I Can we change our concept of reality to better understand quantum theory?

[Simple question]

1) Never written "it has no magnetic moment". I've written, it has no magnetic moment "in the z+ direction" and "in the z_ direction" (unless the system is already in the up, or down, eigenstate of magnetic moment, of course).

So are you saying that you choose some random z axis because you know in advance that the magnetic moments of the Ag atoms is orthogonal (not none, not zero) to that specific z direction only ?
That's not how the Ag atom are prepared, they are not in the X direction eigenstate.

2) Yes, the records are changes affecting the device only. *Everything* else is interpretation

This is perfectly fine and rational. I could also adopt such a viewpoint (measurement as beable ? QBism ?).

: both what I wrote about the device affecting the system's property (that is having or not z+ component of magnetic momentum) and the system already having that property before measurement (magnetic moments already z+ and z), and the device "only separating them".

OK, I agree that both cases are equivalent then.
Except my point is that each angle chosen (and measurement taken, if you made them in series), depends on the previous ones. Likewise, the first apparatus has to be aligned with the source output.
The link between those measurement are particle path. You cannot get those "magnetic moment" measurement otherwise. So if something is observed to be conserved, is it the apparatuses that "transfer spin" between themselves then ? How classical macroscopic object could do this ? What about nature in the absence of measuring devices ? Aren't measuring devices made of quantum particles themselves ?

3) Yes, collapse, of course, I just wrote it in a different way, hope it's not necessary to always repeat the same word to express a concept and certainly I didn't mean to express something weird.

So am I correct in thinking that you mean collapse of the measuring device only ?

4) We have photons which polarization state is in the plane orthogonal to the X-Y plane and which intersection with the last one is the straight line y = x, that is the 45º bisector of the first and third quadrant. Said with an analogy/metaphor: Does the vector xi+yj on the plane have "only x or only y components"? Certainly not. In the same way if a polarization state of the photon is at 45º, does the polarizing filter along X axis measures its x component? I would say no, since the subsequent detector register "yes" or "no" photn presence.

I don't understand the "since". How a "pass or not pass" would imply "has not X component" ? Actually the X and Y component are precisely equals. So it has 0.5 chances to pass. How could it be otherwise ? Which other value could it have ? a 1/2 frequency maybe ?
Even trying to adopt your point of view, if is is not based on the X component of the photon, how would a polarizing filter "decide" ?

5) Don't understand your "what". Momentum p = γmv is not frame invariant.
*Four* momentum is frame invariant.

Yes, but my point is that you don't "create" momentum by "changing frame". It is conversed, and all inertial frame agree. So it does not belong or depend-on any "frame"

6) Then I don't belong to that class of thinkers.

OK. But I have a hard time understanding your ontology. Do you have some reference to point me to ? Maybe it is something like Peter Morgan describe in this other thread ?

 

[weirdoguy]

It is conversed, and all inertial frame agree. So it does not belong or depend-on any "frame"

All inertial frames agree that momentum is conserved, but they do not agree on the "value" since it is frame dependent.

 

[lightarrow]

1) So are you saying that you choose some random z axis because you know in advance that the magnetic moments of the Ag atoms is orthogonal (not none, not zero) to that specific z direction only ?
That's not how the Ag atom are prepared, they are not in the X direction eigenstate.

2) OK, I agree that both cases are equivalent then.
Except my point is that each angle chosen (and measurement taken, if you made them in series), depends on the previous ones. Likewise, the first apparatus has to be aligned with the source output.
The link between those measurement are particle path. You cannot get those "magnetic moment" measurement otherwise. So if something is observed to be conserved, is it the apparatuses that "transfer spin" between themselves then ? How classical macroscopic object could do this ? What about nature in the absence of measuring devices ? Aren't measuring devices made of quantum particles themselves ?

3) So am I correct in thinking that you mean collapse of the measuring device only ?

4) I don't understand the "since". How a "pass or not pass" would imply "has not X component" ? Actually the X and Y component are precisely equals. So it has 0.5 chances to pass. How could it be otherwise ? Which other value could it have ? a 1/2 frequency maybe ?
Even trying to adopt your point of view, if is is not based on the X component of the photon, how would a polarizing filter "decide" ?

5) Yes, but my point is that you don't "create" momentum by "changing frame". It is conversed, and all inertial frame agree. So it does not belong or depend-on any "frame".

6) OK. But I have a hard time understanding your ontology. Do you have some reference to point me to ? Maybe it is something like Peter Morgan describe in this other thread ?

1) I know, but to me, the real mystery is (Sakurai's book on QM helped me understand this) when we measure the u component of spin after the system has been prepared in the v+ component orthogonal to u: if the system really has ("really" in the sense of "intrinsically" or in some other sense I can't name because I'm not experienced with terminology) the v+ component of spin, why does the magnet (u oriented) split the beam in two, equally distributed, different beams and, more important, why does subsequent magnets v oriented again, splits again each beam in other two equally distributed, different beams?
My intuition (don't know if it can be called "interpretation") is that the (gradient of) B field u oriented destroys the "v+" property of the quantum system (Ag beam) and creates the "u+" property in the first splitted beam and the "u-" property in the other; the field does not affect this if it's oriented along the same axis of which the system has been prepared.
So in my vision the magnet/field does 3 different things according to the experimental setting and the initial system's state:

a) if the system has been prepared in the v+ state and the magnet's field is along v, we could even avoid making the "measure" because the system's state after passing the magnet will be the same: v+: the apparatus doesn't affect the system's property.

b) if the system has been prepared in the v+ state and the magnet's field is along u, the "measurement" is, actually, a destruction of that v+ property: the apparatus destroyes the property.

c) In the last case, furthermore, the apparatus creates another property on two different, equally distributed, beams: the u+ property in one beam and the u- property in the other. Even if we don't know in which state the system was prepared, or not, before the "measurement", we know it couldn't be an eigenstate of the u observable (that is of the u component of the magnetic moment).

How can the system and the apparatus interact in such a way to give a), b), c)? Don't know.

2) The system's property is real but the measuring apparatus can: do nothing, destroy, create it, according to the situation. So the property doesn't belong on the system only or on the apparatus only, it depends on both, in general.

3) According to Copenhagen interpretation it's the system, but in my vision what is called "collapse" is something a bit more complicated and we should refer to the previous points 1), 2) ("fenomenology"?)

4) What I mean is that the measuring device is quite a rough one because, on a single photon, it doesn't give the value "x", component of the vector xi+yj, but only "yes" or "no". You would say "that's the way this kind of detector work". So the question is: does the system's property depend only on the system itself or in "how a detector works" too?

5) Don't understand. Momentum is frame dependent so, in a sense, you do create momentum (or energy, or velocity or acceleration, or position, or lenght, ...) by changing frame of reference.

6) Don't know if all this has a name, but it probably has (haven't read much about interpretations in literature), I find it difficult to believe I'm the first to think in these terms.

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[lodbrok]

All inertial frames agree that momentum is conserved, but they do not agree on the "value" since it is frame dependent.

This is an interesting statement, as unpacking it can illuminate the question of measurement and ontology.

Would you say momentum is a property of the system being observed or a property of the "system + observer"? The fact that the "value" varies based on the observer (since different observers may be in different inertial frames) is already a massive hint forcing the issue :
1. If you say it is a property of the system being observed only, then what is observed as different values can't be the same "thing" that is conserved. Then you must have (implicitly or explicitly) in your ontology the idea that there is a conserved "beable" associated with momentum, which manifests itself as different values ("observables") when observed from different inertial frames.
2. But if you say it is a property of the combined "system + observer" only, then, in this case, you do not assume the existence of any underlying "beable" associated with the "observable." This also restricts what you can say about the "system" based on this observed "value." The problem is many who will pick this option (quite reasonably so) go on to discuss and present "value" as though it applied just to the system. This is wrong and leads to more confusion.

Such conceptual clarity is badly needed in the foundations if any significant progress is going to be made.

 

[Simple question]

All inertial frames agree that momentum is conserved, but they do not agree on the "value" since it is frame dependent.

Nor the same frame will agree with its own previous value just by changing units.
Those "values" are not beable/ontologies in any sense, their usefulness is not to be denied, but they are just labels, not true statements about what is real.
The math actually tell us something important, especially if you think symmetries are real, not artifacts of "frames".
So if I take my navel as a frame, I don't change the momentum of a truck heading straight onto me by jumping out of its way. I know it "for real" because it does not require the same change in momentum.

 

[lightarrow]

Nor the same frame will agree with its own previous value just by changing units.
Those "values" are not beable/ontologies in any sense, their usefulness is not to be denied, but they are just labels, not true statements about what is real.
The math actually tell us something important, especially if you think symmetries are real, not artifacts of "frames".

I would name "intrinsic" those properties as mass, charge, spin, which are frame invariant and "not intrinsic" what is not frame invariant, but it's terminology. Don't know the meaning you attribute to the word "ontology" here: momentum is a (very real) physical quantity.

So if I take my navel as a frame, I don't change the momentum of a truck heading straight onto me by jumping out of its way. I know it "for real" because it does not require the same change in momentum.

Because what "counts" here is the momentums difference between your navel and the truck, not their absolute values. Anyway this is a different story from the fact momentum is frame dependent. In this last case momentum is important, and is conserved for an isolated system, providing the frame doesn't change. And if it changes, we simply have to remember to ricalculate all systems momentums. (This is a common mistake among laymen, as you probably know).

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[Simple question]

why does the magnet (u oriented) split the beam in two, equally distributed, different beams and, more important, why does subsequent magnets v oriented again, splits again each beam in other two equally distributed, different beams?

Why not is the question I would ask. And you can only "erase" a component by making it orthogonal. Actually you can use any angle, and then the split will not be equals. All this is pretty straightforward and intuitive, especially for spin.

My intuition (don't know if it can be called "interpretation") is that the (gradient of) B field u oriented destroys the "v+" property of the quantum system (Ag beam) and creates the "u+" property in the first splitted beam and the "u-" property in the other; the field does not affect this if it's oriented along the same axis of which the system has been prepared.

I think I use the same intuition, and that is how I believe measurement device work, the interaction with something existing, (changing it in the process, that's inevitable if you follow strict conservation logic).
That's nudging before is was trendy, and it 's quantum because you get only two outcome.

So in my vision the magnet/field does 3 different things according to the experimental setting and the initial system's state:

I understand why you would want to split "cases", but I prefer a unique (generic) explanation.
BTW your own analyse do depend on the preparation (as it should), so whatever is prepared has to be real before entering the measurement device

2) The system's property is real but the measuring apparatus can: do nothing, destroy, create it, according to the situation. So the property doesn't belong on the system only or on the apparatus only, it depends on both, in general.

Yes, the results depends on the orientation, so it is clear the measurement device do something, it has to.
The property did and will only belong the "particle". There is just a snapshot/collapsed "value" of that property copied/stored in the device. And any identical device put further along will have no choice, but to agree with that "eigenstate". If you change their basis, and only then, there is a clear and progressive change possible in the property.

3) According to Copenhagen interpretation it's the system,

I don't think there are such interpretations. It means more the lack of interpretation.

but in my vision what is called "collapse" is something a bit more complicated and we should refer to the previous points 1), 2) ("fenomenology"?)

It is impossibly complicated if you hang onto locality. I think GRW does it, by taking collapse as a beable, but make different predictions than standard QM (but possibly out of reach of current technical possibility).

5) Don't understand. Momentum is frame dependent so, in a sense, you do create momentum (or energy, or velocity or acceleration, or position, or lenght, ...) by changing frame of reference.

I mean: momentum cannot be changed, it can only be exchanged, whatever the frame.

 

[physika]

the measurement apparatus has a very active role in the creating what is "measured".

Then, you put a Higgs Boson (for example) in a detector, and the detector gives it its spin property ?

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[lightarrow]

Then, you put a Higgs Boson (for example) in a detector, and the detector gives it its spin property ?

.

Sorry, don't know how an Higgs boson behave in a Stern-Gerlach apparatus, we were talking of the usual Ag atoms of the standard experiment.
In my vision, if these atoms were prepared in the z+ state, then an apparatus (the magnet made in that way) which is Y oriented (that is, orthogonal to Z; the beam propagates along X) destroyes that z+ property and creates two other property: y+ and y-, in two different, separated, beams.

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Lightarrow

 

[lightarrow]

This is an interesting statement, as unpacking it can illuminate the question of measurement and ontology.

Would you say momentum is a property of the system being observed or a property of the "system + observer"? The fact that the "value" varies based on the observer (since different observers may be in different inertial frames) is already a massive hint forcing the issue :
1. If you say it is a property of the system being observed only, then what is observed as different values can't be the same "thing" that is conserved. Then you must have (implicitly or explicitly) in your ontology the idea that there is a conserved "beable" associated with momentum, which manifests itself as different values ("observables") when observed from different inertial frames.
2. But if you say it is a property of the combined "system + observer" only, then, in this case, you do not assume the existence of any underlying "beable" associated with the "observable." This also restricts what you can say about the "system" based on this observed "value." The problem is many who will pick this option (quite reasonably so) go on to discuss and present "value" as though it applied just to the system. This is wrong and leads to more confusion.

Such conceptual clarity is badly needed in the foundations if any significant progress is going to be made.

I would disconnect the concepts "frame of reference" and "observer" because you can "observe" every phenomenon in the frame of reference you choose.
Anyway I don't like the term "observe" or "observer" because they belongs to optics. I prefer "measure/analyze in the X frame".

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[lightarrow]

1) Why not is the question I would ask. And you can only "erase" a component by making it orthogonal. Actually you can use any angle, and then the split will not be equals. All this is pretty straightforward and intuitive, especially for spin.

2) I understand why you would want to split "cases", but I prefer a unique (generic) explanation.
BTW your own analyse do depend on the preparation (as it should), so whatever is prepared has to be real before entering the measurement device

1) I can't understand what you mean with "why not is the question I would ask". Yes, if I use other angles the split will not be equal. But, until someone compute the probabilities of detection with this "interpretation" we don't know if it can be correct, at least for this experimental setting.

2) Yes, it would be real, after preparation, but only in relation to the measurement instrument: if it was prepared in z+ state and the instrument is aligned along Z, then it's real. What does it mean? Simply that the magnet destroyes the atom's magnetic moment (m.m.) orientation if it's aligned differently, because it changes the atom's m.m. orientation. Too naive?

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Lightarrow

 

[Simple question]

1) I can't understand what you mean with "why not is the question I would ask".

I emphasis the not because of your post 33 where you declare "the real mystery is" about a totally mundane phenomena that have plethora of classical equivalent.
Bell's elucidate the QM case clearly. There are not that much ways to map ontologies to measurements processes.

So I am going to consider that you think that some property don't exist before measurement (or at least in some arbitrary cases). I've still no clue how you sort out those cases, nor were those property emerge from in those cases.

Yes, if I use other angles the split will not be equal. But, until someone compute the probabilities of detection with this "interpretation" we don't know if it can be correct, at least for this experimental setting.

I mentioned angles because there is a continuum of possible orientation and a continuum of outcome probability. And I don't think that property is "destroyed", when it's probability become 0.5 and only that exact value.

2) Yes, it would be real, after preparation, but only in relation to the measurement instrument: if it was prepared in z+ state and the instrument is aligned along Z, then it's real.

I've added more emphasis. Even without adding entanglement, this does not make a lot of sense to me.
Let's say a bunch of Ag atom are emitted 100 year before and kept nicely in some perfect isolation.
Then we only start building the Stern-Gerlach.
Then we only decide randomly some orientation.
Either all properties are real, or none are.
If the preparation is real, it prepared some real property to be measured.

What does it mean? Simply that the magnet destroyes the atom's magnetic moment (m.m.) orientation if it's aligned differently, because it changes the atom's m.m. orientation. Too naive?

It is not too naive for me, I would say the same, except replacing "destroy" by "changes in response to the initial property value"

 

[lightarrow]

I emphasis the not because of your post 33 where you declare "the real mystery is" about a totally mundane phenomena that have plethora of classical equivalent.

Some examples (or even one)?

Bell's elucidate the QM case clearly. There are not that much ways to map ontologies to measurements processes.

I don't know much about it. Can you give me a link to (a free access to) such a document?

So I am going to consider that you think that some property don't exist before measurement (or at least in some arbitrary cases).

Why "arbitrary"? I believed to have shown the functioning.

I've still no clue how you sort out those cases, nor were those property emerge from in those cases.

Don't know how to explain better than that.

I mentioned angles because there is a continuum of possible orientation and a continuum of outcome probability.

Of course.

And I don't think that property is "destroyed", when it's probability become 0.5 and only that exact value.

Ok, yes you are right, I illustrated just the two limiting cases: the property z+ stay the same when the magnet is oriented as Z, the property is totally destroyed when the magnet is orthogonal to Z and ... the system has partially that property in the other cases.
This weird thing doesn't disturb me, at least no longer. I believe we have to make an effort to completely change paradigm, and, in the end, this kind of change I'm trying to propose here seems to me the only solution.

I've added more emphasis. Even without adding entanglement, this does not make a lot of sense to me.
Let's say a bunch of Ag atom are emitted 100 year before and kept nicely in some perfect isolation.
Then we only start building the Stern-Gerlach.
Then we only decide randomly some orientation.

Ok

Either all properties are real, or none are.

According to some definition of the paradigm "real". Maybe we can't call "real" the paradigm I've proposed, but, apart from terminology, I believe, I repeat, that we have to completely change our naive concept of "reality" and we have to find something more refined. My intuition is strong about it.

If the preparation is real, it prepared some real property to be measured.

Only relatively to the instrument.
I agree with Rovelli's relational interpretation, in this.

It is not too naive for me, I would say the same, except replacing "destroy" by "changes in response to the initial property value"

Sorry, have not understood:

"changes in response to the initial property value"

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[physika]

Sorry, don't know how an Higgs boson behave in a Stern-Gerlach apparatus, we were talking of the usual Ag atoms of the standard experiment.
In my vision, if these atoms were prepared in the z+ state, then an apparatus (the magnet made in that way) which is Y oriented (that is, orthogonal to Z; the beam propagates along X) destroyes that z+ property and creates two other property: y+ and y-, in two different, separated, beams.

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Lightarrow

Higgs Boson have no Spin.

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[lightarrow]

Higgs Boson have no Spin.

I looked up now. It has spin 0, not that "has no spin".
"The colour blue" has "no spin", for example.
Even to say "a photon has no mass" is a language misuse; but physicists understand what it means. Laymen instead don't.
For this reason I prefer to say:
"has zero mass"
"has spin 0"
etc.

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[PeterDonis]

don't know how an Higgs boson behave in a Stern-Gerlach apparatus

Since the Higgs is spin-0, you would only get one output beam--i.e., the action of the apparatus on a beam of Higgs bosons is a no-op.

 

[lightarrow]

Since the Higgs is spin-0, you would only get one output beam--i.e., the action of the apparatus on a beam of Higgs bosons is a no-op.

Yes, after having looked up for the Higgs Boson's properties and found it has spin = 0 it was clear. But I didn't do it before answering physika because I considered his question as provocative.
Thanks, anyway.

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[lightarrow]

...

Anyway, I'd like to thank you for the interesting discussion, simple question.

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[Simple question]

Some examples (or even one)?

Let's see... "heads" and I'll give you one example .. and "tails" ... also.

I don't know much about it. Can you give me a link to (a free access to) such a document?

Aside from the Spontaneous collapse, I think this document may be what you are looking for.
My point was that there are not an infinite number of those, even if some appear from time to time. Like Arnold Neumaier's thermal interpretation, that I think would fall in the non-collapse realist group.

Why "arbitrary"? I believed to have shown the functioning.

Spin gets attributed only by referring to direction. I don't think you've showed how you can "pick arbitrary" some angle, has being qualitatively different from the other. You've only explained how to do that with respect to initial preparation (which is correct). Thus I don't understand how you can declare that the property measure don't exist at preparation.

This weird thing doesn't disturb me, at least no longer. I believe we have to make an effort to completely change paradigm, and, in the end, this kind of change I'm trying to propose here seems to me the only solution.

Well, I am also in favor of trying paradigms, especially if they addresses some issue. If I understood you well (finally ) you are advocating for some sort of Relational Quantum Theory. Which I think are not realist one.
Still it is an interesting paradigm too. I just have no idea how they addresses non-locality or the Heisenberg cut

Maybe we can't call "real" the paradigm I've proposed, but, apart from terminology, I believe, I repeat, that we have to completely change our naive concept of "reality" and we have to find something more refined. My intuition is strong about it.

OK

Sorry, have not understood: "changes in response to the initial property value"

What is there not to understand, is what bothers me.
-My palm interact with that coin.
-An non-uniform magnetic fields interact with the trajectory of some Ag atom

In both cases the initial values are not decided by the measuring device. That's why you need to place those measuring devices in the path of pre-existing "things".

Anyway, I'd like to thank you for the interesting discussion, simple question.

Same here. Have a great day !