In summary, the author provides a concise overview of the light postulate, the principle of relativity, and how these two principles follow from each other. He also discusses how the superselection rule for the fundamental physical constants can be derived from these two principles.
  • #106
We argue that the quantum momentum exchanged in an interaction does not itself interact with the collection of shared, self-consistent information constituting the block universe. That is, it does not have a worldline in the block universe. If it did, then you would need quantum exchanges for the quantum exchanges, since interaction is what establishes worldlines. And where would it end?
 
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  • #107
Gauge invariance is related to conservation principles as we show in our example. I don't have any shorter way to say it than I did there. It's really just Zee's presentation (see reference therein) with our interpretation added. We're not suggesting a need for any new physics here, just a different way to view the (very successful) physics we already have.
 
  • #108
Jimster41 said:
So, I am trying to get my head around the gauge-fixing part of the results from axioms. It seems relevant to the tension I am trying to describe. Just pretending for a second that there are all kinds of PO's not just people (or are people (with the ability to reflect upon and discuss the tension of consistency across TTO's somehow priveledged in the TTO graph vs. say rocks or muons) and being radically democratic with radical empiricism, say you have a couple of atomic PO's deep in the gravity well of the sun. This sun is cranking away with heat, pressure, gravity, geodesic stress - a regular hotbed of tension between said PO's so these two atomic PO's, say a couple of He atoms, are arguing long and loud. What happens next?
POs are not necessarily human, they can be actual or hypothetical data collection devices, e.g., the probe that just landed on an asteroid or a hypothetical probe of some spacetime location inside a star.

Jimster41 said:
I have the similar confusion with Alice and Bob for that matter. After all you are saying conservation only on average... so sometimes Bob get's the final h (Alice must simply agree) sometimes Alice get's it. Poor Bob. How is that represented in the TTO model?
Both Alice and Bob always measure h (##\pm \frac{\hbar}{2}## to be precise) for their spin measurements of the Bell spin state in question. Both are justified in saying the other is the one who has to average their outcomes to obtain the "correct" value of spin to satisfy conservation of spin angular momentum. Just like time dilation and length contraction where Alice(Bob) tells Bob(Alice) that his(her) clocks are slow and his(her) meter sticks are short, both are right. That is the "weird" consequence of conservation per NPRF, i.e., the relativity principle applied to the measurement of h.
 
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  • #109
All of this talk about neutral monism (aka "radical empiricism") does sound a bit "wiggy" for sure. But, foundations opened the door for this with interpretations like QBism. For example, Mermin writes:
QBism takes more seriously than do most physicists the basic notion of empiricism, that all knowledge derives from experience. For a QBist empiricism has a strongly personal flavor to it: the knowledge of each one of us derives from our own personal experience. This is close to what William James called “radical empiricism”.
(cited in our in our Scientific Reports paper and attached here). We reject the subjective nature of QBism, opting instead for one, self-consistent objective account of physical reality (represented by the block universe of shared, self-consistent classical information). And it makes perfect sense given that we're advocating for the fundamentality of principle explanation, i.e., principle explanation doesn't necessarily require a constructive counterpart. If you believe physics is in the business of identifying constraints on experience, as QBism claims, then the constraint "no preferred reference frame" is quite reasonable without a corresponding causal mechanism.
 

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  • #110
RUTA said:
We argue that the quantum momentum exchanged in an interaction does not itself interact with the collection of shared, self-consistent information constituting the block universe. That is, it does not have a worldline in the block universe. If it did, then you would need quantum exchanges for the quantum exchanges, since interaction is what establishes worldlines. And where would it end?

Thank you for the answers! This one clarified things a good bit. I saw that sentence and wondered... if it was a fast one. But, it sounds consistent with persuasive QM Interpretation arguments I've heard saying there is no "there" there without observation, quanta are just models of the rules of observation, and there is no way to claim they exist outside of observation... Not a bad thing. And consistent with the the background W. James non-dual stuff, the observer observing from within the observed etc. Plus I hat infinite regress.

I still struggle with what entropy (or "Energy Rate Density" Chaisson) both high and low is doing in all this. I get it is subject to the constraints and fits in. Part of why this is bugging me is because stuff you are saying is making me think I can put that piece in the puzzle better. Why (and how) does it just happen to describe the shape of the 4D block? Whence that slope? Maybe you are saying it is a principle explanation and doesn't need a constructive account (fair enough), or that it already has one (called biology and chemistry - even more fair they are awesome), But emergent complexity still just leaves me scratching my head. Why? How? Why not just monotonic dissipation. To use your terms... why isn't the "block universe of shared, self-consistent classical information" just shared at coordinate zero. Why such a mess... of a time (for lack of a better word) getting to the other end.

Not saying you were referring to Chaisson but I have heard him called Wiggy (or similar). For my part I think he is a pretty serious physicist and natural philosopher (with an actual reputation to boot) and I enjoyed reading his ideas. I think they are relevant and occupy a gap between physics and biology that needs more monism. It's a gap I certainly don't see a lot of light in - and like I said the (you et al) ideas of NPRF and neutral monism (axioms and results) are tantalizing new terms/clarifications in the context of this questioning (for me anyway).

https://en.wikipedia.org/wiki/Energy_rate_density

I will keep reading all this great stuff as time allows. Thank you.
 
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  • #111
Putting SR aside for a moment, if we consider what could be "incomplete" about QM, there is one obvious candidate: the proposal in 1952 by David Bohm that the initial positions of the particles of an experiment be considered part of the definition of the experiment.

What evolves from this proposal is a clear understanding that the Schrödinger equation describes completely the geometry of the experiment and how that geometry affects particle trajectories (or spin directions or photon polarization).

But this equation, the wave function, is a limited view, one that spawned the 1927 Bohr Interpretation that is still accepted today that enshrines several aspects of the tiny regime to mystery in the form of axioms: the Born Rule, duality between particle and wave, superposition of particles, the indeterminacy of particle trajectories prior to measurement, and the collapse of the wave function, at least.

We obtain a "completing" of QM by simply including the initial positions of the particles. This, plus the idea that the Schrödinger equation be treated as the primary force on the particles, yields deterministic trajectories for particles through the double-slit experiment and similar simplicity for other QM effects.

John Bell did more than just show that local "hidden-variables" theories are wrong, he showed that the Bohm nonlocal "hidden-variables" theory is right, and Bell supported Bohm as a result. What are these non-local "hidden variables"? Nothing more than simply the initial positions of the particles, as Bohm has been unique in stating.

Further confirmation of Bohm's interpretation of QM has come in the form of experiments that demonstrate the actual trajectories of individual particles between the single slit they go through to the screen. While the trajectories of an ensemble of particles are deterministic, the pattern they produce on the screen is the familiar "wave interference" pattern, which is so tempting to interpret as due to wave interference, when both slits are open, and the bar pattern when the unused slit is closed. What has changed by closing the slit? Just the wave function, which describes the experimental configuration. True, this is not classical physics and is false to our common sense, but remember that this is the regime of the very tiny, and things work differently due to its simplicity.

I think Einstein would have found Bohm's interpretation refreshing and in the spirit of a "completion" of QM, because it finally gives a deterministic basis in which a probability distribution is the emergent or computed result (rather than a mysterious axiom), just as the Maxwell-Boltzmann analysis based on molecular motion gives the temperature of a black body radiator as a probabilistic result, rather than as an experimental mystery.
 
  • #112
@RUTA

I do sort of buy a little the problem of Bourne’s critique. The argument that “we need to be able to discuss real events” is in a sense claiming a privilege of observation.

i agree we do but still, feels like “saying simultaneity is subjectively or even objectively indefinite” would be not wrong.

not sure that would cause a problem for your BU or help make the case.

But then maybe one could argue that it can’t be if it is definite for at least one observer.

lord this is painful logic.
 
  • #113
David Spector said:
Putting SR aside for a moment, if we consider what could be "incomplete" about QM, there is one obvious candidate: the proposal in 1952 by David Bohm that the initial positions of the particles of an experiment be considered part of the definition of the experiment.

I think Einstein would have found Bohm's interpretation refreshing and in the spirit of a "completion" of QM, because it finally gives a deterministic basis in which a probability distribution is the emergent or computed result (rather than a mysterious axiom), just as the Maxwell-Boltzmann analysis based on molecular motion gives the temperature of a black body radiator as a probabilistic result, rather than as an experimental mystery.

The problem with Bohm is the use of a preferred frame. This looks a lot like the situation Einstein found himself in (quote from forthcoming in Am. J. Phys. by Moylan):
The point is that at the end of the nineteenth century, physics was in a terrible state of confusion. Maxwell's equations were not preserved under the Galilean transformations and most of the Maxwellian physicists of the time were ready to abandon the relativity of motion principle [3], [4]. They adopted a distinguished frame of reference which was the rest frame of the ``luminiferous aether,'' the medium in which electromagnetic waves propagate and in which Maxwell's equations and the Lorentz force law have their usual forms. In effect they were ready to uproot Copernicus and reinstate a new form of geocentricism.
Even "Einstein was willing to sacrifice the greatest success of 19th century physics, Maxwell’s theory, seeking to replace it by one conforming to an emission theory of light, as the classical, Galilean kinematics demanded" before realizing that such an emission theory would not work (J. Norton, “Einstein’s Special Theory of Relativity and the Problems in the Electrodynamics ofMoving Bodies that Led him to it,” https://www.pitt.edu/~jdnorton/papers/companion.pdf). So, now that we know QM follows from the relativity principle applied to Planck's constant h, just like SR follows from the relativity applied to the speed of light c, (https://arxiv.org/abs/2106.12043), I have to believe Einstein would again defer to relativity principle :-)
 
  • #114
I am not aware that Bohmian Mechanics specifies a preferred intertial frame, the Ether. If you could provide a citation for this fact, especially in Bohm's 1952 paper, I would be very grateful. None of the rest of your comments appears to have any relationship to what I actually wrote. Quantum mechanics itself, to the best of my knowledge, does not "follow" from the existence of Planck's Constant, although it certainly makes use of it in the Schrödinger equation, which is the heart of QM. QM mostly "follows" the strange results seen in experiments involving the very tiny regime of electrons, photons, and even molecules. I do agree fully that SR follows from the constancy of c in all inertial frames.
 
  • #115
David Spector said:
I am not aware that Bohmian Mechanics specifies a preferred intertial frame, the Ether. If you could provide a citation for this fact, especially in Bohm's 1952 paper, I would be very grateful. None of the rest of your comments appears to have any relationship to what I actually wrote. Quantum mechanics itself, to the best of my knowledge, does not "follow" from the existence of Planck's Constant, although it certainly makes use of it in the Schrödinger equation, which is the heart of QM. QM mostly "follows" the strange results seen in experiments involving the very tiny regime of electrons, photons, and even molecules. I do agree fully that SR follows from the constancy of c in all inertial frames.
dBB is non-local, i.e., it uses a faster-than-light causal mechanism (pilot wave). Thus, if you use dBB to explain Bell-inequality-violating QM correlations, you must pick a preferred frame to maintain definite causal ordering. It has nothing to do with the aether. This is a very common complaint against dBB, you can find it addressed in virtually every paper dealing with the dBB interpretation.
 
  • #116
Thank you kindly for your clarification. I'm afraid I don't see the need for faster-than-light causal mechanisms in nonlocal pilot waves, as in it particle trajectories are deterministic, and which Bell supported, according to Making Sense of Quantum Mechanics, Jean Bricmont, Springer, 2016.

If such complaints are indeed common, perhaps you could be so kind as to throw just one citation my way. You would clearly be more likely to find one than I, since you know them to be common, but I don't (I'm not a professional physicist).

I would be grateful to see a criticism of Bohm's 1952 proposal that actually has some merit. Recall that all of physics turned against him, along with his former friend Robert Oppenheimer, when Joseph McCarthy found out that Bohm had briefly been a member of the Communist Party. In my opinion, political issues should not be mixed with physics.
 
  • #117
David Spector said:
Thank you kindly for your clarification. I'm afraid I don't see the need for faster-than-light causal mechanisms in nonlocal pilot waves, as in it particle trajectories are deterministic, and which Bell supported, according to Making Sense of Quantum Mechanics, Jean Bricmont, Springer, 2016.

If such complaints are indeed common, perhaps you could be so kind as to throw just one citation my way. You would clearly be more likely to find one than I, since you know them to be common, but I don't (I'm not a professional physicist).

I would be grateful to see a criticism of Bohm's 1952 proposal that actually has some merit. Recall that all of physics turned against him, along with his former friend Robert Oppenheimer, when Joseph McCarthy found out that Bohm had briefly been a member of the Communist Party. In my opinion, political issues should not be mixed with physics.
There are lots of references for the non-locality given in the Wiki article https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory
 
  • #118
I have read this Wikipedia article, and it is surprisingly accurate: "The theory's explicit non-locality resolves the 'measurement problem', which is conventionally delegated to the topic of interpretations of quantum mechanics in the Copenhagen interpretation."

This supports my point of view, as I have expressed it here. The Copenhagen Interpretation says that we can say nothing until a measurement has occurred, and that measurement involves the "collapse" of the wave function, so that it no longer applies. The Copenhagen Interpretation enshrines ignorance in the name of physics by basing QM on a set of axioms that cannot be further understood. This is nonsense. To understand Nature, all of our assumptions must be investigated and eventually explained. Physics is a body of knowledge that works to describe existing and future experiments and observations. The Standard Interpretation of QM opposes this definition of physics. All that survives the terrible impact of the Standard Interpretation are the highly precise predictions of QM itself.

"De Broglie–Bohm theory was widely deemed unacceptable by mainstream theorists, mostly because of its explicit non-locality. Bell's theorem (1964) was inspired by Bell's discovery of Bohm's work; he wondered whether the theory's obvious nonlocality could be eliminated."

Bell's conclusion, based on the marvelous probabilistic thought experiment called "Bell's Inequality," was thst local "hidden variables" theories were incorrect, but that nonlocal "hidden variables" such as in Bohmian Mechanics worked fine. Bell explicitly wrote in support of Bohm's interpretation, as expressed in Bohm's very readable paper of 1952, A Suggested Interpretation of the Quantum Theory in Terms of "Hidden" Variables.

I agree that nonlocal influence, even happening at the speed of light in a vacuum or slower, is counter to our commonsense physics, based on our senses operating in our standard regime. But so what? Physics is not restricted to the standard regime, and much of our interest in physics explicitly concerns fundamental particles, whose size is tiny. If you are rejecting the very basis of quantum mechanics, nonlocality, I'm afraid I must disagree with you.

In the double-slit experiment, a single photon traveling through a slit appears to be affected by a separate slit, through which it does not travel. Any interpretation must explain this apparent nonlocal mystery of Nature. The Standard Interpretation waves its hands and talks nonsense about how a particle can behave as a wave. Bohmian Mechanics does away with such nonsense.

There is a widespread bias against Bohmian mechanics, and it is usually based on ignorance and doubt. I hope you have thought deeply about the physics and are not merely expressing an unexamined belief.
 
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  • #119
David Spector said:
In the double-slit experiment, a single photon traveling through a slit appears to be affected by a separate slit, through which it does not travel. Any interpretation must explain this apparent nonlocal mystery of Nature. The Standard Interpretation waves its hands and talks nonsense about how a particle can behave as a wave. Bohmian Mechanics does away with such nonsense.

There is a widespread bias against Bohmian mechanics, and it is usually based on ignorance and doubt. I hope you have thought deeply about the physics and are not merely expressing an unexamined belief.
In order to provide a "constructive" account of QM (as required for a proper "interpretation"), one will have to give up something cherished. That's what all the no-go theorems tell us. Since I love special relativity (I got my PhD in general relativity) and SR also lacks any constructive account, I have recently decided that I can live without a constructive account of QM as long as I can find a "principle" account of it as compelling as that for SR (relativity principle and light postulate). And, I have done so (explained in this Insight and others referenced therein). Indeed, this principle account of QM uses the same relativity principle applied to a different constant of Nature, h ("Planck postulate"). I'm content with that :-)
 
  • #120
I am certainly happy that you are content to find an explanation of QM that satisfies you. However, gently, I will point out to you that in this lengthy discussion you have not been able to present a clear explanation of how allowing h to be variable solves any problem in understanding QM, whereas I have explained clearly how simply accepting nonlocality (and the initial positions of particles) does indeed solve the basic mysteries that are encapsulated as postulates by the flawed Copenhagen Interpretation, about which you have not even said whether you accept it or not. If physics is going to really explain how Nature works, it must be clear and understandable, not just the "hit-and-run" game of stating a nonobvious principle and then running away. If you are playing a game with me, Ruta, I do not like it much.
 
  • #121
David Spector said:
I am certainly happy that you are content to find an explanation of QM that satisfies you. However, gently, I will point out to you that in this lengthy discussion you have not been able to present a clear explanation of how allowing h to be variable solves any problem in understanding QM, ... If physics is going to really explain how Nature works, it must be clear and understandable, not just the "hit-and-run" game of stating a nonobvious principle and then running away. If you are playing a game with me, Ruta, I do not like it much.
The relativity principle applied to the measurement of the speed of light c constitute the postulates of SR. As of now, 116 years after the publication of SR, we have nothing else to explain time dilation, length contraction, and the relativity of simultaneity. The relativity principle is not considered "nonobvious" in physics. On the contrary, it has been widely accepted since Galileo. What we showed in our publications (reviewed in this Insight) is that you can recover all of denumerable-dimensional QM with the very same relativity principle applied to the measurement of another fundamental constant of Nature, Planck's constant h. If you believe this principle account of QM lacks explanatory value, then you must also believe the postulates of SR lack explanatory value. You wouldn't be alone in that belief, but the vast majority of physicists disagree and all introductory physics textbooks introduce SR via its postulates.
 
  • #122
We are getting nowhere. I certainly agree with the standard derivation of SR from the constancy of the speed of light in a vacuum. Please give me a reference for what you are talking about so I can educate myself, since obviously you refuse to discuss Bohmian Mechanics.
 
  • #123
David Spector said:
We are getting nowhere. I certainly agree with the standard derivation of SR from the constancy of the speed of light in a vacuum. Please give me a reference for what you are talking about so I can educate myself, since obviously you refuse to discuss Bohmian Mechanics.
My Insight has nothing to do with the dBB interpretation nor have I ever published anything to do with dBB, so I don't know why you expected me to engage in a discussion of dBB. If you want to see how the relativity principle + h underwrites QM just as the relativity principle + c underwrites SR, see https://arxiv.org/abs/2106.12043 written for physics educators. It references our relevant publications if you're interested.
 
  • #124
David Spector said:
We are getting nowhere. I certainly agree with the standard derivation of SR from the constancy of the speed of light in a vacuum. Please give me a reference for what you are talking about so I can educate myself, since obviously you refuse to discuss Bohmian Mechanics.
This article https://arxiv.org/pdf/2107.02089.pdf was just posted on another thread I've been following. You might be interested in reading Section 5.1 "De Broglie-Bohm theory"
 
  • #125
RUTA said:
All this is covered in our book, as you'll see. Chapters 7 & 8 cover the reconciliation of our dynamical experience of time with adynamical or block universe physics.
What is the name of the book again RUTA?

EDIT: Is this it - 'Beyond the Dynamical Universe: Unifying Block Universe Physics and Time as Experienced'?
 
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  • #126
Lynch101 said:
What is the name of the book again RUTA?

EDIT: Is this it - 'Beyond the Dynamical Universe: Unifying Block Universe Physics and Time as Experienced'?
Yes that’s it
 
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  • #127
I've been reading Part 3 of the book and it is very interesting indeed. I would love to explore the ideas further and check to make sure I have understood them. Is this thread the right place for that discussion, or would it be advisable to start a new one?
 
  • #128
Lynch101 said:
I've been reading Part 3 of the book and it is very interesting indeed. I would love to explore the ideas further and check to make sure I have understood them. Is this thread the right place for that discussion, or would it be advisable to start a new one?
In a private conversation is best :-)
 
  • #129
Ch 4 fig 4.20 re K. I want to get this question down because it seems clear re that diagram.

In RBW where “all contextual levels” interact… I buy the “boundary of a boundary is zero” math but I am struggling to imagine a single boundary that is really zero (an experiment with any real “spacetime source elements”) given the second law. You can artificially create one but only at the expense of displacing crucial entropy increasing interaction to some other level or boundary.
So for any real spacetime source element that boundary has be drawn such that entropy doesn’t cancel.

What I mean, is… isn’t that a cube with a temperature or entropy equivalent to “1 bit” or something like that. If it is real doesn’t it have to a spacetime “cost” vis a vis the AGC.
 
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  • #130
Jimster41 said:
Ch 4 fig 4.20 re K. I want to get this question down because it seems clear re that diagram.

In RBW where “all contextual levels” interact… I buy the “boundary of a boundary is zero” math but I am struggling to imagine a single boundary that is really zero (an experiment with any real “spacetime source elements”) given the second law. You can artificially create one but only at the expense of displacing crucial entropy increasing interaction to some other level or boundary.
So for any real spacetime source element that boundary has be drawn such that entropy doesn’t cancel.

What I mean, is… isn’t that a cube with a temperature or entropy equivalent to “1 bit” or something like that. If it is real doesn’t it have to a spacetime “cost” vis a vis the AGC.
I don’t think of a spacetimesource element as “real”. It just represents the relational nature of quantum exchanges of energy-momentum.
 
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  • #131
RUTA said:
I don’t think of a spacetimesource element as “real”. It just represents the relational nature of quantum exchanges of energy-momentum.
I got excited by all the talk about ontological contextual emergence. Re-reading clarified that you consider spacetime source elements as psi-epistemic and what is real are classical events. Is that correct? I also saw a line where you seemed to leave open that what is considered a “classical event” might be over-constrained. I will have to look for that quote.
(One lame thing about an e-book is you can’t mark up the margins etc. I would have marked that one)

I am still confused about how an entity can be psi-epistemic and ontological but maybe I finally start to understand the nuance of those terms.

and I am still curious where the Second Law fits in, if at all I guess, in the fundamental relational exchanges and the relative realism of the diachronic experience.

It also occurred to me while reading the chapter on emergence that non-linearity is a big feature of emergent phenomena (at least what I have read about them). And non-linear math is… not an easy or particularly useful place to start building the idea of math. So it’s not surprising human beings started with smooth differential manifolds, symmetry rules etc.
 
  • #132
Jimster41 said:
I got excited by all the talk about ontological contextual emergence. Re-reading clarified that you consider spacetime source elements as psi-epistemic and what is real are classical events. Is that correct? I also saw a line where you seemed to leave open that what is considered a “classical event” might be over-constrained. I will have to look for that quote.
(One lame thing about an e-book is you can’t mark up the margins etc. I would have marked that one)

I am still confused about how an entity can be psi-epistemic and ontological but maybe I finally start to understand the nuance of those terms.

and I am still curious where the Second Law fits in, if at all I guess, in the fundamental relational exchanges and the relative realism of the diachronic experience.

It also occurred to me while reading the chapter on emergence that non-linearity is a big feature of emergent phenomena (at least what I have read about them). And non-linear math is… not an easy or particularly useful place to start building the idea of math. So it’s not surprising human beings started with smooth differential manifolds, symmetry rules etc.
See Section 3.2.1 of this paper: https://www.mdpi.com/1099-4300/22/5/551/htm for the role of Newton's 2nd law. That's not in the book.
 
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