I The Great Rift In Physics: The Tension Between Relativity and QM

[sahashmi]

TL;DR Summary

A recent paper was published by Tim Maudlin discussing a rift between QM and relativity

Link to paper: https://arxiv.org/abs/2503.20067

Thoughts?

 

[berkeman]

Thread is in Moderation for review by the Mentors.

 

[berkeman]

After a Mentor discussion the thread is approved provisionally.

 

[DaveC426913]

Maybe we could have a summary? Some aspect you want to talk about?

 

[Nugatory]

Maybe we could have a summary? Some aspect you want to talk about?

The abstract is a pretty good tl;dr:

It is commonly remarked that contemporary physics faces a challenge in reconciling quantum theory with Relativity, specifically General Relativity as a theory of gravity. But "challenge" is too mild a descriptor. Once one understands both what John Bell proved and what Einstein himself demanded of Relativity it becomes clear that the predictions of quantum theory, predictions that have been verified in the lab, are flatly incompatible with what Einstein wanted and built into General Relativity. There is not merely a tension but an incompatibility between the predictions of quantum theory and Relativity, and what has to give way is the Relativistic account of space-time structure and dynamics.​

However, I’d recommend reading the whole thing now that you know where Mauldin is going with his argument.

Do note that the incompatibility that Mauldin identifies is with “what Einstein himself demanded of Relativity”. That’s not quite the same thing as “Relativity”.

 

[Hornbein]

It seems to me the paper is all things I already knew. The conclusion is that Bell's theorem shows nonlocality while GR assumes locality so the theories are incompatible. It is presented quite clearly, which is nice. My only objection is to the author's predilection for italic font. While I enjoyed reading it and think it would be good reading for some people I confess that I got bored and skimmed through the second half.

 

[sahashmi]

The abstract is a pretty good tl;dr:

It is commonly remarked that contemporary physics faces a challenge in reconciling quantum theory with Relativity, specifically General Relativity as a theory of gravity. But "challenge" is too mild a descriptor. Once one understands both what John Bell proved and what Einstein himself demanded of Relativity it becomes clear that the predictions of quantum theory, predictions that have been verified in the lab, are flatly incompatible with what Einstein wanted and built into General Relativity. There is not merely a tension but an incompatibility between the predictions of quantum theory and Relativity, and what has to give way is the Relativistic account of space-time structure and dynamics.​

However, I’d recommend reading the whole thing now that you know where Mauldin is going with his argument.

Do note that the incompatibility that Mauldin identifies is with “what Einstein himself demanded of Relativity”. That’s not quite the same thing as “Relativity”.

Well he does explicitly say “There is not merely a tension but an incompatibility between the predictions of quantum theory and Relativity”, so it does seem as if he is saying relativity is incompatible with QM.

Note to other readers that he personally believes relativity is emergent and that we should work on a theory that has a preferred frame (and thus no relativistic space time) but in such a way where relativity is still emergent in the scales that we see. I’m not sure if this is the only way to tackle this issue though

 

[martinbn]

TL;DR Summary: A recent paper was published by Tim Maudlin discussing a rift between QM and relativity

Link to paper: https://arxiv.org/abs/2503.20067

Thoughts?

What about your thoughts?! Isn't this a bad way to start a topic for discussion. "Here is a paper, go."

 

[sahashmi]

What about your thoughts?! Isn't this a bad way to start a topic for discussion. "Here is a paper, go."

My thoughts echo the paper but I’ll summarize the pretty clear logical argument.

1. In the case of perfect correlations, Einstein determined, as per his EPR argument, that the only way to explain these correlations locally is through determinism. If each particle was evolving through local dynamics but was not determined, then over a series of trials, it makes no sense for each particle to always have the opposite spin on the same axis. So in some sense, Einstein ruled out local “non determinism”

2. Bell’s theorem and the experiments confirming it ruled out a local predetermined explanation. So, Bell ruled out local determinism

3. Since local determinism and local “non determinism” were both ruled out, non locality is unquestionably true, and physicists denying this are ultimately denying the results of experiments

 

[PeroK]

Perhaps someone should try to formulate a theory of quantum gravity?

 

[Fra]

TL;DR Summary: A recent paper was published by Tim Maudlin discussing a rift between QM and relativity

Link to paper: https://arxiv.org/abs/2503.20067

Thoughts?

My thoughts from reading it

1) I am guessing that Dr Chinese must love it!!??

2) I enjoy seeing his confidence in this, and it was nice summary of some historical turns

3) When I see his arguments, I think I understand more clearly why it's hard to see things from a different paradigm. It made me think, and i gave me some ideas.

/Fredrik

 

[javisot]

TL;DR Summary: A recent paper was published by Tim Maudlin discussing a rift between QM and relativity

Link to paper: https://arxiv.org/abs/2503.20067

Thoughts?

My first thought is "isn't QFT a theory that weakly reconciles GR and QM?" It is incorrect to say that GR and QM are not reconcilable, we could say that perhaps they are not completely reconcilable.

The last thing I thought is that the author's logic is built assuming that there is no theory without non-local influence capable of explaining all QM experimental data, an assumption that may be correct or incorrect.

It is easy to accept that non-local influence is necessary to explain all QM experimental data, but this does not seem appropriate if we want to reconcile GR and QM completely into an integrated theory.

 

[DrChinese]

My thoughts from reading it

1) I am guessing that Dr Chinese must love it!!??

But of course!

PS I am not Tim Maudlin hiding under an alias… :)

 

[PeterDonis]

My first thought is "isn't QFT a theory that weakly reconciles GR and QM?"

Not really. It's a theory that weakly reconciles special relativity and QM, by describing quantum phenomena in a way that's consistent with Lorentz invariance.

You can do QFT in a curved spacetime, or at least in some curved spacetimes (the asymptotically flat ones). But you're not really reconciling QM with GR, because there is no link between the spacetime curvature, as described by GR, and the matter-energy content, as described by the quantum fields. You have to specify the spacetime geometry by hand and hope that it's reasonably consistent with the matter content. And even that has limitations.

 

[sahashmi]

Note that the paper argues that QM is incompatible with special and general relativity, not just GR

 

[javisot]

Note that the paper argues that QM is incompatible with special and general relativity, not just GR

Have you read the paper? The paper deals with GR, not SR.

The author's words can cause confusion since he repeatedly uses "relativity" and "general relativity" to refer to the same thing.

 

[weirdoguy]

Note that the paper argues that QM is incompatible with special and general relativity, not just GR

Note that QFTs exist and are one of the most successfull theories to date, so arguing that QM may not be compatible with SR is, well, just crackpottery.

EDIT: Of course I'm not saying that non-relativistic QM is compatible with SR, since, well, that's obvious it's not, but there is also nothing to complain about, because it's non-relativistic

 

[Morbert]

Does the paper say anything novel or is it just reheated arguments Maudlin has made elsewhere?

 

[martinbn]

Does the paper say anything novel or is it just reheated arguments Maudlin has made elsewhere?

I didn't see anything new that has not been discussed here on PF.

 

[Lord Jestocost]

.... The last thing I thought is that the author's logic is built assuming that there is no theory without non-local influence capable of explaining all QM experimental data ....

When one takes for granted all assumptions of realism or classicality, all classical theories that allow for violations of the Bell inequality must be non-local.

 

[WernerQH]

Locality, causality, and determinism are firmly rooted in the classical (macroscopic) world picture. There is no reason to believe that these concepts must necessarily carry over to quantum theory. I quite like Maudlin's discussion of non-locality, but I strongly disagree with his take on relativity and determinism. Others have already mentioned QFT as a union of sorts of quantum theory with relativity. It strikes me as absurd to portray quantum theory as deterministic. We never predict the specific responses of particular detectors. What's possible in the real world are just statements after the fact about correlations between the responses of different detectors.

It is quite misleading to say that a detector oriented at, say, 90 degrees "measures" the polarisation of a photon. Just as well it might have been 30 degrees (with 25% probability) or circular polarization (with 50% probability). Polarization can be viewed as a property of the detector as much as that of a photon. It is usually inferred, attributed to a photon with hindsight, knowing the experimental setup (the "beam preparation"). What Bell's theorem shows is the impossibility of ascribing definite polarizations to photons in general.
My conclusion is that photons do not exist, at least not in the usual sense of quantum "objects" moving through space. In the Aspect et al. experiments excited calcium atoms lose a certain amount of energy, and a few nanoseconds later that energy is absorbed by atoms in the detectors. Quantum electrodynamics is silent about the whereabouts of that energy, other than that it is somewhere "in the field".

But wait, isn't it obvious that photons must exist? How else can we explain the correlations? Owing to our classical mindset (giving so much weight to causality), there is an extremely strong urge to explain correlations, rather than just describe them and accept them as a fact of Nature. Is quantum electrodynamics at all conceivable without photons? There is a historical precedent: for Maxwell electromagnetic waves were inconceivable without a medium carrying them (the ether). The existence of the ether was so obvious to him that he enquired about the possibility of determining the "motion of the solar system through the luminiferous ether" through accurate measurements of the eclipses of the Jovian satellites. Nowadays we know that Maxwell's equations make perfect sense without an ether, and we see the Michelson-Morley experiments as evidence against the ether. Perhaps future physicists will interpret the Bell-type experiments as evidence against the existence of photons. Not only quantum theory, but also experiments require an interpretation (which might be subject to change)!

To be clear, I do think that we can talk about photons in a meaningful way, but we have to be careful about the possible metaphysical connotations. One could say that the ether was not abolished, but replaced by something with higher symmetry that we now call vacuum. For me, the photon "propagator" merely expresses the non-local correlations between current fluctuations in what we perceive as "emission" and "absorption" events in the "source" and "detectors".

 

[martinbn]

His description of differential geometry in the beginning shows that he doesn't know any. Which of course is ok, one doesn't have to study every subfield of mathematics if one is interested in philosophy of science, but it implies that he cannot possibly understand general relativity beyond a very basic level. He also uses a few different notions of locality/nonlocality but pretends they are the same. So proving that relativity is wrong because it is local and experiments confirming violations of Bell's inequalities show nonlocality is very non-convincing. Also I am not convinced by the argument that locality in EPR implies that non measured variables have values. That is taken as obvious, but why is it? The only argument given is "how can it be otherwise".

 

[DrChinese]

1. Polarization can be viewed as a property of the detector as much as that of a photon. It is usually inferred, attributed to a photon with hindsight, knowing the experimental setup (the "beam preparation"). What Bell's theorem shows is the impossibility of ascribing definite polarizations to photons in general.

2. My conclusion is that photons do not exist, at least not in the usual sense of quantum "objects" moving through space. In the Aspect et al. experiments excited calcium atoms lose a certain amount of energy, and a few nanoseconds later that energy is absorbed by atoms in the detectors. Quantum electrodynamics is silent about the whereabouts of that energy, other than that it is somewhere "in the field".

OK, I'm only responding to these comments as they relate to EPR/Bell/Entanglement Experiments.

1. Without me trying to parse out or criticize your words, I just want to say: The combination of the polarizer and the detector cannot have any influence on the recorded outcomes. With PDC Bell tests, you have two of these apparati. If they contributed anything to speak of, you could not have the so-called perfect correlations with polarization/spin entanglement.

2. I can predict, with a narrow spacetime region, when and where a PDC photon will be detected. And I know similarly when/where it originated. So I would describe that as a quantum object moving through spacetime.

 

[javisot]

Let's assume this is true: nonlocal influence (in the Einsteinian sense) is necessary to fully explain the QM experimental data set. Let's deny the existence of QFT.

So we claim that GR and QM are completely irreconcilable but both theories are experimentally true, then there is no QFT, no string theory, no theory of quantum gravity, nothing.

And now?
Does anyone have a better plan?

 

[PeterDonis]

Let's deny the existence of QFT.

Why would we want to do that?

 

[javisot]

Why would we want to do that?

Obviously there is QFT, and ST and QG. I ask this for those who, like the author of the paper, claim that GR and QM are not compatible because one theory is local and the other is non-local, so are we stuck?

It seems contradictory to accept that nonlocality as the only explanation for quantum correlations and at the same time thought they could reconcile the two theories.

 

[A. Neumaier]

When one takes for granted all assumptions of realism or classicality, all classical theories that allow for violations of the Bell inequality must be non-local.

They must only be classically nonlocal. Note that Bell's theorem is not a theorem about quantum mechanics, but about classical local hidden variable theories. Thus the viaolation of the Bell inequalities only demonstrates that quantum mechanics is not a classical local hidden variable theory.

It does not demonstrate the incompatibility of special relativity and quantum mechanics. On the contrary, we know that special relativity and quantum mechanics are compatible since the local quantum field theory called QED is fully relativistic and fully consistent with the violation of Bell inequalities. After all, the relevant experiments were made with photons satisfying QED.

Thus classical Bell-nonlocality and quantum relativistic locality are two compatible concepts.

 

[sahashmi]

Have you read the paper? The paper deals with GR, not SR.

The author's words can cause confusion since he repeatedly uses "relativity" and "general relativity" to refer to the same thing.

No. He argues that any theory that has locality built into it and relativistic space time cannot explain the results. Thus, this includes special relativity. The paper is very clear on this.

In other avenues, he’s repeatedly argued that physicists are mistaken in thinking that QM is compatible with (even special) relativity

See 1:43:20 here:

 

[sahashmi]

Note that QFTs exist and are one of the most successfull theories to date, so arguing that QM may not be compatible with SR is, well, just crackpottery.

EDIT: Of course I'm not saying that non-relativistic QM is compatible with SR, since, well, that's obvious it's not, but there is also nothing to complain about, because it's non-relativistic

You can’t write down all the equations in QFT cleanly using only relativistic space time structure. So in that sense, no, it’s not “deeply” relativistic as Maudlin says in the video I just linked.

QFT also does not explain entanglement. It’s simply a workaround. There is no way to explain the bell type experiments with purely relativistic space time. If you think you can give a clear account of what is happening in those experiments step by step while only using relativistic space time, go ahead.

 

[sahashmi]

When one takes for granted all assumptions of realism or classicality, all classical theories that allow for violations of the Bell inequality must be non-local.

This distinction between “realistic” and “non realistic” is a misnomer. Science is about explaining what we observe. What we observe is “real”. No one who believes in “non realism” has ever managed to explain what that even means

 

[sahashmi]

Locality, causality, and determinism are firmly rooted in the classical (macroscopic) world picture. There is no reason to believe that these concepts must necessarily carry over to quantum theory. I quite like Maudlin's discussion of non-locality, but I strongly disagree with his take on relativity and determinism. Others have already mentioned QFT as a union of sorts of quantum theory with relativity. It strikes me as absurd to portray quantum theory as deterministic. We never predict the specific responses of particular detectors. What's possible in the real world are just statements after the fact about correlations between the responses of different detectors.

It is quite misleading to say that a detector oriented at, say, 90 degrees "measures" the polarisation of a photon. Just as well it might have been 30 degrees (with 25% probability) or circular polarization (with 50% probability). Polarization can be viewed as a property of the detector as much as that of a photon. It is usually inferred, attributed to a photon with hindsight, knowing the experimental setup (the "beam preparation"). What Bell's theorem shows is the impossibility of ascribing definite polarizations to photons in general.
My conclusion is that photons do not exist, at least not in the usual sense of quantum "objects" moving through space. In the Aspect et al. experiments excited calcium atoms lose a certain amount of energy, and a few nanoseconds later that energy is absorbed by atoms in the detectors. Quantum electrodynamics is silent about the whereabouts of that energy, other than that it is somewhere "in the field".

But wait, isn't it obvious that photons must exist? How else can we explain the correlations? Owing to our classical mindset (giving so much weight to causality), there is an extremely strong urge to explain correlations, rather than just describe them and accept them as a fact of Nature. Is quantum electrodynamics at all conceivable without photons? There is a historical precedent: for Maxwell electromagnetic waves were inconceivable without a medium carrying them (the ether). The existence of the ether was so obvious to him that he enquired about the possibility of determining the "motion of the solar system through the luminiferous ether" through accurate measurements of the eclipses of the Jovian satellites. Nowadays we know that Maxwell's equations make perfect sense without an ether, and we see the Michelson-Morley experiments as evidence against the ether. Perhaps future physicists will interpret the Bell-type experiments as evidence against the existence of photons. Not only quantum theory, but also experiments require an interpretation (which might be subject to change)!

To be clear, I do think that we can talk about photons in a meaningful way, but we have to be careful about the possible metaphysical connotations. One could say that the ether was not abolished, but replaced by something with higher symmetry that we now call vacuum. For me, the photon "propagator" merely expresses the non-local correlations between current fluctuations in what we perceive as "emission" and "absorption" events in the "source" and "detectors".

The interesting part about Maudlin’s paper is you don’t even need to believe in quantum theory.

Even if you had no idea what quantum theory is, whether photons exist or not exist, the fact of the matter is that there are correlations occurring that CANNOT be explained by local influences. And those observations occur in labs in the macro scale that none of us can deny. That’s the beauty of the experiment. So trying to escape this conclusion by resorting to “how the quantum world is different” just simply doesn’t work.

They must only be classically nonlocal. Note that Bell's theorem is not a theorem about quantum mechanics, but about classical local hidden variable theories. Thus the viaolation of the Bell inequalities only demonstrates that quantum mechanics is not a classical local hidden variable theory.

It does not demonstrate the incompatibility of special relativity and quantum mechanics. On the contrary, we know that special relativity and quantum mechanics are compatible since the local quantum field theory called QED is fully relativistic and fully consistent with the violation of Bell inequalities. After all, the relevant experiments were made with photons satisfying QED.

Thus classical Bell-locality and quantum relativistic locality are two compatible concepts.

Read above. This notion that you can escape the conclusion by talking about how the conclusions don’t apply to a “quantum world” simply doesn’t work

 

[PeroK]

No. He argues that any theory that has locality built into it and relativistic space time cannot explain the results. Thus, this includes special relativity. The paper is very clear on this.

In other avenues, he’s repeatedly argued that physicists are mistaken in thinking that QM is compatible with (even special) relativity

See 1:43:20 here:

Physics isn't philosophy. What is the definition of compatible? Unless you can show a contradiction in the mathematics, saying two things are incompatible is meaningless.

 

[weirdoguy]

That’s the beauty of the experiment.

Yes, and those say that QM and SR are compatible in form of QFT.

You can’t write down all the equations in QFT cleanly using only relativistic space time structure.

Which equations can't be written? Give us concrete example of such equation.

 

[sahashmi]

Physics isn't philosophy. What is the definition of compatible? Unless you can show a contradiction in the mathematics, saying two things are incompatible is meaningless.

I just gave you a metric. Write down all the equations in QFT using relativistic space time. Secondly, explain entanglement using QFT.

The correlations in entanglement are ultimately considered brute in QFT. There is no explanation for why certain particles that are locally independent of each other correlate. The point of Bell’s theorem is that you cannot explain these correlations without non local influences.

Note that we have never in scientific history observed strong non local correlations that did not end up having a cause. So when people say that non local causes violate relativity, that is correct.

But having no non local causes violates the Reichenbach's Common Cause Principle. This is the claim that if two events are correlated, then either there is a causal connection between the correlated events that is responsible for the correlation or there is a third event, a so called (Reichenbachian) common cause, which brings about the correlation. This principle has stood the test of time even longer than relativity.

 

[PeroK]

I just gave you a metric. Write down all the equations in QFT using relativistic space time. Secondly, explain entanglement using QFT.

The correlations in entanglement are ultimately considered brute in QFT. There is no explanation for why certain particles that are locally independent of each other correlate. The point of Bell’s theorem is that you cannot explain these correlations without non local influences.

Note that we have never in scientific history observed strong non local correlations that did not end up having a cause. So when people say that non local causes violate relativity, that is correct.

But having no non local causes violates the Reichenbach's Common Cause Principle. This is the claim that if two events are correlated, then either there is a causal connection between the correlated events that is responsible for the correlation or there is a third event, a so called (Reichenbachian) common cause, which brings about the correlation. This principle has stood the test of time even longer than relativity.

All this boils down to is saying that 20th century physics is wrong because it fails to satisfy pre 20th century philosophical beliefs.

 

[weirdoguy]

Write down all the equations in QFT using relativistic space time. Secondly, explain entanglement using QFT.

Have you even seen any QFT textbook? xD With all due respect, you don't know what you're talking about. Big time.

 

[mitchell porter]

I started on the paper and right away came upon what I thought was a stupid statement - that the Wheeler--de Witt equation, produced by naively combining GR and QM, is evidence of a "degenerating research program" because the resulting operator equation equals zero rather than being an ordinary Schrodinger equation. "Degenerating research program" is philosophy-of-science jargon for a research direction that is producing poor results and therefore going nowhere. I mean, give the poor equation a chance! How many years did it take Dirac and his peers to go from the Dirac equation to its quantum field interpretation?

Maudlin must know that Wheeler--de Witt is still commonly used in quantum gravity, I guess I'll see if he really does reject it based on some rigid first impression, or if he's just making some methodological point about changes to first principles...

edit: OK, in this paper he really does leave it there. But from remarks elsewhere, I find that his real problem with WdW is that it doesn't have obvious time evolution, leading to a "problem of time" and the suggestion in some quarters (e.g. Julian Barbour) that time is unreal. Well, I agree with him that time is real (more specifically, that change is real) - but it's not apriori clear how that works. The flow of time may be "local" or "internal" to individual physical systems... And besides, classical GR already led to many proclamations, including from Einstein himself, that time is in some sense unreal! You don't even need to bring in QM, to find GR challenging one's intuitions about time.

I found more from Maudlin on WdW, in a blog discussion hosted by Sabine Hossenfelder in 2016. Perhaps thanks to blog decay, Maudlin's comments show up as "Unknown" [as do many other posters], while his antagonists are two string theorists posting as "dark star" and "black hole guy". They are largely talking about WdW in the context of AdS/CFT, but many broader issues of quantum, and even classical, GR, come up.

 

[javisot]

No. He argues that any theory that has locality built into it and relativistic space time cannot explain the results. Thus, this includes special relativity. The paper is very clear on this.

Due to the generalized correspondence principle you can only mention GR and still include SR. The separation you mention doesn't make sense since SR is a subset of GR.

Regarding other things that both you and the author of the paper have said,I prefer not to comment..

 

[sahashmi]

All this boils down to is saying that 20th century physics is wrong because it fails to satisfy pre 20th century philosophical beliefs.

Well, when experiments seem to contradict relativity, simply asserting that it doesn’t is itself a philosophical belief. I’m not sure you understand that interpreting any experimental result involves a philosophical belief.

The Reichenbach principle is not just a belief. It’s a physical principle that has always been correct. The same applies to relativity. One has to go. You just choose to believe that the second remains intact. And that’s a belief not based in science as much as you think.

 

[sahashmi]

Due to the generalized correspondence principle you can only mention GR and still include SR. The separation you mention doesn't make sense since SR is a subset of GR.

My point was in response to people who seem to think QM is compatible with SR but not GR. Maudlin’s point is that it is compatible with neither. What you just said agrees with what I said. I’m not the one who made the separation

 

[PeroK]

Well, when experiments seem to contradict relativity, simply asserting that it doesn’t is itself a philosophical belief. I’m not sure you understand that interpreting any experimental result involves a philosophical belief.

The Reichenbach principle is not just a belief. It’s a physical principle that has always been correct. The same applies to relativity. One has to go. You just choose to believe that the second remains intact. And that’s a belief not based in science as much as you think.

There's a discussion on Bell's Theorem and QFT here:

https://physics.stackexchange.com/q...ith-or-even-predicted-by-quantum-field-theory

I choose to believe empirical science over the pure thought of philosophy.

That said, this is a science forum and philosophy is not discussed partly for the reason that there never be a reconciliation in these cases.

 

[PeroK]

My point was in response to people who seem to think QM is compatible with SR but not GR. Maudlin’s point is that it is compatible with neither. What you just said agrees with what I said. I’m not the one who made the separation

And from a physics point of view you are wrong and wasting everyone's time. Physics goes on whether you accept it or not. This forum is to discuss that physics. If you don't want to learn physics, then please leave and join a philosophy forum.

 

[Nugatory]

This principle has stood the test of time even longer than relativity.

Until quantum entanglement demonstrated its limitations….

And seriously, you are somewhat misrepresenting the problem.
Consider that the quantum description of nature does not conflict with anything in relativity: spacelike-separated measurements commute; entanglement experiments with spacelike-separated detectors produce the same outcomes no matter which one came “first”; it is impossible to detect any causal influence from outside of a past light cone so no conflict with relativistic causality, a solid “no signalling” theorem that shows QM disallows violation of relativistic causality…. QM is a theory about measurement results, and these results are not in conflict with relativity.
So what is the problem?
The problem is that, unlike QM, relativity is a theory of physical processes, and we have been unable to imagine any physical process that could lead to the measurement results predicted by QM and is consistent with relativity.

 

[sahashmi]

There's a discussion on Bell's Theorem and QFT here:

https://physics.stackexchange.com/q...ith-or-even-predicted-by-quantum-field-theory

I choose to believe empirical science over the pure thought of philosophy.

That said, this is a science forum and philosophy is not discussed partly for the reason that there never be a reconciliation in these cases.

You’re not understanding my point.

The empirical science agrees with non local theories that contradict relativity and any theories that don’t contradict it. That choice is based upon interpretation, not “empirical science.”

Your belief that the experiments do not contradict relativity is a philosophical belief on your part. So by your own standards, you should reserve judgment.

 

[sahashmi]

And from a physics point of view you are wrong and wasting everyone's time. Physics goes on whether you accept it or not. This forum is to discuss that physics. If you don't want to learn physics, then please leave and join a philosophy forum.

Again, your belief that the experiments do not contradict relativity is a belief, not science.

If you are intending to say that non local theories such as Bohmian mechanics or any other theories that may violate relativity are false, please show scientific evidence for this.

Until then, you are the one ironically espousing philosophy, and you are the one not talking about physics.

 

[sahashmi]

Until quantum entanglement demonstrated its limitations….

And seriously, you are somewhat misrepresenting the problem.
Consider that the quantum description of nature does not conflict with anything in relativity: spacelike-separated measurements commute; entanglement experiments with spacelike-separated detectors produce the same outcomes no matter which one came “first”; it is impossible to detect any causal influence from outside of a past light cone so no conflict with relativistic causality, a solid “no signalling” theorem that shows QM disallows violation of relativistic causality…. QM is a theory about measurement results, and these results are not in conflict with relativity.
So what is the problem?
The problem is that, unlike QM, relativity is a theory of physical processes, and we have been unable to imagine any physical process that could lead to the measurement results predicted by QM.

We are not unable to imagine it. Bohmian mechanics is a perfectly legitimate physical theory that imagines it. And who knows what else may come about.

You say that entanglement demonstrated the reichenbach common cause principle’s limitations. But that is merely a belief on your part. It could simply be evidence of relativity’s (and not the principle’s) limitations as well. This choice that you are making is not based on experiment

 

[sahashmi]

Have you even seen any QFT textbook? xD With all due respect, you don't know what you're talking about. Big time.

With all due respect, personal insults aren’t arguments. Please give me a clear step by step process by what leads to the correlations we see in bell like experiments using QFT, or admit that you instead don’t know what you’re talking about

 

[javisot]

With all due respect, personal insults aren’t arguments. Please give me a clear step by step process by what leads to the correlations we see in bell like experiments using QFT, or admit that you instead don’t know what you’re talking about

Since you're starting the discussions, at least look at the links they send you (the one from PeroK)

 

[sahashmi]

Since you're starting the discussions, at least look at the links they send you (the one from PeroK)

I did look at the link. The answer is correct that microcasuality (which is a locality condition) does not violate locality, but that is true for obvious reasons. QFT was built to be local at its very foundation.

This does not mean it explains entanglement. An explanation of entanglement should show why two entangled particles, the states of which are not predetermined, happen to correlate non locally once they’ve left the source at which they are created.

From scouring around this forum, it seems as if some physicists have the mistaken impression that the Bell experiments force you to choose between locality and realism. This is a false choice. Maudlin’s paper is written to highlight that.

This answer on the physics stack exchange also gives clear, logical reasons for why no local (realistic or “non realistic”) theory can explain the results of the experiments: https://physics.stackexchange.com/q...ne-explain-quantum-entanglement/828005#828005

 

[javisot]

My point was in response to people who seem to think QM is compatible with SR but not GR. Maudlin’s point is that it is compatible with neither. What you just said agrees with what I said. I’m not the one who made the separation

I reiterate, if Maudlin and you claim that GR and QM are incompatible it's not true, because QFT exists. (@Peter objected that it's more correct to say "SR is compatible with QM", but it's also true that SR is a subset of GR)

It's correct to say "SR and QM are compatible" and "GR and QM are partially compatible," unlike Maudlin and you, . I don't see the point in using Bell correlations to claim that.