Questions on QFT & QM: Is QM or QFT Absolute Time?

[Lynch101]

You're missing the point: Poincare's derivation does not start with an absolute reference frame. There is no absolute reference frame anywhere in the math. The only "absolute reference frame" was in Poincare's personal interpretation.

I'm basing it on this:

the transformations involved three reference frames. Frame S0 is at rest in the ether, S is a Galilean frame moving with velocity v with respect to S0 , and S' is an auxiliary frame that also moves with velocity v with respect to S0 . S0 and S are connected by the Galilean transformations, whereas S and S' are connected by the [Lorenntz transformations]. Combining these two transformations we obtain the transformations connecting So and S'

Pablo Acuña L. - On the Empirical Equivalence between Special Relativity and Lorentz’s Ether Theory

The thrust of the paper is to give further reasoning for favoring Einstein's interpretation over the Lorentz-Poincare interpretation, but in the paper he tries to create a steelman of the LP interpretation where he says that the Ether can be removed from the theory to leave just the absolute reference frame. My thinking is that this can be removed as well.

Please give specific references.

I'll take a look for these.

 

[PeterDonis]

I'm basing it on this

What does this have to do with Poincare's derivation? The footnote it appears in in the paper you referenced talks about a work by Lorentz. Also, the quote you give talks about a Galilean transformation as well as a Lorentz transformation, so whatever it is, it isn't a derivation of the Lorentz transformation.

 

[Lynch101]

What does this have to do with Poincare's derivation? The footnote it appears in in the paper you referenced talks about a work by Lorentz.

Does it not form the basis for Poincaré's derivation?

Also, the quote you give talks about a Galilean transformation as well as a Lorentz transformation, so whatever it is, it isn't a derivation of the Lorentz transformation.

Is that not how the Lorentz transformation was derived by Lorentz?

 

[vanhees71]

Can QFT be considered fundamental if it doesn't explain what happens in individual experiments?

Yes, since this is indeed what's observed in the experiments: Depending on the preparation of the measured system the outcome of measurements of all but maybe a few observables is indetermined.

Of course, whether or not this is inherent randomness of nature or just our ignorance of some hidden variables (i.e., observables not yet known and thus not taken into account), one can of course not decide. However, as the very well established violation of Bell's inequalities prove, if there's a deterministic HV theory describing all the facts QT is describing, it must be a non-local theory, and to find such a theory is at least very difficult in connection with relativity. Nevertheless as far as I know, there's also no mathematical proof of a corresponding "no-go theorem", i.e., it could be that indeed such a non-local deterministic theory exists. If so, it's not found yet.

 

[PeterDonis]

Does it not form the basis for Poincaré's derivation?

Not what is referred to in that footnote, no.

Is that not how the Lorentz transformation was derived by Lorentz?

Not what is referred to in that footnote, no.

 

[vanhees71]

I've never seen Poincare's derivation of the LT. Can you point me to the paper (if possible in English or German translation; my French is close to inexistent :-(().

 

[PeterDonis]

I've never seen Poincare's derivation of the LT.

As far as I can tell from looking at sources available online, neither Lorentz nor Poincare actually derived the LT at all, in the sense of starting from some more basic axioms. They simply observed that Maxwell's Equations were invariant under the LT, not Galilean transformations, and tried to draw inferences from that fact. So the first actual derivation of the LT might well be Einstein's in his 1905 paper.

 

[vanhees71]

Sure, the great breakthrough by Einstein was to realize that the invariance of Maxwell's equations under Lorentz transformations (as we'd formulate it today) is not simply a mathematical curiosity but a fundamental discovery for all of physics, not only for electrodynamics. It lead to the unique idea that the description of space and time for all of physics has to be changed.

The mathematics was known much earlier. The earliest reference I know is a paper by Woldemar Voigt:

https://eudml.org/doc/180122

It's not the final version of the LT though.

 

[Lynch101]

Not what is referred to in that footnote, no.
Not what is referred to in that footnote, no.

My apologies, I was under the impression that Einstein derived the LT from his two postulates, with the one-way SoL being the 2nd postulate and that the relativity of simultaneity was a consequence of the one-way SoL.

 

[PeterDonis]

I was under the impression that Einstein derived the LT from his two postulates

You didn't mention Einstein in the post of yours that I responded to in the response you quoted in post #69. You mentioned Poincare and Lorentz. Their derivations of the LT (to the extent they are "derivations" at all--see my post #67) are not the same as Einstein's. You can't keep moving the goalposts whenever you are told you have an incorrect understanding.

with the one-way SoL being the 2nd postulate and that the relativity of simultaneity was a consequence of the one-way SoL

Have you read Einstein's 1905 paper? It's here:

http://hermes.ffn.ub.es/luisnavarro/nuevo_maletin/Einstein_1905_relativity.pdf
Read it and what you think. It's always best to go to the primary source instead of relying on second-hand accounts.