Interpretations of Quantum Mechanics (is there a general consensus?)

[StevieTNZ]

Sure, but then realists are likely to ask "information about what" and "whose information"?

Here is a paper by Renato Renner and co, entitled: Completeness of quantum theory implies that wave functions are physical properties

Given the wave function associated with a physical system, quantum theory allows us to compute predictions for the outcomes of any measurement. Since, within quantum theory, a wave function corresponds to an extremal state and is therefore maximally informative, one possible view is that it can be considered an (objective) physical property of the system. However, an alternative view, often motivated by the probabilistic nature of quantum predictions, is that the wave function represents incomplete (subjective) knowledge about some underlying physical properties. Recently, Pusey et al. [arXiv:1111.3328, 2011] showed that the latter, subjective interpretation would contradict certain physically plausible assumptions, in particular that it is possible to prepare multiple systems such that their (possibly hidden) physical properties are uncorrelated. Here we present a novel argument, showing that a subjective interpretation of the wave function can be ruled out as a consequence of the completeness of quantum theory. This allows us to establish that wave functions are physical properties, using only minimal assumptions. Specifically, the (necessary) assumptions are that quantum theory correctly predicts the statistics of measurement outcomes and that measurement settings can (in principle) be chosen freely.

http://arxiv.org/abs/1111.6597

 

[bhobba]

The wave function cannot exist in 3-D space. Predictions of QM depend on the 3N-dimensional space that get lost in the 3-D representation (e.g. information about correlations among different parts of the system, that are experimentally observed are left out). For a philosophical discussion of this see the following thread:

The reality of configuration space
https://www.physicsforums.com/showthread.php?t=554543

Cant follow that one. It can be considered a complex function f(x1,...,xn) - the xi are positions of n particles in ordinary 3d space - it doesn't have to emerge from anything. f gives the probability amplitudes of the particles having those positions. Such functions can be expanded in terms of a infinite but countable basis for theoretical convenience but that does not mean it literally resides in such abstract spaces. If you consider the f real then there is an issue exactly where it resides - it may reside just as a conjecture in some rolled up higher dimensional space that the xi are also in - but 3d space does not have to emerge from anything - its existence is built into the xi.

 

[martinbn]

I am with bohm2 on this one. And I am puzzled about what the meaning of 'real' is to people that say that the wave function is real! Usually it is said that it is real in the same way as the electromagnetic field is, but it is obviously not real in that way. To me real means that there is an object that is in 3D space that intereacts with other objects. Then clearly the wave function is not such a thing. So what does real mean to those poeple?

 

[bhobba]

I am with bohm2 on this one. And I am puzzled about what the meaning of 'real' is to people that say that the wave function is real! Usually it is said that it is real in the same way as the electromagnetic field is, but it is obviously not real in that way. To me real means that there is an object that is in 3D space that intereacts with other objects. Then clearly the wave function is not such a thing. So what does real mean to those poeple?

Real means it has an external existence and not just a calculational device. In saying it is real like an electromagnetic field it is meant it has an external existence. There are all sorts of possibilities of how that can be - here is an interesting one:
http://arxiv.org/pdf/1104.2822v1.pdf

You mentioned Bohm2 - Bohms pilot wave would be something that also had real existence - the theory is a bit vague about exactly what it is.

Thanks
Bill

 

[martinbn]

Real means it has an external existence and not just a calculational device. In saying it is real like an electromagnetic field it is meant it has an external existence. There are all sorts of possibilities of how that can be - here is an interesting one:
http://arxiv.org/pdf/1104.2822v1.pdf

You mentioned Bohm2 - Bohms pilot wave would be something that also had real existence - the theory is a bit vague about exactly what it is.

Thanks
Bill

Yes, the pilot wave would be an example, but my puzzlement remains. How can something have and external existence and its mathematical discription be a function defined on configuration space?! I think that is what bohm2 is saying also.

 

[bhobba]

Yes, the pilot wave would be an example, but my puzzlement remains. How can something have and external existence and its mathematical discription be a function defined on configuration space?! I think that is what bohm2 is saying also.

The same way the Bohm pilot wave, which can also be viewed the same way can:
http://www-physique.u-strasbg.fr/cours/l3/divers/meca_q_hervieux/Articles/Nine_form.pdf
'The quantum potential Q(x1,x2,t) changes instantaneously throughout configuration space whenever the wavefunction changes, and this mechanism is responsible for the nonlocal correlations that are so characteristic of quantum mechanics. A rather natural mechanism prevents human beings from tapping into this instantaneous change for the purpose of faster-than-light communications.'

Interestingly that paper discusses another equivalent formulation of Quantum mechanics, the Second Quantization Formulation, usually associated with QFT, but can also be a formulation for bog standard QM, which can be viewed as a field of creation and annihilation operators at all points of space.

Thanks
Bill

 

[Ken G]

Sure, but then realists are likely to ask "information about what" and "whose information"?

"Whose" information is easy-- ours. Information about what? That isn't something that physics ever tells us, any more than it tells us if there is a big guy with a beard above the clouds.

 

[Ken G]

Here is a paper by Renato Renner and co, entitled: Completeness of quantum theory implies that wave functions are physical properties

And look at what goes into their argument: "...a wave function corresponds to an extremal state and is therefore maximally informative" (my bold), and "Specifically, the (necessary) assumptions are that quantum theory correctly predicts the statistics of measurement outcomes and that measurement settings can (in principle) be chosen freely." All these statements about information, they prove only things about the nature of that information. Where does that add up to reality? Completeness of information means that it isn't information any more? And just what is "complete" information? Does the wavefunction tell us what an electron is, or what its charge or mass are, or why it obeys quantum mechanics? Does it even tell us the outcome of an individual trial? Whatever they mean by "complete", it is a purely information-related definition, and statistically so.

 

[bohm2]

"Whose" information is easy-- ours. Information about what? That isn't something that physics ever tells us, any more than it tells us if there is a big guy with a beard above the clouds.

So electrons and gravity are on par with the big guy with the beard above the clouds?

 

[Ken G]

So electrons and gravity are on par with the big guy with the beard above the clouds?

In regard to the aspect you mentioned, yes. The concepts of electrons and gravity are much more predictively useful, which is why they are physics and not religion. But that isn't what I was talking about, because predictive power is all about manipulating information. You asked what the information was information about, and that's the part that is perfectly on a par with the "big guy", expressly because there is no experiment that tells us anything about the answer to your question. Think of it this way. If you have a conversation with someone, you have no idea what is on the "other end" of that conversation outside of how it acts in the conversation, except that in that particular case you can put a "mini me" over there, and assume that what their mind is like is a lot like yours. That's exactly what you cannot do with electrons and gravity. I believe this is just what Wittgenstein meant when he famously quipped, "if a lion could talk we wouldn't understand it."

 

[bohm2]

You asked what the information was information about, and that's the part that is perfectly on a par with the "big guy", expressly because there is no experiment that tells us anything about the answer to your question.

I'm still confused here. I understand the difference between what some candidate model/theory posits as being "real" versus what is actually "real" (mind-independent reality). But irrespective of these issues, our theories/models/experiments must be about something? Doesn't information require something to be informed? The mathematical entities must represent something that there is in the world.

 

[Ken G]

But irrespective of these issues, our theories/models/experiments must be about something?

Presumably, but the issue is not what they are about, it is what we can say (using physics) about what they are about. But what we can say is exactly the same thing as the information we have-- there's just no distinction there. Not in physics, anyway, philosophy is more free to speculate.

Doesn't information require something to be informed?

Certainly-- us. We are the thing that is informed.

The mathematical entities must represent something that there is in the world.

Yet the representation is what we use in physics. One can say that experiments are done on the real world, but what the physicist manipulates to interpret, understand, and predict those observations is entirely information. Nothing else, certainly nothing in the real world. Indeed I would say this is the entire purpose of physics-- to replace the real world with useful representations (whether those representations be pointer readings, for the observer, or mathematical expressions, for the theorist). That is how we bring reality into our minds where we can do something with it.

 

[bohm2]

Certainly-- us. We are the thing that is informed.

Consider this example from molecular biology:

...in modern molecular biology, it is assumed that the DNA molecule constitutes a code (i.e. a language), and that the RNA molecules 'read' this code, and are thus in effect 'informed' as to what kind of proteins they are to make. The form of the DNA molecule thus enters into the general energy and activity of the cell. At any given moment, most of the form is inactive, as only certain parts of it are being 'read' by the RNA, according to the stage of growth and the circumstances of the cell. Here, we have a case in which the notion of active information does not depend on anything constructed by human beings.This shows that the idea of active information is not restricted to a human context, and suggests that such information may apply quite generally.

How would you describe this using your scheme? Why can't this scheme also apply in the case of sub-atomic entities as suggested by some like Hiley, Bohm, etc:

From the Heisenberg Picture to Bohm: a New Perspective on Active Information and its relation to Shannon Information.
http://www.bbk.ac.uk/tpru/BasilHiley/Vexjo2001W.pdf

Active Information and Teleportation.
http://www.bbk.ac.uk/tpru/BasilHiley/ActInfoTeleWein.pdf

 

[bhobba]

I'm still confused here. I understand the difference between what some candidate model/theory posits as being "real" versus what is actually "real" (mind-independent reality). But irrespective of these issues, our theories/models/experiments must be about something? Doesn't information require something to be informed? The mathematical entities must represent something that there is in the world.

Think of a possibly loaded dice. How it behaves is described by 6 non negative numbers that add up to one called a state vector. It doesn't represent something out there but rather a codification of the complex behavior of the dice.

The same with QM - its state vector may not represent something out there but may simply be the codification of experimentally observed behavior.

If you want a discussion of the issues involved here I suggest Chapter 9 of Ballentine QM - A Modern Development.

This view was the view of Einstein and the real crux of the Einstein-Bohr debates not the kiddy version the popular press portrays. Einstein did not believe QM was incorrect - merely incomplete - what he disliked about the Copenhagen interpretation was its view that QM was a complete theory. The view of the state vector of QM being like the state vector of probability theory suggests like when you toss a dice other factors are at work and the fact you have to resort to probabilities suggests there MAY be more to it than the Copenhagen interpretation would have you believe - we just don't know what they are yet. Note the use of the word MAY - nature may be like that at its fundamental level and there is nothing deeper - who knows.

Thanks
Bill

 

[bohm2]

Think of a possibly loaded dice. How it behaves is described by 6 non negative numbers that add up to one called a state vector. It doesn't represent something out there but rather a codification of the complex behavior of the dice.

I'm not suggesting anything like this or suggest that Einstein's view was correct. There are 3 major positions with respect to wave function ontology:

1. Wavefunctions are epistemic and there is some underlying ontic state. Quantum mechanics is the statistical theory of these ontic states in analogy with Liouville mechanics. (The scientific realism of Einstein, Rob Spekkens, Matt Leifer, etc.)

2. Wavefunctions are epistemic, but there is no deeper underlying reality. (Anti-realism-Bohr)

3. Wavefunctions are ontic (there may also be additional ontic degrees of freedom, which is an important distinction but not relevant to the present discussion). This includes: the scientific realism of Everett/many-worlds interpretation, de Broglie-Bohm theory, and spontaneous collapse models.

I'm really arguing for position 3. Ken G seems to be arguing for position 2.

This scheme comes from this site:

Can the quantum state be interpreted statistically?
http://mattleifer.info/2011/11/20/can-the-quantum-state-be-interpreted-statistically/

While there is still some debate, it seems option 1. above has been recently ruled out via the PBR paper.

 

[bhobba]

You forgot one - the Ensemble interpretation, which I hold to, which Balentine in his well respected textbook adheres to, which Einstein adhered to, which a lot of other physicists like Lubos Motol adhere to (in fact he is very critical of that link you posted - I don't agree with him on that - but he knows his stuff). I do not agree the link you gave disproves the statistical interpretation - I do not agree with Lubos who thinks its a load of rubbish, but I do not agree it disproves anything.

Wavefunctions are epistemic and there is some underlying ontic state[/I]. Quantum mechanics is the statistical theory of these ontic states in analogy with Liouville mechanics. (The scientific realism of Einstein, Rob Spekkens, Matt Leifer, etc.)

Ontic (from the Greek ὄν, genitive ὄντος: "of that which is") is physical, real or factual existence.

No mate - that is most definitely not the statistical interpretation - its more along the lines of Nelsons Stochastic interpretation. The statistical interpretation doesn't ascribe any status to a quantum state any more than probability theory ascribes an 'ontic' existence to a probability vector.

Wavefunctions are epistemic, but there is no deeper underlying reality[/I]. (Anti-realism-Bohr)

I am not a philosophy type dude but I think that is the ensemble interpretation and not Copenhagen which takes the quantum state as fundamental and not merely as a useful device to calculate probabilities. Anyway here is a definition of it:
'The attempt to conceive the quantum-theoretical description as the complete description of the individual systems leads to unnatural theoretical interpretations, which become immediately unnecessary if one accepts the interpretation that the description refers to ensembles of systems and not to individual systems.'

And here is a link about it just to make sure we are on the same page:
http://www.kevinaylward.co.uk/qm/index.html

By the way previous discussions I have had with Ken makes me think he holds to something similar to the Ensemble intterpretation - but I could be wrong.

Thanks
Bill

 

[Ken G]

Consider this example from molecular biology: "... At any given moment, most of the form is inactive, as only certain parts of it are being 'read' by the RNA, according to the stage of growth and the circumstances of the cell. Here, we have a case in which the notion of active information does not depend on anything constructed by human beings. This shows that the idea of active information is not restricted to a human context, and suggests that such information may apply quite generally." How would you describe this using your scheme?

I would say they are quite mistaken. Notice how they have anthropomorphized the DNA and RNA! So of course there is a human there-- it is the human who wrote that anthropomorphism, who made sense of those words by applying the concept of information the way we do. They did just exactly what I meant about putting a "mini me" at the other end of the phone conversation to try and understand whatever is on the other end. For electrons and gravity, no one even tries to do that, for RNA molecules, apparently someone does, but it's really not much more than a useful analogy.

The point is, no RNA molecule is "reading" any information, nor "processing" it, that is things that our brain does when it tries to understand whatever the molecule is actually doing. The place where the information is being read is still in our heads-- we are reading the "code", that is how we think, and we are projecting how we think onto the molecules. It certainly has its purposes to do so, but we should not ignore that we are doing it, and make claims that human information processing is not involved when a human imagines a "mini me" looking over the shoulder of the functioning of mindless molecules!

Why can't this scheme also apply in the case of sub-atomic entities as suggested by some like Hiley, Bohm, etc:

We can certainly use that scheme, we do it all the time. We use information, all the time, and we imagine that information in some way "lives" in the physical world, independently of us. That's part of how information works, we ignore our role in it, because our role in it is just the part that we don't understand, having no useful model of ourselves to include in what information is. So we do it, and we benefit from it, but we should not pretend we aren't doing it. There's no need to ignore our role, just because we don't understand our role.

From the Heisenberg Picture to Bohm: a New Perspective on Active Information and its relation to Shannon Information.
http://www.bbk.ac.uk/tpru/BasilHiley/Vexjo2001W.pdf

Active Information and Teleportation.
http://www.bbk.ac.uk/tpru/BasilHiley/ActInfoTeleWein.pdf

I'm sure these are very nice applications of the concept of information, and I'm sure they are written by human intelligences, using information, just the way human intelligences give meaning to that concept.

 

[Ken G]

By the way previous discussions I have had with Ken makes me think he holds to something similar to the Ensemble intterpretation - but I could be wrong.

I can see the appeal in the ensemble interpretation, but my general approach is that there is not much point in holding to anyone interpretation-- interpretations are simply not things we should hold to. Instead, what we should hold to is a clear sense that interpretations are just that-- ways to picture what a theory is saying. We should be able to move between them, to use each like taking a different angle on the same animal. We should not view interpretations as world views-- that's what I object to. Even things like many-worlds I have no problem with if viewed as an interpretation, my issue is when people take that interpretation and argue for the actual existence of the many worlds. That's just not what interpretations are for.

Granted, some of the interpretations seem to go beyond quantum mechanics, or at least they suggest different directions to look for the next theory. That's all well and good, and all the more reason to have multiple interpretations-- it gives us more places to look. Each person might have a favorite interpretation that they like to use, and they might use it to motivate them to look somewhere different for the next theory (if they are into looking for new theories, that's certainly quite a challenge). But if we are talking about new theories, the only way we will adjudicate them is the usual way-- by observation, not by argumentation.

As an example of how similar I view interpretations, I would say that Bohm, ensemble, and Copenhagen are all essentially the same, because they all involve averaging over some set of possibilities when they talk about a wave function. Bohm averages over what we don't know about the initial condition, the ensemble averages over a set of final conditions (without specifying where what we don't know about those systems is entering the question), and Copenhagen averages over what is viewed as unknowable about the system. Put like that, it's clear why the three are all effectively the same, at least until we find some way to figure out where the need for averaging is entering. That's going to be some new theory that isn't quantum mechanics any more, and can only be adjudicated by observation.

 

[bohm2]

I would say they are quite mistaken. Notice how they have anthropomorphized the DNA and RNA! So of course there is a human there-- it is the human who wrote that anthropomorphism, who made sense of those words by applying the concept of information the way we do.

When biologists use the word "read", they don't literally mean "read" as in exactly the same way as we use the term "read" in human context. They mean the process of translation/transcription. A triplet code of a DNA molecule is transcribed into the triplet code of an mRNA molecule, etc. and ultimately translated into proteins. So the genetic code is the set of rules by which information encoded in genetic material (DNA or mRNA sequences) is translated into proteins (amino acid sequences) by living cells.

 

[Ken G]

When biologists use the word "read", they don't literally mean "read" as in exactly the same way as we use the term "read" in human context. They mean the process of translation/transcription.

Of course. My point is that the process of translationg/transcription is a very specific thing, it has nothing to do with "reading" any "information" until we say that it does. All those words make no sense until a human brain is involved-- molecules are just dumb molecules, there's absolutely no "information" there, active or otherwise, until our brains get into the act. This is exactly the point they are missing when they argue that molecules are reading and processing active information, which only makes sense when our brains are also in that sentence-- that is just what we do to understand, predict, characterize, and gain knowledge of, whatever is the mindless process that molecules are actually doing (which has nothing to do with information, and demonstrably so).

So the genetic code is the set of rules by which information encoded in genetic material (DNA or mRNA sequences) is translated into proteins (amino acid sequences) by living cells.

Yes, look at your own words: "code", "rules", and "information." That's all us, not the molecules. When we see order and purpose, it's what we do. That's how we understand things. That's how we use the concept of "information." We use it to great advantage, of course, and it is convenient to enter into a kind of lazy terminology that imagines the "information" is there with or without us, but of course it isn't, that's all just anthropomorphism, because information is all about how we understand things that have no need of understanding themselves. This isn't some fringe philosophy, everything I'm saying is perfectly demonstable-- just try and define information, or how it operates in the real world, without a mind to say what it is.

To claim that we are not involved, it seems perfectly obvious that anthropomorphisms must be explicitly and completely avoided. Are they? Why would someone use blanket anthropomorphisms in the very same sentence as a claim that human intelligence is not involved? Is there another way to say what they mean without the anthropomorphisms? I say no-- "information" is inherently anthropic, and what is so ironic is how totally anthropomorphic is their very argument that it isn't!

 

[bohm2]

I say no-- "information" is inherently anthropic, and what is so ironic is how totally anthropomorphic is their very argument that it isn't!

I'm not an expert on this stuff but there's a whole branch in theoretical biology, etc. I believe that questions whether information is inherently anthropic:

Biological Information
http://plato.stanford.edu/entries/information-biological/

Information in Biological Systems
http://collier.ukzn.ac.za/papers/Information in Biological Systems.pdf

Life and semiosis: The real nature of information and meaning
http://www.degruyter.com/view/j/semi.2006.2006.issue-158/sem.2006.007/sem.2006.007.xml

Information is any type of pattern that influences the formation or transformation of other patterns. In this sense, there is no need for a conscious mind to perceive, much less appreciate, the pattern. Consider, for example, DNA. The sequence of nucleotides is a pattern that influences the formation and development of an organism without any need for a conscious mind.

Information
http://en.wikipedia.org/wiki/Information

 

[bohm2]

You forgot one - the Ensemble interpretation, which I hold to, which Balentine in his well respected textbook adheres to, which Einstein adhered to, which a lot of other physicists like Lubos Motol adhere to (in fact he is very critical of that link you posted - I don't agree with him on that - but he knows his stuff). I do not agree the link you gave disproves the statistical interpretation - I do not agree with Lubos who thinks its a load of rubbish, but I do not agree it disproves anything.

I don't think PBR affects Ballentine's scheme because that model is concerned not with the epistemic probabilities, but with objective ones. This is how I interpreted this paper that just got posted today regarding PBR:

Abstract: Different realistic attitudes towards wavefunctions and quantum states areas old as quantum theory itself. Recently Pusey, Barret and Rudolph (PBR) on the one hand, and Auletta and Tarozzi (AT) on the other, have proposed new interesting arguments in favor of a broad realistic interpretation of quantum mechanics that can be considered the modern heir to some views held by the fathers of quantum theory. In this paper we give a new and detailed presentation of such arguments, propose a new taxonomy of different realistic positions in the foundations of quantum mechanics and assess the scope, within this new taxonomy, of these realistic arguments.

Statistical-Realism versus Wave-Realism in the Foundations of Quantum Mechanics
http://philsci-archive.pitt.edu/902...m_in_the_Foundations_of_Quantum_Mechanics.pdf

 

[bhobba]

I don't think PBR affects Ballentine's scheme because that model is concerned not with the epistemic probabilities, but with objective ones. This is how I interpreted this paper that just got posted today regarding PBR:

Statistical-Realism versus Wave-Realism in the Foundations of Quantum Mechanics
http://philsci-archive.pitt.edu/902...m_in_the_Foundations_of_Quantum_Mechanics.pdf

The Ensemble Interpretation is not a realism based one - the wave-function is simply a device for calculating probabilities and has no existence other than what a theorist uses in calculations. Because of that wave-function collapse is not an issue and solves Schrodinger's Cat with ease - it is no more of a mystery than lifting your hand to observe a tossed coin. It is however an issue for Copenhagen because it considers wave-function collapse real and a result of interaction of a quantum system with the observing apparatus. The link you gave where the person thought Copenhagen was not realism based is incorrect - any interpretation that worries about wave-function collapse is realism based - because if it wasn't real then there is nothing to worry about.

Think about it for a minute - does the six probability numbers that predicts the random behavior of a dice have a real existence? Is it something to worry about when the dice is thrown and that suddenly changes so that one of those six possible outcomes has a one in it? That's basically the Ensemble interpretation - its simply the standard law of large numbers interpretation of probability. You consider a state to be an extremely large number of systems prepared the same but divided into categories with a different measurement outcome - the proportion giving the probability.

I have zero idea what you mean by epistemic and objective probabilities. Probabilities are simply a way of codifying the behavior of systems whose outcome we cannot predict. We notice that when prepared exactly the same while we can not predict individual outcomes the proportion of those outcomes approaches a stable limit as the number of times we prepare the system and observe it increases. It is merely a calculational device. I can't see how you can divide probabilities into objective or epistemic - in fact my understanding of both those terms means probabilities are both. But I know philosophy types can use words in funny sorts of ways different to guys like me whose background is applied math.

I have read your link and disagree with one of its tenants:
'It is maybe worth recalling here the distinction between epistemic probabilities, i.e. probabilities understood as degrees of belief, and objective probabilities, such as relative frequencies. The probability p(λ/P) is an example of the first kind of The term “ontic” was introduced into modern philosophical language by Martin Heidegger, in order to grasp the notion of something before any contact with the knowing subject. Harrigan and Spekkens (2007) refer to λ as the “ontic state”. On a more careful analysis it seems to us that the λ they introduce is a hypothesis of the subject, so we believe the term “ontological” to be more appropriate. probabilities, since it encodes our hypothesis about the properties of a system given a certain preparation method.'

There are a number of philosophical foundations for probability. The ensemble interpretation is the usual one taught to students like me that studies applied math and built around the law of large numbers. There are other ones such as the Kolmogorov axioms (used more by those interested in certain theoretical aspects of probability such as measure theory and rigorous proof of stuff such as the continuity and mathematical existence of Wiener processes) and others still such as the propensity and degrees of belief one the paper mentions. Anyone of them can be used as the basis of the Statistical interpretation - it doesn't make any difference - the ensemble one is used simply for pictorial vividness and resides nowhere except in the theorists mind.

But seeing you find it such an issue, for the purpose of this discussion, I will base the Statistical interpretation instead on the Kolmogorov axioms which are totally abstract.

Thanks
Bill

 

[Ken G]

I'm not an expert on this stuff but there's a whole branch in theoretical biology, etc. I believe that questions whether information is inherently anthropic:
"Information is any type of pattern that influences the formation or transformation of other patterns. In this sense, there is no need for a conscious mind to perceive, much less appreciate, the pattern. Consider, for example, DNA. The sequence of nucleotides is a pattern that influences the formation and development of an organism without any need for a conscious mind."

Yet more anthroporphisms! If what they were claiming really made any sense, don't you think they could argue it without using terms like "patterns" and "influences"? What makes them think there is any such thing as a pattern or an influence without a mind to say those things? Does a dumb molecule care if it has a string of atoms like ABABABAB or AABABBAA? How is one any different from the other if there isn't a brain to imagine that there is a difference there? Dumb molecules don't have patterns by themselves, we might imagine they have locations or wave functions or whatever other ways the human mind has devised to describe them, but it's clear that the pattern is something our brain is doing. And do they really think that a molecule "influences" another molecule, without a human mind to say what that means? These are all models, made by our heads, to great advantage. If someone says that nature really involves "influences", rather than just repeated correlations that we have chosen to notice using our minds, then I would challenge them to tell me what is the definition of an influence. That's all you have to do-- define "pattern" and "influence," and exactly where you have invoked the human mind becomes obvious.

The argument that any of these things exist independently of the human mind is quite naive. It's essentially the same thing as saying that a tree can fall and make noise without a human mind, but what is actually meant is that a tree can fall and make noise without a human mind being present in the forest-- which does not imply that any of those words make the least bit of sense without a human mind to say they do. Those are two very different issues, but it is the latter, not the former, that speaks to the question of what information is.

 

[bohm2]

The link you gave where the person thought Copenhagen was not realism based is incorrect - any interpretation that worries about wave-function collapse is realism based - because if it wasn't real then there is nothing to worry about.

I didn't think there was a necessary relationship between wave function "realism" and wave function collapse. For example, Bohmian, many-minds interpretation, and MWI treat the wavefunction as "real" but none involve collapsing wavefunctions.

The argument that any of these things exist independently of the human mind is quite naive.

In your scheme does "gravity" exist independently of the human mind?

 

[Ken G]

I didn't think there was a necessary relationship between wave function "realism" and wave function collapse. For example, Bohmian, many-minds interpretation, and MWI treat the wavefunction as "real" but none involve collapsing wavefunctions.

I think bhobba's point was that taking the wavefunction seriously is a subset of realism, and wavefunction collapse is a subset of taking the wavefunction seriously, so wavefunction collapse is a subset of realism. If so, then other forms of realism that take the wavefunction seriously but don't refer to collapse are not counterexamples. I think he is making a valid point, although I think you are alluding to the fact that the Bohr vs. Einstein debate is often characterized as non-realism vs. realism (in regard to possible elements of reality that are outside of the wavefunction). I have always seen some irony in that way of painting things-- in my view, Bohr's approach is more "realistic", because it is realistic to recognize that our models of reality are designed to connect reality to our experience, but most people think of "realism" as independent of our experience, which I view as quite unrealistic! To anyone who thinks it makes sense to talk about reality outside of how we perceive and interact with it, I say, "get real."

 

[bhobba]

I didn't think there was a necessary relationship between wave function "realism" and wave function collapse. For example, Bohmian, many-minds interpretation, and MWI treat the wavefunction as "real" but none involve collapsing wavefunctions.

My comment had to do with the link you gave to Mat Leifer
http://mattleifer.info/2011/11/20/can-the-quantum-state-be-interpreted-statistically/

That is generally a good article that explains why the PBR paper doesn't really rule out any of the three alternatives he gives. It was better than Lubos's rant that, as Mat correctly pointed out, missed the point.

But even Mat gets something wrong - that is lumping Copenhagen in category 2 ie Wave-functions are epistemic, but there is no deeper underlying reality.

Copenhagen believes a system evolves according to the Schroedinger equation then every now and then interacts with a measuring apparatus and instantaneously changes to another state - this is the wave-function collapse issue. It is an operational interpretation and the wave function collapse is a real collapse and change of the quantum system bought about by the interaction with the measuring appartus - as an operationally based interpretation you really can't think of the things you are being operational about as not real:
http://en.wikipedia.org/wiki/Wave_function_collapse

The existence of the wave function collapse is required in
the Copenhagen interpretation
the objective collapse interpretations
the transactional interpretation
the von Neumann interpretation in which consciousness causes collapse.

On the other hand, the collapse is considered as a redundant or optional approximation in
the Bohm interpretation
the Ensemble Interpretation
the Many-Worlds Interpretation
interpretations based on Consistent Histories

This is one reason Consistent Histories was introduced as a modern variant of Copenhagen - it is Copenhagen done right some would say - it specifically avoids the issue. My suspicion is Mat really means Consistent Histories and not Copenhagen. I have Griffiths book on Consistent Histories and read it a while ago now, but it might be a good idea for me to give it another read.

Thanks
Bill

 

[Len M]

Does a dumb molecule care if it has a string of atoms like ABABABAB or AABABBAA? How is one any different from the other if there isn't a brain to imagine that there is a difference there? Dumb molecules don't have patterns by themselves, we might imagine they have locations or wave functions or whatever other ways the human mind has devised to describe them, but it's clear that the pattern is something our brain is doing. And do they really think that a molecule "influences" another molecule, without a human mind to say what that means? These are all models, made by our heads, to great advantage. If someone says that nature really involves "influences", rather than just repeated correlations that we have chosen to notice using our minds, then I would challenge them to tell me what is the definition of an influence. That's all you have to do-- define "pattern" and "influence," and exactly where you have invoked the human mind becomes obvious.

I could do with some clarification and maybe some direction here. I get confused by your usage of the term “mind” – I get the impression that you refer to “thought” as being the factor that gives us patterns and thus outside of that thought there are no patterns. Rather like looking at the stars, many people make up constellations, but outside of that thought, there are no constellations, just a random collection of stars in space.

But what if the patterns are subject to “rules” that exist within the construct that is our reality? By a construct I mean a reality that is not produced from the hardware of a dualistic brain, rather mind emerges from “something” that gives us empirical reality. Within that reality brains are the same stuff as external objects, everything is a dualist construct from “something”. So the “hardware” of the rock doesn’t exist without the “hardware” of the senses and the brain. But within that “whole” surely we can then say that “rules” exist without thought. That doesn’t imply the “rules” exist in that cause/effect manner outside of the “whole”, but within the “whole”, they can be thought of as existing without any cognitive action on our part.

Imagine a scenario where by nature outside of the “whole” consists of random irreducible elements not “existing” in space or time. We cannot logically think of an exception to this scenario that involves a brain sitting in a corner taking in all of these elements from “something” and creating “rules” – the brain can only be part of a dualistic construct that emerges from this “something”. That construct consists of “rules” that give rise to mechanisms that allow us to use our brains in apprehending the results of these “rules”. The mechanisms change from sense organ to sense organ, the eyes uses a lens and not a uniform transparent material, the ear uses a diaphragm - these are all mechanisms that requires “rules” of our reality and are independent of cognitive thought. The molecules do not care about their differences, but those differences involve “rules” that are part of our reality and are used in the emergence of the hardware that is us. Those “rules” will be there whether we discern patterns or not.

None of this is to suggest that gravity exists as gravity (to make use of bhom2’s question) outside of the “whole”. Outside of the “whole” from my perspective lay “true” mind independent reality, and it would be a reality that can’t be conceived of in terms of our familiar notions – those notions are only applicable to our “whole”, so gravity or anything else exists in that place. But I make a distinction between cognitive thought and mind. Gravity exists outside of cognitive thought, but outside of mind, matter, space, time (in other words everything that constitutes our reality) gravity doesn’t exist. “Rules” that manifest themselves in terms of lenses, ears etc. do exist outside of cognitive thought but do not exist (at least in any kind familiar cause/effect form operating within space and time) outside of the “whole” (our reality).

I just don’t think that you can easily use the dualism of our reality to imply that cognitive thought gives rise to that dualism (unless one considers that dualisms exists as such within mind independent reality). To my mind it is the construct of dualism that gives us “rules” and those “rules” are independent of any cognitive process that arises from dualism. It is the construct (the “whole”) that comes first and the cognitive thoughts second – existence comes before knowledge.

None of this implies that our senses and brain do not have an effect on what we perceive, but that effect takes place within the construct that is the “whole” and within that “whole” there are rules that manifest themselves in terms of mechanisms that are purposeful and independent of cognitive thoughts. The lens of the eye emerges to aid our survival in accordance with “rules” governing objects to be perceived. The diaphragm of the ear emerges in accordance with different “rules”. There is not a universal sense organ responding to irreducible random elements that our cognitive thoughts organise into perceptions, like the brain in a vat scenario. Within our reality, (our “whole”) there seems to be purposeful things going on according to “rules”. It is those “rules” that constitutes physics and we assign lots of interpretations to those “rules” (and thus I see physics as exploring the rules of our reality but not those of mind independent reality). But fundamentally, those “rules” are surely independent of the interpretations or of any cognitive process that fits the “rules” to our perception of things. There are “rules” that mean if we throw a ball, that same ball will come down. Our cognitive thought process expands and fits those “rules” to differing frameworks, but at the end of the day, that ball falling down is part of a mechanism that exists within our reality (the “whole”) that is independent of any cognitive thought. The ball doesn’t get thrown or fall down outside of our “whole” but the “rules” that manifest themselves in terms of the thrown and falling ball maybe emerge in some unknown form (not in any terms of cause and effect) from outside of the “whole” i.e. outside of mind, intersubjective agreement, space and time. In other words within “true” mind independent reality.

It is almost as if you talk about “cognitive thought independent reality” as a notion where as I take d’Espagnat’s more literal notion of “mind independent reality”. The former seems to me to model our reality as if our brain is in one corner absorbing irreducible random elements from nature and creating phenomena. The latter sees dualism as “real” along with the “rules” that exist within that dualism, but that dualism is itself a construct that cannot be separated into part mind and part object, everything - objects, space, time, us, brains (the hardware) emerges in terms of mind. So whilst we may see patterns in the molecules and label them as this or that, those patterns exist in terms of necessary mechanisms within the “whole” and thus they exist outside of thought, but not outside of the “whole”.

This is a rather lengthy piece, and I am not implying that I see your stance in the manner I describe, but it is a perception I do get. And that perception of mine seems to be a sticking point in trying to distinguish between “thoughts” determining the nature of our reality and “rules” that exist independently of thoughts, but not independently (in any kind of cause/effect manner) of the “whole” (our reality, or empirical reality). In other words, whilst we cannot separate mind from our reality, within our reality there are mechanisms going on that do not seem to be connected with the mind, other than we have the ability to classify and expound on the mechanisms. There seems to me to be inherent mechanisms that gives rise to everything we apprehend which fundametally is "there" independently of that apprehension (though not "there" outside of the dualistic construct that constitutes our reality).

 

[jambaugh]

The existence of the wave function collapse is required in
the Copenhagen interpretation
[...]

Do be clear here. CI invokes wave function collapse but the wave function itself is understood to represent knowledge about the system, not to represent the reality of the system. The wave function collapses "on paper". It is, I believe, many peoples failure to appreciate this point which leads them to object to CI because they feel it reeks of "mind over matter". The wave-function collapse here is rather "matter over mind", we see something happen and update our knowledge. It is not qualitatively distinct from the collapse of a classical probability distribution for a system when we make an observation. (e.g. the collapse of the expectation value for a lotto ticket to $0 when the drawing occurs.)

For a good exposition of CI see Stanford Encyclopedia of Philosophy: Copenhagen Interpretation of Quantum Mechanics.

 

[bhobba]

Do be clear here. CI invokes wave function collapse but the wave function itself is understood to represent knowledge about the system, not to represent the reality of the system. The wave function collapses "on paper". It is, I believe, many peoples failure to appreciate this point which leads them to object to CI because they feel it reeks of "mind over matter". The wave-function collapse here is rather "matter over mind", we see something happen and update our knowledge. It is not qualitatively distinct from the collapse of a classical probability distribution for a system when we make an observation. (e.g. the collapse of the expectation value for a lotto ticket to $0 when the drawing occurs.)

For a good exposition of CI see Stanford Encyclopedia of Philosophy: Copenhagen Interpretation of Quantum Mechanics.

Ok - a question then. According to Copenhagen when the position of a quantum particle is measured prior to that it may not even have the property of position - it is the interaction with the measurement apparatus that gives it the property of position. I can't quite follow how something could not have been said to happen to the quantum particle as a result of the measurement. The Ensemble interpretation says its simply a statistical observation like tossing a dice and is silent on what happens to the particle - but Copenhagen seems to be saying something happened to it caused by interaction with the measurement apparatus.

Thanks
Bill