Quantum Confusion: Philosophical Assumptions Behind Mechanics

[DevilsAvocado]

lol That's one of my favorite MP skits.

Well it’s Christmas time, here you go:

https://www.youtube.com/watch?v=<object width="640" height="385"><param name="movie" value="http://www.youtube.com/v/npjOSLCR2hE&hl=en_US&fs=1&rel=0&color1=0x402061&amp;color2=0x9461ca"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/npjOSLCR2hE&hl=en_US&fs=1&rel=0&color1=0x402061&amp;color2=0x9461ca" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="640" height="385"></embed></object>

 

[yoda jedi]

So, Non-local Realism is alive and kicking as before!

that's true.

 

[yoda jedi]

yes, i basically agree.
tentatively, because who knows, maybe there are definite values, if not, it doesn't matter because we have vagueness or indefiniteness or unsharpness,
...a state of unformed potential (I thought the same thing, in almost identical terms)

.....Quantum mechanical position is typically indeterminate but can, in principle, be measured precisely (i.e., with arbitrary accuracy) and be determinate (to a high degree) immediately after measurement (but with the result that momentum is disturbed
and indefinite, and vice-versa). However, at least one of the two quantities, position and momentum (and typically each of these), is also limited in its determination. In the case of quantum systems, properties can be considered objectively indefinite and sets of propositions regarding them complementary to specific other sets of propositions, so that it becomes impossible to jointly attribute them. Thus, quantum mechanics involves a unique form of vagueness...

.....The novel feature in the description of physical reality brought about with the advent of quantum mechanics is thus the fact that physical properties will not in general be either actual or absent but indefinite or indeterminate.....

...as an element of empirical reality, an actual property has the capacity to act, to actualize an indicative measurement outcome if a measurement is performed. By contrast, when a property is absent it has no capacity to act. We propose the idea of an interpolation between the two extremes of full actuality and absence of a property...

...It is also appropriate to think of an indeterminate property as an element of unsharp reality...

 

[george walton]

I am confused by the philosophical assumptions behind Quantum Mechanics. Are physicists logical positivists? The reason I ask that is because it seems that they believe that if something in intrinsically unknowable it does not exist as a truthful proposition. For example before the collapse what is happening? Suppose, I have an impregnable box ( even logically necessarily impregnable) . I do not know if there is a brick ( particle) or water ( wave) inside. Does that mean that one possibility is not correct and the other is also not correct? I am totally confused! Please help!

Logical positivists embraced two standards of truth: analytic and synthetic.

Something can either be true by definition [or logically impregnable] or confirmed as true empirically. Others, however, soon pointed out that even scientific "truths" reflect only assumptions made regarding long standing correlations. And correlations are not necessarily a true reflection of cause and effect.

Consequently, we can't really know anything is true. A least not for all people and for all time and in all sets of circumstances.

Karl Popper then introduced the idea of falsifying propositions even if we can never actually verify them.

 

[apeiron]

But your "offering" has no physical validity! You didn't back it up with anything to be able to differentiate it from the rest. You just TOLD him and that's that! I do not consider that to be valid.

So where does this leave rational concepts then? You know, the very stuff of logic, maths and metaphysics? If I suggest 1+1=2, do I have to now present the empirical evidence here?

I told him about vagueness - a well-established philosophical concept. I'm happy to refer anyone to a whole thread of resources on vagueness I have already compiled in this forum.

You can accuse the OP being hazy on both the theoretical concepts and the empirical observations (though I thought we could all pretty easily interpret his essential query). But a more sophisticated level of discussion (especially in a philosophy forum) must show its familiarity with both the physics and metaphysics involved. Yet your responses always sound like someone saying ooh yuck, personal tastes, when it comes to the conceptual aspects of a discussion.

 

[ZapperZ]

So where does this leave rational concepts then? You know, the very stuff of logic, maths and metaphysics? If I suggest 1+1=2, do I have to now present the empirical evidence here?

What you are suggesting is nowhere near such logic as 1+1=2. If it is, we won't have to perform experimental test of it and such tests won't be accepted in Nature, PRL, etc! You somehow cannot see the obvious contradictions and inconsistencies in your own argument based on what has transpired!

Zz.

 

[yoda jedi]

So where does this leave rational concepts then? You know, the very stuff of logic, maths and metaphysics? If I suggest 1+1=2, do I have to now present the empirical evidence here?

I told him about vagueness - a well-established philosophical concept. I'm happy to refer anyone to a whole thread of resources on vagueness I have already compiled in this forum.

You can accuse the OP being hazy on both the theoretical concepts and the empirical observations (though I thought we could all pretty easily interpret his essential query). But a more sophisticated level of discussion (especially in a philosophy forum) must show its familiarity with both the physics and metaphysics involved. Yet your responses always sound like someone saying ooh yuck, personal tastes, when it comes to the conceptual aspects of a discussion.

and physical !
i posted it at the post #53

...Thus, quantum mechanics involves a unique form of vagueness...

...The novel feature in the description of physical reality brought about with the advent of quantum mechanics is thus the fact that physical properties will not in general be either actual or absent but indefinite or indeterminate...

...as an element of empirical reality, an actual property has the capacity to act, to actualize an indicative measurement outcome if a measurement is performed. By contrast, when a property is absent it has no capacity to act. We propose the idea of an interpolation between the two extremes of full actuality and absence of a property...

...It is also appropriate to think of an indeterminate property as an element of unsharp reality...

 

[apeiron]

and physical !
i posted it at the post #53

Yes, that Busch/Jaeger paper is an extremely valuable contribution here. Thanks yoda...
http://arxiv.org/PS_cache/arxiv/pdf/1005/1005.0604v2.pdf

Zeilinger's take on the metaphysics is also worth reading (as no one can complain about his empirical credentials )...
http://www.quantum.at/fileadmin/zeilinger/philosoph.pdf

Anyway, from Busch/Jaeger is this elegant statement of the need for bold new metaphysics (and not to allow the "shut up and calculate" old guard shout us down)...

These quotations capture the tension between two opposing philosophical positions:
scientific realism versus instrumentalist empiricism. On the one hand, Einstein’s concern
was to uphold a world view based on what is commonly referred to as “local realism,”
in which probability plays a primarily epistemic role, whereas Heisenberg was prepared
to accept quantum indeterminacy and probability as primarily ontic, that is, as essential
features of the physical world. On the other hand, there is still a strong presence of the
view that Quantum Mechanics is nothing more than a formalism for the calculation of
measurement statistics.
Many physicists now adopt a pragmatic double approach: they practice a realist outlook
for the purposes of heuristic explorations of new models and the discussion of experiments, using intuitive pictures of individual (sub)atomic objects; but when challenged, they only admit to the minimal probabilistic or statistical interpretation of QuantumMechanics. This conflicted attitude has similarly been noted by D’Espagnat [4].
It seems to us that a more coherent and productive approachwould be to investigate systematically all possible variants of realist interpretations of Quantum Mechanics, including those in which probabilities are not essentially epistemic.

Zeilinger is not nearly so specific about the proper focus of this next step, but he endorses a holistic approach in general...

It is very highly likely that the new paradigm will contain holistic aspects. This follows in the most direct way from the fact, that in the Copenhagen interpretation it is impossible to dissect a quantum phenomenon into its parts. This may be expressed by saying that the preparation of a quantum system, its evolution and its observation, form one whole entity which, following both Bohr and Wheeler, we call the quantum phenomenon. Holistic aspects also follow from the fact that in a multi-particle-system it is not possible, not even for perfect correlations, to pre-assign properties to the individual members of the ensembles[35]. Such properties can only be assigned in the specific context of the whole experimental setup for all particles together. Then, in any case, they show up only in the correlations. This, I suggest, is another beautiful corroboration of Bohr's point of view[36].

In this statement further on in Busch/Jaeger, they get precisely to the heart of the problem as I have frequently outlined it...

In the case of quantum systems, properties can be considered objectively indefinite and sets of propositions regarding them complementary to specific other sets of propositions, so that it becomes impossible to jointly attribute them. Thus, quantum mechanics involves a unique form of vagueness distinct from those considered before.

What is crucial here is that complementarity (asymmetry, dichotomy) is part of the QM package. The logic involves both the initiating conditions, the indeterminate potential that is vague, and then also the decohering observation, the global set of constraints that crisply dichotomises this potential.

This is what is missing from most ontic vagueness proposals. People say well a vagueness is free do develop in any fashion really. But no. Only dichotomous outcomes are in fact possible. This was Anaximander's insight 2400 years ago. It has echoed down the years in the I Ching, Hegelian logic, etc. Yet people still seem to manage to overlook it.

There is just no accident that QM is based on orthogonal or complementary crisp observables. Systems logic says it could be no other way!

Here Busch/Jaeger state a consequence of this view. We can then go on to define vagueness (empirically, physically!) in complementary terms. It is a mixed state - a mixture of paired, dichotomous, outcomes.

It is also appropriate to think of an indeterminate property as an element of unsharp reality in the following sense. If a property P is indeterminate, then so is its complement P⊥ = I −P. Thus, both P and P⊥ have a nonzero degree of reality, they coexist, to a nonzero degree of actuality, in the given state. In this sense they are both simultaneously but “unsharply” defined. This description seems to be in agreement with Bohr’s account of the uncertainty relation: in a quantum state given by (say) a Gaussian wave function, the position and momentum of the quanton are, according to Bohr, both defined with a latitude. Bohr uses the phrase “unsharply defined individual” to characterize this situation.

Busch/Jaeger keep on hitting the mark. They correctly get the distinction between vagueness and fuzzy logic approaches...

It is important to note that the nature of the fuzziness of quantum effects differs fundamentally from that of fuzzy sets, however. In the latter case, the rule for the application of one of a set of alternative fuzzy sets is based on there being an underlying fine-grained level of actual reality.

So as I replied to the OP, between total realism and total unrealism, there is the intermediate ontic position which takes indeterminacy seriously.

And Busch and Jaeger is probably the best paper I've seen on this so far.

 

[apeiron]

What you are suggesting is nowhere near such logic as 1+1=2. If it is, we won't have to perform experimental test of it and such tests won't be accepted in Nature, PRL, etc! You somehow cannot see the obvious contradictions and inconsistencies in your own argument based on what has transpired!

You seem the one struggling to follow the argument here. Models involve both theory and measurements. The two work in tandem and neither should be neglected.

You keep harping on about the need to be up to date with the empirical content. Which of course I agree with. But it was actually not particularly relevant in this thread as the essential QM issue has been clear from the beginning. It was that which I addressed, and which you have so far failed to address.

If you have some enlightening comments on the "third path" of quantum vagueness, especially in light ot the very fine Bausch/Jaeger paper (much better than other recent QM vagueness papers such as http://www.sorites.org/Issue_15/chibeni.htm), then let's hear them...

 

[ZapperZ]

You seem the one struggling to follow the argument here. Models involve both theory and measurements. The two work in tandem and neither should be neglected.

What does that have anything to do with what you were proposing? A "theory" isn't a hand-waving argument. For theory and experiment to "work in tandem", a theory must produce quantitative predictions and the experiment must be able to measure such quantities! Are you telling me that what you told the OP falls under a category of a "theory"? Really?

You keep harping on about the need to be up to date with the empirical content. Which of course I agree with. But it was actually not particularly relevant in this thread as the essential QM issue has been clear from the beginning. It was that which I addressed, and which you have so far failed to address.

You offered a hand-waving argument with no empirical support. This is a fact that you haven't and can't dispute. That's the end of the story.

Zz.

 

[apeiron]

You offered a hand-waving argument with no empirical support. This is a fact that you haven't and can't dispute. That's the end of the story.

All the evidence that QM is not-local and not-real is precisely my empirical support here. That is what is driving theorists like Busch and Jaeger.

So yes, as usual it is stunningly easy to dispute your version of events.

 

[DevilsAvocado]

All the evidence that QM is not-local and not-real is precisely my empirical support here.

This looks like a very strong candidate for the next Nobel Prize in Physics? Reference please!

 

[apeiron]

This looks like a very strong candidate for the next Nobel Prize in Physics? Reference please!

Oh please! I deliberately separated the two to make the usual point that not all the loopholes have been closed. If I wanted to say "local realism" had been proved wrong, that's what I would have said.

But if you are asking me what I believe, I do believe that both locality and realism are concepts that both need to be revised. Which is what a systems approach does.

The systems approach argues for top-down or contextual causality (which undercuts locality, or bottom-up, efficient cause as being all there is). And it also argues for vague initial conditions (which undercuts naive realism - local or global).

But if you really want a reference, I think this is a fair statement of the current state of play. If you are a fan of hidden variables and praying for a loophole, the tide has been going out on you for many years now...

The ultimate test of Bell’s theorem is still missing: a single experiment that closes all the loopholes at once. It is very unlikely that such an experiment will disagree with the prediction of quantum mechanics, since this would imply that nature makes use of both the detection loophole in the Innsbruck experiment and of the locality loophole in the NIST experiment. Nevertheless, nature could be vicious, and such an experiment is desirable if we are to finally close the book on local realism.

Two things are clear from these experiments. First, it is insufficient to give up completely the notion of locality. Second, one has to abandon at least the notion of naïve realism that particles have certain properties (in our case polarization) that are independent of any observation.

http://www.quantum.at/fileadmin/Presse/2008-07-01-MG-PW_A_Quantum__Renaissance.pdf

 

[DevilsAvocado]

Oh please! I deliberately separated the two to make the usual point that not all the loopholes have been closed.

"Deliberately separated"... "loopholes"... I don’t understand anything...

Honestly, if you are referring to "empirical support" and "evidence", you should at least get the most basics facts correct. How could we else be helping OP getting it right??

Bell's theorem (aka Bell's inequality) is stating that:

No physical theory of Local Hidden Variables (LHV) can ever reproduce all of the predictions of QM.​

All performed EPR-Bell test experiments performed so far verifies Bell's theorem, and another word for Local Hidden Variables is Local Realism, which by the scientific community is considered "dead" (naturally).

This does NOT mean that we now have evidence that QM is not-local and not-real. All we can say is that the predictions of QM and all experiments performed so far is telling us that the microscopic world must be non-local AND/OR non-real.

To me, this is a HUGE difference, since nothing is really settled yet. There are still three (3) options and the person(s) who can tell us which is correct will most probably get the Nobel Prize in Physics.

I’m not in any "camp", I’m just here to listen and learn. Furthermore I’m not a big fan of the "shut up and calculate" –model, neither can I see the use of building large "Philosophical Castles" on shaky grounds...

I must agree with ZapperZ that using logic as 1+1=2 is nothing but a catastrophe when discussing EPR-Bell and the real nature of the microscopic world.

Why!?

Because if we take the simplest version of Bell's inequality, by Nick Herbert:

N(+30°, -30°) ≤ N(+30°, 0°) + N(0°, -30°)

And reduce it, you will get:

1+1=2

This is the classical assumption we all think is "natural". But is this what QM predicts and experiments verify...??

Well, when we do the math and run the EPR-Bell test experiments, we will always find that:

1+1=3

!

...Get it...?

 

[yoda jedi]

Yes, that Busch/Jaeger paper is an extremely valuable contribution here. Thanks yoda...
http://arxiv.org/PS_cache/arxiv/pdf/1005/1005.0604v2.pdf

very SHARP remark.

 

[yoda jedi]

between total realism and total unrealism, there is the intermediate ontic position which takes indeterminacy seriously.

long time ago sirs...

Aristotle:

"about anything that exists just because of its existence and not because of any special qualities it has"...




and now again:(the same essence)

"Reality is the state of things as they actually exist"






Being Qua Being

there is no need of so "ENTANGLED" definitions...