In other TH-cam videos, Tim has described the situation in trying to understand quantum mechanics (QM) as a “morass.” There are many ways to understand QM in the foundations community, but most are constructive, so they violate locality (e.g., Bohmian mechanics) or statistical independence (e.g., superdeterminism or retrocausality) or intersubjective agreement (e.g., QBism) or the uniqueness of experimental outcomes (e.g., Many-Worlds). This situation with constructive approaches to understanding the Hilbert space formalism of QM is much like that in the late 19th century concerning constructive approaches to understanding the Lorentz transformations (e.g., the luminiferous ether). In that situation, Einstein wrote: “By and by I despaired of the possibility of discovering the true laws by means of constructive efforts based on known facts. The longer and the more despairingly I tried, the more I came to the conviction that only the discovery of a universal formal principle could lead us to assured results.” Thus, he formulated special relativity (SR) as a “principle theory,” i.e., a theory whose formalism is derived from an empirically discovered fact. That is, since c is a constant of Nature according to Maxwell's electromagnetism, the relativity principle says c must be the same in all inertial reference frames. And, since inertial reference frames are related by uniform relative motions (boosts), the relativity principle tells us the light postulate must obtain. So, SR is a principle theory because its kinematics (Lorentz transformations) follows from an empirically discovered fact (the light postulate). And, importantly, the light postulate is justified by the relativity principle (“no preferred reference frame,” NPRF). Today, this understanding of the Lorentz transformations is so widely accepted that it appears in our introductory physics textbooks (e.g., Knight, 2022, Serway & Jewitt, 2019) and “constructive efforts” to explain the light postulate are virtually nonexistent, so physicists must find NPRF to be compelling. As we explain in Chapter 1 of our book, “Einstein’s Entanglement: Bell Inequalities, Relativity, and the Qubit” (Oxford UP, 2024), there is a reason that physicists find NPRF so compelling, which brings me back to this talk by Tim. At 7:41 Tim notes that the word “empiricism” is derived from the Greek word for “experience” and he then points out that physics is an empirical science. He concludes that some people may erroneously infer that any empirical science must therefore make reference to observers. His slide says, “Physics would then be tasked with predicting - and therefore presumably explaining - that experience.” But, he points out, that would require physics solve the mind/body problem “which no physics has ever done and no physics has any prospect of doing.” His reasoning stems from a constructive ontological starting point. If one rather assumes that physics is simply a game of reconciling disparate subjective experiences via a single objective model, without first making ontological assumptions (e.g., A. Einstein, “Physics and Reality,” Journal of the Franklin Institute 221(3), 349-382 (1936)), then NPRF is obviously compelling and we can pursue an understanding of the Hilbert space formalism of QM like Einstein did with the Lorentz transformations, i.e., in principle fashion. In that case, it’s perfectly reasonable to talk about “measurement” and “observation” without requiring an ontology for “observers.” We simply leave any underlying ontology (corresponding constructive account) for later study (which, as with SR, may not prove necessary). This avoids the mind/body problem and his worry about needing observers for observers for … . When talking about beables, Tim says they are local so “that we can hope to formulate some notion of local causality.” Bell acknowledged that we might have to give up on the existence of local beables for some quantum phenomena and Tim says, “If that’s the way you want to go, fine, just say it up front and address how you will deal with the problems that arise from doing that.” This is precisely what the axiomatic reconstruction of QM via information-theoretic principles has done and the result is quite surprising. That is, the quantum reconstruction program (QRP) has successfully rendered QM a principle theory by deriving its kinematics (finite-dimensional Hilbert space) from an empirically discovered fact called Information Invariance & Continuity (wording from 2009 by Brukner and Zeilinger). However, there are two reasons this accomplishment has not made QM “look a lot less mysterious.” First, Information Invariance & Continuity is not nearly as physically intuitive as the light postulate. Second, QRP offered no compelling fundamental principle to justify Information Invariance & Continuity, like NPRF does for the light postulate. We solve these two problems in our book by showing that Information Invariance & Continuity means everyone measures the same value for Planck’s constant h, regardless of their relative spatial orientations or locations. Let me call that the “Planck postulate” in analogy with the light postulate. Since h is a constant of Nature per Planck’s radiation law, just like c is a constant of Nature per Maxwell’s equations, and since inertial reference frames are related by spatial rotations and translations as well as boosts, NPRF says the Planck postulate must be true just like it says the light postulate must be true. That means QRP has rendered QM a principle theory, exactly like SR. And, the corresponding principle explanation of the Bell-inequality-violating correlations (Chapter 7) does not require non-local, superdeterministic or retro causal mechanisms, neither does it require violating intersubjective agreement or the uniqueness of experimental outcomes. This is totally analogous to the fact that SR does not require a causal mechanism to explain the light postulate (e.g., length contraction via the luminiferous aether). Thus, this principle account of QM reveals a deep (and surprising) unity between QM and SR, while escaping the morass of the constructive accounts resulting from the constructive bias (e.g., as advocated by Tim in this talk). Of course, SR as a principle theory has no issue with ontology while QM as a principle theory per QRP does. We address that at length in Chapter 9 via what we call "quantum-classical contextuality," which is a form of multiscale contextual emergence (see “Emergence in Context” by Bishop, Silberstein & Pexton (Oxford UP, 2022)). However, an ontology is not needed for QRP's principle account of QM's Bell-inequality-violating correlations, which is as clear as SR's principle account of length contraction via the relativity of simultaneity.
I am not a fan of Dr. Maudlin's dualistic tendencies but, putting that aside, this is overall a great lecture. Carlo Rovelli has written pretty much the same thing in his book _Helgoland_ pointing out that there is no clear _observables_ in MWI. It's hard to even consider MWI a serious interpretation.
@@Al-ji4gd Poor Dr. Ingram is so distraught with quantum mechanics he has not only taken Maudlin's side that there must be something wrong with it, but he has also recently taken to rejecting physical reality entirely, becoming a Kastrupite mystic claiming we all live inside of a "cosmic consciousness."
@@Al-ji4gd Oh we got two Kastrupites in the house. He does indeed claim physics contradicts itself and therefore proves physical reality doesn't even exist. You cannot claim physics doesn't exist and say you don't reject physics. But, you know this, you're a Kastrupist, your entire schtick is to play word games because you cannot defend your mystical ideas otherwise.
Maudlin likes to deflect from the fact that he doesn't understand physics by talking about all kinds of things that have nothing to do with physics in the first place. :-)
In other TH-cam videos, Tim has described the situation in trying to understand quantum mechanics (QM) as a “morass.” There are many ways to understand QM in the foundations community, but most are constructive, so they violate locality (e.g., Bohmian mechanics) or statistical independence (e.g., superdeterminism or retrocausality) or intersubjective agreement (e.g., QBism) or the uniqueness of experimental outcomes (e.g., Many-Worlds).
This situation with constructive approaches to understanding the Hilbert space formalism of QM is much like that in the late 19th century concerning constructive approaches to understanding the Lorentz transformations (e.g., the luminiferous ether). In that situation, Einstein wrote:
“By and by I despaired of the possibility of discovering the true laws by means of constructive efforts based on known facts. The longer and the more despairingly I tried, the more I came to the conviction that only the discovery of a universal formal principle could lead us to assured results.”
Thus, he formulated special relativity (SR) as a “principle theory,” i.e., a theory whose formalism is derived from an empirically discovered fact. That is, since c is a constant of Nature according to Maxwell's electromagnetism, the relativity principle says c must be the same in all inertial reference frames. And, since inertial reference frames are related by uniform relative motions (boosts), the relativity principle tells us the light postulate must obtain. So, SR is a principle theory because its kinematics (Lorentz transformations) follows from an empirically discovered fact (the light postulate). And, importantly, the light postulate is justified by the relativity principle (“no preferred reference frame,” NPRF). Today, this understanding of the Lorentz transformations is so widely accepted that it appears in our introductory physics textbooks (e.g., Knight, 2022, Serway & Jewitt, 2019) and “constructive efforts” to explain the light postulate are virtually nonexistent, so physicists must find NPRF to be compelling.
As we explain in Chapter 1 of our book, “Einstein’s Entanglement: Bell Inequalities, Relativity, and the Qubit” (Oxford UP, 2024), there is a reason that physicists find NPRF so compelling, which brings me back to this talk by Tim.
At 7:41 Tim notes that the word “empiricism” is derived from the Greek word for “experience” and he then points out that physics is an empirical science. He concludes that some people may erroneously infer that any empirical science must therefore make reference to observers. His slide says, “Physics would then be tasked with predicting - and therefore presumably explaining - that experience.” But, he points out, that would require physics solve the mind/body problem “which no physics has ever done and no physics has any prospect of doing.” His reasoning stems from a constructive ontological starting point. If one rather assumes that physics is simply a game of reconciling disparate subjective experiences via a single objective model, without first making ontological assumptions (e.g., A. Einstein, “Physics and Reality,” Journal of the Franklin Institute 221(3), 349-382 (1936)), then NPRF is obviously compelling and we can pursue an understanding of the Hilbert space formalism of QM like Einstein did with the Lorentz transformations, i.e., in principle fashion. In that case, it’s perfectly reasonable to talk about “measurement” and “observation” without requiring an ontology for “observers.” We simply leave any underlying ontology (corresponding constructive account) for later study (which, as with SR, may not prove necessary). This avoids the mind/body problem and his worry about needing observers for observers for … .
When talking about beables, Tim says they are local so “that we can hope to formulate some notion of local causality.” Bell acknowledged that we might have to give up on the existence of local beables for some quantum phenomena and Tim says, “If that’s the way you want to go, fine, just say it up front and address how you will deal with the problems that arise from doing that.” This is precisely what the axiomatic reconstruction of QM via information-theoretic principles has done and the result is quite surprising.
That is, the quantum reconstruction program (QRP) has successfully rendered QM a principle theory by deriving its kinematics (finite-dimensional Hilbert space) from an empirically discovered fact called Information Invariance & Continuity (wording from 2009 by Brukner and Zeilinger). However, there are two reasons this accomplishment has not made QM “look a lot less mysterious.” First, Information Invariance & Continuity is not nearly as physically intuitive as the light postulate. Second, QRP offered no compelling fundamental principle to justify Information Invariance & Continuity, like NPRF does for the light postulate. We solve these two problems in our book by showing that Information Invariance & Continuity means everyone measures the same value for Planck’s constant h, regardless of their relative spatial orientations or locations. Let me call that the “Planck postulate” in analogy with the light postulate. Since h is a constant of Nature per Planck’s radiation law, just like c is a constant of Nature per Maxwell’s equations, and since inertial reference frames are related by spatial rotations and translations as well as boosts, NPRF says the Planck postulate must be true just like it says the light postulate must be true.
That means QRP has rendered QM a principle theory, exactly like SR. And, the corresponding principle explanation of the Bell-inequality-violating correlations (Chapter 7) does not require non-local, superdeterministic or retro causal mechanisms, neither does it require violating intersubjective agreement or the uniqueness of experimental outcomes. This is totally analogous to the fact that SR does not require a causal mechanism to explain the light postulate (e.g., length contraction via the luminiferous aether). Thus, this principle account of QM reveals a deep (and surprising) unity between QM and SR, while escaping the morass of the constructive accounts resulting from the constructive bias (e.g., as advocated by Tim in this talk).
Of course, SR as a principle theory has no issue with ontology while QM as a principle theory per QRP does. We address that at length in Chapter 9 via what we call "quantum-classical contextuality," which is a form of multiscale contextual emergence (see “Emergence in Context” by Bishop, Silberstein & Pexton (Oxford UP, 2022)). However, an ontology is not needed for QRP's principle account of QM's Bell-inequality-violating correlations, which is as clear as SR's principle account of length contraction via the relativity of simultaneity.
I am not a fan of Dr. Maudlin's dualistic tendencies but, putting that aside, this is overall a great lecture. Carlo Rovelli has written pretty much the same thing in his book _Helgoland_ pointing out that there is no clear _observables_ in MWI. It's hard to even consider MWI a serious interpretation.
Dr. Maudlin brings such a delightful "common sense" to it all. The castles of obtuse logic that many thinkers build these days just blow my mind.
Yeah, because Bohmian mechanics is soooo common-sensical....not.
@@Al-ji4gd Poor Dr. Ingram is so distraught with quantum mechanics he has not only taken Maudlin's side that there must be something wrong with it, but he has also recently taken to rejecting physical reality entirely, becoming a Kastrupite mystic claiming we all live inside of a "cosmic consciousness."
@@amihartz I don't ever remember Kastrup rejecting physics outright.
@@Al-ji4gd Oh we got two Kastrupites in the house. He does indeed claim physics contradicts itself and therefore proves physical reality doesn't even exist. You cannot claim physics doesn't exist and say you don't reject physics. But, you know this, you're a Kastrupist, your entire schtick is to play word games because you cannot defend your mystical ideas otherwise.
@@Al-ji4gd Oh we got two Kastrupites in the house.
Wow less than two hours, must be a record for this guy.
Maudlin likes to deflect from the fact that he doesn't understand physics by talking about all kinds of things that have nothing to do with physics in the first place. :-)
You're insulting a philosopher for talking about philosophy... c'mon man.
@@amihartz I am saying that a man hasn't done his homework.