs/1311.0437
http://lanl.arxiv.org/abs/1310.2144
http://lanl.arxiv.org/abs/1309.0907
http://lanl.arxiv.org/abs/1109.5654
http://lanl.arxiv.org/abs/1105.4845
http://lanl.arxiv.org/abs/1102.5002
http://lanl.arxiv.org/abs/1012.5348
http://lanl.arxiv.org/abs/1004.2901
http://lanl.arxiv.org/abs/1003.5366
http://lanl.arxiv.org/abs/0801.1547
http://lanl.arxiv.org/abs/0711.3822
http://lanl.arxiv.org/abs/gr-qc/0412086
http://lanl.arxiv.org/abs/gr-qc/0410001
http://lanl.arxiv.org/abs/hep-ph/0109215

Published in peer-reviewed journal
http://lanl.arxiv.org/abs/1504.03305, http://iopscience.iop.org/article/10.1088/1475-7516/2015/08/016/meta
http://lanl.arxiv.org/abs/1503.08911
http://lanl.arxiv.org/abs/1409.2687
http://lanl.arxiv.org/abs/1408.4774
http://lanl.arxiv.org/abs/1407.6014
http://lanl.arxiv.org/abs/1312.0405
http://lanl.arxiv.org/abs/1311.7144
http://lanl.arxiv.org/abs/1310.5338
http://lanl.arxiv.org/abs/1310.5115
http://lanl.arxiv.org/abs/1309.4778
http://lanl.arxiv.org/abs/1302.6965 (not a journal, but edited by Ashtekar and Petkov)
http://lanl.arxiv.org/abs/1302.4189
http://lanl.arxiv.org/abs/1301.7122
http://lanl.arxiv.org/abs/1211.4402
http://lanl.arxiv.org/abs/1210.4940
http://lanl.arxiv.org/abs/1207.6530
http://lanl.arxiv.org/abs/1206.6296
http://lanl.arxiv.org/abs/1201.2882
http://lanl.arxiv.org/abs/1110.3753
http://lanl.arxiv.org/abs/1109.4495
http://lanl.arxiv.org/abs/1109.0823
http://lanl.arxiv.org/abs/1108.1835
http://lanl.arxiv.org/abs/1107.1892
http://lanl.arxiv.org/abs/1106.3955
http://lanl.arxiv.org/abs/1104.2889
http://lanl.arxiv.org/abs/1103.2197
http://lanl.arxiv.org/abs/1011.6466
http://lanl.arxiv.org/abs/1008.4351
http://lanl.arxiv.org/abs/1007.4572
http://lanl.arxiv.org/abs/1007.2594
http://lanl.arxiv.org/abs/1003.1283
http://lanl.arxiv.org/abs/1001.4823
http://lanl.arxiv.org/abs/0907.3180
http://lanl.arxiv.org/abs/0905.2446
http://lanl.arxiv.org/abs/0905.0328
http://lanl.arxiv.org/abs/0812.1050
http://lanl.arxiv.org/abs/0811.2797
http://lanl.arxiv.org/abs/0807.2639
http://lanl.arxiv.org/abs/0806.4319
http://lanl.arxiv.org/abs/0805.4067
http://lanl.arxiv.org/abs/0802.0521
http://lanl.arxiv.org/abs/0801.0516, http://link.springer.com/article/10.1007/s10714-008-0648-y
http://lanl.arxiv.org/abs/0709.1011
http://lanl.arxiv.org/abs/0706.0704
http://lanl.arxiv.org/abs/0705.1565
http://lanl.arxiv.org/abs/gr-qc/0703093
http://lanl.arxiv.org/abs/gr-qc/0608052
http://lanl.arxiv.org/abs/gr-qc/0605082
http://lanl.arxiv.org/abs/gr-qc/0604088
http://lanl.arxiv.org/abs/gr-qc/0603058
http://lanl.arxiv.org/abs/gr-qc/0602004
http://lanl.arxiv.org/abs/gr-qc/0509121
http://lanl.arxiv.org/abs/gr-qc/0507059
http://lanl.arxiv.org/abs/hep-ph/0505211
http://lanl.arxiv.org/abs/gr-qc/0504005
http://lanl.arxiv.org/abs/gr-qc/0502066
http://lanl.arxiv.org/abs/gr-qc/0402005
http://lanl.arxiv.org/abs/hep-th/0108097

 

[atyy]

My own take is that Einstein-Aether is not relevant to the OP. It's a pretty standard Beyond the Standard Model topic (like string theory, LQG).

 

[Dale]

As you say, Einstein aether is not relevant to LET. Of the ones in peer reviewed journals, not one of the first 10 was actually about LET. "Little or no debate" is looking pretty well substantiated.

 

[Demystifier]

Note that the vast majority of those never made it through peer review in a reputable journal.

To check this claim, I have done the actual counting. I have discarded the first 10 papers because they are still relatively new, so some of them may become accepted for publication later. The result of my counting is:
Out of 68 papers having "aether" in the title, 42 are published in a peer reviewed journal.

Do you still stand with your claim above? Or do you want me count the number of papers in reputable journals such as Phys. Rev. D, Phys. Lett. B, etc?

EDIT: Now I saw that atty also made the counting.

 

[Demystifier]

As you say, Einstein aether is not relevant to LET. Of the ones in peer reviewed journals, not one of the first 10 was actually about LET. "Little or no debate" is looking pretty well substantiated.

So, shell we allow discussions about Einstein aether? If yes, then I will make no further complaints in this thread.

It's not that I particularly like Einstein aether. (As a matter of fact, I like block universe much more http://fqxi.org/community/forum/topic/259 .)

It's that I generally don't like banning.

 

[harrylin]

That is a good idea. Most of those threads end in a closure and/or a ban. If you remember one that didn't end like that then it might be a good one to point to.

I think that they all were closed, for obvious reasons; a thread being closed to further discussion doesn't mean that it is void of useful information!

 

[Dale]

Note that the vast majority of those never made it through peer review in a reputable journal.

Do you still stand with your claim above?

No, I don't. My claim was based on a biased sample.

I do stand by the original claim in the article that there is "little or no debate". The search you did is not particularly relevant since it contains many theories that are not LET but have the word aether in them.

And even so, even the inflated total "aether" number of 42 is still small. Professional science has simply moved on past the LET vs block universe argument.

 

[Dale]

So, shell we allow discussions about Einstein aether? If yes, then I will make no further complaints in this thread.

It's not that I particularly like Einstein aether. (As a matter of fact, I like block universe much more http://fqxi.org/community/forum/topic/259 .)

It's that I generally don't like banning.

Did you read the article? It doesn't even discuss Einstein aether, just LET and block universe, which are non gravitational theories. Also, discussions of LET and block universe are not banned, only assertions that one or the other is "true".

 

[harrylin]

Did you read the article? [..]

I understand him to mean that he wrote it.

 

[JDoolin]

We really should make an honest attempt to describe all hypotheses as clearly as we can. Only when those hypotheses are clearly understood can clear distinctions be made between them. Only once those distinctions are clear can we begin testing those hypotheses against empirical evidence.

I hear a lot of people talking about "misconceptions". You can't tell if something is a "misconception" unless you know the truth. If all you have is a working model, then all you can say is that "That can be correctly said of my working model." or "That cannot be correctly said of my working model."

The moderators here apparently have a shared concept of the universe--and if I understand right, it is the same model that Saul Perlmutter and Brian Schmidt used in their research that got them a Nobel prize in Physics in 2011. I have come to refer to this as "the standard cosmological model"

The trouble is, I have no idea how this model compares to the Block Universe model, or the LET models.

I think your most important line here was "There are two primary philosophical interpretations: the Block Universe (BU) and Lorentz Aether Theory (LET). The BU considers the universe to exist as a single fixed 4D geometric structure which is not dynamically evolving over time since time is one of the dimensions of the structure. The LET considers the universe to be a 3D world evolving over time and with a single undetectable “true” rest frame."

The way you've put it here, both of them seem to steer people away from thinking about the implications of the Relativity of Simultaneity on universal scales. LET theory essentially rejects the existence of the relativity of simultaneity. BU rejects that ROS has any importance, because every event can be mapped on a single space-time diagram, and all space-time diagrams are equivalent through Lorentz Transformation.

Even when ideas are mathematically the same, the philosophical differences between two ideas can be important, because it is philosophy, rather than math, that directs our behavior--decides what is interesting, important, or good.

 

[vanhees71]

If it's philosophy and not physics (or math relevant to describe the physics), it is not (and imho it should not) be a topic in this forum. I'm sure there are forums for philosophers available in the WWW, and if I'd want to discuss philosophy I'd try to find one via google. This forum is a unique place in the WWW in that it is very well moderated, and the crackpot noise is thus very low. Philosophical discussions, particularly like the implications of the fact that the spacetime structure of the world is way better discribed by relativistic spacetime models than Newtonian ones, triggers crackpot discussions, and that's why I'm very thankful for the great works our moderators do here to keep the forum clean from crackpotery.

You have, of course a point, here, which is physical again. The question is, whether the BU or Lorentz aether theory are really different physical models or mere philosophical interpretations of (special or general) relativity. In the former case, there must be predictions for observable facts about nature, that can decide between the one or the other (spacetime) model, and then it's physics. In the latter case, it's a personal decision, which philosophical or metaphysical interpretation I follow, because the models are all equivalent to relativity. Then it is not (and imho should not be) an allowed topic in these forums!

 

[stevendaryl]

You have, of course a point, here, which is physical again. The question is, whether the BU or Lorentz aether theory are really different physical models or mere philosophical interpretations of (special or general) relativity. In the former case, there must be predictions for observable facts about nature, that can decide between the one or the other (spacetime) model, and then it's physics. In the latter case, it's a personal decision, which philosophical or metaphysical interpretation I follow, because the models are all equivalent to relativity. Then it is not (and imho should not be) an allowed topic in these forums!

Well, I made the point earlier (although it didn't receive any replies--sniff) that even when two interpretations/models are exactly equivalent as far as testable predictions, they can have extensions that are inequivalent. So understanding alternative models can be important in coming up with new theories. For that reason, I think that a practicing theoretical physicist should be aware of alternative interpretations.

 

[harrylin]

The question is, whether the BU or Lorentz aether theory are really different physical models or mere philosophical interpretations of (special or general) relativity. [..]

It is our consensus that no mismatch can be found between either interpretation and SR. However, such models become subtly testable (in the sense of possible to reject) in general physics, as one tries to fuse SR with QM in way that makes sense. At first sight (Bell and later commentators) QM is incompatible with "BU", but apparently some recent papers that I don't understand still managed to make the BU concept fit with the "instant action at a distance" concept. Similarly other papers that I don't fully understand claim that the "LET" concept cannot be matched to GR except when making subtle but in principle testable differences in predictions (see for example Ilja's contributions).

In other words, I would say that while SR and tests of SR cannot give an answer, such interpretations definitely belong to physics.

 

[vanhees71]

Ok, if an alternative model makes the same observable predictions as SR, it's a mere reinterpretation of SR, and thus not a different physical model. If you have a model that makes predictions that subtly differ from GR, one can test one model against the other, and then that's science.

 

[PeterDonis]

I have no idea how this model compares to the Block Universe model, or the LET models.

It doesn't. The Block Universe and LET models are interpretations of SR, i.e., flat spacetime. The "standard cosmological model" is a model of a curved spacetime (a solution of the Einstein Field Equation in GR) that describes our universe to a reasonable approximation.

 

[Dale]

Moderators note: a bunch of posts either about QM interpretations, QM books, or about philosophy in general have been removed. I believe that the thread is now more focused on the BU vs LET topic.

 

[nikkkom]

What's up with "Blockworld and its Foundational Implications" insights articles being published on RF starting on November 5 2015? The author seems to be promoting a POV that BU is the "correct" interpretation of SR/GR [his argument seems to be that it follows from relativity of simultaneity].

Here's the link:

https://www.physicsforums.com/insig...ions-part-1-time-dilation-length-contraction/

 

[Dale]

Comments on that thread have been disabled. We should not use this thread as a way to get around that.

As with all interpretations, no interpretation can lay claim to being uniquely correct.