Which quantum interpretation do you favour?
- Bohm2
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Which quantum interpretation do you favour?
A Snapshot of Foundational Attitudes Toward Quantum Mechanics
http://lanl.arxiv.org/pdf/1301.1069.pdf
Another Survey of Foundational Attitudes Towards Quantum Mechanics
http://lanl.arxiv.org/pdf/1303.2719.pdf
Yet Another Snapshot of Foundational Attitudes Toward Quantum Mechanics
http://lanl.arxiv.org/pdf/1306.4646.pdf
Which quantum interpretation do you prefer? What are the reasons that you favour that particular interpretation over others?
- Radar
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Re: Which quantum interpretation do you favour?
I prefer my own. When it comes to interpreting something as ambivalent as QM, one man's interpretation is as good as another's.Bohm2 wrote:A number of these polls have been done with physicists but I was wondering how people more interested in philosophy/philosophy of science would respond. For example:
A Snapshot of Foundational Attitudes Toward Quantum Mechanics
http://lanl.arxiv.org/pdf/1301.1069.pdf
Another Survey of Foundational Attitudes Towards Quantum Mechanics
http://lanl.arxiv.org/pdf/1303.2719.pdf
Yet Another Snapshot of Foundational Attitudes Toward Quantum Mechanics
http://lanl.arxiv.org/pdf/1306.4646.pdf
Which quantum interpretation do you prefer? What are the reasons that you favour that particular interpretation over others?
- Bohm2
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Re: Which quantum interpretation do you favour?
The interpretations may be ambivalent but QM is not. It is, by far, our most successful theory where one finds an 11-decimal place agreement between theory and experiment for some phenomena. Given such accuracy, it would be a miracle if it were not saying something at least approximately true about the world.Radar wrote:I prefer my own. When it comes to interpreting something as ambivalent as QM, one man's interpretation is as good as another's.
- Radar
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Re: Which quantum interpretation do you favour?
I know. That's why it's a large part of my philosophy.Bohm2 wrote:The interpretations may be ambivalent but QM is not. It is, by far, our most successful theory where one finds an 11-decimal place agreement between theory and experiment for some phenomena. Given such accuracy, it would be a miracle if it were not saying something at least approximately true about the world.Radar wrote:I prefer my own. When it comes to interpreting something as ambivalent as QM, one man's interpretation is as good as another's.
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Re: Which quantum interpretation do you favour?
M-theory's multiverse appeals to me because we have consistently been fooled by scale, always believing our "thing" - be it the Earth, the solar system and then the galaxy was all there was. If there are billions of galaxies, then why not billions of universes? Also, the multi-dimensional postulations open up interesting possibilities.
-- Updated 18 Mar 2014, 03:51 to add the following --
Bohm, I'm wondering how a) the recent discovery of the Higgs and 2) the even more recent discovery of quantum gravity by BASIC2 would impact the above postulations.
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Re: Which quantum interpretation do you favour?
I studied physics at Uni and was briefly a physics teacher, but still don't really know which interpretation, if any, I favour. My physics degree is over 20 years old so I suspect that plenty of people who haven't formally studied the subject but who have kept more up to date with recent developments might be better qualified to decide on an answer.
Having said that, the little lecture embedded in this post from some time ago:
onlinephilosophyclub.com/forums/viewtop ... ch#p110699
makes an interesting case for the many worlds interpretation. So I'm going to vote Many Worlds.
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Re: Which quantum interpretation do you favour?
- Bohm2
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Re: Which quantum interpretation do you favour?
A fairly recent paper that is critical of the many worlds interpretation can be found in link below. A theoretical physicist summarizes that paper below in the first quote:Steve3007 wrote:makes an interesting case for the many worlds interpretation. So I'm going to vote Many Worlds.
To define separate worlds of MWI, one needs a preferred basis, which is an old well-known problem of MWI. In modern literature, one often finds the claim that the basis problem is solved by decoherence. What J-M Schwindt points out is that decoherence is not enough. Namely, decoherence solves the basis problem only if it is already known how to split the system into subsystems (typically, the measured system and the environment). But if the state in the Hilbert space is all what exists, then such a split is not unique. Therefore, MWI claiming that state in the Hilbert space is all what exists cannot resolve the basis problem, and thus cannot define separate worlds. Period! One needs some additional structure not present in the states of the Hilbert space themselves. As reasonable possibilities for the additional structure, he mentions observers of the Copenhagen interpretation and particles of the Bohmian interpretation... But whatever the additional structure is, it is no longer pure MWI. It is MWI with an additional structure, which may be fine, but then one cannot use the typical MWI argument that it is the simplest interpretation without an additional structure
Nothing happens in the Universe of the Everett InterpretationThe Many World Interpretation is therefore rather a No World Interpretation (according to the simple factorization), or a Many Many Worlds Interpretation (because each of the arbitrary more complicated factorizations tells a different story about Many Worlds...The state vector of the universe in the EI (Everett Interpretation)has no environment or observer it can relate to, and is therefore completely meaningless. The appearance of interacting subsystems of the universe are only due to a choice of a “samsara” basis, which is however completely arbitrary, just like a slicing of Minkowski spacetime is possible, which makes it look like an expanding universe . One has to add something to give the state vector and QM a meaning.
http://lanl.arxiv.org/pdf/1210.8447.pdf
My own favourite QM interpretation is the deBroglie/Bohmian interpretation, although the necessary non-locality is hard to conceptualize. My major reason for preferring this interpretation is the result of fairly recent Yves Couder walking droplet experiments (a macroscopic pilot wave experimental model) that can reproduce a lot (but not all) of the quantum mechanical stuff at the macroscale including single-particle diffraction, interference, tunneling, quantized orbits, Zeeman effect, etc.
I started a thread on the topic a few years ago in the physics forum:
Wave-particle duality at Macro scale?
http://www.physicsforums.com/showthread.php?t=550729
John Bush at MIT has also done a lot of stuff in this area (check out the videos in link below):
Hydrodynamic quantum analogs
http://math.mit.edu/~bush/?page_id=484
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Re: Which quantum interpretation do you favour?
- Bohm2
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Re: Which quantum interpretation do you favour?
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Re: Which quantum interpretation do you favour?
I am more-or-less a Copenhagenist, though I reject Bohr's insistence on the sharp divide between quantum scale and macro scale, mostly due to the advent of decoherence models. CI keeps QM focused on what it does best, leaving all the ontologizing to philosophy where it belongs. Even so, I think Bohr's Principle of Complementarity is philosophical genius, though I sometimes feel Bohr missed the upshot of his own principle.
I will admit, however, that when I'm in a generous and ontologically-speculative mood, Feynman's sum-over-histories and some of the newer theories based in alternate histories really strike me as on track. I might add that the various alternate-history types of theory are consistent with the character of Bohm's Implicate Order. I prefer these theories to Bohm because they eschew any semblance of trying to ground QM in philosophical realism, which is what I think may have driven Bohm's speculations, and is clearly driving Many Worlds and Cramer's transactional interpretation as well.
- Bohm2
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Re: Which quantum interpretation do you favour?
Inflationary Cosmology as a Probe of Primordial Quantum MechanicsShould inflation be very firmly established, and should it be found that the predictions of quantum theory continue to hold well at all accessible lengthscales during the inflationary era, then this would constitute considerable evidence against the hypothesis of quantum nonequilibrium at the big bang (though of course, nonequilibrium from an earlier era might simply have not survived into the inflationary phase). Furthermore, it would rather undermine the view that quantum theory is merely an effective description of an equilibrium state. In principle, one could still believe that hidden variables exist, and that the hidden variables distribution is restricted to quantum equilibrium even at the shortest distances and earliest times. But in the complete absence of nonequilibrium, the detailed behaviour of the hidden variables (such as the precise form of the trajectories in de Broglie-Bohm theory) would be forever untestable. While exact equilibrium always and everywhere may constitute a logically possible world, from a general scientific point of view it seems unacceptable, and the complete ruling out of quantum nonequilibrium by experiment would suggest that hidden-variables theories should be abandoned. On the other hand, a positive detection of quantum nonequilibrium phenomena in the early universe (or indeed elsewhere) would be of fundamental interest, opening up a new and deeper level of nature to experimental investigation.
http://lanl.arxiv.org/pdf/0805.0163.pdf
I agree that non-locality is hard to envision but it is interesting to note hat no physicist before the advent of relativity interpreted the instantaneous action at a distance of Newton’s gravity as a sign of non-realism. But there are differences between Newtonian action at a distance and quantum non-locality that arguably make it somewhat more radical as it would not also have to be FTL (instantaneous) but would also have to be unattenuated and discriminating as Maudlin notes:
The quantum connection is unattenuated:
The quantum connection is discriminating:Since the gravitational force drops off as the square of the distance it eventually becomes negligible if one is concerned with observable effects...The quantum connection, in contrast, appears to be unaffected by distance. Quantum theory predicts that exactly the same correlations will continue unchanged no matter how far apart the two wings of the experiment are.
As an aside there are a number of prominent physicists (Gisin, for example) who have argued that the observed violations of Bell's inequalities implies that nature is non-local, irrespective of issues of realism, determinism, hidden variables, etc. Maudlin and Norsen have also suggested this:The effects of the sparrow’s fall ripple outward, diminishing as distance increases, jiggling every massive object in its way. Equally massive objects situated the same distance from the sparrow feel identical tugs. Gravitational forces affect similarly situated objects in the same way...The quantum connection, however, is a private arrangement between our two photons. When one is measured its twin is affected, but no other particle in the universe need be...The quantum connection depends on history. Only particles which have interacted with each other in the past seem to retain this power of private communication. No classical force exhibits this kind of exclusivity.
One can divide reasons for disagreement (with Bell’s own interpretation of the significance of his theorem) into two classes. First, there are those who assert that the derivation of a Bell Inequality relies not just on the premise of locality, but on some additional premises as well. The usual suspects here include Realism, Hidden Variables, Determinism, and Counter-Factual-Definiteness. (Note that the items on this list are highly overlapping, and often commentators use them interchangeably.) The idea is then that, since it is only the conjunction of locality with some other premise which is in conflict with experiment, and since locality is so strongly motivated by SR, we should reject the other premise. Hence the widespread reports that Bell’s theorem finally refutes the hidden variables program, the principle of determinism, the philosophical notion of realism, etc.
Local Causality and Completeness: Bell vs. JarrettSince all the crucial aspects of Bell’s formulation of locality are thus meaningful only relative to some candidate theory, it is perhaps puzzling how Bell thought we could say anything about the locally causal character of Nature. Wouldn’t the locality condition only allow us to assess the local character of candidate theories? How then did Bell think we could end up saying something interesting about Nature?...That is precisely the beauty of Bell’s theorem, which shows that no theory respecting the locality condition (no matter what other properties it may or may not have – e.g., hidden variables or only the non-hidden sort, deterministic or stochastic, particles or fields or both or neither, etc.) can agree with the empirically-verified QM predictions for certain types of experiment. That is (and leaving aside the various experimental loopholes), no locally causal theory in Bell’s sense can agree with experiment, can be empirically viable, can be true. Which means the true theory (whatever it might be) necessarily violates Bell’s locality condition. Nature is not locally causal.
http://arxiv.org/pdf/0808.2178v1.pdf
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Re: Which quantum interpretation do you favour?
Observations give the impression of a wave function guiding subatomic particles. None of the attempts to understand the anomalies have explained them. The simple fact that waves require a medium is completely ignored in each and everyone.Bohm2 wrote:Nobody is claiming that this model is QM. But the fact that a macroscopic observable system shows tunnelling across a subsurface barrier (Eddi et al. 2009b), single-particle diffraction in both single- and double-slit geometries (Couder & Fort 2006), quantized orbits analogous to Landau levels in quantum mechanics (Fort et al. 2010), orbital level splitting (Eddi et al. 2012), "pseudo-non-locality", etc. is remarkable, especially since it is consistent with one of the major ontological interpretations of QM; namely, deBroglie's model. By studying such analogues, it may be possible for scientists to gain some insights on QM.
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Re: Which quantum interpretation do you favour?
I imagine that the phrase "the quantum connection" used in your post #12 corresponds to the "quantum potential" of Bohmian mechanics. If so, I'm a little bit puzzled about why you think of Bohm's Implicate Order as nonsense while at the same time you don't seem to have any trouble entertaining the quantum potential, a concept that is equally unscientific. (I assume you accept the quantum potential since it is at the heart of Bohmian mechanics). Since the quantum potential has the characteristics of a field that does not diminish with distance while also being hidden, (offering no empirically unverifiable manifestation in space-time), it strikes me that the Implicate Order is a made-to-order metaphor for the quantum potential, and is rather easy to intuit given that it functions as a hypothetical "subquantum layer" of reality, out of which space-time (the Explicate Order) can be intuited as an emergent property.I think Bohm's stuff on implicate order is nonsense, even though his physics is very clear.
I have long considered that the measurement problem is a chimera, and as such, unsolvable. It is an example of "asking all the wrong questions" given that measurement qua measurement is inherently a macroscopic function and therefore merely a cataloguing of a relationship between a quantum phenomenon and a macroscopic measuring device; a projection foisted upon the quantum scale, not a description of any innate features of quanta. Decoherence provides a picture that is better appreciated from the view of complexity theory, not quantum theory. If he had lived long enough, I think Bohm would have appreciated how complexity theory supports his later writings' musings on Wholeness and the Holomovement.Decoherence, by itself cannot solve the measurement problem.
- Bohm2
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Re: Which quantum interpretation do you favour?
Most Bohmians don't think much of either Bohm's philosophical stuff on implicate order or even his introduction of the 'quantum potential' to explain quantum phenomena. These 'minimalist' Bohmians (like Durr, Goldstein, Zanghi (DGZ) regard configuration space as only a mathematical tool and the wave function as nomological (a law of nature). However, there are problems with treating the wave function as nomological (denoting a law of nature) because, "laws aren’t supposed to be dynamical objects, (as) they aren’t supposed to change with time, but the wave function of a system typically does...(since), we can in (a) sense control the wave function of a system. But we don’t control a law of nature. This makes it a bit difficult to regard the wave function as nomological."A Poster He or I wrote:I imagine that the phrase "the quantum connection" used in your post #12 corresponds to the "quantum potential" of Bohmian mechanics. If so, I'm a little bit puzzled about why you think of Bohm's Implicate Order as nonsense while at the same time you don't seem to have any trouble entertaining the quantum potential, a concept that is equally unscientific.
There are some Bohmians, however, that do seem sympathetic to Bohm's suggestion of "quantum potential" versus the more minimalist Bohmians like Durr, Goldstein, Zanghi (DGZ). They suggest that Bohm's concept of quantum potential may be useful in comparison to the minimalist Bohmian (DGZ) scheme. For example, Belousek writes:
Formalism, Ontology and Methodology in Bohmian MechanicsOn the DGZ view, then, the guidance equation allows for only the prediction of particle trajectories. And while correct numerical prediction via mathematical deduction is constitutive of a good physical explanation, it is not by itself exhaustive thereof, for equations are themselves 'causes' (in some sense) of only their mathematical-logical consequences and not of the phenomena they predict. So we are left with just particles and their trajectories as the basis within the DGZ view of Bohmian mechanics. But, again, are particle trajectories by themselves sufficient to explain quantum phenomena? Or, rather are particle trajectories, considered from the point of view of Bohmian mechanics itself, as much a part of the quantum phenomena that needs to be explained?...the mere existence of those trajectories is by itself insufficient for explanation. For example, to simply specify correctly the motion of a body with a certain mass and distance from the sun in terms of elliptical space-time orbit is not to explain the earth's revolving around the sun but rather to redescribe that state of affairs in a mathematically precise way. What remains to be explained is how it is that the earth revolves around the sun in that way, and within classical mechanics, Newton's law of universal gravitation and second law provide that explanation.
https://www.academia.edu/3474625/Formal ... _Mechanics
This was also discussed on another thread on the physics forum who made a similar point:
Antony Valentini (another supporter of the deBroglie/Bohm interpretation) tries to thread to a middle position in between Bohm's and the minimalist Bohmian position. He accepts reality of configuration space but not Bohm's/Hiley's 'quantum potential'. He disagrees with Goldstein and thinks the wave function is not just nomonological (a law of nature). Valentini suggests that configuration space is "real" (like Albert, it seems) and argues that the quantum wave is a new type of "causal" agent that may take some time for us to understand it, in the same way scientists had difficulties accepting the concept of "fields" when they were first introduced. So he sees an evolution (see slides in video) from forces to fields to this non-local quantum wave (which does not vary with distance and appears to be completely unaffected by matter in between). So in his scheme, the configuration space is always there where the pilot wave (a radically new kind of causal agent that is more abstract than conventional forces or fields in 3-D space) propagates. See video below:There is a very serious and obvious problem with their interpretation; in claiming that the wavefunction is nomological (a law-like entity like the Hamiltonian as you said), and because they want to claim deBB is a fundamentally complete formulation of QM, they also claim that there are no underlying physical fields/variables/mediums in 3-space that the wavefunction is only a mathematical approximation to (unlike in classical mechanics where that is the case with the Hamiltonian or even statistical mechanics where that is the case with the transition probability solution to the N-particle diffusion equation). For these reasons, they either refuse to answer the question of what physical field/variable/entity is causing the physically real particles in the world to move with a velocity field so accurately prescribed by this strictly mathematical wavefunction, or, when pressed on this issue (I have discussed this issue before with DGZ), they simply deny that this question is meaningful. The only possiblity on their view then is that the particles, being the only physically real things in the world (along with their mass and charge properties of course), just somehow spontaneously move on their own in such a way that this law-like wavefunction perfectly prescribes via the guiding equation. This is totally unconvincing, in addition to being quite a bizarre view of physics, in my opinion, and is counter to all the evidence that the equations and dynamics from deBB theory are suggesting, namely that the wavefunction is either a physically real field on its own or is a mathematical approximation to an underlying and physically real sort of field/variable/medium, such as in a stochastic mechanical type of theory.
http://streamer.perimeterinstitute.ca/F ... iewer.html
But there are also problems with Valentini's model as Belousek notes:
This is where I think/hope that insights from Couder quantum analogue experiments may shed some light. I know that Gerhard Groessing has done some work trying to use Couder's stuff to argue that QM emerges from a deeper, more exact theory on a sub-quantum level:Next, Valentini claims that his interpretation of ψ as a ‘guiding field of information’ is “free of complications”. In claiming this, he evidently does not see the irreducibly multi-dimensional character of ψ as a “complication”. This point brings out an internal tension in his guidance view. He wants to interpret ψ (via the pilot wave S) in realistic terms as representing a physically real causal entity, yet he never expressly takes a stand regarding the status of the configuration space in which ψ exists. He introduces further ambiguity by equivocating upon the real physical status of ψ itself. While in one place he takes the view that “The pilot-wave theory is much better regarded in terms of an abstract ‘guiding field’ (pilot-wave) in configuration space...” , in another he states that “The quantum mechanical wave function ψ(x, t) is interpreted as an objectively existing ‘guiding field’ (or pilot-wave wave) in configuration space...”. Is ψ a concrete entity existing in a physically real space or is it only an abstract entity existing in a mathematical space? Valentini does, though, somewhat clarify his view elsewhere by stating that “the pilot wave ψ should be interpreted as a new causal agent, more abstract than forces or ordinary fields. This causal agent is grounded in configuration space...” .
Thus, the pilot wave or ‘guiding field’, while being more abstract than forces or classical fields, in the sense of being further removed conceptually from ordinary experience-the concept of ‘guiding field’ is achieved by abstracting the notion of ‘force’ from the classical concept of ‘field’, is nonetheless an objectively existing causal entity. But, that such an entity is grounded in configuration space implies that configuration space itself must be taken to be physically real in some sense. Whereas Albert takes an unequivocal (though perhaps incoherent) stand on this, Valentini leaves us without a clear idea of in what sense configuration space is to be regarded as physically real. Is configuration space itself the only physical reality? Or are both configuration space and ordinary space physically real? And, if so, are they real in the same physical sense? These questions remain to be answered for any interpretation of Bohmian mechanics that would postulate entities in configuration space.
An explanation of interference effects in the double slit experiment: Classical trajectories plus ballistic diffusion caused by zero-point fluctuations
http://arxiv.org/pdf/1106.5994v3.pdf
The Quantum as an Emergent System
http://arxiv.org/pdf/1205.3393.pdf
And if by 'implicate order' that is what Bohm implying, then fine, but the way he and Hiley wrote about it, in their book was very confusing.
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