Lorentzian relativity

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Main Question or Discussion Point

H.E. Lorentz, a Nobel Prize-winning physicist, was an older contemporary of Einstein's who inspired and guided Einstein in his work. Lorentz, however, never fully subscribed to special or general relativity and believed to his death that what is now called "Lorentz Ether Theory" was the better interpretation of special relativity.

I'm researching modern efforts to generalize LET as an alternative to general relativity. I've thus far reviewed attempts by Herbert Ives, John Bell, Quentin Smith, Antony Valentini, Franco Selleri, and Reginald Cahill to create some type of generalized LET.

Bell and many others have focused on Alain Aspect's experiments confirming non-locality as the basis for a revision of SR and GR. With instantaneous action at a distance, confirmed experimentally by Aspect and many others many times over, the basis for SR is significantly (or perhaps completely) undermined, because Einstein's clock synchronization convention was based on the inability to establish any kind of absolute simultaneity. But with non-locality, determining absolute simultaneity, as Karl Popper and others have pointed out, becomes possible.

Does anyone know of other attempts to generalize LET? Any thoughts on how to assess which efforts are the most credible?
 

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  • #3
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Dale, I won't try and say it better than Popper, so here are his words:

[W]e have to give up Einstein's interpretation of special relativity and return to Lorentz's interpretation and with it to … absolute space and time.... The reason for this assertion is that the mere existence of an infinite velocity entails [the existence] of an absolute simultaneity and thereby of an absolute space. Whether or not an infinite velocity can be attained in the transmission of signals is irrelevant for this argument: the one inertial system for which Einsteinian simultaneity coincides with absolute simultaneity … would be the system at absolute rest – whether or not this system of absolute rest can be experimentally identified.1
 
  • #4
JesseM
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But the idea of instantaneous physical influences is a misunderstanding of what people mean by "non-locality" in QM, there's no experiment where you do something to a particle at one location and it "instantaneously" leads to an observable change in a particle at another location. Rather, quantum non-locality has to do with the fact that if two experimenters make measurements of entangled particles at times of their own choosing and later get together to compare results, they'll find their results were correlated. In itself this would be possible in classical physics too--imagine I mail pairs of envelopes to different observers, with one envelope always containing a red piece of paper and the other always containing a green one, so the results of their observations of what's in their envelopes are always correlated--but in QM the statistics of observed results have a special way of resisting the interpretation that the correlations are merely due to preexisting properties of the particles that were assigned to them when they were created (like the preexisting color of the paper inside an envelope before an observer opens it), see my analogy in post #3 of this thread.
 
  • #5
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JesseM, I'm not so sure it's a mistake. Your interpretation of the experiments is very different than Bell's and Aspect's interpretation - they showed that measuring the entangled particles in different order lead to different results, showing that there was an instantaneous signaling of some sort.

As Popper points out, however, the shift in point of view re absolute simultaneity doesn't require actual instantaneous signaling by humans. As I first realized in reading Einstein's works, his structure rests upon his asserted relativity of simultaneity, which is itself a function of his view that the best way to synchronize events occurring at different locations was with light signals. Even if we accept that light signal synchronization is a good way to synchronize distant clocks, it does not follow that there aren't simultaneous events in an absolute sense. Einstein's structure, as many physical theories do, in my opinion (as a philosopher), mistakes epistemology for ontology. Just because light signals may be used for synchronization doesn't mean that there isn't an underlying absolute simultaneity or that time dilation or length contraction are real phenomena. The Minkowskian spacetime formulation of special relativity was, in my view, the basis for the view that prevails today regarding the ontological validity of spacetime as a four-dimensional unchanging structure that comprises the universe. Instead, we may view Einsteinian/Minkowskian relativity as a way of interpreting the mathematical formalisms that has some advantages (by reducing all four dimensions to geometry, some simplicity is achieved), but some major disadvantages also, such as the necessary conclusion that time and thus free will don't exist. In the block universe, there is no becoming, there is only existence, as Einstein himself stated. And if there is only existence, there is no time and no ability to influence the future (free will). I, for one, find these to be very disturbing consequences of the mainstream interpretation of the mathematical formalisms of SR.
 
  • #6
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[W]e have to give up Einstein's interpretation of special relativity and return to Lorentz's interpretation
Popper is wrong. Lorentz and Einstein make the exact predictions for all experiments, so there can be no experimental justification for picking one over the other. If Einstein falls, so does Lorentz.
 
  • #7
JesseM
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JesseM, I'm not so sure it's a mistake. Your interpretation of the experiments is very different than Bell's and Aspect's interpretation - they showed that measuring the entangled particles in different order lead to different results, showing that there was an instantaneous signaling of some sort.
Measuring "in a different order" changes the results? For measurements with a spacelike separation? (remember, even in SR all frames agree on the order of events with a timelike or lightlike separation) If you think that's the case, I'm sure you're misunderstanding something, since it would natually lead to an experimentally-testable absolute definition of simultaneity--can you give a link or other reference to the results you're talking about?
 
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  • #8
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Dale, experimental support for SR is, as you state, quite good (though not entirely unchallenged). However, we may still utilize the Lorentz transformations as a way to translate between inertial frames even if there is instantaneous action at a distance. But it seems that LET is now to be preferred over Einsteinian/Minkowskian SR because there is a "preferred foliation" made clear through experiments demonstrating non-locality. This preferred foliation is Lorentz's ether. As such, the Lorentz transformations are still helpful, but the apparent length contraction and time dilation are not now a consequence of the distortion of space itself; rather, they are a consequence of electromagnetic interaction between matter and the ether - "ether drag" is how I think of it. But Lorentz talked about "local time" vs. absolute time, which allows us to incorporate nonlocality by accepting that there may be (either as a purely mathematical artifact or as an actual physical effect) a local time for each inertial frame, but these local times may be linked exactly to the absolute time of the absolute rest frame represented by the ether.
 
  • #9
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Jesse, here is a recent description of what I mentioned, from "Non-Local Correlations in Quantum Theory: Some Ways the Trick Might be Done", Einstein, Relativity, and Absolute Simultaneity, ed. Quentin Smith and William Lane Craig, Routledge (2008). Page 162 states:

"The exact outcome of the experiment depends on which electron goes through the device first. If the right-hand electron is measured first, it will be found to have x-spin up and the left-hand electron x-spin down, but if the left-hand electron is measured first, one will get the opposite outcome. And this holds no matter how far apart the two electrons are, and holds without the action of any intermediary particles or fields traveling between the two sides of the experiment. So the behavior of the right-hand electron at some moment depends on what has happened (arbitrarily far away) to the left-hand electron."
 
  • #10
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PS. This quote is from Tim Maudlin, a contributor to the Craig and Smith volume.
 
  • #11
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But it seems that LET is now to be preferred over Einsteinian/Minkowskian SR because there is a "preferred foliation" made clear through experiments demonstrating non-locality. This preferred foliation is Lorentz's ether.
This is a common misconception by uninformed supporters of Lorentz over Einstein. Lorentz's aether is, by design, experimentally undetectable. An experiment that detects the aether frame will falsify both Einstein (who says there is no aether) and Lorentz (who says it is not detectable). You cannot simply claim any old aether frame and call it support for Lorentz.

There can be no experimental justification for picking Lorentz over Einstein, but if you want it for aestetic reasons then you are certainly free to do so.
 
  • #12
JesseM
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"The exact outcome of the experiment depends on which electron goes through the device first. If the right-hand electron is measured first, it will be found to have x-spin up and the left-hand electron x-spin down, but if the left-hand electron is measured first, one will get the opposite outcome. And this holds no matter how far apart the two electrons are, and holds without the action of any intermediary particles or fields traveling between the two sides of the experiment. So the behavior of the right-hand electron at some moment depends on what has happened (arbitrarily far away) to the left-hand electron."
Much of this section can be viewed on google books here. From the context it seems to me he may be talking only about the predictions of Bohmian mechanics. Consider some of the paragraphs surrounding the ones you quote, with me putting some parts in bold for emphasis, and adding some parenthetical comments of my own in bolded square brackets:
If one begins with non-relativistic Bohmian mechanics one notices that distant correlations in that theory are explained directly by the dynamics because the dynamics governs the total configuration of particle positions by a global law rather than governing the positions of individual particles by a local law. That means that where a particular particle goes may depend on where an arbitrarily distant particle is and, most strikingly, on what is being done to the distant particle. In the non-relativistic theory, determining where the distant particle is requires the use of absolute simultaneity: we mean where the distant particle is at the very same moment for which the velocity of the local particle is to be determined.

This feature of the theory is best illuminated by an example discussed by David Albert (1992: 155-60). In Bohmian mechanics, when one does a spin measurement on a particle that is not in an eigenstate of spin (so quantum mechanics makes only probabilistic predictions), the outcome of the measurement will depend, first, on exactly how the spin-measuring device is constructed and, second on the exact initial location of the particle.

...

To be concrete, suppose we prepare a beam of particles in the state y-spin up, and then subject the particles in the beam to an x-spin measurement. Quantum mechanics predicts that half of the particles in the beam will exit the device going up and half going down. Bohmian mechanics further implies, for an apparatus like a Stern-Gerlach device, that the particles that exit going up were all initially located in the upper region of their wave function, and the half that go down were originally located in the lower half.

But the outcome of an x-spin measurement cannot always be determined in such a straightforward way, from the initial location of the particle being measured. As Albert points out, the situation becomes much more interesting if we make x-spin measurements on pairs of particles that are entangled. If, for example, we create a pair of electrons in a singlet state and then measure the x-spin of both, quantum mechanics predicts that the results will always be anti-correlated: one electron will exhibit x-spin up and the other x-spin down. But whether a particular electron exhibits a particular result cannot be determined simply by the initial location of that particle [by which I think Maudlin means the initial location of the particle in Bohmian mechanics, where particles have well-defined positions at all times]: if it could, then there would be a completely local account of the spin measurements, and they could not violate Bell's inequality (which they do). Suppose, for example, each of the pair of electrons is initially in the upper spatial region of the wave function [I think this assumption about the hidden Bohmian position may be crucial in hsi further discussion]. Then it cannot be that each electron will exit the device headed toward the ceiling if it enters the device in the upper region: that would violate the perfect anti-correlation. So what determines which electron will go up and which go down?

As Albert shows, the exact outcome of the experiment depends on which electron goes through the device first. If the right-hand electron is measured first, it will be found to have x-spin up and the left-hand electron x-spin down, but if the left-hand electron is measured first, one will get the opposite outcome. [But it may be that this is only true if you initially assume that 'each of the pair of electrons is initially in the upper spatial region of the wave function' as he said above; perhaps if each was initially in the lower region, the opposite would be true. And since the spatial location is part of the Bohmian hidden variables, we never actually know what region the electrons are in on a given trial, so this might not give us an experimentally testable way of determining whether the right electron had already been measured based on the direction of the left electron. The other possibility which occurs to me is that Bohmian mechanics does predict an experimental test of which electron was measured first, and that it matches nonrelativistic QM in this respect (since Bohmian mechanics is designed to always match nonrelativistic QM's predictions about experimental results), but that relativistic QM would predict something different.] And this holds no matter how far apart the two electrons are, and it holds without the action of any intermediary particles or fields traveling between the two sides of the experiment. So the behavior of the right-hand electron at some moment depends on what has happened (arbitrarily far away) to the left-hand electron. The dynamical non-locality of Bohm's theory is thereby manifest.

Since the exact outcome of the experiment depends on which x-spin measurement is made first, the notion of "first" and "second" has an ineliminable physical role in Bohm's theory. [I would think if he was concluding it had an 'ineliminable physical role' in orthodox QM, he would say so.] In the non-relativistic theory, which measurement comes first and which second is determined by absolute simultaneity. And if one is to transfer the Bohmian dynamics to a spacetime with a Lorentzian structure, one needs there to be something fit to play the same dynamical role. Since no such structure is determined by the Lorentzian metric, the simplest thing to do is to add the required structure: to add a foliation relative to which the relevant sense of "first" and "second" (or "before" and "after") is defined. The foliation would then be invoked in the statement of the fundamental dynamical law governing the particles.
 
  • #13
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Dale, what you write is not quite accurate vis a vis this discussion. I agree with you that Lorentz's ether was in principle undetectable and I agree that any neo-Lorentzian ether will also be in principle undetectable.

What I am referring to re a "preferred foliation" is not itself detectable, because the foliation is not itself a thing - it's just an abstraction that corresponds to the ether. The foliation consists of all simultaneous events in our universe. So the preferred foliation represents absolute time in a Newtonian sense.

Lorentz's ether was in principle undetectable because any attempts to measure differences in the speed of light, based on the motion of the observer (Michelson-Morley being the most famous example) would not detect any difference in light's velocity because of length contraction that perfectly canceled out the anisotropic speed of light.

However - to go a step or two deeper - some physicists, most vigorously Reg Cahill, at Flinders University in Australia, have shown that the standard interpretations of Michelson-Morley and other similar experiments are very likely wrong for a variety of reasons. According to Cahill (you can look up his papers on Arxiv.org), we have detected the anisotropic speed of light many times over, as our planet moves through the ether. But even this admittedly controversial interpretation does not violate Lorentz's prohibition against detecting the ether itself. Just as bubble chambers allow us to "see" subatomic particles through their interaction with other elements, without us directly viewing the particles, we may discern certain features of the ether without directly detecting the ether itself.
 
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  • #14
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What I am referring to re a "preferred foliation" is not itself detectable
If it is not detectable then how do you propose it as experimental evidence against Einstein?
 
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  • #16
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Dale, the Aspect experiments are the evidence that weigh heavily against Einsteinian SR and in favor of LET. This is the case b/c they show that the universe does, in at least certain situations (and perhaps pervasively) communicate instantaneously over long distances. Through such experimental evidence, Einstein's convention of light signal clock synchronization is mooted. But, even if we didn't have the Aspect experiments, we have many reasons to support LET over SR because of what I mentioned above: the confusion of epistemological limitations with ontology. Even if we were limited to light signal synchronization, this doesn't mean space and time are malleable as Einstein asserted. Rather, it is entirely possible to interpret the mathematical formalisms in a way that preserves the commonsensical notions of absolute time and space. If we have two interpretations that are empirically equivalent and one interpretation leads to very discomfiting consequences for the nature of becoming and free will, and another that does not, shouldn't we pick the latter?
 
  • #17
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Through such experimental evidence, Einstein's convention of light signal clock synchronization is mooted.
Einstein's synchronization is the same as Lorentz's, so if it "moots" Einstein it "moots" Lorentz.

Look, these claims are common. We get one every couple of months around here. So far, none of you have convincingly demonstrated that these experiments can be used to establish a simultaneity convention. Second, none of you have established that the simultaneity convention thus established is "absolute" in any sense. Finally, none of you have ever even attempted to demonstrate that it conforms to the Lorentz transform. Until you do all three of these it is very premature to start asserting that you have experimental evidence for Lorentz and against Einstein.

Don't forget, the mere existence of FTL phenomena does not by itself invalidate relativity, even if that FTL phenomena can be used to transmit information. Most people who claim that these experiments invalidate SR simply say "FTL therefore not SR", but that is insufficient.
 
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  • #18
JesseM
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Jesse, I agree that much of Maudlin's discussion hinges on a Bohmian QM, but the statement I quoted is true regardless of the context of the statement.
What do you mean "regardless of the context"? My first interpretation was that they were saying the right-hand electron's x-spin would tell you whether the left electron had been measured first only if you make some assumptions about the hidden Bohmian position variables both electrons started out with; even if we assume Bohmian mechanics is correct, my guess would be that if the experimenters don't know the value of these initial hidden position variables, then they can't use the result of the measurement of the right-hand electron to deduce whether the left electron has already been measured. If the key question is whether there is any experimental way to determine absolute simultaneity (as opposed to the question of whether it exists on some "hidden" untestable level), then I don't think the section you quoted is meant to support such a notion of experimentally-determinable absolute simultaneity. Do you disagree?
Tam Hunt said:
For longer discussions of the Aspect experiments, see Bell and Aspect's Speakable and Unspeakable in Quantum Mechanics:

https://www.amazon.com/dp/0521818621/?tag=pfamazon01-20&tag=pfamazon01-20

And Nadeau and Kafatos's The Non-Local Universe:

https://www.amazon.com/dp/0195144082/?tag=pfamazon01-20&tag=pfamazon01-20
Are you claiming that either of these books support the idea that QM can provide experimental evidence for a preferred definition of simultaneity? If so, please give some relevant quotes/page numbers.
 
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  • #19
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Dale, we seem to be speaking past each other a bit. I wrote above that LET may be preferred over SR regardless of any experimental evidence re nonlocality. Again, this is because the entire SR structure is built upon the light signal synchronization convention and this convention does not in any way require that the universe actually allow malleable space and time. Are you fine with an acceptance that there is no free will or any elapse of time? These are personal decisions, but I would be surprised if you are indeed amenable to these consequences of the E/M interpretation of SR.
 
  • #20
JesseM
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Are you fine with an acceptance that there is no free will
I don't think the traditional notion of "free will" is even logically coherent (how can events neither follow a mathematical pattern nor be random, when randomness is defined in terms of the lack of a regular pattern?), but I'll note that there are plenty of religious believers who think free will is compatible with the idea that God already knows all the free choices humans will make in the future, so I don't see why those inclined to believe in free will should necessarily view it as incompatible with "block time".
Tam Hunt said:
or any elapse of time?
Proper time along worldlines is still an objective coordinate-independent reality in relativity.
 
  • #21
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Jesse, looking back I now agree with you that the Bohmian QM discussion was relevant to the quote I first used. However, the books I cited describe in detail the nature of nonlocality, which experiments are interpreted by many respected physicists as demonstrating superluminal transmission of information. The sticking point is, of course, whether we can use that information in any way. Regardless, again, my arguments re the problems with the E/M interpretation of SR are valid whether the Aspect experiments demonstrate nonlocality or not.
 
  • #22
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Jesse, re free will, what I mean by this phrase is not necessarily a religious concept (though it could be). Rather, what I am referring to is the validity of human choice on our own behavior and how the universe unfolds for each of us. In short: is the universe deterministic or non-deterministic? I would like to believe that the universe is non-deterministic because it matches my hard-core commonsense notion of freedom and free will and because I simply prefer to believe that I exert control over my actions. I choose to type this sentence. I am not pre-ordained to write this sentence. Interestingly, social experiments have shown that when young subjects are told as a prelude to the experiment that science has shown they do/do not have free will, they behave differently - those told that free will does exist behave more ethically.

Regardless, Alfred North Whitehead developed a detailed ontology that preserved free will, most completely in his monumental book Process Physics (1929). I highly recommend it (he did not challenge the validity of the mathematical formalism of SR, but did challenge the idea that the universe is deterministic). Last, Einstein himself struggled with the notion of determinism throughout his career - and engaged in many moral struggles that he certainly would have liked to believe were undertaken due to his free will. But he generally believed that the universe was in fact deterministic.

Re "proper time along worldlines," can you send some cites? My understanding of E/M SR is that time is nothing more than another dimension and that the past, present and future all exist in a very real way together - ergo, the universe is deterministic because everything has already "happened."
 
  • #23
JesseM
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Jesse, looking back I now agree with you that the Bohmian QM discussion was relevant to the quote I first used. However, the books I cited describe in detail the nature of nonlocality, which experiments are interpreted by many respected physicists as demonstrating superluminal transmission of information.
I think they would acknowledge that this is just an interpretation and not a firm conclusion from the evidence, though. Advocates of the http://www.npl.washington.edu/TI/ [Broken] would interpret the results differently, in ways that do not imply absolute simultaneity.
Tam Hunt said:
The sticking point is, of course, whether we can use that information in any way.
It's been proven that in orthodox QM you can't use entanglement to transmit information FTL, a result known as Eberhard's Theorem--see the second-to-last paragraph of my post #22 here.
Tam Hunt said:
Regardless, again, my arguments re the problems with the E/M interpretation of SR are valid whether the Aspect experiments demonstrate nonlocality or not.
But aren't these arguments all philosophical objections rather than physical objections with experimental consequences?
 
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  • #24
JesseM
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Jesse, re free will, what I mean by this phrase is not necessarily a religious concept (though it could be). Rather, what I am referring to is the validity of human choice on our own behavior and how the universe unfolds for each of us. In short: is the universe deterministic or non-deterministic? I would like to believe that the universe is non-deterministic because it matches my hard-core commonsense notion of freedom and free will and because I simply prefer to believe that I exert control over my actions. I choose to type this sentence. I am not pre-ordained to write this sentence.
But would you distinguish free will from mere randomness? A non-deterministic universe with a random element does not necessarily imply free will--if you take a deterministic A.I. computer program and let its output be influenced by the results from measurements of the decay of radioactive isotopes (assuming for the sake of argument that radioactive decay is truly random), I don't think most people would say the resulting system has "free will" even though it's no longer deterministic. Nothing in relativity denies the possibility of genuine randomness, but as I said, I don't think the notion of a third alternative to determinism and randomness is even a coherent idea...but this would be an issue better discussed in the philosophy forum rather than here.
Tam Hunt said:
Re "proper time along worldlines," can you send some cites? My understanding of E/M SR is that time is nothing more than another dimension and that the past, present and future all exist in a very real way together - ergo, the universe is deterministic because everything has already "happened."
I didn't mean my statement about proper time on worldlines to contradict the notion of time as a dimension. Perhaps I misunderstood what you meant by "any elapse of time"? I just wanted to point out that there is an objective truth about the amount of proper time between events on a particular worldline (though different frames disagree about the amount of coordinate time between these same events), just like there is an objective truth about the spatial distance along a curve in 2D Euclidean geometry.
 
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  • #25
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I wrote above that LET may be preferred over SR regardless of any experimental evidence re nonlocality.
Certainly. The LET may be prefered over SR for purely aestetic reasons as I mentioned in post 11. You don't need to have any reason better than "I like it more" in order to pick LET over SR. Feel free to pick either over the other, it is your perogative. Personally, I use both, LET for understanding relativistic Doppler, and SR for everything else.

The problem arises when you and your fellows think there is some experimental justification for that choice. There is not. Experimentally, SR and LET rise and fall together since they always use the same Lorentz transform to make the same predictions. That is my primary point. If you think that QM provides experimental evidence against SR then you must also reject LET as the same evidence goes against both.
 
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