Bell (2014:82): each particle ... IS unpolarised

Foundations of physics and/or philosophy of physics, and in particular, posts on unresolved or controversial issues

Bell (2014:82): each particle ... IS unpolarised

Postby Gordon Watson » Wed Jul 05, 2017 5:43 pm

minkwe wrote:
Gordon Watson wrote:
In Bell's terms, as I recall, he writes (with his emphasis) --"each particle, considered separately, IS unpolarised here." So, when an unpolarised particle becomes polarised, that for me is a new property. NB: Since my ideas confront Bellians head-on, I try to use Bellian terms when/wherever they are suitable.

What then is mean by "Polarisation" in the context of a particle? You only need to scratch the surface a little to see that we now have another misunderstood concept, or at the very least, inconsistently applied definitions -- and Bell himself is not immune to this problem.


minkwe et al: I'd welcome technical comments (and surface scratchings) on the above.

Tks; Gordon
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby minkwe » Wed Jul 05, 2017 9:05 pm

Gordon Watson wrote:
minkwe wrote:
Gordon Watson wrote:
In Bell's terms, as I recall, he writes (with his emphasis) --"each particle, considered separately, IS unpolarised here." So, when an unpolarised particle becomes polarised, that for me is a new property. NB: Since my ideas confront Bellians head-on, I try to use Bellian terms when/wherever they are suitable.

What then is mean by "Polarisation" in the context of a particle? You only need to scratch the surface a little to see that we now have another misunderstood concept, or at the very least, inconsistently applied definitions -- and Bell himself is not immune to this problem.


minkwe et al: I'd welcome technical comments (and surface scratchings) on the above.

Tks; Gordon

What does Bell mean by
1. "Polarisation"
2. "Each particle is unpolarised"

It will be helpful if you provide the relevant quotes from Bell.
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby Gordon Watson » Wed Jul 05, 2017 10:37 pm

minkwe wrote:What does Bell mean by
1. "Polarisation"
2. "Each particle is unpolarised"

It will be helpful if you provide the relevant quotes from Bell.


1. As far as I know he gives no sign that he is departing from accepted physics.*

2: Bell's essay (via CERN typescript) is here -- http://cds.cern.ch/record/610098/files/ ... 369328.pdf -- see page 2, second paragraph.

* PS: BUT see page 1, middle second paragraph: "preceded by filters that pass only particles of given polarisation, say those with spin projections +1/2 along z axis." That is odd wording imho; though I'm sure I know what he means: i.e., the particles are polarised by the filters such that those with spin projections +1/2 along z axis pass.
.
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby minkwe » Fri Jul 07, 2017 8:45 pm

Gordon Watson wrote:1. As far as I know he gives no sign that he is departing from accepted physics.*

Your description of his view gives no sign that he is sticking to accepted physics either.
2: Bell's essay (via CERN typescript) is here -- http://cds.cern.ch/record/610098/files/ ... 369328.pdf -- see page 2, second paragraph.

* PS: BUT see page 1, middle second paragraph: "preceded by filters that pass only particles of given polarisation, say those with spin projections +1/2 along z axis." That is odd wording imho; though I'm sure I know what he means: i.e., the particles are polarised by the filters such that those with spin projections +1/2 along z axis pass.
.

So which is it? Are individual particles polarized or not? I'm glad you found the contradiction by yourself.
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby Gordon Watson » Sun Jul 09, 2017 3:05 am

minkwe wrote:
Gordon Watson wrote:1. As far as I know he gives no sign that he is departing from accepted physics.*

Your description of his view gives no sign that he is sticking to accepted physics either.
2: Bell's essay (via CERN typescript) is here -- http://cds.cern.ch/record/610098/files/ ... 369328.pdf -- see page 2, second paragraph.

* PS: BUT see page 1, middle second paragraph: "preceded by filters that pass only particles of given polarisation, say those with spin projections +1/2 along z axis." That is odd wording imho; though I'm sure I know what he means: i.e., the particles are polarised by the filters such that those with spin projections +1/2 along z axis pass.
.

So which is it? Are individual particles polarized or not? I'm glad you found the contradiction by yourself.


I'm happy to sort Bell out as follows: Each pristine particle is unpolarised; those passing the filter are appropriately polarised.
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby minkwe » Sun Jul 09, 2017 7:58 pm

And what does "pristine particle" mean? Before answering, consider this. I have prepared a particle, and it is headed towards you. It will arrive tomorrow. Now the question: Before you get to measure it tomorrow, is the particle polarized as far as you are concerned? Is the particle pristine as far as you are concerned?
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby FrediFizzx » Sun Jul 09, 2017 8:54 pm

minkwe wrote:And what does "pristine particle" mean? Before answering, consider this. I have prepared a particle, and it is headed towards you. It will arrive tomorrow. Now the question: Before you get to measure it tomorrow, is the particle polarized as far as you are concerned? Is the particle pristine as far as you are concerned?

Gordon sure does like his adjectives. :) I would imagine in this case that pristine means it has not gone through a polarizer.
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby minkwe » Mon Jul 10, 2017 2:12 pm

FrediFizzx wrote:
minkwe wrote:And what does "pristine particle" mean? Before answering, consider this. I have prepared a particle, and it is headed towards you. It will arrive tomorrow. Now the question: Before you get to measure it tomorrow, is the particle polarized as far as you are concerned? Is the particle pristine as far as you are concerned?

Gordon sure does like his adjectives. :) I would imagine in this case that pristine means it has not gone through a polarizer.

I'm trying to get him to realize that pristine, is a subjective concept. That is why I asked him to tell me if my particle I prepared was pristine or not. The moment he says it is pristine, I would have responded that I just passed it through a polarizer before sending it to him. So all of a sudden the pristine particle is no longer pristine, just because he acquired new information about what I did to the particle before sending it to him. If I revealed the value of every property of the particle, nobody will be able to say if it is pristine or not. Unless I told them how the particle came to be like that. Thus "pristineness" is not a property of a particle. It is a property of our knowledge of what happened to the particle.

The key question that started all this was Gordon's claim that Bell believes individual particles are unpolarized? Which raises a question, what polarization means in the first place. Does Bell mean it is similar to "pristine" as I described above? In that, it is only polarized if we know certain information about it (eg it passed through a polarizer)? Say I revealed the value of every relevant property of the particle, is it possible to tell that it is polarized or not? All that passing a particle through a polarizer does is to narrow our uncertainty about the values of certain properties the particle now has. Say I have 2 particles with exactly the same values of all relevant properties. The only difference is one of them arrived at those values by passing through a polarizer, but not the other. Why would we call the first one "polarized" but not the second one? Both particles will behave in exactly the same way when tested further! It will be strange if polarization were defined in such a non-physical manner. If this is the definition of "polarized", then it can't be a property of the particle. Like "pristineness" it would have to be a property of our knowledge about what the particle passed through.

On the other hand, we could understand polarization as actually a properties of individual particles, whether we passed it through "polarizers" (a misnomer) or not. "Polarizers" do not polarize individual particles, they either change the polarization of incident photons to specific directions, or block particles whose polarization does not meet certain criteria, or both. In this (IMHO accurate) view, individual particles are polarized even if we may not know what the direction of polarization is. This is the more consistent approach IMHO, contrary to what Bell claims, although he seems to be mixing the two approaches as evidenced by the quote provided by Gordon.
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby Gordon Watson » Mon Jul 10, 2017 3:46 pm

minkwe wrote:And what does "pristine particle" mean? Before answering, consider this. I have prepared a particle, and it is headed towards you. It will arrive tomorrow. Now the question: Before you get to measure it tomorrow, is the particle polarized as far as you are concerned? Is the particle pristine as far as you are concerned?


Pristine, in the context here, means "in its original condition" -- i.e., it will arrive in my locale in the same condition that it left yours.

All I know is that a particle is on its way! And its running late!
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby Gordon Watson » Mon Jul 10, 2017 3:59 pm

FrediFizzx wrote:
minkwe wrote:And what does "pristine particle" mean? Before answering, consider this. I have prepared a particle, and it is headed towards you. It will arrive tomorrow. Now the question: Before you get to measure it tomorrow, is the particle polarized as far as you are concerned? Is the particle pristine as far as you are concerned?

Gordon sure does like his adjectives. :) I would imagine in this case that pristine means it has not gone through a polarizer.


See above. Though I've often wondered at your [adjective omitted] imaginings: ;)
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby Gordon Watson » Mon Jul 10, 2017 4:31 pm

minkwe wrote:
FrediFizzx wrote:
minkwe wrote:And what does "pristine particle" mean? Before answering, consider this. I have prepared a particle, and it is headed towards you. It will arrive tomorrow. Now the question: Before you get to measure it tomorrow, is the particle polarized as far as you are concerned? Is the particle pristine as far as you are concerned?

Gordon sure does like his adjectives. :) I would imagine in this case that pristine means it has not gone through a polarizer.

I'm trying to get him to realize that pristine, is a subjective concept. That is why I asked him to tell me if my particle I prepared was pristine or not. The moment he says it is pristine, I would have responded that I just passed it through a polarizer before sending it to him. So all of a sudden the pristine particle is no longer pristine, just because he acquired new information about what I did to the particle before sending it to him. If I revealed the value of every property of the particle, nobody will be able to say if it is pristine or not. Unless I told them how the particle came to be like that. Thus "pristineness" is not a property of a particle. It is a property of our knowledge of what happened to the particle.

The key question that started all this was Gordon's claim that Bell believes individual particles are unpolarized? Which raises a question, what polarization means in the first place. Does Bell mean it is similar to "pristine" as I described above? In that, it is only polarized if we know certain information about it (eg it passed through a polarizer)? Say I revealed the value of every relevant property of the particle, is it possible to tell that it is polarized or not? All that passing a particle through a polarizer does is to narrow our uncertainty about the values of certain properties the particle now has. Say I have 2 particles with exactly the same values of all relevant properties. The only difference is one of them arrived at those values by passing through a polarizer, but not the other. Why would we call the first one "polarized" but not the second one? Both particles will behave in exactly the same way when tested further! It will be strange if polarization were defined in such a non-physical manner. If this is the definition of "polarized", then it can't be a property of the particle. Like "pristineness" it would have to be a property of our knowledge about what the particle passed through.

On the other hand, we could understand polarization as actually a properties of individual particles, whether we passed it through "polarizers" (a misnomer) or not. "Polarizers" do not polarize individual particles, they either change the polarization of incident photons to specific directions, or block particles whose polarization does not meet certain criteria, or both. In this (IMHO accurate) view, individual particles are polarized even if we may not know what the direction of polarization is. This is the more consistent approach IMHO, contrary to what Bell claims, although he seems to be mixing the two approaches as evidenced by the quote provided by Gordon.


1.Let's get this first point sorted: For me, pristine is not subjective; a gold coin in pristine condition is in mint condition; i.e., it gets to me in the same condition that it left the mint. And, if I have doubts, the mint can objectively assess that condition and give me a certificate to that effect.

2. Re you single particle: Make available a beam of such particles until I tell you to switch it off --- so that they arrive in mint condition; i.e., in the same condition as the first --- and (since I only have a linear filter), I'll tell you whether they were linearly polarised or NOT polarized.

Please comment on this possibility? Does it not sink your IMHO? THUS: Does my correction of Bell's text thus leave his use of UNpolarized correct?

PS: I am here distinguishing between unpolarised particles and unpolarised beams.

3. Are the particles in EPRB polarised or unpolarised when they leave the source?
.
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby minkwe » Tue Jul 11, 2017 7:22 am

Gordon Watson wrote:1.Let's get this first point sorted: For me, pristine is not subjective; a gold coin in pristine condition is in mint condition; i.e., it gets to me in the same condition that it left the mint. And, if I have doubts, the mint can objectively assess that condition and give me a certificate to that effect.

Easy to say for a gold coin but we are talking about particles. How do you know that the particle is pristine, if I do not tell you in what state it left my station? How do you distinguish between two particles which arrive at your location having identical properties, but one arrived at you differently from how it left me, and the other arrived at you exactly in the state at which it left me. By your definition, one is pristine and the other is not. So it is very easy to see that "pristineness", is not a property of a particle. If you insist it is a property of the particle, then you should be able to tell just by examining the particles, which particle is pristine and which one is not, which you can't, and such a property is instantaneously acquired the moment I reveal to you the original state of the particles when they left me. If that is not subjective, I don't know what you mean by subjective.

2. Re you single particle: Make available a beam of such particles until I tell you to switch it off --- so that they arrive in mint condition; i.e., in the same condition as the first --- and (since I only have a linear filter), I'll tell you whether they were linearly polarised or NOT polarized.

Ask yourself why you found the need to introduce "beam" into the discussion. The answer is revealing. If you can't make the same point with a single particle, then you concede my point -- You are confusing the polarization of the "source" vs the polarization of the "particle". This is why I asked in my first question, what you think Bell meant by "polarization". A polarized "source" produces a "beam" of particles each with their individual polarization vector directions aligned relative to each other in some way. That is a different thing from saying each individual particle is not polarized. So again what do you, or Bell mean by "polarization".

Please comment on this possibility? Does it not sink your IMHO? THUS: Does my correction of Bell's text thus leave his use of UNpolarized correct?

It does not sink anything but perhaps if you define what meaning of "Polarization" Bell(you) are referring to, then this could be cleared up.

PS: I am here distinguishing between unpolarised particles and unpolarised beams.

But that is the point! You haven't distinguished. What is a "polarized particle" and what is an "unpolarized particle". What is a "polarized beam" and what is an "unpolarized beam"? Are you saying the concept of "polarization" does not even apply to individual particles? or as you saying the concept applies but an individual particle is unpolarized just as an "unpolarized beam" is unpolarized. You haven't been clear.
3. Are the particles in EPRB polarised or unpolarised when they leave the source?


Every particle is polarized, even if they are part of a beam that is "unpolarized", and even if they are produced from a source that produces "unpolarized beams". The polarization of a beam or a source relates to the correlation between the polarization directions of the particles that make up the beam, produced by the source.
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby Gordon Watson » Tue Jul 11, 2017 3:34 pm

minkwe wrote:
Gordon Watson wrote:1.Let's get this first point sorted: For me, pristine is not subjective; a gold coin in pristine condition is in mint condition; i.e., it gets to me in the same condition that it left the mint. And, if I have doubts, the mint can objectively assess that condition and give me a certificate to that effect.

Easy to say for a gold coin but we are talking about particles. How do you know that the particle is pristine, if I do not tell you in what state it left my station? How do you distinguish between two particles which arrive at your location having identical properties, but one arrived at you differently from how it left me, and the other arrived at you exactly in the state at which it left me. By your definition, one is pristine and the other is not. So it is very easy to see that "pristineness", is not a property of a particle. If you insist it is a property of the particle, then you should be able to tell just by examining the particles, which particle is pristine and which one is not, which you can't, and such a property is instantaneously acquired the moment I reveal to you the original state of the particles when they left me. If that is not subjective, I don't know what you mean by subjective.

2. Re you single particle: Make available a beam of such particles until I tell you to switch it off --- so that they arrive in mint condition; i.e., in the same condition as the first --- and (since I only have a linear filter), I'll tell you whether they were linearly polarised or NOT polarized.

Ask yourself why you found the need to introduce "beam" into the discussion. The answer is revealing. If you can't make the same point with a single particle, then you concede my point -- You are confusing the polarization of the "source" vs the polarization of the "particle". This is why I asked in my first question, what you think Bell meant by "polarization". A polarized "source" produces a "beam" of particles each with their individual polarization vector directions aligned relative to each other in some way. That is a different thing from saying each individual particle is not polarized. So again what do you, or Bell mean by "polarization".

Please comment on this possibility? Does it not sink your IMHO? THUS: Does my correction of Bell's text thus leave his use of UNpolarized correct?

It does not sink anything but perhaps if you define what meaning of "Polarization" Bell(you) are referring to, then this could be cleared up.

PS: I am here distinguishing between unpolarised particles and unpolarised beams.

But that is the point! You haven't distinguished. What is a "polarized particle" and what is an "unpolarized particle". What is a "polarized beam" and what is an "unpolarized beam"? Are you saying the concept of "polarization" does not even apply to individual particles? or as you saying the concept applies but an individual particle is unpolarized just as an "unpolarized beam" is unpolarized. You haven't been clear.
3. Are the particles in EPRB polarised or unpolarised when they leave the source?


Every particle is polarized, even if they are part of a beam that is "unpolarized", and even if they are produced from a source that produces "unpolarized beams". The polarization of a beam or a source relates to the correlation between the polarization directions of the particles that make up the beam, produced by the source.


1. I use the term "pristine" to be clear about a key assumption: that the particles reach Alice and Bob in the same condition that they were in when they left the source.

2. I concede no points by discussing particles and beams. An unpolarised beam might be built from unpolarised particles or particles of varied polarisations.

3. What do you mean by "the polarisation of the source"? For example, in the decay of an excited calcium atom [the source] to produce a pairwise-correlated photon-pair.

4. As for my clarity: except for "unpolarised particles", I'm confident that you know the meanings of the terms that I use. Now, earlier, you referred to your "IMHO" position. So let's be specific with a concrete example based on my understanding of your position: i.e., every particle is polarised.

Please derive the EPRB and the Aspect (2004) correlations with every pristine particle polarised.

PS: If that's not possible, what other factors are involved in your successful derivations?

Please spell out your position in some detail; you know I'm the beginner here. :?

Tks.
.
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby minkwe » Wed Jul 12, 2017 9:51 pm

Gordon Watson wrote:1. I use the term "pristine" to be clear about a key assumption: that the particles reach Alice and Bob in the same condition that they were in when they left the source.

That is fine, and I understand that. But "pristineness" is not a property of a particle. It is an adjective you use to describe a particle based on information you may have about the history of the particle. You may be in possession of complete information about the current state of a particle and still not be able to ascribe "pristineness" without information that is external to the particle at the moment. Such that different observers who may or may not have that external information may draw different conclusions about "pristineness". I'm not saying it is a useless concept. Rather, it is very useful. All I'm telling you is that you should let go of the idea that it is an "objective property" of the particle. It is not.
2. I concede no points by discussing particles and beams. An unpolarised beam might be built from unpolarised particles or particles of varied polarisations.

So then tell me what you mean by an "each particle ... IS unpolarised". The last time I asked, you started talking about beams. The question is about "each particle". Why do you find the need to bring beams into the discussion when explaining what you (or Bell) mean by "each particle ... IS unpolarised"?

3. What do you mean by "the polarisation of the source"? For example, in the decay of an excited calcium atom [the source] to produce a pairwise-correlated photon-pair.

I explained that pretty clearly I think. If a source produces particles such that their individual polarization vectors (or spin directions if you prefer) have a well defined relationship between them, then the source is polarized as far as it's production of particles is concerned. Any such beam of particles is a polarized beam. Examples of such "well defined relationship" include "linear polarization" and "circular polarization". If there is no well defined relationship, then the source is unpolarized and any such beam is unpolarized. Is there anyting in this description that is unclear?

4. As for my clarity: except for "unpolarised particles", I'm confident that you know the meanings of the terms that I use.

And that is the central point. You haven't been clear about that. In explaining Bell's contradiction, you said:

* PS: BUT see page 1, middle second paragraph: "preceded by filters that pass only particles of given polarisation, say those with spin projections +1/2 along z axis." That is odd wording imho; though I'm sure I know what he means: i.e., the particles are polarised by the filters such that those with spin projections +1/2 along z axis pass.

Now, I've explained to great detail why that explanation does not hold -- like "pristineness", it makes polarization out to be an epistemic property that only makes sense if you know that a particle passed through a filter. In other words, two particles that are exactly identical in all properties could have different "polarization" status if one passed though a filter and the other was "pristine". In such a case, polarization can't be a property of particles, since complete information about the current state of a particle will not allow you to ascribe polarization. Perhaps you should simply admit that Bell's use of "polarization" is inconsistent, or at least your characterization of it is?

Please derive the EPRB and the Aspect (2004) correlations with every pristine particle polarised.

PS: If that's not possible, what other factors are involved in your successful derivations?


WTF?! What has that got to do with this discussion? This is as far off to left field as me concluding this post by saying:
Therefore please prove Poincare's conjecture :?

Please spell out your position in some detail; you know I'm the beginner here. :?

IMHO The point of this discussion in this thread is about the meaning of polarization as it relates to a single particle! What did you think the thread is about?
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby Gordon Watson » Sat Jul 15, 2017 3:56 am

This thread relates to its OP, though it's moot since I dropped essay-references to Bell's "Unpolarised' claim some time ago.

Poincare's conjecture has been proven. Your WTF is related to one way of proving your position; alas, Watson's conjecture has been proven too. :)

Nevertheless, it has been helpful; so thanks for that: me trusting we agree with the beability of polarised particles and beams and unpolarised beams. :)
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby minkwe » Sat Jul 15, 2017 2:15 pm

it's moot since I dropped essay-references to Bell's "Unpolarised' claim some time ago.

Didn't know you had dropped it, but does it's absence from the essay imply you no-longer believe it, if not then it isn't a moot point. In any case, there is perhaps another another lesson to ponder here (conciseness), if it was so unimportant to the point you wanted to make that it could easily be taken out, why did you add to the essay it in the first place?


Gordon Watson wrote:Your WTF is related to one way of proving your position; alas, Watson's conjecture has been proven too. :)

I hadn't realised my point needed a proof to be valid, still don't. A clear definition and it's consistent application does not require a proof. Rather any proof that is not based on one will be shaky. That's why I was taken aback by the sudden request to prove a claim I didn't make and hadn't even raised in the discussion this far.

Nevertheless, it has been helpful; so thanks for that:

Glad to be helpful ;) .
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Re: Bell (2014:82): each particle ... IS unpolarised

Postby Gordon Watson » Sat Jul 15, 2017 2:57 pm

Hey, to the best of my recollection, I've never EVER relied upon it in MY theorising! I probably used it some years back, in the context of perturbation via interaction, against Bell's position; i.e., since Bell agrees that the particles are polarised "ex-filter", and Bell maintains that they we "unpolarised ex-source", then perturbation had occurred via interaction with "the filter" (thus justifying Bohr's insight and my use of it).

As for belief; I tend to have few! Though one thing I (almost) believe is this: I shouldn't argue when I'm tied up in other projects (or, with you, even maybe never) :P ; so big apologies for that. However, I thought (and did verily believe) that my OP was intended to get your expert view about Bell's position. :oops: :?:

So, please, may I have that now; when convenient?
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