Re: Interpretation of Superposition

[agrayson2000]

On Monday, November 5, 2018 at 8:05:21 AM UTC, Pierz wrote:
>
>
>
> On Sunday, November 4, 2018 at 7:50:30 AM UTC+11, agrays...@gmail.com 
> wrote:
>>
>>
>>
>> On Thursday, November 1, 2018 at 11:22:46 PM UTC, Pierz wrote:
>>>
>>>
>>>
>>> On Monday, October 15, 2018 at 9:40:39 PM UTC+11, agrays...@gmail.com 
>>> wrote:



 On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:
>
> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
> > In a two state system, such as a qubit, what forces the 
> interpretation 
> > that the system is in both states simultaneously before measurement, 
> > versus the interpretation that we just don't what state it's in 
> before 
> > measurement? Is the latter interpretation equivalent to Einstein 
> > Realism? And if so, is this the interpretation allegedly falsified 
> by 
> > Bell experiments? AG 
>
> It is indeed inconsistent with QM itself as Bell has shown. 
> Experiments 
> have later demonstrated that the Bell inequalities are violated in 
> precisely the way predicted by QM.  This then rules out local hidden 
> variables, therefore the information about the outcome of a 
> measurement 
> is not already present locally in the environment. 
>
> Saibal 
>

 What puzzles me is this; why would the Founders assume that a system in 
 a superposition is in all component states simultaneously -- contradicting 
 the intuitive appeal of Einstein realism -- when that assumption is not 
 used in calculating probabilities (since the component states are 
 orthogonal)? AG 

>>>
>>> I think because of interference. 
>>>
>>
*Are you unaware of the fact that when a superposition of states is written 
in the form of eigenstates of the operator, there is no interference?!  
Eigenstates with distinct eigenvalues are orthogonal, meaning there is no 
interference between any pair. AG *

Consider the paradigmatic double slit, with the single electron going 
>>> through it. It sure looks like the electron was in two place at once, 
>>> doesn't it?
>>>
>>

*No. It's never been observed. All you "see" is an interference pattern 
when you don't look at the slits. AG *

>
>> *Yes, that's my assessment how the erroneous interpretation took hold, 
>> but only if you restrict yourself to the particle interpretation. If the 
>> electron travels as a wave, it can go through both slits simultaneously and 
>> interfere with itself. This is my preferred interpretation; the only one 
>> that makes sense. AG*
>>
>
> Although as stated I think "being in two states at once" is a manner of 
> speaking quasi-classically about non-classical phenomena, it seems you 
> still have a very classical imagination of what's going on here, but I have 
> my doubts:
> 1 - You say it makes sense, but I'm not sure that an electron "travelling 
> as a wave" but being measured as a particle makes an awful lot more sense! 
>


*There is no satisfying model or picture of a slit experiment. However, one 
CAN think of a *probability* wave that interferes with itself -- they're 
generally used in quantum mechanics -- without being able to explain how 
the interfering waves coalesce into a particle when the measurement occurs. 
This is the great unsolved problem and I am content for now to leave it as 
such. But the attempt to use zig-zag paths that go forward and backward in 
time seems like a much worse model in terms of having explanatory value. AG 
*

2 - Schrödinger initially thought of his equation (the one that applies to 
> double slits) as being the equation for a physical wave, as you seem to be 
> doing. 
>


*I never referred to a physical wave. I meant a probability wave. AG *

However he was forced eventually to accept that it was something a lot more 
> abstract than that. The statistical interpretation formulated by Born 
> superseded any such notion. Interference happens whenever a quantum system 
> can reach the same state via more than one history. In the case of quantum 
> computers, complex interfering superpositions are constructed in which it 
> is impossible to conceive of the "wave function" as literally describing 
> some kind of mechanical wave. 
>

*Not a mechanical or physical wave, but a probability wave. See above. AG *

>
>> I'm not sure what you mean by "that assumption is not used in calculating 
>>> probabilities". 
>>>
>>
>> *If the operator whose eigenvalues are being measured has a well defined 
>> mathematical form -- e.g., not like |alive> -- it has specific eigenvectors 
>> and eigenvalues, and the state function can be written as superposition of 
>> these eigenvectors. It can be shown that eigenvectors with distinct 
>> eigenvalues are orthogonal, meaning the Kronecker delta applies to their 
>> mutual inner products. Therefore, to calculate the probability of observing 
>> a particular eigenvalue, one must take the inner product of the wf with the 
>> 

Re: Interpretation of Superposition

[Pierz]

On Sunday, November 4, 2018 at 7:50:30 AM UTC+11, agrays...@gmail.com wrote:
>
>
>
> On Thursday, November 1, 2018 at 11:22:46 PM UTC, Pierz wrote:
>>
>>
>>
>> On Monday, October 15, 2018 at 9:40:39 PM UTC+11, agrays...@gmail.com 
>> wrote:
>>>
>>>
>>>
>>> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:

 On 14-10-2018 15:24, agrays...@gmail.com wrote: 
 > In a two state system, such as a qubit, what forces the 
 interpretation 
 > that the system is in both states simultaneously before measurement, 
 > versus the interpretation that we just don't what state it's in 
 before 
 > measurement? Is the latter interpretation equivalent to Einstein 
 > Realism? And if so, is this the interpretation allegedly falsified by 
 > Bell experiments? AG 

 It is indeed inconsistent with QM itself as Bell has shown. Experiments 
 have later demonstrated that the Bell inequalities are violated in 
 precisely the way predicted by QM.  This then rules out local hidden 
 variables, therefore the information about the outcome of a measurement 
 is not already present locally in the environment. 

 Saibal 

>>>
>>> What puzzles me is this; why would the Founders assume that a system in 
>>> a superposition is in all component states simultaneously -- contradicting 
>>> the intuitive appeal of Einstein realism -- when that assumption is not 
>>> used in calculating probabilities (since the component states are 
>>> orthogonal)? AG 
>>>
>>
>> I think because of interference. Consider the paradigmatic double slit, 
>> with the single electron going through it. It sure looks like the electron 
>> was in two place at once, doesn't it?
>>
>
> *Yes, that's my assessment how the erroneous interpretation took hold, but 
> only if you restrict yourself to the particle interpretation. If the 
> electron travels as a wave, it can go through both slits simultaneously and 
> interfere with itself. This is my preferred interpretation; the only one 
> that makes sense. AG*
>

Although as stated I think "being in two states at once" is a manner of 
speaking quasi-classically about non-classical phenomena, it seems you 
still have a very classical imagination of what's going on here, but I have 
my doubts:
1 - You say it makes sense, but I'm not sure that an electron "travelling 
as a wave" but being measured as a particle makes an awful lot more sense! 
2 - Schrödinger initially thought of his equation (the one that applies to 
double slits) as being the equation for a physical wave, as you seem to be 
doing. However he was forced eventually to accept that it was something a 
lot more abstract than that. The statistical interpretation formulated by 
Born superseded any such notion. Interference happens whenever a quantum 
system can reach the same state via more than one history. In the case of 
quantum computers, complex interfering superpositions are constructed in 
which it is impossible to conceive of the "wave function" as literally 
describing some kind of mechanical wave. 

>
> I'm not sure what you mean by "that assumption is not used in calculating 
>> probabilities". 
>>
>
> *If the operator whose eigenvalues are being measured has a well defined 
> mathematical form -- e.g., not like |alive> -- it has specific eigenvectors 
> and eigenvalues, and the state function can be written as superposition of 
> these eigenvectors. It can be shown that eigenvectors with distinct 
> eigenvalues are orthogonal, meaning the Kronecker delta applies to their 
> mutual inner products. Therefore, to calculate the probability of observing 
> a particular eigenvalue, one must take the inner product of the wf with the 
> eigenvector which has that eigenvalue. Due to the orthogonality, all terms 
> drop out except for the term in the superposition which contains the 
> eigenvector whose eigenvalue you want to measure. As you should see, there 
> is nothing in this process of calculating probabilities that in any way 
> implies, assumes, or uses, the concept that the system is simultaneously in 
> ALL component states of the superposition (written as a sum of 
> eigenvectors). AG*
>  
>
Sure, but this relates to measurement *outcomes* not to the question fo 
what state the system is in while not being measured. Clearly the fact that 
the vector spans more than one dimension expresses a state that *in a 
mathematical sense* is a combination of more than one component state. If 
it weren't for interference and entanglement (per Bell), no doubt 
scientists would simply consider this combination of states a measure of 
our ignorance of the underlying reaility (the hidden variables). But those 
three elements of quantum weirdness make it impossible to sustain that view.

If you take a sum-over-histories approach it's explicitly assumed the 
>> electron went via all possible paths.
>>
>
> *I don't know that method, but offhand POSSIBLE PATHS might have nothing 
> to do 

Re: Interpretation of Superposition

[Philip Thrift]

On Sunday, November 4, 2018 at 1:42:49 PM UTC-6, agrays...@gmail.com wrote:
>
>
>
> On Sunday, November 4, 2018 at 3:01:50 PM UTC, Philip Thrift wrote:
>>
>>
>>
>> On Sunday, November 4, 2018 at 7:27:12 AM UTC-6, agrays...@gmail.com 
>> wrote:
>>>
>>>
>>>
>>> On Sunday, November 4, 2018 at 1:05:36 AM UTC, Philip Thrift wrote:



 On Saturday, November 3, 2018 at 6:21:18 PM UTC-5, agrays...@gmail.com 
 wrote:
>
>
>
> On Saturday, November 3, 2018 at 9:33:54 PM UTC, Philip Thrift wrote:
>>
>>
>>
>> On Saturday, November 3, 2018 at 3:50:30 PM UTC-5, 
>> agrays...@gmail.com wrote:
>>>
>>>
>>>
>>> On Thursday, November 1, 2018 at 11:22:46 PM UTC, Pierz wrote:



 On Monday, October 15, 2018 at 9:40:39 PM UTC+11, 
 agrays...@gmail.com wrote:
>
>
>
> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:
>>
>> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
>> > In a two state system, such as a qubit, what forces the 
>> interpretation 
>> > that the system is in both states simultaneously before 
>> measurement, 
>> > versus the interpretation that we just don't what state it's in 
>> before 
>> > measurement? Is the latter interpretation equivalent to 
>> Einstein 
>> > Realism? And if so, is this the interpretation allegedly 
>> falsified by 
>> > Bell experiments? AG 
>>
>> It is indeed inconsistent with QM itself as Bell has shown. 
>> Experiments 
>> have later demonstrated that the Bell inequalities are violated 
>> in 
>> precisely the way predicted by QM.  This then rules out local 
>> hidden 
>> variables, therefore the information about the outcome of a 
>> measurement 
>> is not already present locally in the environment. 
>>
>> Saibal 
>>
>
> What puzzles me is this; why would the Founders assume that a 
> system in a superposition is in all component states simultaneously 
> -- 
> contradicting the intuitive appeal of Einstein realism -- when that 
> assumption is not used in calculating probabilities (since the 
> component 
> states are orthogonal)? AG 
>

 I think because of interference. Consider the paradigmatic double 
 slit, with the single electron going through it. It sure looks like 
 the 
 electron was in two place at once, doesn't it?

>>>
>>> *Yes, that's my assessment how the erroneous interpretation took 
>>> hold, but only if you restrict yourself to the particle interpretation. 
>>> If 
>>> the electron travels as a wave, it can go through both slits 
>>> simultaneously 
>>> and interfere with itself. This is my preferred interpretation; the 
>>> only 
>>> one that makes sense. AG*
>>>
>>> I'm not sure what you mean by "that assumption is not used in 
 calculating probabilities". 

>>>
>>> *If the operator whose eigenvalues are being measured has a well 
>>> defined mathematical form -- e.g., not like |alive> -- it has specific 
>>> eigenvectors and eigenvalues, and the state function can be written as 
>>> superposition of these eigenvectors. It can be shown that eigenvectors 
>>> with 
>>> distinct eigenvalues are orthogonal, meaning the Kronecker delta 
>>> applies to 
>>> their mutual inner products. Therefore, to calculate the probability of 
>>> observing a particular eigenvalue, one must take the inner product of 
>>> the 
>>> wf with the eigenvector which has that eigenvalue. Due to the 
>>> orthogonality, all terms drop out except for the term in the 
>>> superposition 
>>> which contains the eigenvector whose eigenvalue you want to measure. As 
>>> you 
>>> should see, there is nothing in this process of calculating 
>>> probabilities 
>>> that in any way implies, assumes, or uses, the concept that the system 
>>> is 
>>> simultaneously in ALL component states of the superposition (written as 
>>> a 
>>> sum of eigenvectors). AG*
>>>  
>>>
 If you take a sum-over-histories approach it's explicitly assumed 
 the electron went via all possible paths.

>>>
>>> *I don't know that method, but offhand POSSIBLE PATHS might have 
>>> nothing to do with, and possibly independent of SUPERPOSITIONS OF 
>>> STATE. AG*
>>>
>>> I don't see what the orthogonality of the basis vectors (and hence 
 component states) has to do with the question of interpretation of 
 superposition. 

>>>
>>> *Explained in detail above. AG*
>>>
>>> Clearly the system will be measured in only 

Re: Interpretation of Superposition

[agrayson2000]

On Sunday, November 4, 2018 at 3:01:50 PM UTC, Philip Thrift wrote:
>
>
>
> On Sunday, November 4, 2018 at 7:27:12 AM UTC-6, agrays...@gmail.com 
> wrote:
>>
>>
>>
>> On Sunday, November 4, 2018 at 1:05:36 AM UTC, Philip Thrift wrote:
>>>
>>>
>>>
>>> On Saturday, November 3, 2018 at 6:21:18 PM UTC-5, agrays...@gmail.com 
>>> wrote:



 On Saturday, November 3, 2018 at 9:33:54 PM UTC, Philip Thrift wrote:
>
>
>
> On Saturday, November 3, 2018 at 3:50:30 PM UTC-5, agrays...@gmail.com 
> wrote:
>>
>>
>>
>> On Thursday, November 1, 2018 at 11:22:46 PM UTC, Pierz wrote:
>>>
>>>
>>>
>>> On Monday, October 15, 2018 at 9:40:39 PM UTC+11, 
>>> agrays...@gmail.com wrote:



 On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:
>
> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
> > In a two state system, such as a qubit, what forces the 
> interpretation 
> > that the system is in both states simultaneously before 
> measurement, 
> > versus the interpretation that we just don't what state it's in 
> before 
> > measurement? Is the latter interpretation equivalent to Einstein 
> > Realism? And if so, is this the interpretation allegedly 
> falsified by 
> > Bell experiments? AG 
>
> It is indeed inconsistent with QM itself as Bell has shown. 
> Experiments 
> have later demonstrated that the Bell inequalities are violated in 
> precisely the way predicted by QM.  This then rules out local 
> hidden 
> variables, therefore the information about the outcome of a 
> measurement 
> is not already present locally in the environment. 
>
> Saibal 
>

 What puzzles me is this; why would the Founders assume that a 
 system in a superposition is in all component states simultaneously -- 
 contradicting the intuitive appeal of Einstein realism -- when that 
 assumption is not used in calculating probabilities (since the 
 component 
 states are orthogonal)? AG 

>>>
>>> I think because of interference. Consider the paradigmatic double 
>>> slit, with the single electron going through it. It sure looks like the 
>>> electron was in two place at once, doesn't it?
>>>
>>
>> *Yes, that's my assessment how the erroneous interpretation took 
>> hold, but only if you restrict yourself to the particle interpretation. 
>> If 
>> the electron travels as a wave, it can go through both slits 
>> simultaneously 
>> and interfere with itself. This is my preferred interpretation; the only 
>> one that makes sense. AG*
>>
>> I'm not sure what you mean by "that assumption is not used in 
>>> calculating probabilities". 
>>>
>>
>> *If the operator whose eigenvalues are being measured has a well 
>> defined mathematical form -- e.g., not like |alive> -- it has specific 
>> eigenvectors and eigenvalues, and the state function can be written as 
>> superposition of these eigenvectors. It can be shown that eigenvectors 
>> with 
>> distinct eigenvalues are orthogonal, meaning the Kronecker delta applies 
>> to 
>> their mutual inner products. Therefore, to calculate the probability of 
>> observing a particular eigenvalue, one must take the inner product of 
>> the 
>> wf with the eigenvector which has that eigenvalue. Due to the 
>> orthogonality, all terms drop out except for the term in the 
>> superposition 
>> which contains the eigenvector whose eigenvalue you want to measure. As 
>> you 
>> should see, there is nothing in this process of calculating 
>> probabilities 
>> that in any way implies, assumes, or uses, the concept that the system 
>> is 
>> simultaneously in ALL component states of the superposition (written as 
>> a 
>> sum of eigenvectors). AG*
>>  
>>
>>> If you take a sum-over-histories approach it's explicitly assumed 
>>> the electron went via all possible paths.
>>>
>>
>> *I don't know that method, but offhand POSSIBLE PATHS might have 
>> nothing to do with, and possibly independent of SUPERPOSITIONS OF STATE. 
>> AG*
>>
>> I don't see what the orthogonality of the basis vectors (and hence 
>>> component states) has to do with the question of interpretation of 
>>> superposition. 
>>>
>>
>> *Explained in detail above. AG*
>>
>> Clearly the system will be measured in only one state, and this is 
>>> what the orthogonal vectors represent. However the quantum state itself 
>>> typically spans more than one dimension of the vector space - that's 
>>> what a 
>>> superposition is. However I think when physicists say 

Re: Interpretation of Superposition

[Philip Thrift]

On Sunday, November 4, 2018 at 7:27:12 AM UTC-6, agrays...@gmail.com wrote:
>
>
>
> On Sunday, November 4, 2018 at 1:05:36 AM UTC, Philip Thrift wrote:
>>
>>
>>
>> On Saturday, November 3, 2018 at 6:21:18 PM UTC-5, agrays...@gmail.com 
>> wrote:
>>>
>>>
>>>
>>> On Saturday, November 3, 2018 at 9:33:54 PM UTC, Philip Thrift wrote:



 On Saturday, November 3, 2018 at 3:50:30 PM UTC-5, agrays...@gmail.com 
 wrote:
>
>
>
> On Thursday, November 1, 2018 at 11:22:46 PM UTC, Pierz wrote:
>>
>>
>>
>> On Monday, October 15, 2018 at 9:40:39 PM UTC+11, agrays...@gmail.com 
>> wrote:
>>>
>>>
>>>
>>> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:

 On 14-10-2018 15:24, agrays...@gmail.com wrote: 
 > In a two state system, such as a qubit, what forces the 
 interpretation 
 > that the system is in both states simultaneously before 
 measurement, 
 > versus the interpretation that we just don't what state it's in 
 before 
 > measurement? Is the latter interpretation equivalent to Einstein 
 > Realism? And if so, is this the interpretation allegedly 
 falsified by 
 > Bell experiments? AG 

 It is indeed inconsistent with QM itself as Bell has shown. 
 Experiments 
 have later demonstrated that the Bell inequalities are violated in 
 precisely the way predicted by QM.  This then rules out local 
 hidden 
 variables, therefore the information about the outcome of a 
 measurement 
 is not already present locally in the environment. 

 Saibal 

>>>
>>> What puzzles me is this; why would the Founders assume that a system 
>>> in a superposition is in all component states simultaneously -- 
>>> contradicting the intuitive appeal of Einstein realism -- when that 
>>> assumption is not used in calculating probabilities (since the 
>>> component 
>>> states are orthogonal)? AG 
>>>
>>
>> I think because of interference. Consider the paradigmatic double 
>> slit, with the single electron going through it. It sure looks like the 
>> electron was in two place at once, doesn't it?
>>
>
> *Yes, that's my assessment how the erroneous interpretation took hold, 
> but only if you restrict yourself to the particle interpretation. If the 
> electron travels as a wave, it can go through both slits simultaneously 
> and 
> interfere with itself. This is my preferred interpretation; the only one 
> that makes sense. AG*
>
> I'm not sure what you mean by "that assumption is not used in 
>> calculating probabilities". 
>>
>
> *If the operator whose eigenvalues are being measured has a well 
> defined mathematical form -- e.g., not like |alive> -- it has specific 
> eigenvectors and eigenvalues, and the state function can be written as 
> superposition of these eigenvectors. It can be shown that eigenvectors 
> with 
> distinct eigenvalues are orthogonal, meaning the Kronecker delta applies 
> to 
> their mutual inner products. Therefore, to calculate the probability of 
> observing a particular eigenvalue, one must take the inner product of the 
> wf with the eigenvector which has that eigenvalue. Due to the 
> orthogonality, all terms drop out except for the term in the 
> superposition 
> which contains the eigenvector whose eigenvalue you want to measure. As 
> you 
> should see, there is nothing in this process of calculating probabilities 
> that in any way implies, assumes, or uses, the concept that the system is 
> simultaneously in ALL component states of the superposition (written as a 
> sum of eigenvectors). AG*
>  
>
>> If you take a sum-over-histories approach it's explicitly assumed the 
>> electron went via all possible paths.
>>
>
> *I don't know that method, but offhand POSSIBLE PATHS might have 
> nothing to do with, and possibly independent of SUPERPOSITIONS OF STATE. 
> AG*
>
> I don't see what the orthogonality of the basis vectors (and hence 
>> component states) has to do with the question of interpretation of 
>> superposition. 
>>
>
> *Explained in detail above. AG*
>
> Clearly the system will be measured in only one state, and this is 
>> what the orthogonal vectors represent. However the quantum state itself 
>> typically spans more than one dimension of the vector space - that's 
>> what a 
>> superposition is. However I think when physicists say that the 
>> superposition is in all states simultaneously, it's only in a manner of 
>> speaking - a way of conveying the mathematical situation in natural 
>> language that is inherently classical. 
>>
>
>
> 

Re: Interpretation of Superposition

[agrayson2000]

On Sunday, November 4, 2018 at 1:05:36 AM UTC, Philip Thrift wrote:
>
>
>
> On Saturday, November 3, 2018 at 6:21:18 PM UTC-5, agrays...@gmail.com 
> wrote:
>>
>>
>>
>> On Saturday, November 3, 2018 at 9:33:54 PM UTC, Philip Thrift wrote:
>>>
>>>
>>>
>>> On Saturday, November 3, 2018 at 3:50:30 PM UTC-5, agrays...@gmail.com 
>>> wrote:



 On Thursday, November 1, 2018 at 11:22:46 PM UTC, Pierz wrote:
>
>
>
> On Monday, October 15, 2018 at 9:40:39 PM UTC+11, agrays...@gmail.com 
> wrote:
>>
>>
>>
>> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:
>>>
>>> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
>>> > In a two state system, such as a qubit, what forces the 
>>> interpretation 
>>> > that the system is in both states simultaneously before 
>>> measurement, 
>>> > versus the interpretation that we just don't what state it's in 
>>> before 
>>> > measurement? Is the latter interpretation equivalent to Einstein 
>>> > Realism? And if so, is this the interpretation allegedly falsified 
>>> by 
>>> > Bell experiments? AG 
>>>
>>> It is indeed inconsistent with QM itself as Bell has shown. 
>>> Experiments 
>>> have later demonstrated that the Bell inequalities are violated in 
>>> precisely the way predicted by QM.  This then rules out local hidden 
>>> variables, therefore the information about the outcome of a 
>>> measurement 
>>> is not already present locally in the environment. 
>>>
>>> Saibal 
>>>
>>
>> What puzzles me is this; why would the Founders assume that a system 
>> in a superposition is in all component states simultaneously -- 
>> contradicting the intuitive appeal of Einstein realism -- when that 
>> assumption is not used in calculating probabilities (since the component 
>> states are orthogonal)? AG 
>>
>
> I think because of interference. Consider the paradigmatic double 
> slit, with the single electron going through it. It sure looks like the 
> electron was in two place at once, doesn't it?
>

 *Yes, that's my assessment how the erroneous interpretation took hold, 
 but only if you restrict yourself to the particle interpretation. If the 
 electron travels as a wave, it can go through both slits simultaneously 
 and 
 interfere with itself. This is my preferred interpretation; the only one 
 that makes sense. AG*

 I'm not sure what you mean by "that assumption is not used in 
> calculating probabilities". 
>

 *If the operator whose eigenvalues are being measured has a well 
 defined mathematical form -- e.g., not like |alive> -- it has specific 
 eigenvectors and eigenvalues, and the state function can be written as 
 superposition of these eigenvectors. It can be shown that eigenvectors 
 with 
 distinct eigenvalues are orthogonal, meaning the Kronecker delta applies 
 to 
 their mutual inner products. Therefore, to calculate the probability of 
 observing a particular eigenvalue, one must take the inner product of the 
 wf with the eigenvector which has that eigenvalue. Due to the 
 orthogonality, all terms drop out except for the term in the superposition 
 which contains the eigenvector whose eigenvalue you want to measure. As 
 you 
 should see, there is nothing in this process of calculating probabilities 
 that in any way implies, assumes, or uses, the concept that the system is 
 simultaneously in ALL component states of the superposition (written as a 
 sum of eigenvectors). AG*
  

> If you take a sum-over-histories approach it's explicitly assumed the 
> electron went via all possible paths.
>

 *I don't know that method, but offhand POSSIBLE PATHS might have 
 nothing to do with, and possibly independent of SUPERPOSITIONS OF STATE. 
 AG*

 I don't see what the orthogonality of the basis vectors (and hence 
> component states) has to do with the question of interpretation of 
> superposition. 
>

 *Explained in detail above. AG*

 Clearly the system will be measured in only one state, and this is what 
> the orthogonal vectors represent. However the quantum state itself 
> typically spans more than one dimension of the vector space - that's what 
> a 
> superposition is. However I think when physicists say that the 
> superposition is in all states simultaneously, it's only in a manner of 
> speaking - a way of conveying the mathematical situation in natural 
> language that is inherently classical. 
>


 *It's a totally misleading way to discuss the quantum superpositions.  
 Even classically, say for the vector space of "little pointy things" in a 
 plane, each vector can be expressed in uncountably many bases, both 
 

Re: Interpretation of Superposition

[Philip Thrift]

On Saturday, November 3, 2018 at 6:21:18 PM UTC-5, agrays...@gmail.com 
wrote:
>
>
>
> On Saturday, November 3, 2018 at 9:33:54 PM UTC, Philip Thrift wrote:
>>
>>
>>
>> On Saturday, November 3, 2018 at 3:50:30 PM UTC-5, agrays...@gmail.com 
>> wrote:
>>>
>>>
>>>
>>> On Thursday, November 1, 2018 at 11:22:46 PM UTC, Pierz wrote:



 On Monday, October 15, 2018 at 9:40:39 PM UTC+11, agrays...@gmail.com 
 wrote:
>
>
>
> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:
>>
>> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
>> > In a two state system, such as a qubit, what forces the 
>> interpretation 
>> > that the system is in both states simultaneously before 
>> measurement, 
>> > versus the interpretation that we just don't what state it's in 
>> before 
>> > measurement? Is the latter interpretation equivalent to Einstein 
>> > Realism? And if so, is this the interpretation allegedly falsified 
>> by 
>> > Bell experiments? AG 
>>
>> It is indeed inconsistent with QM itself as Bell has shown. 
>> Experiments 
>> have later demonstrated that the Bell inequalities are violated in 
>> precisely the way predicted by QM.  This then rules out local hidden 
>> variables, therefore the information about the outcome of a 
>> measurement 
>> is not already present locally in the environment. 
>>
>> Saibal 
>>
>
> What puzzles me is this; why would the Founders assume that a system 
> in a superposition is in all component states simultaneously -- 
> contradicting the intuitive appeal of Einstein realism -- when that 
> assumption is not used in calculating probabilities (since the component 
> states are orthogonal)? AG 
>

 I think because of interference. Consider the paradigmatic double slit, 
 with the single electron going through it. It sure looks like the electron 
 was in two place at once, doesn't it?

>>>
>>> *Yes, that's my assessment how the erroneous interpretation took hold, 
>>> but only if you restrict yourself to the particle interpretation. If the 
>>> electron travels as a wave, it can go through both slits simultaneously and 
>>> interfere with itself. This is my preferred interpretation; the only one 
>>> that makes sense. AG*
>>>
>>> I'm not sure what you mean by "that assumption is not used in 
 calculating probabilities". 

>>>
>>> *If the operator whose eigenvalues are being measured has a well defined 
>>> mathematical form -- e.g., not like |alive> -- it has specific eigenvectors 
>>> and eigenvalues, and the state function can be written as superposition of 
>>> these eigenvectors. It can be shown that eigenvectors with distinct 
>>> eigenvalues are orthogonal, meaning the Kronecker delta applies to their 
>>> mutual inner products. Therefore, to calculate the probability of observing 
>>> a particular eigenvalue, one must take the inner product of the wf with the 
>>> eigenvector which has that eigenvalue. Due to the orthogonality, all terms 
>>> drop out except for the term in the superposition which contains the 
>>> eigenvector whose eigenvalue you want to measure. As you should see, there 
>>> is nothing in this process of calculating probabilities that in any way 
>>> implies, assumes, or uses, the concept that the system is simultaneously in 
>>> ALL component states of the superposition (written as a sum of 
>>> eigenvectors). AG*
>>>  
>>>
 If you take a sum-over-histories approach it's explicitly assumed the 
 electron went via all possible paths.

>>>
>>> *I don't know that method, but offhand POSSIBLE PATHS might have nothing 
>>> to do with, and possibly independent of SUPERPOSITIONS OF STATE. AG*
>>>
>>> I don't see what the orthogonality of the basis vectors (and hence 
 component states) has to do with the question of interpretation of 
 superposition. 

>>>
>>> *Explained in detail above. AG*
>>>
>>> Clearly the system will be measured in only one state, and this is what 
 the orthogonal vectors represent. However the quantum state itself 
 typically spans more than one dimension of the vector space - that's what 
 a 
 superposition is. However I think when physicists say that the 
 superposition is in all states simultaneously, it's only in a manner of 
 speaking - a way of conveying the mathematical situation in natural 
 language that is inherently classical. 

>>>
>>>
>>> *It's a totally misleading way to discuss the quantum superpositions.  
>>> Even classically, say for the vector space of "little pointy things" in a 
>>> plane, each vector can be expressed in uncountably many bases, both 
>>> orthogonal and non-orthogonal. So to claim that one basis is somehow 
>>> preferred, and the vector being expressed as a sum or superposition in that 
>>> basis, is simultaneously in all components of that particular basis, 

Re: Interpretation of Superposition

[agrayson2000]

On Saturday, November 3, 2018 at 9:33:54 PM UTC, Philip Thrift wrote:
>
>
>
> On Saturday, November 3, 2018 at 3:50:30 PM UTC-5, agrays...@gmail.com 
> wrote:
>>
>>
>>
>> On Thursday, November 1, 2018 at 11:22:46 PM UTC, Pierz wrote:
>>>
>>>
>>>
>>> On Monday, October 15, 2018 at 9:40:39 PM UTC+11, agrays...@gmail.com 
>>> wrote:



 On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:
>
> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
> > In a two state system, such as a qubit, what forces the 
> interpretation 
> > that the system is in both states simultaneously before measurement, 
> > versus the interpretation that we just don't what state it's in 
> before 
> > measurement? Is the latter interpretation equivalent to Einstein 
> > Realism? And if so, is this the interpretation allegedly falsified 
> by 
> > Bell experiments? AG 
>
> It is indeed inconsistent with QM itself as Bell has shown. 
> Experiments 
> have later demonstrated that the Bell inequalities are violated in 
> precisely the way predicted by QM.  This then rules out local hidden 
> variables, therefore the information about the outcome of a 
> measurement 
> is not already present locally in the environment. 
>
> Saibal 
>

 What puzzles me is this; why would the Founders assume that a system in 
 a superposition is in all component states simultaneously -- contradicting 
 the intuitive appeal of Einstein realism -- when that assumption is not 
 used in calculating probabilities (since the component states are 
 orthogonal)? AG 

>>>
>>> I think because of interference. Consider the paradigmatic double slit, 
>>> with the single electron going through it. It sure looks like the electron 
>>> was in two place at once, doesn't it?
>>>
>>
>> *Yes, that's my assessment how the erroneous interpretation took hold, 
>> but only if you restrict yourself to the particle interpretation. If the 
>> electron travels as a wave, it can go through both slits simultaneously and 
>> interfere with itself. This is my preferred interpretation; the only one 
>> that makes sense. AG*
>>
>> I'm not sure what you mean by "that assumption is not used in calculating 
>>> probabilities". 
>>>
>>
>> *If the operator whose eigenvalues are being measured has a well defined 
>> mathematical form -- e.g., not like |alive> -- it has specific eigenvectors 
>> and eigenvalues, and the state function can be written as superposition of 
>> these eigenvectors. It can be shown that eigenvectors with distinct 
>> eigenvalues are orthogonal, meaning the Kronecker delta applies to their 
>> mutual inner products. Therefore, to calculate the probability of observing 
>> a particular eigenvalue, one must take the inner product of the wf with the 
>> eigenvector which has that eigenvalue. Due to the orthogonality, all terms 
>> drop out except for the term in the superposition which contains the 
>> eigenvector whose eigenvalue you want to measure. As you should see, there 
>> is nothing in this process of calculating probabilities that in any way 
>> implies, assumes, or uses, the concept that the system is simultaneously in 
>> ALL component states of the superposition (written as a sum of 
>> eigenvectors). AG*
>>  
>>
>>> If you take a sum-over-histories approach it's explicitly assumed the 
>>> electron went via all possible paths.
>>>
>>
>> *I don't know that method, but offhand POSSIBLE PATHS might have nothing 
>> to do with, and possibly independent of SUPERPOSITIONS OF STATE. AG*
>>
>> I don't see what the orthogonality of the basis vectors (and hence 
>>> component states) has to do with the question of interpretation of 
>>> superposition. 
>>>
>>
>> *Explained in detail above. AG*
>>
>> Clearly the system will be measured in only one state, and this is what 
>>> the orthogonal vectors represent. However the quantum state itself 
>>> typically spans more than one dimension of the vector space - that's what a 
>>> superposition is. However I think when physicists say that the 
>>> superposition is in all states simultaneously, it's only in a manner of 
>>> speaking - a way of conveying the mathematical situation in natural 
>>> language that is inherently classical. 
>>>
>>
>>
>> *It's a totally misleading way to discuss the quantum superpositions.  
>> Even classically, say for the vector space of "little pointy things" in a 
>> plane, each vector can be expressed in uncountably many bases, both 
>> orthogonal and non-orthogonal. So to claim that one basis is somehow 
>> preferred, and the vector being expressed as a sum or superposition in that 
>> basis, is simultaneously in all components of that particular basis, make 
>> no sense whatsoever. AG*
>>
>> Reading Born's exchange of letters with Einstein (I'm proud to say Born 
>>> was my great grandfather), it's clear that Born had a conception of QM that 
>>> was still 

Re: Interpretation of Superposition

[Philip Thrift]

On Saturday, November 3, 2018 at 3:50:30 PM UTC-5, agrays...@gmail.com 
wrote:
>
>
>
> On Thursday, November 1, 2018 at 11:22:46 PM UTC, Pierz wrote:
>>
>>
>>
>> On Monday, October 15, 2018 at 9:40:39 PM UTC+11, agrays...@gmail.com 
>> wrote:
>>>
>>>
>>>
>>> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:

 On 14-10-2018 15:24, agrays...@gmail.com wrote: 
 > In a two state system, such as a qubit, what forces the 
 interpretation 
 > that the system is in both states simultaneously before measurement, 
 > versus the interpretation that we just don't what state it's in 
 before 
 > measurement? Is the latter interpretation equivalent to Einstein 
 > Realism? And if so, is this the interpretation allegedly falsified by 
 > Bell experiments? AG 

 It is indeed inconsistent with QM itself as Bell has shown. Experiments 
 have later demonstrated that the Bell inequalities are violated in 
 precisely the way predicted by QM.  This then rules out local hidden 
 variables, therefore the information about the outcome of a measurement 
 is not already present locally in the environment. 

 Saibal 

>>>
>>> What puzzles me is this; why would the Founders assume that a system in 
>>> a superposition is in all component states simultaneously -- contradicting 
>>> the intuitive appeal of Einstein realism -- when that assumption is not 
>>> used in calculating probabilities (since the component states are 
>>> orthogonal)? AG 
>>>
>>
>> I think because of interference. Consider the paradigmatic double slit, 
>> with the single electron going through it. It sure looks like the electron 
>> was in two place at once, doesn't it?
>>
>
> *Yes, that's my assessment how the erroneous interpretation took hold, but 
> only if you restrict yourself to the particle interpretation. If the 
> electron travels as a wave, it can go through both slits simultaneously and 
> interfere with itself. This is my preferred interpretation; the only one 
> that makes sense. AG*
>
> I'm not sure what you mean by "that assumption is not used in calculating 
>> probabilities". 
>>
>
> *If the operator whose eigenvalues are being measured has a well defined 
> mathematical form -- e.g., not like |alive> -- it has specific eigenvectors 
> and eigenvalues, and the state function can be written as superposition of 
> these eigenvectors. It can be shown that eigenvectors with distinct 
> eigenvalues are orthogonal, meaning the Kronecker delta applies to their 
> mutual inner products. Therefore, to calculate the probability of observing 
> a particular eigenvalue, one must take the inner product of the wf with the 
> eigenvector which has that eigenvalue. Due to the orthogonality, all terms 
> drop out except for the term in the superposition which contains the 
> eigenvector whose eigenvalue you want to measure. As you should see, there 
> is nothing in this process of calculating probabilities that in any way 
> implies, assumes, or uses, the concept that the system is simultaneously in 
> ALL component states of the superposition (written as a sum of 
> eigenvectors). AG*
>  
>
>> If you take a sum-over-histories approach it's explicitly assumed the 
>> electron went via all possible paths.
>>
>
> *I don't know that method, but offhand POSSIBLE PATHS might have nothing 
> to do with, and possibly independent of SUPERPOSITIONS OF STATE. AG*
>
> I don't see what the orthogonality of the basis vectors (and hence 
>> component states) has to do with the question of interpretation of 
>> superposition. 
>>
>
> *Explained in detail above. AG*
>
> Clearly the system will be measured in only one state, and this is what 
>> the orthogonal vectors represent. However the quantum state itself 
>> typically spans more than one dimension of the vector space - that's what a 
>> superposition is. However I think when physicists say that the 
>> superposition is in all states simultaneously, it's only in a manner of 
>> speaking - a way of conveying the mathematical situation in natural 
>> language that is inherently classical. 
>>
>
>
> *It's a totally misleading way to discuss the quantum superpositions.  
> Even classically, say for the vector space of "little pointy things" in a 
> plane, each vector can be expressed in uncountably many bases, both 
> orthogonal and non-orthogonal. So to claim that one basis is somehow 
> preferred, and the vector being expressed as a sum or superposition in that 
> basis, is simultaneously in all components of that particular basis, make 
> no sense whatsoever. AG*
>
> Reading Born's exchange of letters with Einstein (I'm proud to say Born 
>> was my great grandfather), it's clear that Born had a conception of QM that 
>> was still very realistic in the Einstein sense. Though they disagreed 
>> significantly and somewhat heatedly, Born still seems to have regarded QM 
>> probabilities as classical probabilities in disguise.
>>
>
> 

Re: Interpretation of Superposition

[agrayson2000]

On Thursday, November 1, 2018 at 11:22:46 PM UTC, Pierz wrote:
>
>
>
> On Monday, October 15, 2018 at 9:40:39 PM UTC+11, agrays...@gmail.com 
> wrote:
>>
>>
>>
>> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:
>>>
>>> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
>>> > In a two state system, such as a qubit, what forces the interpretation 
>>> > that the system is in both states simultaneously before measurement, 
>>> > versus the interpretation that we just don't what state it's in before 
>>> > measurement? Is the latter interpretation equivalent to Einstein 
>>> > Realism? And if so, is this the interpretation allegedly falsified by 
>>> > Bell experiments? AG 
>>>
>>> It is indeed inconsistent with QM itself as Bell has shown. Experiments 
>>> have later demonstrated that the Bell inequalities are violated in 
>>> precisely the way predicted by QM.  This then rules out local hidden 
>>> variables, therefore the information about the outcome of a measurement 
>>> is not already present locally in the environment. 
>>>
>>> Saibal 
>>>
>>
>> What puzzles me is this; why would the Founders assume that a system in a 
>> superposition is in all component states simultaneously -- contradicting 
>> the intuitive appeal of Einstein realism -- when that assumption is not 
>> used in calculating probabilities (since the component states are 
>> orthogonal)? AG 
>>
>
> I think because of interference. Consider the paradigmatic double slit, 
> with the single electron going through it. It sure looks like the electron 
> was in two place at once, doesn't it?
>

*Yes, that's my assessment how the erroneous interpretation took hold, but 
only if you restrict yourself to the particle interpretation. If the 
electron travels as a wave, it can go through both slits simultaneously and 
interfere with itself. This is my preferred interpretation; the only one 
that makes sense. AG*

I'm not sure what you mean by "that assumption is not used in calculating 
> probabilities". 
>

*If the operator whose eigenvalues are being measured has a well defined 
mathematical form -- e.g., not like |alive> -- it has specific eigenvectors 
and eigenvalues, and the state function can be written as superposition of 
these eigenvectors. It can be shown that eigenvectors with distinct 
eigenvalues are orthogonal, meaning the Kronecker delta applies to their 
mutual inner products. Therefore, to calculate the probability of observing 
a particular eigenvalue, one must take the inner product of the wf with the 
eigenvector which has that eigenvalue. Due to the orthogonality, all terms 
drop out except for the term in the superposition which contains the 
eigenvector whose eigenvalue you want to measure. As you should see, there 
is nothing in this process of calculating probabilities that in any way 
implies, assumes, or uses, the concept that the system is simultaneously in 
ALL component states of the superposition (written as a sum of 
eigenvectors). AG*
 

> If you take a sum-over-histories approach it's explicitly assumed the 
> electron went via all possible paths.
>

*I don't know that method, but offhand POSSIBLE PATHS might have nothing to 
do with, and possibly independent of SUPERPOSITIONS OF STATE. AG*

I don't see what the orthogonality of the basis vectors (and hence 
> component states) has to do with the question of interpretation of 
> superposition. 
>

*Explained in detail above. AG*

Clearly the system will be measured in only one state, and this is what the 
> orthogonal vectors represent. However the quantum state itself typically 
> spans more than one dimension of the vector space - that's what a 
> superposition is. However I think when physicists say that the 
> superposition is in all states simultaneously, it's only in a manner of 
> speaking - a way of conveying the mathematical situation in natural 
> language that is inherently classical. 
>


*It's a totally misleading way to discuss the quantum superpositions.  Even 
classically, say for the vector space of "little pointy things" in a plane, 
each vector can be expressed in uncountably many bases, both orthogonal and 
non-orthogonal. So to claim that one basis is somehow preferred, and the 
vector being expressed as a sum or superposition in that basis, is 
simultaneously in all components of that particular basis, make no sense 
whatsoever. AG*

Reading Born's exchange of letters with Einstein (I'm proud to say Born was 
> my great grandfather), it's clear that Born had a conception of QM that was 
> still very realistic in the Einstein sense. Though they disagreed 
> significantly and somewhat heatedly, Born still seems to have regarded QM 
> probabilities as classical probabilities in disguise.
>

*Einstein realism seems to have been falsified due to Bell experiments. If 
that's the case, it would mean that BEFORE measurement of a quantum system, 
it is not only NOT in all states of a superposition simultaneously for the 
reasons I have 

Re: Interpretation of Superposition

[Pierz]

On Monday, October 15, 2018 at 9:40:39 PM UTC+11, agrays...@gmail.com wrote:
>
>
>
> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:
>>
>> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
>> > In a two state system, such as a qubit, what forces the interpretation 
>> > that the system is in both states simultaneously before measurement, 
>> > versus the interpretation that we just don't what state it's in before 
>> > measurement? Is the latter interpretation equivalent to Einstein 
>> > Realism? And if so, is this the interpretation allegedly falsified by 
>> > Bell experiments? AG 
>>
>> It is indeed inconsistent with QM itself as Bell has shown. Experiments 
>> have later demonstrated that the Bell inequalities are violated in 
>> precisely the way predicted by QM.  This then rules out local hidden 
>> variables, therefore the information about the outcome of a measurement 
>> is not already present locally in the environment. 
>>
>> Saibal 
>>
>
> What puzzles me is this; why would the Founders assume that a system in a 
> superposition is in all component states simultaneously -- contradicting 
> the intuitive appeal of Einstein realism -- when that assumption is not 
> used in calculating probabilities (since the component states are 
> orthogonal)? AG 
>

I think because of interference. Consider the paradigmatic double slit, 
with the single electron going through it. It sure looks like the electron 
was in two place at once, doesn't it? I'm not sure what you mean by "that 
assumption is not used in calculating probabilities". If you take a 
sum-over-histories approach it's explicitly assumed the electron went via 
all possible paths. I don't see what the orthogonality of the basis vectors 
(and hence component states) has to do with the question of interpretation 
of superposition. Clearly the system will be measured in only one state, 
and this is what the orthogonal vectors represent. However the quantum 
state itself typically spans more than one dimension of the vector space - 
that's what a superposition is. However I think when physicists say that 
the superposition is in all states simultaneously, it's only in a manner of 
speaking - a way of conveying the mathematical situation in natural 
language that is inherently classical. Reading Born's exchange of letters 
with Einstein (I'm proud to say Born was my great grandfather), it's clear 
that Born had a conception of QM that was still very realistic in the 
Einstein sense. Though they disagreed significantly and somewhat heatedly, 
Born still seems to have regarded QM probabilities as classical 
probabilities in disguise. I don't think he would ever have endorsed the 
notion that a particle is truly in all of the states of the superposition 
simultaneously. 
 

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Re: Interpretation of Superposition

[Philip Thrift]

On Tuesday, October 23, 2018 at 10:33:13 AM UTC-5, Bruno Marchal wrote:
>
>
> On 23 Oct 2018, at 11:20, Philip Thrift > 
> wrote:
>
>
>
> On Tuesday, October 23, 2018 at 1:41:06 AM UTC-5, scerir wrote:
>>
>>
>> *The original 'cat' was, of course, Einstein's 'gunpowder' paradox.*
>>
>> *'The system is a substance in chemically unstable equilibrium, perhaps a 
>> charge of gunpowder that, by means of intrinsic forces, can spontaneously 
>> combust, and where the average life span of the whole setup is a year. In 
>> principle this can quite easily be represented quantum-mechanically. In the 
>> beginning the psi-function characterizes a reasonably well-defined 
>> macroscopic state. But, according to your equation [i.e., the Schrödinger 
>> equation], after the course of a year this is no longer the case. Rather, 
>> the psi-function then describes a sort of blend of not-yet and 
>> already-exploded systems. Through no art of interpretation can this 
>> psi-function be turned into an adequate description of a real state of 
>> affairs; in reality there is no intermediary between exploded and 
>> not-exploded.' *
>>
>> *Letter from Einstein to Schrödinger, dated 8 August 1935. in Fine, A. 
>> The Shaky Game: Einstein, Realism, and the Quantum Theory, University of 
>> Chicago Press, Chicago (1986). Letter from Einstein to Schrödinger, dated 8 
>> August 1935.*
>>
>>
>>
>
> *Through no art of interpretation can this psi-function be turned into an 
> adequate description of a real state of affairs; *
>
>
>
The quote above is taken from the letter Einstein wrote above.




(I guess this is from AG).
>
> It is a description of (interfering physically) many “real” state of 
> affairs. That is what is strange in QM: it describes an evolving wave of 
> “possibilities”.
>
> Without collapse, you can only obtain what the observer can predict and 
> observe from inside those possibilities. Actuality is a possibility (a 
> consistent set of propositions) seen from inside.
>
>
>
>
> *in reality there is no intermediary between exploded and not-exploded.’*
>
>
>
> There are many intermediaries. Like some measure on the histories where it 
> exploded, and histories where it did not. It can explode in all histories 
> or in none, or in x percent of them. That does not give the measure per se, 
> without defining histories and the mean of self-reference to define a 
> “possibility seen from inside”.
>
>
>
>
>
>
>
>
>
> This is interesting.
>
> Einstein (but other physicists too) avoiding retrocausality and 
> stochasticity, like vampires avoiding sunlight and running water. :)
>
>
>

The Price-Wharton take: https://arxiv.org/abs/1307.7744 (Dispelling the 
Quantum Spooks -- a Clue that Einstein Missed?)

 

> He was wise, imo.  He did not pushes the relativity far enough, probably 
> because it took the mind-body relation from granted.
>
> Assuming mechanism, it is a fact that the arithmetical reality emulates 
> all observers view of consistent “histories” of some sort. 
>
> The existence of a physical universe looks like a miracle to me, and I 
> prefer to invoke miracle only in the last resort, and that feeling is 
> amplified when you study the (negative) mathematics trying to see the limit 
> of the art of prestidigitation of the digital. It is not computably 
> bound-able.
>
> I don’t yet see the trick, but computer science and mathematical logic put 
> a lot of light for this inquiry.
>
> Bruno
>
>
>
>

Matter is a mystery. Why so many particles (the awfully named The Standard 
Model)? I think of

[ http://www.toomanynotes.com/Amadeus.htm ]

  replace "notes" with "particles" ]

...
EMPEROR: Exactly. Very well put. Too many notes. 

MOZART: I don't understand. There are just as many notes, Majesty, as are 
required. Neither more nor less. 

EMPEROR: My dear fellow, there are in fact only so many notes the ear can 
hear in the course of an evening. I think I'm right in saying that, aren't 
I, Court Composer? 

SALIERI: Yes! yes! er, on the whole, yes, Majesty. 

MOZART: But this is absurd! 

EMPEROR: My dear, young man, don't take it too hard. Your work is 
ingenious. It's quality work. And there are simply too many notes, that's 
all. Cut a few and it will be perfect. 

MOZART: Which few did you have in mind, Majesty? 

EMPEROR: Well. There it is. 




- pt 

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Re: Interpretation of Superposition

[Bruno Marchal]

> On 23 Oct 2018, at 11:20, Philip Thrift  wrote:
> 
> 
> 
> On Tuesday, October 23, 2018 at 1:41:06 AM UTC-5, scerir wrote:
> 
> 
> The original 'cat' was, of course, Einstein's 'gunpowder' paradox.
> 
> 'The system is a substance in chemically unstable equilibrium, perhaps a 
> charge of gunpowder that, by means of intrinsic forces, can spontaneously 
> combust, and where the average life span of the whole setup is a year. In 
> principle this can quite easily be represented quantum-mechanically. In the 
> beginning the psi-function characterizes a reasonably well-defined 
> macroscopic state. But, according to your equation [i.e., the Schrödinger 
> equation], after the course of a year this is no longer the case. Rather, the 
> psi-function then describes a sort of blend of not-yet and already-exploded 
> systems. Through no art of interpretation can this psi-function be turned 
> into an adequate description of a real state of affairs; in reality there is 
> no intermediary between exploded and not-exploded.'
> 
> Letter from Einstein to Schrödinger, dated 8 August 1935. in Fine, A. The 
> Shaky Game: Einstein, Realism, and the Quantum Theory, University of Chicago 
> Press, Chicago (1986). Letter from Einstein to Schrödinger, dated 8 August 
> 1935.
> 
>> 
> 
> 
> 
> Through no art of interpretation can this psi-function be turned into an 
> adequate description of a real state of affairs;

(I guess this is from AG).

It is a description of (interfering physically) many “real” state of affairs. 
That is what is strange in QM: it describes an evolving wave of “possibilities”.

Without collapse, you can only obtain what the observer can predict and observe 
from inside those possibilities. Actuality is a possibility (a consistent set 
of propositions) seen from inside.




> in reality there is no intermediary between exploded and not-exploded.’


There are many intermediaries. Like some measure on the histories where it 
exploded, and histories where it did not. It can explode in all histories or in 
none, or in x percent of them. That does not give the measure per se, without 
defining histories and the mean of self-reference to define a “possibility seen 
from inside”.







> 
> 
> This is interesting.
> 
> Einstein (but other physicists too) avoiding retrocausality and 
> stochasticity, like vampires avoiding sunlight and running water. :)

He was wise, imo.  He did not pushes the relativity far enough, probably 
because it took the mind-body relation from granted.

Assuming mechanism, it is a fact that the arithmetical reality emulates all 
observers view of consistent “histories” of some sort. 

The existence of a physical universe looks like a miracle to me, and I prefer 
to invoke miracle only in the last resort, and that feeling is amplified when 
you study the (negative) mathematics trying to see the limit of the art of 
prestidigitation of the digital. It is not computably bound-able.

I don’t yet see the trick, but computer science and mathematical logic put a 
lot of light for this inquiry.

Bruno



> 
> -pt
> 
> -- 
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Re: Interpretation of Superposition

['scerir' via Everything List]

> Il 23 ottobre 2018 alle 13.42 agrayson2...@gmail.com ha scritto:
> 
> 
> 
> On Tuesday, October 23, 2018 at 10:36:16 AM UTC, scerir wrote:
> 
> > > 
> > 
> > > > > Il 23 ottobre 2018 alle 11.20 Philip Thrift < 
> > cloud...@gmail.com> ha scritto:
> > > 
> > > 
> > > 
> > > On Tuesday, October 23, 2018 at 1:41:06 AM UTC-5, scerir 
> > > wrote:
> > > 
> > > > > > > 
> > > > 
> > > > The original 'cat' was, of course, Einstein's 
> > > > 'gunpowder' paradox.
> > > > 
> > > > 'The system is a substance in chemically unstable 
> > > > equilibrium, perhaps a charge of gunpowder that, by means of intrinsic 
> > > > forces, can spontaneously combust, and where the average life span of 
> > > > the whole setup is a year. In principle this can quite easily be 
> > > > represented quantum-mechanically. In the beginning the psi-function 
> > > > characterizes a reasonably well-defined macroscopic state. But, 
> > > > according to your equation [i.e., the Schrödinger equation], after the 
> > > > course of a year this is no longer the case. Rather, the psi-function 
> > > > then describes a sort of blend of not-yet and already-exploded systems. 
> > > > Through no art of interpretation can this psi-function be turned into 
> > > > an adequate description of a real state of affairs; in reality there is 
> > > > no intermediary between exploded and not-exploded.'
> > > > 
> > > > Letter from Einstein to Schrödinger, dated 8 August 
> > > > 1935. in Fine, A. The Shaky Game: Einstein, Realism, and the Quantum 
> > > > Theory, University of Chicago Press, Chicago (1986). Letter from 
> > > > Einstein to Schrödinger, dated 8 August 1935.
> > > > 
> > > > > > > > > 
> > > > > > > > > > >  
> > > > > > 
> > > > > > > > > > > > > 
> > > > > > > 
> > > > > > > > > > > > > 
> > > > > > > > > > > 
> > > > > > > > > 
> > > > > > > 
> > > 
> > > Through no art of interpretation can this psi-function be 
> > > turned into an adequate description of a real state of affairs; in 
> > > reality there is no intermediary between exploded and not-exploded.'
> > > 
> > > 
> > > This is interesting.
> > > 
> > > Einstein (but other physicists too) avoiding retrocausality 
> > > and stochasticity, like vampires avoiding sunlight and running water. :)
> > > 
> > > -pt
> > > 
> > >  
> > > 
> > > > > 
> > There are situations in which a superposition is a superposition 
> > and not an "expectation-catalogue" or a mixture. See 
> > https://www.springer.com/gp/book/9780306456602 
> > https://www.springer.com/gp/book/9780306456602 pages 8 etc.
> > 
> > > 
> Can you post the relevant pages? The cost for access is high. TIA, AG
> 

Try this (it is a very good book)   https://tinyurl.com/y7f6y7rs   and read 
page 11

> 
> > > 
> >  
> > 
> > > You received this message because you are subscribed to the 
> > Google Groups "Everything List" group.
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Re: Interpretation of Superposition

[agrayson2000]

On Tuesday, October 23, 2018 at 10:36:16 AM UTC, scerir wrote:
>
>
> Il 23 ottobre 2018 alle 11.20 Philip Thrift  > ha scritto: 
>
>
>
> On Tuesday, October 23, 2018 at 1:41:06 AM UTC-5, scerir wrote:
>
>
> *The original 'cat' was, of course, Einstein's 'gunpowder' paradox.*
>
> *'The system is a substance in chemically unstable equilibrium, perhaps a 
> charge of gunpowder that, by means of intrinsic forces, can spontaneously 
> combust, and where the average life span of the whole setup is a year. In 
> principle this can quite easily be represented quantum-mechanically. In the 
> beginning the psi-function characterizes a reasonably well-defined 
> macroscopic state. But, according to your equation [i.e., the Schrödinger 
> equation], after the course of a year this is no longer the case. Rather, 
> the psi-function then describes a sort of blend of not-yet and 
> already-exploded systems. Through no art of interpretation can this 
> psi-function be turned into an adequate description of a real state of 
> affairs; in reality there is no intermediary between exploded and 
> not-exploded.' *
>
> *Letter from Einstein to Schrödinger, dated 8 August 1935. in Fine, A. The 
> Shaky Game: Einstein, Realism, and the Quantum Theory, University of 
> Chicago Press, Chicago (1986). Letter from Einstein to Schrödinger, dated 8 
> August 1935.*
>
>  
>
>
>
>
> *Through no art of interpretation can this psi-function be turned into an 
> adequate description of a real state of affairs; in reality there is no 
> intermediary between exploded and not-exploded.'* 
>
>
> This is interesting.
>
> Einstein (but other physicists too) avoiding retrocausality and 
> stochasticity, like vampires avoiding sunlight and running water. :)
>
> -pt
>
>  
>
> There are situations in which a superposition is a superposition and not 
> an "expectation-catalogue" or a mixture. See 
> https://www.springer.com/gp/book/9780306456602 pages 8 etc.
>

*Can you post the relevant pages? The cost for access is high. TIA, AG*

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> Groups "Everything List" group. 
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> . 
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> For more options, visit https://groups.google.com/d/optout. 
>
>

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Re: Interpretation of Superposition

[agrayson2000]

On Tuesday, October 23, 2018 at 6:41:06 AM UTC, scerir wrote:
>
>
> Il 22 ottobre 2018 alle 23.20 agrays...@gmail.com  ha 
> scritto: 
>
>
>
> On Saturday, October 20, 2018 at 5:39:28 PM UTC, agrays...@gmail.com 
> wrote:
>
>
>
> On Friday, October 19, 2018 at 9:08:47 PM UTC, Brent wrote:
>
>
>
> On 10/19/2018 10:59 AM, agrays...@gmail.com wrote: 
>
>
>
> On Friday, October 19, 2018 at 5:44:10 PM UTC, Brent wrote:
>
>
>
> On 10/19/2018 12:17 AM, agrays...@gmail.com wrote: 
>
> *I can see how recoherence is impossible FAPP, but after some time elapses 
> the state of the cat could Dead or Alive; not necessarily the original 
> state, Alive. A*G  
>
>
> When recoherence is no longer possible that's a real physical change.  The 
> system has evolved. 
>
>
> *Since decoherence is a unitary process, isn't recoherence always 
> possible, even if not FAPP? AG*
>
>
> Sure.  If you could reverse the outgoing waves and the local universe. 
>
>
> *Since recoherence is always possible, even if astronomically unlikely 
> like many physical macro processes, why do you make the point that there's 
> a real physical change when it's no longer possible (which is never)?  I 
> ask because your comment is confusing. AG* 
>
>
> That's the real physical change.  Outgoing radiation has left at the speed 
> of light out into an expanding universe; it ain't comin' back.  Why is that 
> confusing? 
>
>
> *You seem to conflate two concepts; Irreversible FAPP, and Irreversible 
> (aka Absolutely Irreversible, aka Irreversible in Principle). I tend to 
> believe that every unitary process is either easily reversible, or 
> irreversible FAPP (meaning possibly reversible even if hugely improbable). 
> In the case of two closed containers attached to each other, one in vacuum 
> state and the other filled with gas at some temperature, one can imagine 
> all the gas in one container finally equalizing in both containers. That 
> would occur in finite time, but is Irreversible FAPP. In your example 
> above, one can imagine the outgoing photons bending around super dense 
> masses and returning to their original positions or states. So I would say 
> this outcome is Irreversible FAPP, but you say it's Irreversible, meaning 
> Absolutely Irreversible or Irreversible in Principle. So which is it? AG* 
>
> *The more interesting issue is whether the WF in the Cat experiment, or 
> for an atom with a half life for decay, evolves in time while the box is 
> closed. I say it must evolve because the probability amplitudes are time 
> dependent. What say you? AG*
>
>
> *Seriously; if the wf for a radioactive atom evolves in time, why would 
> placing it in a box change that (or do I misunderstand what you and Bruce 
> are claiming)? AG *
>
> *The original 'cat' was, of course, Einstein's 'gunpowder' paradox.*
>
> *'The system is a substance in chemically unstable equilibrium, perhaps a 
> charge of gunpowder that, by means of intrinsic forces, can spontaneously 
> combust, and where the average life span of the whole setup is a year. In 
> principle this can quite easily be represented quantum-mechanically. In the 
> beginning the psi-function characterizes a reasonably well-defined 
> macroscopic state. But, according to your equation [i.e., the Schrödinger 
> equation], after the course of a year this is no longer the case. Rather, 
> the psi-function then describes a sort of blend of not-yet and 
> already-exploded systems. Through no art of interpretation can this 
> psi-function be turned into an adequate description of a real state of 
> affairs; in reality there is no intermediary between exploded and 
> not-exploded.' *
>
>  

> *Letter from Einstein to Schrödinger, dated 8 August 1935. in Fine, A. The 
> Shaky Game: Einstein, Realism, and the Quantum Theory, University of 
> Chicago Press, Chicago (1986). Letter from Einstein to Schrödinger, dated 8 
> August 1935.*
>

*Just to be clear; when I asserted that the wf for a radioactive source or 
Schroedinger's Cat evolves when placed in a box which is then closed, I did 
NOT mean the two state system is ever in both state simultaneously; rather, 
that the probability of being in either state changes with time. AG *

>
>
> Brent 
>
>  
> -- 
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>
>

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Visit this 

Re: Interpretation of Superposition

['scerir' via Everything List]

> Il 23 ottobre 2018 alle 11.20 Philip Thrift  ha 
> scritto:
> 
> 
> 
> On Tuesday, October 23, 2018 at 1:41:06 AM UTC-5, scerir wrote:
> 
> > > 
> > 
> > The original 'cat' was, of course, Einstein's 'gunpowder' paradox.
> > 
> > 'The system is a substance in chemically unstable equilibrium, 
> > perhaps a charge of gunpowder that, by means of intrinsic forces, can 
> > spontaneously combust, and where the average life span of the whole setup 
> > is a year. In principle this can quite easily be represented 
> > quantum-mechanically. In the beginning the psi-function characterizes a 
> > reasonably well-defined macroscopic state. But, according to your equation 
> > [i.e., the Schrödinger equation], after the course of a year this is no 
> > longer the case. Rather, the psi-function then describes a sort of blend of 
> > not-yet and already-exploded systems. Through no art of interpretation can 
> > this psi-function be turned into an adequate description of a real state of 
> > affairs; in reality there is no intermediary between exploded and 
> > not-exploded.'
> > 
> > Letter from Einstein to Schrödinger, dated 8 August 1935. in Fine, 
> > A. The Shaky Game: Einstein, Realism, and the Quantum Theory, University of 
> > Chicago Press, Chicago (1986). Letter from Einstein to Schrödinger, dated 8 
> > August 1935.
> > 
> > > > > 
> > > > > > >  
> > > > 
> > > > > > > > > 
> > > > > 
> > > > > > > > > 
> > > > > > > 
> > > > > 
> > > 
> 
> Through no art of interpretation can this psi-function be turned into an 
> adequate description of a real state of affairs; in reality there is no 
> intermediary between exploded and not-exploded.'
> 
> 
> This is interesting.
> 
> Einstein (but other physicists too) avoiding retrocausality and 
> stochasticity, like vampires avoiding sunlight and running water. :)
> 
> -pt
> 
>  
> 

There are situations in which a superposition is a superposition and not an 
"expectation-catalogue" or a mixture. See 
https://www.springer.com/gp/book/9780306456602 pages 8 etc.

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Re: Interpretation of Superposition

[Philip Thrift]

On Tuesday, October 23, 2018 at 1:41:06 AM UTC-5, scerir wrote:
>
>
> *The original 'cat' was, of course, Einstein's 'gunpowder' paradox.*
>
> *'The system is a substance in chemically unstable equilibrium, perhaps a 
> charge of gunpowder that, by means of intrinsic forces, can spontaneously 
> combust, and where the average life span of the whole setup is a year. In 
> principle this can quite easily be represented quantum-mechanically. In the 
> beginning the psi-function characterizes a reasonably well-defined 
> macroscopic state. But, according to your equation [i.e., the Schrödinger 
> equation], after the course of a year this is no longer the case. Rather, 
> the psi-function then describes a sort of blend of not-yet and 
> already-exploded systems. Through no art of interpretation can this 
> psi-function be turned into an adequate description of a real state of 
> affairs; in reality there is no intermediary between exploded and 
> not-exploded.' *
>
> *Letter from Einstein to Schrödinger, dated 8 August 1935. in Fine, A. The 
> Shaky Game: Einstein, Realism, and the Quantum Theory, University of 
> Chicago Press, Chicago (1986). Letter from Einstein to Schrödinger, dated 8 
> August 1935.*
>
>
>

*Through no art of interpretation can this psi-function be turned into an 
adequate description of a real state of affairs; in reality there is no 
intermediary between exploded and not-exploded.'*


This is interesting.

Einstein (but other physicists too) avoiding retrocausality and 
stochasticity, like vampires avoiding sunlight and running water. :)

-pt

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Re: Interpretation of Superposition

['scerir' via Everything List]

> Il 22 ottobre 2018 alle 23.20 agrayson2...@gmail.com ha scritto:
> 
> 
> 
> On Saturday, October 20, 2018 at 5:39:28 PM UTC, agrays...@gmail.com 
> wrote:
> 
> > > 
> > 
> > On Friday, October 19, 2018 at 9:08:47 PM UTC, Brent wrote:
> > 
> > > > > 
> > > 
> > > On 10/19/2018 10:59 AM, agrays...@gmail.com wrote:
> > > 
> > > > > > > 
> > > > 
> > > > On Friday, October 19, 2018 at 5:44:10 PM UTC, Brent 
> > > > wrote:
> > > > 
> > > > > > > > > 
> > > > > 
> > > > > On 10/19/2018 12:17 AM, agrays...@gmail.com wrote:
> > > > > 
> > > > > > > > > > > 
> > > > > > > > > > > > > 
> > > > > > > > > > > > > > >   
> > > > > > >   I can see how recoherence is impossible FAPP, but 
> > > > > > > after some time elapses the state of the cat could Dead or Alive; 
> > > > > > > not necessarily the original state, Alive. AG 
> > > > > > > > 
> > > > > > > > > > > > > > >   
> > > > > > > >   When recoherence is no longer possible that's a real 
> > > > > > > > physical change.  The system has evolved.
> > > > > > > 
> > > > > > > > > > > > > 
> > > > > > Since decoherence is a unitary process, 
> > > > > > isn't recoherence always possible, even if not FAPP? AG
> > > > > > 
> > > > > > > > > > > Sure.  If you 
> > > > > > could reverse the outgoing waves and the local universe.
> > > > > 
> > > > > > > > > 
> > > > Since recoherence is always possible, even if 
> > > > astronomically unlikely like many physical macro processes, why do you 
> > > > make the point that there's a real physical change when it's no longer 
> > > > possible (which is never)?  I ask because your comment is confusing. AG
> > > > 
> > > > > > > That's the real physical change.  
> > > > Outgoing radiation has left at the speed of light out into an expanding 
> > > > universe; it ain't comin' back.  Why is that confusing?
> > > 
> > > > > 
> > You seem to conflate two concepts; Irreversible FAPP, and 
> > Irreversible (aka Absolutely Irreversible, aka Irreversible in Principle). 
> > I tend to believe that every unitary process is either easily reversible, 
> > or irreversible FAPP (meaning possibly reversible even if hugely 
> > improbable). In the case of two closed containers attached to each other, 
> > one in vacuum state and the other filled with gas at some temperature, one 
> > can imagine all the gas in one container finally equalizing in both 
> > containers. That would occur in finite time, but is Irreversible FAPP. In 
> > your example above, one can imagine the outgoing photons bending around 
> > super dense masses and returning to their original positions or states. So 
> > I would say this outcome is Irreversible FAPP, but you say it's 
> > Irreversible, meaning Absolutely Irreversible or Irreversible in Principle. 
> > So which is it? AG
> > 
> > The more interesting issue is whether the WF in the Cat experiment, 
> > or for an atom with a half life for decay, evolves in time while the box is 
> > closed. I say it must evolve because the probability amplitudes are time 
> > dependent. What say you? AG
> > 
> > > 
> Seriously; if the wf for a radioactive atom evolves in time, why would 
> placing it in a box change that (or do I misunderstand what you and Bruce are 
> claiming)? AG
> 

The original 'cat' was, of course, Einstein's 'gunpowder' paradox.

'The system is a substance in chemically unstable equilibrium, perhaps a charge 
of gunpowder that, by means of intrinsic forces, can spontaneously combust, and 
where the average life span of the whole setup is a year. In principle this can 
quite easily be represented quantum-mechanically. In the beginning the 
psi-function characterizes a reasonably well-defined macroscopic state. But, 
according to your equation [i.e., the Schrödinger equation], after the course 
of a year this is no longer the case. Rather, the psi-function then describes a 
sort of blend of not-yet and already-exploded systems. Through no art of 
interpretation can this psi-function be turned into an adequate description of 
a real state of affairs; in reality there is no intermediary between exploded 
and not-exploded.'

Letter from Einstein to Schrödinger, dated 8 August 1935. in Fine, A. The Shaky 
Game: Einstein, Realism, and the Quantum Theory, University of Chicago Press, 
Chicago (1986). Letter from Einstein to Schrödinger, dated 8 August 1935.

> 
> > > 
> > 
> > > > > 
> > > Brent
> > > 
> > > > > 
> > > 
>  
> 
> --
> You received this message because you are subscribed to the Google Groups 

Re: Interpretation of Superposition

[agrayson2000]

On Saturday, October 20, 2018 at 5:39:28 PM UTC, agrays...@gmail.com wrote:
>
>
>
> On Friday, October 19, 2018 at 9:08:47 PM UTC, Brent wrote:
>>
>>
>>
>> On 10/19/2018 10:59 AM, agrays...@gmail.com wrote:
>>
>>
>>
>> On Friday, October 19, 2018 at 5:44:10 PM UTC, Brent wrote: 
>>>
>>>
>>>
>>> On 10/19/2018 12:17 AM, agrays...@gmail.com wrote:
>>>
>>> *I can see how recoherence is impossible FAPP, but after some time 
 elapses the state of the cat could Dead or Alive; not necessarily the 
 original state, Alive. A*G  


 When recoherence is no longer possible that's a real physical change.  
 The system has evolved.

>>>
>>> *Since decoherence is a unitary process, isn't recoherence always 
>>> possible, even if not FAPP? AG*
>>>
>>>
>>> Sure.  If you could reverse the outgoing waves and the local universe.
>>>
>>
>> *Since recoherence is always possible, even if astronomically unlikely 
>> like many physical macro processes, why do you make the point that there's 
>> a real physical change when it's no longer possible (which is never)?  I 
>> ask because your comment is confusing. AG*
>>
>>
>> That's the real physical change.  Outgoing radiation has left at the 
>> speed of light out into an expanding universe; it ain't comin' back.  Why 
>> is that confusing?
>>
>
>
> *You seem to conflate two concepts; Irreversible FAPP, and Irreversible 
> (aka Absolutely Irreversible, aka Irreversible in Principle). I tend to 
> believe that every unitary process is either easily reversible, or 
> irreversible FAPP (meaning possibly reversible even if hugely improbable). 
> In the case of two closed containers attached to each other, one in vacuum 
> state and the other filled with gas at some temperature, one can imagine 
> all the gas in one container finally equalizing in both containers. That 
> would occur in finite time, but is Irreversible FAPP. In your example 
> above, one can imagine the outgoing photons bending around super dense 
> masses and returning to their original positions or states. So I would say 
> this outcome is Irreversible FAPP, but you say it's Irreversible, meaning 
> Absolutely Irreversible or Irreversible in Principle. So which is it? AG *
>
> *The more interesting issue is whether the WF in the Cat experiment, or 
> for an atom with a half life for decay, evolves in time while the box is 
> closed. I say it must evolve because the probability amplitudes are time 
> dependent. What say you? AG*
>


*Seriously; if the wf for a radioactive atom evolves in time, why would 
placing it in a box change that (or do I misunderstand what you and Bruce 
are claiming)? AG *

>
>
>
>> Brent
>>
>

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Re: Interpretation of Superposition

[agrayson2000]

On Friday, October 19, 2018 at 9:08:47 PM UTC, Brent wrote:
>
>
>
> On 10/19/2018 10:59 AM, agrays...@gmail.com  wrote:
>
>
>
> On Friday, October 19, 2018 at 5:44:10 PM UTC, Brent wrote: 
>>
>>
>>
>> On 10/19/2018 12:17 AM, agrays...@gmail.com wrote:
>>
>> *I can see how recoherence is impossible FAPP, but after some time 
>>> elapses the state of the cat could Dead or Alive; not necessarily the 
>>> original state, Alive. A*G  
>>>
>>>
>>> When recoherence is no longer possible that's a real physical change.  
>>> The system has evolved.
>>>
>>
>> *Since decoherence is a unitary process, isn't recoherence always 
>> possible, even if not FAPP? AG*
>>
>>
>> Sure.  If you could reverse the outgoing waves and the local universe.
>>
>
> *Since recoherence is always possible, even if astronomically unlikely 
> like many physical macro processes, why do you make the point that there's 
> a real physical change when it's no longer possible (which is never)?  I 
> ask because your comment is confusing. AG*
>
>
> That's the real physical change.  Outgoing radiation has left at the speed 
> of light out into an expanding universe; it ain't comin' back.  Why is that 
> confusing?
>


*You seem to conflate two concepts; Irreversible FAPP, and Irreversible 
(aka Absolutely Irreversible, aka Irreversible in Principle). I tend to 
believe that every unitary process is either easily reversible, or 
irreversible FAPP (meaning possibly reversible even if hugely improbable). 
In the case of two closed containers attached to each other, one in vacuum 
state and the other filled with gas at some temperature, one can imagine 
all the gas in one container finally equalizing in both containers. That 
would occur in finite time, but is Irreversible FAPP. In your example 
above, one can imagine the outgoing photons bending around super dense 
masses and returning to their original positions or states. So I would say 
this outcome is Irreversible FAPP, but you say it's Irreversible, meaning 
Absolutely Irreversible or Irreversible in Principle. So which is it? AG *

*The more interesting issue is whether the WF in the Cat experiment, or for 
an atom with a half life for decay, evolves in time while the box is 
closed. I say it must evolve because the probability amplitudes are time 
dependent. What say you? AG*



> Brent
>

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Re: Interpretation of Superposition

[Brent Meeker]

On 10/19/2018 10:59 AM, agrayson2...@gmail.com wrote:



On Friday, October 19, 2018 at 5:44:10 PM UTC, Brent wrote:



On 10/19/2018 12:17 AM, agrays...@gmail.com  wrote:



*I can see how recoherence is impossible FAPP, but after
some time elapses the state of the cat could Dead or Alive;
not necessarily the original state, Alive. A*G


When recoherence is no longer possible that's a real physical
change.  The system has evolved.


*Since decoherence is a unitary process, isn't recoherence always
possible, even if not FAPP? AG*


Sure.  If you could reverse the outgoing waves and the local universe.


*Since recoherence is always possible, even if astronomically unlikely 
like many physical macro processes, why do you make the point that 
there's a real physical change when it's no longer possible (which is 
never)?  I ask because your comment is confusing. AG*


That's the real physical change.  Outgoing radiation has left at the 
speed of light out into an expanding universe; it ain't comin' back.  
Why is that confusing?


Brent

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Re: Interpretation of Superposition

[Bruno Marchal]

> On 18 Oct 2018, at 21:57, Brent Meeker  wrote:
> 
> 
> 
> On 10/18/2018 8:11 AM, Bruno Marchal wrote:
>>> On 16 Oct 2018, at 21:13, Brent Meeker  wrote:
>>> 
>>> 
>>> 
>>> On 10/16/2018 7:40 AM, Bruno Marchal wrote:
 The problem of the “many-world” is that a “world” is not an easy concept 
 that we could take for granted.
>>> But it's the concept used in modal logic.
>> 
>> Yes, but there a world is defined by an element of a set. The “worlds” of 
>> modal logic are quite abtract.
> 
> Just like arithmetic.

Arithmetic is one concrete world, compared to the notion of world used in modal 
logic.

In fact, I can’t imagine something more concrete than the atomic arithmetical 
proposition. 
Our brain has a lot of work to do to make us believe the contrary.

Bruno



> 
> Brent
> 
>> They relate to the world of metaphysics like the gravitation center of the 
>> sun relate to the sun. But identifying the sun to a point makes sense, to 
>> study the orbit of earth, and the “world” of modal logic makes sense to 
>> prove the independence of modal logical formula.
>> 
>> Bruno
>> 
>> 
>> 
>>> Brent
>>> 
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Re: Interpretation of Superposition

[Bruno Marchal]

> On 18 Oct 2018, at 21:56, Brent Meeker  wrote:
> 
> 
> 
> On 10/18/2018 8:07 AM, Bruno Marchal wrote:
>> Goldblatt, the modal logician who has studied S4Grz, but also the modal 
>> logic B and shown its relation with Quantum logics, which I use to extract 
>> quantum logic from arithmetic self-reference, has also studied a modality 
>> related to 4-dimensional Minkowski space-time (the modality is “now and 
>> forever”.
> 
> So this modality is derived from relativity theory.  Does that show that 
> relativity theory is ontologically prior to it?

No. Why would it? And Diodorus found that modality a long time before 
relativity theory. 

It is unclear if by relativity theory you talk about the human theories off it, 
the model obeying to it, like a possible universe or the possible view on all 
computations. 

Bruno





> 
> Brent
> 
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Re: Interpretation of Superposition

[agrayson2000]

On Friday, October 19, 2018 at 5:44:10 PM UTC, Brent wrote:
>
>
>
> On 10/19/2018 12:17 AM, agrays...@gmail.com  wrote:
>
> *I can see how recoherence is impossible FAPP, but after some time elapses 
>> the state of the cat could Dead or Alive; not necessarily the original 
>> state, Alive. A*G  
>>
>>
>> When recoherence is no longer possible that's a real physical change.  
>> The system has evolved.
>>
>
> *Since decoherence is a unitary process, isn't recoherence always 
> possible, even if not FAPP? AG*
>
>
> Sure.  If you could reverse the outgoing waves and the local universe.
>

*Since recoherence is always possible, even if astronomically unlikely like 
many physical macro processes, why do you make the point that there's a 
real physical change when it's no longer possible (which is never)?  I ask 
because your comment is confusing. AG*

>
> Brent
>

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Re: Interpretation of Superposition

[Brent Meeker]

On 10/19/2018 12:17 AM, agrayson2...@gmail.com wrote:



*I can see how recoherence is impossible FAPP, but after some
time elapses the state of the cat could Dead or Alive; not
necessarily the original state, Alive. A*G


When recoherence is no longer possible that's a real physical
change.  The system has evolved.


*Since decoherence is a unitary process, isn't recoherence is always 
possible, even if not FAPP? AG*


Sure.  If you could reverse the outgoing waves and the local universe.

Brent

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Re: Interpretation of Superposition

[agrayson2000]

On Thursday, October 18, 2018 at 8:33:10 PM UTC, Brent wrote:
>
>
>
> On 10/18/2018 12:16 PM, agrays...@gmail.com  wrote:
>
>
>
> On Monday, October 15, 2018 at 11:17:56 AM UTC, Bruce wrote: 
>>
>> From: 
>>
>>
>> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote: 
>>>
>>> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
>>> > In a two state system, such as a qubit, what forces the interpretation 
>>> > that the system is in both states simultaneously before measurement, 
>>> > versus the interpretation that we just don't what state it's in before 
>>> > measurement? Is the latter interpretation equivalent to Einstein 
>>> > Realism? And if so, is this the interpretation allegedly falsified by 
>>> > Bell experiments? AG 
>>>
>>> It is indeed inconsistent with QM itself as Bell has shown. Experiments 
>>> have later demonstrated that the Bell inequalities are violated in 
>>> precisely the way predicted by QM.  This then rules out local hidden 
>>> variables, therefore the information about the outcome of a measurement 
>>> is not already present locally in the environment. 
>>>
>>> Saibal 
>>>
>>
>> What puzzles me is this; why would the Founders assume that a system in a 
>> superposition is in all component states simultaneously -- contradicting 
>> the intuitive appeal of Einstein realism -- when that assumption is not 
>> used in calculating probabilities (since the component states are 
>> orthogonal)? AG
>>
>>
>> I think the problem arises with thinking of a superposition as an 
>> expression of a fact of the system being in all components of the 
>> superposition simultaneously. This mistaken interpretation leads to the 
>> Schrödinger cat paradox, which you have worried about for a while.
>>
>> But this is a mistake. A superposition is just an expansion of a wave 
>> function in some basis or the other -- the choice of basis is arbitrary, so 
>> it makes no sense to think of this expansion as representing anything that 
>> happens in "reality" (in Einstein's sense of "reality"). The state is still 
>> the original state until decoherence kicks in 
>>
>
>
> *Here's where I think you're mistaken. When the box is closed in the Cat 
> experiment, time continues to increase, so the wf evolves independent of 
> decoherence; before it sets in; before it takes effect, however short that 
> duration might be. But since the expansion of the superposition is 
> arbitrary wrt the basis used in the expansion, it still makes no sense to 
> attribute any physical reality to it, much less a simultaneous state of all 
> components. Do agree with this? TIA, AG *
>
>
> This example gets confused.  Schroedinger intended it to be absurd and it 
> was absurd not only because the cat was both alive and dead at the same 
> time but also because it suddenly changed to one or the other when he 
> looked in.  In fact there can be non "wf evolves independent of coherence" 
> when the box is closed.  
>

*Assuming no decoherence, the wf must evolve while the box is shut since 
the probability amplitudes are time dependent. AG *
 

> The cat, the box, the very spacetime field of the radioactive decay 
> products are enough for decoherence to have occurred.  The over 
> idealization makes it hard to discuss these because all talk of the cat in 
> a superposition is metaphorical.  It would be much clearer if you just 
> discussed a single radioactive atom, say a beta emitter, in a "box" that is 
> just a location you can inspect in the vacuum.  Until you test it the atom 
> is in a superposition of decayed and not-decayed.  Whenever it decays, that 
> is a definite event; the state of the datom decoheres into mixture of 
> decayed or not-decayed because of interaction with the degrees of freedom 
> of the electron and anti-neutrino fields.  So the superposition is best 
> thought of as your mathematical representation of the atom, which changes 
> when you test it.
>

*I'll get back to this later. AG*

>
> I've assumed that your test is just for decayed vs not-decayed.  But you 
> could also consider the direction of emission by looking at the recoil of 
> the atom.  In that case your not-decayed state is a superposition of all 
> possible recoil directions you can measure and the decayed state 
> corresponds with just one of those directions.
>
>  
>
>> and then, because of einselection of a preferred basis, we can say that 
>> the separate states are "real" -- namely orthogonal, so that one other 
>> other is chosen. Until that time, the only state around is the original 
>> state, as can be demonstrated by the possibility of recoherence, in which 
>> case you recover just the initial state and nothing else.
>>
>
> *I can see how recoherence is impossible FAPP, but after some time elapses 
> the state of the cat could Dead or Alive; not necessarily the original 
> state, Alive. A*G  
>
>
> When recoherence is no longer possible that's a real physical change.  The 
> system has evolved.
>
> Brent
>
>
>> So for 

Re: Interpretation of Superposition

[agrayson2000]

On Thursday, October 18, 2018 at 8:33:10 PM UTC, Brent wrote:
>
>
>
> On 10/18/2018 12:16 PM, agrays...@gmail.com  wrote:
>
>
>
> On Monday, October 15, 2018 at 11:17:56 AM UTC, Bruce wrote: 
>>
>> From: 
>>
>>
>> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote: 
>>>
>>> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
>>> > In a two state system, such as a qubit, what forces the interpretation 
>>> > that the system is in both states simultaneously before measurement, 
>>> > versus the interpretation that we just don't what state it's in before 
>>> > measurement? Is the latter interpretation equivalent to Einstein 
>>> > Realism? And if so, is this the interpretation allegedly falsified by 
>>> > Bell experiments? AG 
>>>
>>> It is indeed inconsistent with QM itself as Bell has shown. Experiments 
>>> have later demonstrated that the Bell inequalities are violated in 
>>> precisely the way predicted by QM.  This then rules out local hidden 
>>> variables, therefore the information about the outcome of a measurement 
>>> is not already present locally in the environment. 
>>>
>>> Saibal 
>>>
>>
>> What puzzles me is this; why would the Founders assume that a system in a 
>> superposition is in all component states simultaneously -- contradicting 
>> the intuitive appeal of Einstein realism -- when that assumption is not 
>> used in calculating probabilities (since the component states are 
>> orthogonal)? AG
>>
>>
>> I think the problem arises with thinking of a superposition as an 
>> expression of a fact of the system being in all components of the 
>> superposition simultaneously. This mistaken interpretation leads to the 
>> Schrödinger cat paradox, which you have worried about for a while.
>>
>> But this is a mistake. A superposition is just an expansion of a wave 
>> function in some basis or the other -- the choice of basis is arbitrary, so 
>> it makes no sense to think of this expansion as representing anything that 
>> happens in "reality" (in Einstein's sense of "reality"). The state is still 
>> the original state until decoherence kicks in 
>>
>
>
> *Here's where I think you're mistaken. When the box is closed in the Cat 
> experiment, time continues to increase, so the wf evolves independent of 
> decoherence; before it sets in; before it takes effect, however short that 
> duration might be. But since the expansion of the superposition is 
> arbitrary wrt the basis used in the expansion, it still makes no sense to 
> attribute any physical reality to it, much less a simultaneous state of all 
> components. Do agree with this? TIA, AG *
>
>
> This example gets confused.  Schroedinger intended it to be absurd and it 
> was absurd not only because the cat was both alive and dead at the same 
> time but also because it suddenly changed to one or the other when he 
> looked in.  In fact there can be non "wf evolves independent of coherence" 
> when the box is closed.  The cat, the box, the very spacetime field of the 
> radioactive decay products are enough for decoherence to have occurred.  
> The over idealization makes it hard to discuss these because all talk of 
> the cat in a superposition is metaphorical.  It would be much clearer if 
> you just discussed a single radioactive atom, say a beta emitter, in a 
> "box" that is just a location you can inspect in the vacuum.  Until you 
> test it the atom is in a superposition of decayed and not-decayed.  
> Whenever it decays, that is a definite event; the state of the atom 
> decoheres into mixture of decayed or not-decayed because of interaction 
> with the degrees of freedom of the electron and anti-neutrino fields.  So 
> the superposition is best thought of as your mathematical representation of 
> the atom, which changes when you test it.
>
> I've assumed that your test is just for decayed vs not-decayed.  But you 
> could also consider the direction of emission by looking at the recoil of 
> the atom.  In that case your not-decayed state is a superposition of all 
> possible recoil directions you can measure and the decayed state 
> corresponds with just one of those directions.
>
>  
>
>> and then, because of einselection of a preferred basis, we can say that 
>> the separate states are "real" -- namely orthogonal, so that one other 
>> other is chosen. Until that time, the only state around is the original 
>> state, as can be demonstrated by the possibility of recoherence, in which 
>> case you recover just the initial state and nothing else.
>>
>
> *I can see how recoherence is impossible FAPP, but after some time elapses 
> the state of the cat could Dead or Alive; not necessarily the original 
> state, Alive. A*G  
>
>
> When recoherence is no longer possible that's a real physical change.  The 
> system has evolved.
>

*Since decoherence is a unitary process, isn't recoherence is always 
possible, even if not FAPP? AG*

>
> Brent
>
>
>> So for Schrödinger's cat, for example, if you could recohere the system 
>> 

Re: Interpretation of Superposition

[Brent Meeker]

On 10/18/2018 12:16 PM, agrayson2...@gmail.com wrote:



On Monday, October 15, 2018 at 11:17:56 AM UTC, Bruce wrote:

From: >


On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:

On 14-10-2018 15:24, agrays...@gmail.com wrote:
> In a two state system, such as a qubit, what forces the
interpretation
> that the system is in both states simultaneously before
measurement,
> versus the interpretation that we just don't what state
it's in before
> measurement? Is the latter interpretation equivalent to
Einstein
> Realism? And if so, is this the interpretation allegedly
falsified by
> Bell experiments? AG

It is indeed inconsistent with QM itself as Bell has shown.
Experiments
have later demonstrated that the Bell inequalities are
violated in
precisely the way predicted by QM.  This then rules out local
hidden
variables, therefore the information about the outcome of a
measurement
is not already present locally in the environment.

Saibal


What puzzles me is this; why would the Founders assume that a
system in a superposition is in all component states
simultaneously -- contradicting the intuitive appeal of Einstein
realism -- when that assumption is not used in calculating
probabilities (since the component states are orthogonal)? AG


I think the problem arises with thinking of a superposition as an
expression of a fact of the system being in all components of the
superposition simultaneously. This mistaken interpretation leads
to the Schrödinger cat paradox, which you have worried about for a
while.

But this is a mistake. A superposition is just an expansion of a
wave function in some basis or the other -- the choice of basis is
arbitrary, so it makes no sense to think of this expansion as
representing anything that happens in "reality" (in Einstein's
sense of "reality"). The state is still the original state until
decoherence kicks in


*Here's where I think you're mistaken. When the box is closed in the 
Cat experiment, time continues to increase, so the wf evolves 
independent of decoherence; before it sets in; before it takes effect, 
however short that duration might be. But since the expansion of the 
superposition is arbitrary wrt the basis used in the expansion, it 
still makes no sense to attribute any physical reality to it, much 
less a simultaneous state of all components. Do agree with this? TIA, AG

*


This example gets confused.  Schroedinger intended it to be absurd and 
it was absurd not only because the cat was both alive and dead at the 
same time but also because it suddenly changed to one or the other when 
he looked in.  In fact there can be non "wf evolves independent of 
coherence" when the box is closed.  The cat, the box, the very spacetime 
field of the radioactive decay products are enough for decoherence to 
have occurred.  The over idealization makes it hard to discuss these 
because all talk of the cat in a superposition is metaphorical.  It 
would be much clearer if you just discussed a single radioactive atom, 
say a beta emitter, in a "box" that is just a location you can inspect 
in the vacuum.  Until you test it the atom is in a superposition of 
decayed and not-decayed. Whenever it decays, that is a definite event; 
the state of the atom decoheres into mixture of decayed or not-decayed 
because of interaction with the degrees of freedom of the electron and 
anti-neutrino fields.  So the superposition is best thought of as your 
mathematical representation of the atom, which changes when you test it.


I've assumed that your test is just for decayed vs not-decayed.  But you 
could also consider the direction of emission by looking at the recoil 
of the atom.  In that case your not-decayed state is a superposition of 
all possible recoil directions you can measure and the decayed state 
corresponds with just one of those directions.



and then, because of einselection of a preferred basis, we can say
that the separate states are "real" -- namely orthogonal, so that
one other other is chosen. Until that time, the only state around
is the original state, as can be demonstrated by the possibility
of recoherence, in which case you recover just the initial state
and nothing else.


*I can see how recoherence is impossible FAPP, but after some time 
elapses the state of the cat could Dead or Alive; not necessarily the 
original state, Alive. A*G


When recoherence is no longer possible that's a real physical change.  
The system has evolved.


Brent



So for Schrödinger's cat, for example, if you could recohere the
system after one hour, say, you would find the cat alive in the
box and the vial of cyanide unbroken with the radioactive atom
undecayed -- exactly as you set the 

Re: Interpretation of Superposition

[Brent Meeker]

On 10/18/2018 8:11 AM, Bruno Marchal wrote:

On 16 Oct 2018, at 21:13, Brent Meeker  wrote:



On 10/16/2018 7:40 AM, Bruno Marchal wrote:

The problem of the “many-world” is that a “world” is not an easy concept that 
we could take for granted.

But it's the concept used in modal logic.


Yes, but there a world is defined by an element of a set. The “worlds” of modal 
logic are quite abtract.


Just like arithmetic.

Brent


They relate to the world of metaphysics like the gravitation center of the sun 
relate to the sun. But identifying the sun to a point makes sense, to study the 
orbit of earth, and the “world” of modal logic makes sense to prove the 
independence of modal logical formula.

Bruno




Brent

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Re: Interpretation of Superposition

[Brent Meeker]

On 10/18/2018 8:07 AM, Bruno Marchal wrote:
Goldblatt, the modal logician who has studied S4Grz, but also the 
modal logic B and shown its relation with Quantum logics, which I use 
to extract quantum logic from arithmetic self-reference, has also 
studied a modality related to 4-dimensional Minkowski space-time (the 
modality is “now and forever”.


So this modality is derived from relativity theory.  Does that show that 
relativity theory is ontologically prior to it?


Brent

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Re: Interpretation of Superposition

[agrayson2000]

On Monday, October 15, 2018 at 11:17:56 AM UTC, Bruce wrote:
>
> From: >
>
>
> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote: 
>>
>> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
>> > In a two state system, such as a qubit, what forces the interpretation 
>> > that the system is in both states simultaneously before measurement, 
>> > versus the interpretation that we just don't what state it's in before 
>> > measurement? Is the latter interpretation equivalent to Einstein 
>> > Realism? And if so, is this the interpretation allegedly falsified by 
>> > Bell experiments? AG 
>>
>> It is indeed inconsistent with QM itself as Bell has shown. Experiments 
>> have later demonstrated that the Bell inequalities are violated in 
>> precisely the way predicted by QM.  This then rules out local hidden 
>> variables, therefore the information about the outcome of a measurement 
>> is not already present locally in the environment. 
>>
>> Saibal 
>>
>
> What puzzles me is this; why would the Founders assume that a system in a 
> superposition is in all component states simultaneously -- contradicting 
> the intuitive appeal of Einstein realism -- when that assumption is not 
> used in calculating probabilities (since the component states are 
> orthogonal)? AG
>
>
> I think the problem arises with thinking of a superposition as an 
> expression of a fact of the system being in all components of the 
> superposition simultaneously. This mistaken interpretation leads to the 
> Schrödinger cat paradox, which you have worried about for a while.
>
> But this is a mistake. A superposition is just an expansion of a wave 
> function in some basis or the other -- the choice of basis is arbitrary, so 
> it makes no sense to think of this expansion as representing anything that 
> happens in "reality" (in Einstein's sense of "reality"). The state is still 
> the original state until decoherence kicks in 
>


*Here's where I think you're mistaken. When the box is closed in the Cat 
experiment, time continues to increase, so the wf evolves independent of 
decoherence; before it sets in; before it takes effect, however short that 
duration might be. But since the expansion of the superposition is 
arbitrary wrt the basis used in the expansion, it still makes no sense to 
attribute any physical reality to it, much less a simultaneous state of all 
components. Do agree with this? TIA, AG*
 

> and then, because of einselection of a preferred basis, we can say that 
> the separate states are "real" -- namely orthogonal, so that one other 
> other is chosen. Until that time, the only state around is the original 
> state, as can be demonstrated by the possibility of recoherence, in which 
> case you recover just the initial state and nothing else.
>

*I can see how recoherence is impossible FAPP, but after some time elapses 
the state of the cat could Dead or Alive; not necessarily the original 
state, Alive. A*G  

>
> So for Schrödinger's cat, for example, if you could recohere the system 
> after one hour, say, you would find the cat alive in the box and the vial 
> of cyanide unbroken with the radioactive atom undecayed -- exactly as you 
> set the system up. It is only because the cat and apparatus are large warm 
> classical objects that this recoherence is not possible FAPP. To think of 
> the cat at some intermediate time as being both dead and alive is just a 
> confusion -- it is at all times either one or the other.
>

*The Cat does have an intermediate state since time is evolving causing the 
wf to evolve, but as I argue above, it's not in both states of the 
superposition because the choice of basis is arbitrary, and by extension, 
certainly not in both states simultaneously.  I generally agree with your 
arguments, which I articulated half-a-dozen times or more last summer, but 
no one here seemed to understand or agree. When you remind us that the 
choice of basis is arbitrary, this is KEY, and all one has to do is apply 
what's anathema to see the seminal error; common sense applied to the fact 
that the basis used in the superposition is arbitrary! It seems there 
remains an undeserved impulse, a cottage industry as it were, to claim some 
mysteries in QM that don't exist. AG *

>
> Bruce
>

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Re: Interpretation of Superposition

[Bruno Marchal]

> On 17 Oct 2018, at 00:33, Bruce Kellett  wrote:
> 
> From: mailto:agrayson2...@gmail.com>>
>> 
>> On Monday, October 15, 2018 at 3:28:17 PM UTC, agrays...@gmail.com 
>>  wrote:
>> 
>> On Monday, October 15, 2018 at 11:17:56 AM UTC, Bruce wrote:
>> 
>> 
>> The state is still the original state until decoherence kicks in and then, 
>> because of einselection of a preferred basis, we can say that the separate 
>> states are "real" -- namely orthogonal, so that one other other is chosen. 
>> Until that time, the only state around is the original state, as can be 
>> demonstrated by the possibility of recoherence, in which case you recover 
>> just the initial state and nothing else.
>> 
>> Aren't the component states orthogonal prior to decoherence? IIUC, they must 
>> be if they have distinct eigenvalues. AG
>> 
>> I conclude that not every superposition has components that are eigenvectors 
>> of the operator for the observable. So these components are not orthogonal. 
>> But there is always an expansion whose components are eigenvectors and thus 
>> are orthogonal. I don't think this has anything to do with decoherence. AG
> 
> My use of the word "orthogonal" was careless -- basis vectors can be 
> orthogonal or not, it makes no difference to the state or the fact of 
> superposition. What I meant about decoherence was that it renders the density 
> matrix diagonal (FAPP), so that the superposed states no longer interfere.
> 
>> What continues to puzzle me is why the alleged experts here of quantum 
>> computing (and I think Wiki as well) claim that qbits are in both states 
>> simultaneously, when we know this is not a correct interpretation of a 
>> superposition. Does the theory of quantum computing depend in any way on 
>> what appears to be an erroneous interpretation of a superposition? TIA, AG
> 
> I leave quantum computing experts to comment on this, but I tend to think 
> that such language is misleading at best.

I might develop this when I have more time, and it is anything but easy. Let me 
say that it is hard for me to conceive that the superposition are not all real 
“in some sense” to understand how the quantum Fourier transform work. It is 
hard for me to conceive a non “many-things” theory to remain a bit realist on 
physics, and to grasp how a (quantum) computer can physically factorise a big 
number n (in polynomial time P(n)).

That might be as complex as showing that P = NP. 

Bruno





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Re: Interpretation of Superposition

[Bruno Marchal]

> On 16 Oct 2018, at 21:13, Brent Meeker  wrote:
> 
> 
> 
> On 10/16/2018 7:40 AM, Bruno Marchal wrote:
>> 
>> The problem of the “many-world” is that a “world” is not an easy concept 
>> that we could take for granted.
> 
> But it's the concept used in modal logic.


Yes, but there a world is defined by an element of a set. The “worlds” of modal 
logic are quite abtract. They relate to the world of metaphysics like the 
gravitation center of the sun relate to the sun. But identifying the sun to a 
point makes sense, to study the orbit of earth, and the “world” of modal logic 
makes sense to prove the independence of modal logical formula.

Bruno



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Re: Interpretation of Superposition

[Bruno Marchal]

> On 16 Oct 2018, at 05:29, Brent Meeker  wrote:
> 
> 
> 
> On 10/15/2018 11:21 AM, smitra wrote:
>> On 15-10-2018 12:40, agrayson2...@gmail.com wrote:
>>> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:
>>> 
 On 14-10-2018 15:24, agrays...@gmail.com wrote:
> In a two state system, such as a qubit, what forces the
 interpretation
> that the system is in both states simultaneously before
 measurement,
> versus the interpretation that we just don't what state it's in
 before
> measurement? Is the latter interpretation equivalent to Einstein
> Realism? And if so, is this the interpretation allegedly falsified
 by
> Bell experiments? AG
 
 It is indeed inconsistent with QM itself as Bell has shown.
 Experiments
 have later demonstrated that the Bell inequalities are violated in
 precisely the way predicted by QM. This then rules out local hidden
 
 variables, therefore the information about the outcome of a
 measurement
 is not already present locally in the environment.
 
 Saibal
>>> 
>>> What puzzles me is this; why would the Founders assume that a system
>>> in a superposition is in all component states simultaneously --
>>> contradicting the intuitive appeal of Einstein realism -- when that
>>> assumption is not used in calculating probabilities (since the
>>> component states are orthogonal)? AG
>> 
>> It may look like one can re-interpret QM as being consistent with Einstein 
>> realism, but Bell disproved this (if you assume locality). Note also what 
>> Bruce said about "simultaneously".
>> 
>> My own idea is that we need to think about how to interpret time evolution, 
>> instead of making all this fuss about superpositions. Without collapse, the 
>> time evolution of a system can be interpreted as a simple change of basis. 
>> You still have access to the initial state, at least in theory. But if the 
>> system collapses (in the MWI this is then an effective collapse due to you 
>> getting entangled with the system), you cannot access the initial state 
>> anymore (in practice, you might not have been able to do that anyway).
>> 
>> This all suggests to me that we live in a multiverse where each moment of 
>> time defines a different universe, memories of the past refer to alternative 
>> universes. We need to keep in mind that in experiments we can only ever 
>> directly measure the present state. 
> 
> But what does 'the present state' mean?  The present second?  The present 
> milli-second?  "Present" is not a relativistic concept.

I would have said that “present” is the most relativistic concept ever. It 
depends on t. (I don’t put an exclamation point to avoid a confusion with the 
factorial).

Now, I might agree that “present state of mind”, a bit like “observer moment” 
is a rather fuzzy term.

In the logic of the first person, that is, the logic S4Grz (the logic of []p & 
p), which is also a logic of subjective time, and which is imposed by 
incompleteness, there are topological model where the “present instant” is a 
enumerable sequence of interval enclosing each other. The intersection of all 
those interval is not an open set, and does not itself belong to the "present 
instant”.

Goldblatt, the modal logician who has studied S4Grz, but also the modal logic B 
and shown its relation with Quantum logics, which I use to extract quantum 
logic from arithmetic self-reference, has also studied a modality related to 
4-dimensional Minkowski space-time (the modality is “now and forever”. It shows 
it to obey a modality studied by Diodorus, and known as the Dioderean Modality 
by the Ancient, and is characteristic axiom is <>[]p -> []<>p, known by modern 
logician as 2. S4.2 is the logic S4 + that formula named “2”. 

I speculate that X1* (the logic of []p & <>t & p, atomic p obeying p -> []p, 
(the modal view of sigma_1 completeness, the restriction to the computable, 
computationalism translated into a language that the universal machine can 
understand) might hide some interesting modalities, imposing relativistic 
geometry on the structure of the present instant. 

Bruno


(*) Goldblatt, Robert. Diodorean Modality in Minkowski Space time, Studia 
Logica 39 (1980), 219-236.

The other two keys paper (used in an important way in my derivations) are

GOLDBLATT R., 1978, Arithmetical Necessity, Provability and Intuitionistic 
Logic, Theoria, Vol 44, pp. 38-46.

For the intutionistic logic of the first person (the first person I)

and,

GOLDBLATT R. I., 1974, Semantic Analysis of Orthologic, Journal of 
Philosophical Logic, 3, pp. 19-35. 

for the extraction of the (variate) yet orthomodular quantum logics. Here the 
fact that “orthomodilarity” is not elementary (definable in first order logic) 
comes from the fact that Löb’s formula is itself not elementary.






> 
>> If you dig up a bone of a dinosaur, what you are seeing is a result of 
>> processes in your brain right now. These are then 

Re: Interpretation of Superposition

[Bruno Marchal]

> On 16 Oct 2018, at 00:18, Bruce Kellett  wrote:
> 
> From: smitra mailto:smi...@zonnet.nl>>
>> 
>> It may look like one can re-interpret QM as being consistent with 
>> Einstein realism, but Bell disproved this (if you assume locality). Note 
>> also what Bruce said about "simultaneously".
>> 
>> My own idea is that we need to think about how to interpret time 
>> evolution, instead of making all this fuss about superpositions. Without 
>> collapse, the time evolution of a system can be interpreted as a simple 
>> change of basis. You still have access to the initial state, at least in 
>> theory. But if the system collapses (in the MWI this is then an 
>> effective collapse due to you getting entangled with the system), you 
>> cannot access the initial state anymore (in practice, you might not have 
>> been able to do that anyway).
> 
> I think this is the important observation for MWI vs collapse. In MWI, 
> entanglement of the observer with the system is an effective collapse -- one 
> no longer has access to either the initial state or to the other branches of 
> the superposition.

I agree with this, although Mitra’s use of “effective” can be misleading. There 
is collapse at all, but for the point of view of the observers, it is an 
irreversible collapse in all practical interactions (involving a large number 
of parameters).



> This is the heart of Bruno's FPI,

Right!


> and it means that MWI is only of philosophical interest -- it cannot have any 
> relevance as an explanation of experience.

Except that, unlike Saibal, I do not assume a physical universe, and explain 
its appearance by that “effective collapse”, due to the fact that computations 
diverge all the time in arithmetic (due to different data, or oracles, …) and 
consciousness differentiate accordingly. 

I am not the one saying that arithmetic (theories of models) emulates all 
computations. That has been discovered somehow by Gödel (who missed the 
Church’s thesis, and so did not see the impact) but rediscovered by Turing, and 
related by Turing, and many others, to his thesis (and thus too Church’s one).

That theory, which is just mechanism (which presupposed arithmetic or Turing 
equivalent, but nothing more) explains the origin of the physical reality, 
which becomes indeed part of the “observable” phenomenology of the universal 
Turing machine.

It might not be used in any particle physics, but that was never its intent, 
which is more about the complete global picture and explanation based on simple 
principle that everyone agree with, like x + 0 = x, etc.
It says something theological, if only because it make first person death non 
sensical, and show that most question about the relation between mind and 
matter remains extremely complex, yet formulable into equations. 

Bruno




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> 
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Re: Interpretation of Superposition

[Bruce Kellett]

From: mailto:agrayson2...@gmail.com>>


On Monday, October 15, 2018 at 3:28:17 PM UTC, agrays...@gmail.com 
 wrote:



On Monday, October 15, 2018 at 11:17:56 AM UTC, Bruce wrote:


The state is still the original state until decoherence kicks
in and then, because of einselection of a preferred basis, we
can say that the separate states are "real" -- namely
orthogonal, so that one other other is chosen. Until that
time, the only state around is the original state, as can be
demonstrated by the possibility of recoherence, in which case
you recover just the initial state and nothing else.


*Aren't the component states orthogonal prior to decoherence?
IIUC, they must be if they have distinct eigenvalues. AG*


*I conclude that not every superposition has components that are 
eigenvectors of the operator for the observable. So these components 
are not orthogonal. But there is always an expansion whose components 
are eigenvectors and thus are orthogonal. I don't think this has 
anything to do with decoherence. AG

*


My use of the word "orthogonal" was careless -- basis vectors can be 
orthogonal or not, it makes no difference to the state or the fact of 
superposition. What I meant about decoherence was that it renders the 
density matrix diagonal (FAPP), so that the superposed states no longer 
interfere.


*What continues to puzzle me is why the alleged experts here of 
quantum computing (and I think Wiki as well) claim that qbits are in 
both states simultaneously, when we know this is not a correct 
interpretation of a superposition. Does the theory of quantum 
computing depend in any way on what appears to be an erroneous 
interpretation of a superposition? TIA, AG*


I leave quantum computing experts to comment on this, but I tend to 
think that such language is misleading at best.


Bruce

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Re: Interpretation of Superposition

[Brent Meeker]

On 10/16/2018 7:40 AM, Bruno Marchal wrote:


The problem of the “many-world” is that a “world” is not an easy 
concept that we could take for granted.


But it's the concept used in modal logic.

Brent

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Re: Interpretation of Superposition

[Philip Thrift]

On Tuesday, October 16, 2018 at 9:40:05 AM UTC-5, Bruno Marchal wrote:
>
>
> On 14 Oct 2018, at 20:01, Philip Thrift > 
> wrote:
>
>
>
> On Sunday, October 14, 2018 at 8:24:29 AM UTC-5, agrays...@gmail.com 
> wrote:
>>
>> In a two state system, such as a qubit, what forces the interpretation 
>> that the system is in both states simultaneously before measurement, versus 
>> the interpretation that we just don't what state it's in before 
>> measurement? Is the latter interpretation equivalent to Einstein Realism? 
>> And if so, is this the interpretation allegedly falsified by Bell 
>> experiments? AG
>>
>
>
> Interpretations of quantum computing (QC) follow interpretations of 
> quantum mechanics (QM) itself.
>
> Here's two:
>
> 1. *An introduction to many worlds in quantum computation*
> - https://arxiv.org/pdf/0802.2504.pdf
>
> 2. *The sum-over-histories formulation of quantum computing*
> - https://arxiv.org/pdf/quant-ph/0607151.pdf
>
>
>
> Quite interesting paper. I wish I had more time to meditate on this, but 
> I’m rather busy up to the end of November. 
>
>
>
>
> If one is familiar with these two interpretations in QM, 
>
>
> I would call them different formulations. 
>
> Interpretation remains difficult, but as far as I grasp it, it support the 
> 0 world but many points-of-view/"dreams”  interpretation of (universal) 
> truth. (The truth on all “Turing machines”, or all “combinators").
>
>
>
> one can at least follow how they would work in a semantics for QC.
>
> As far as I know it's a matter of personal preference which one you might 
> like (but I wouldn't choose door #1!).
>
>
>
> The problem of the “many-world” is that a “world” is not an easy concept 
> that we could take for granted. Relative state is better, but sum on 
> histories can be even better. 
>
> The difficulty (when we assume mechanism) is in justifying the linearity 
> at the bottom for the "measure one” of the observable. It has become a 
> mathematical problem, just to see if the arithmetical observable (which are 
> well defined through the logics of self-reference) are linear enough.
>
> Bruno
>
>
>
>
For me, I take the Feynman Path + Backward Causation 
interpretation/formulation "realistically", hence:

The Reflective Path Integral w/ Stochastic Concurrent Prolog

and

The WPU (the Wheeler Processing Unit) and the Wheeler-Feynman (or 
Wheeler-Feynman-vonNeumann) computer.

https://codicalist.wordpress.com/2018/03/16/mirror-mirror/
https://codicalist.wordpress.com/2018/04/08/cp-stochastic-concurrent-prolog/
https://codicalist.wordpress.com/2018/05/05/a-cp-formulation-of-the-path-integral/
https://codicalist.wordpress.com/2018/09/25/retrosignaling-in-the-quantum-substrate/

- pt

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Re: Interpretation of Superposition

[agrayson2000]

On Monday, October 15, 2018 at 3:28:17 PM UTC, agrays...@gmail.com wrote:
>
>
>
> On Monday, October 15, 2018 at 11:17:56 AM UTC, Bruce wrote:
>>
>> From: 
>>
>>
>> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote: 
>>>
>>> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
>>> > In a two state system, such as a qubit, what forces the interpretation 
>>> > that the system is in both states simultaneously before measurement, 
>>> > versus the interpretation that we just don't what state it's in before 
>>> > measurement? Is the latter interpretation equivalent to Einstein 
>>> > Realism? And if so, is this the interpretation allegedly falsified by 
>>> > Bell experiments? AG 
>>>
>>> It is indeed inconsistent with QM itself as Bell has shown. Experiments 
>>> have later demonstrated that the Bell inequalities are violated in 
>>> precisely the way predicted by QM.  This then rules out local hidden 
>>> variables, therefore the information about the outcome of a measurement 
>>> is not already present locally in the environment. 
>>>
>>> Saibal 
>>>
>>
>> What puzzles me is this; why would the Founders assume that a system in a 
>> superposition is in all component states simultaneously -- contradicting 
>> the intuitive appeal of Einstein realism -- when that assumption is not 
>> used in calculating probabilities (since the component states are 
>> orthogonal)? AG
>>
>>
>> I think the problem arises with thinking of a superposition as an 
>> expression of a fact of the system being in all components of the 
>> superposition simultaneously. 
>>
>
> *This is precisely what I argued here as recently as last summer, 
> whereupon those who claim knowledge of quantum computers asserted that 
> qbits assume exactly that, that qbits are in both states simultaneously. AG*
>
> This mistaken interpretation leads to the Schrödinger cat paradox, which 
>> you have worried about for a while.
>>
>> But this is a mistake. A superposition is just an expansion of a wave 
>> function in some basis or the other -- the choice of basis is arbitrary, so 
>> it makes no sense to think of this expansion as representing anything that 
>> happens in "reality" (in Einstein's sense of "reality").
>>
>
> *I agree and argued the same last summer.  I quoted Dirac, which quote 
> appears in the Wiki article on quantum superposition, who makes the mistake 
> you reference, which IMO Schroedinger falsified. Some claim Schroedinger 
> didn't falsify the error (show it was an error) because he was unaware of 
> decoherence. I disagree with this analysis. AG*
>
> The state is still the original state until decoherence kicks in and then, 
>> because of einselection of a preferred basis, we can say that the separate 
>> states are "real" -- namely orthogonal, so that one other other is chosen. 
>> Until that time, the only state around is the original state, as can be 
>> demonstrated by the possibility of recoherence, in which case you recover 
>> just the initial state and nothing else.
>>
>
> *Aren't the component states orthogonal prior to decoherence? IIUC, they 
> must be if they have distinct eigenvalues. AG*
>


*I conclude that not every superposition has components that are 
eigenvectors of the operator for the observable. So these components are 
not orthogonal. But there is always an expansion whose components are 
eigenvectors and thus are orthogonal. I don't think this has anything to do 
with decoherence. AG*

*What continues to puzzle me is why the alleged experts here of quantum 
computing (and I think Wiki as well) claim that qbits are in both states 
simultaneously, when we know this is not a correct interpretation of a 
superposition. Does the theory of quantum computing depend in any way on 
what appears to be an erroneous interpretation of a superposition? TIA, AG*

>
>> So for Schrödinger's cat, for example, if you could recohere the system 
>> after one hour, say, you would find the cat alive in the box and the vial 
>> of cyanide unbroken with the radioactive atom undecayed -- exactly as you 
>> set the system up. It is only because the cat and apparatus are large warm 
>> classical objects that this recoherence is not possible FAPP. To think of 
>> the cat at some intermediate time as being both dead and alive is just a 
>> confusion -- it is at all times either one or the other.
>>
>> Bruce
>>
>

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Re: Interpretation of Superposition

[Bruno Marchal]

> On 14 Oct 2018, at 20:01, Philip Thrift  wrote:
> 
> 
> 
> On Sunday, October 14, 2018 at 8:24:29 AM UTC-5, agrays...@gmail.com wrote:
> In a two state system, such as a qubit, what forces the interpretation that 
> the system is in both states simultaneously before measurement, versus the 
> interpretation that we just don't what state it's in before measurement? Is 
> the latter interpretation equivalent to Einstein Realism? And if so, is this 
> the interpretation allegedly falsified by Bell experiments? AG
> 
> 
> Interpretations of quantum computing (QC) follow interpretations of quantum 
> mechanics (QM) itself.
> 
> Here's two:
> 
> 1. An introduction to many worlds in quantum computation
> - https://arxiv.org/pdf/0802.2504.pdf
> 
> 2. The sum-over-histories formulation of quantum computing
> - https://arxiv.org/pdf/quant-ph/0607151.pdf


Quite interesting paper. I wish I had more time to meditate on this, but I’m 
rather busy up to the end of November. 



> 
> If one is familiar with these two interpretations in QM,

I would call them different formulations. 

Interpretation remains difficult, but as far as I grasp it, it support the 0 
world but many points-of-view/"dreams”  interpretation of (universal) truth. 
(The truth on all “Turing machines”, or all “combinators").



> one can at least follow how they would work in a semantics for QC.
> 
> As far as I know it's a matter of personal preference which one you might 
> like (but I wouldn't choose door #1!).


The problem of the “many-world” is that a “world” is not an easy concept that 
we could take for granted. Relative state is better, but sum on histories can 
be even better. 

The difficulty (when we assume mechanism) is in justifying the linearity at the 
bottom for the "measure one” of the observable. It has become a mathematical 
problem, just to see if the arithmetical observable (which are well defined 
through the logics of self-reference) are linear enough.

Bruno




>  
> - pt
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Re: Interpretation of Superposition

[Bruce Kellett]

From: *Brent Meeker* mailto:meeke...@verizon.net>>


On 10/15/2018 10:29 PM, Bruce Kellett wrote:

From: *Brent Meeker* mailto:meeke...@verizon.net>>


On 10/15/2018 11:21 AM, smitra wrote:

> This all suggests to me that we live in a multiverse where each 
moment

> of time defines a different universe, memories of the past refer to
> alternative universes. We need to keep in mind that in experiments we
> can only ever directly measure the present state.

But what does 'the present state' mean?  The present second?  The
present milli-second?  "Present" is not a relativistic concept.


Your pedantry is misplaced. The present state and the present moment 
are both sufficiently well-defined for quantum system essentially at 
rest relative to you in your laboratory. The view of some remote 
observer with relative velocity approaching that of light is not a 
relevant consideration.


It is relevant to which parts of a non-local state are in the 
"present" when we measure the state.


Muddying the waters by irrelevant references to EPR and non-locality 
again, Brent? We are talking about superposition, not entanglement...


Bruce

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Re: Interpretation of Superposition

[Brent Meeker]

On 10/15/2018 10:29 PM, Bruce Kellett wrote:

From: *Brent Meeker* mailto:meeke...@verizon.net>>


On 10/15/2018 11:21 AM, smitra wrote:

> This all suggests to me that we live in a multiverse where each moment
> of time defines a different universe, memories of the past refer to
> alternative universes. We need to keep in mind that in experiments we
> can only ever directly measure the present state.

But what does 'the present state' mean?  The present second?  The
present milli-second?  "Present" is not a relativistic concept.


Your pedantry is misplaced. The present state and the present moment 
are both sufficiently well-defined for quantum system essentially at 
rest relative to you in your laboratory. The view of some remote 
observer with relative velocity approaching that of light is not a 
relevant consideration.


It is relevant to which parts of a non-local state are in the "present" 
when we measure the state.


Brent



That aside, however. I do think that Saibal's idea that "each moment 
of time defines a different universe" is a bit screwball.



> If you dig up a bone of a dinosaur, what you are seeing is a result of
> processes in your brain right now. These are then the result of
> photons interacting with your eye and ultimately you can draw an
> inference about life on Earth, say, 150 million years ago.

And you can draw an inference about a few tenths of a second ago. But
you can't draw and inference about now.


But that is what you do in fact do. The laws of physics allow you to 
draw inferences from the present state into the future. Your pedantry 
is getting the better of you, Brent.


Bruce
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Re: Interpretation of Superposition

[Bruce Kellett]

From: *Brent Meeker* mailto:meeke...@verizon.net>>


On 10/15/2018 11:21 AM, smitra wrote:

> This all suggests to me that we live in a multiverse where each moment
> of time defines a different universe, memories of the past refer to
> alternative universes. We need to keep in mind that in experiments we
> can only ever directly measure the present state.

But what does 'the present state' mean?  The present second? The
present milli-second?  "Present" is not a relativistic concept.


Your pedantry is misplaced. The present state and the present moment are 
both sufficiently well-defined for quantum system essentially at rest 
relative to you in your laboratory. The view of some remote observer 
with relative velocity approaching that of light is not a relevant 
consideration.


That aside, however. I do think that Saibal's idea that "each moment of 
time defines a different universe" is a bit screwball.



> If you dig up a bone of a dinosaur, what you are seeing is a result of
> processes in your brain right now. These are then the result of
> photons interacting with your eye and ultimately you can draw an
> inference about life on Earth, say, 150 million years ago.

And you can draw an inference about a few tenths of a second ago. But
you can't draw and inference about now.


But that is what you do in fact do. The laws of physics allow you to 
draw inferences from the present state into the future. Your pedantry is 
getting the better of you, Brent.


Bruce

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Re: Interpretation of Superposition

[Brent Meeker]

On 10/15/2018 11:21 AM, smitra wrote:

On 15-10-2018 12:40, agrayson2...@gmail.com wrote:

On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:


On 14-10-2018 15:24, agrays...@gmail.com wrote:

In a two state system, such as a qubit, what forces the

interpretation

that the system is in both states simultaneously before

measurement,

versus the interpretation that we just don't what state it's in

before

measurement? Is the latter interpretation equivalent to Einstein
Realism? And if so, is this the interpretation allegedly falsified

by

Bell experiments? AG


It is indeed inconsistent with QM itself as Bell has shown.
Experiments
have later demonstrated that the Bell inequalities are violated in
precisely the way predicted by QM. This then rules out local hidden

variables, therefore the information about the outcome of a
measurement
is not already present locally in the environment.

Saibal


What puzzles me is this; why would the Founders assume that a system
in a superposition is in all component states simultaneously --
contradicting the intuitive appeal of Einstein realism -- when that
assumption is not used in calculating probabilities (since the
component states are orthogonal)? AG


It may look like one can re-interpret QM as being consistent with 
Einstein realism, but Bell disproved this (if you assume locality). 
Note also what Bruce said about "simultaneously".


My own idea is that we need to think about how to interpret time 
evolution, instead of making all this fuss about superpositions. 
Without collapse, the time evolution of a system can be interpreted as 
a simple change of basis. You still have access to the initial state, 
at least in theory. But if the system collapses (in the MWI this is 
then an effective collapse due to you getting entangled with the 
system), you cannot access the initial state anymore (in practice, you 
might not have been able to do that anyway).


This all suggests to me that we live in a multiverse where each moment 
of time defines a different universe, memories of the past refer to 
alternative universes. We need to keep in mind that in experiments we 
can only ever directly measure the present state. 


But what does 'the present state' mean?  The present second?  The 
present milli-second?  "Present" is not a relativistic concept.


If you dig up a bone of a dinosaur, what you are seeing is a result of 
processes in your brain right now. These are then the result of 
photons interacting with your eye and ultimately you can draw an 
inference about life on Earth, say, 150 million years ago. 


And you can draw an inference about a few tenths of a second ago. But 
you can't draw and inference about now.


Brent

But an explanation for the presence of the bones is ultimately just 
information compression, we can account for information in our 
universe "today" in terms of information present in an alternative 
"past" universe.


According to classical physics, information is conserved in a one to 
one way between the past and present, and this allows for an 
interpretation of time evolution that says that our universe is 
evolving in time. in QM this naive interpretation breaks down, 
information is not conserved after collapse when you consider only one 
term of a superposition. But there is no problem if you just stick to 
the view where each moment in time defines a universe. The idea that 
all information present in one universe can be accounted for in terms 
of a single past universe", is false.


Another aspect of this is how a particle can tunnel through a 
potential barrier. Here there is no intermediary state where the 
particle is in the "classically forbidden region". So, we have a final 
state, an initial state, but no intermediary state. Clearly this fits 
in much better with the idea that time evolution is not real, it just 
allows you to account for information in some universe in terms of 
information in other universes.


Saibal



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Re: Interpretation of Superposition

[Bruce Kellett]

From: *smitra* mailto:smi...@zonnet.nl>>


It may look like one can re-interpret QM as being consistent with
Einstein realism, but Bell disproved this (if you assume locality). Note
also what Bruce said about "simultaneously".

My own idea is that we need to think about how to interpret time
evolution, instead of making all this fuss about superpositions. Without
collapse, the time evolution of a system can be interpreted as a simple
change of basis. You still have access to the initial state, at least in
theory. But if the system collapses (in the MWI this is then an
effective collapse due to you getting entangled with the system), you
cannot access the initial state anymore (in practice, you might not have
been able to do that anyway).


I think this is the important observation for MWI vs collapse. In MWI, 
entanglement of the observer with the system is an effective collapse -- 
one no longer has access to either the initial state or to the other 
branches of the superposition. This is the heart of Bruno's FPI, and it 
means that MWI is only of philosophical interest -- it cannot have any 
relevance as an explanation of experience.


Bruce

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Re: Interpretation of Superposition

[Philip Thrift]

On Monday, October 15, 2018 at 1:21:28 PM UTC-5, smitra wrote:
>
>
> It may look like one can re-interpret QM as being consistent with 
> Einstein realism, but Bell disproved this (if you assume locality). Note 
> also what Bruce said about "simultaneously". 
>
>

Not exactly.


https://arxiv.org/abs/1510.06712

*A Live Alternative to Quantum Spooks*
Huw Price, Ken Wharton

*Quantum weirdness has been in the news recently, thanks to an ingenious 
new experiment by a team led by Roland Hanson, at the Delft University of 
Technology. Much of the coverage presents the experiment as good (even 
conclusive) news for spooky action-at-a-distance, and bad news for local 
realism. We point out that this interpretation ignores an alternative, 
namely that the quantum world is retrocausal. We conjecture that this 
loophole is missed because it is confused for superdeterminism on one side, 
or action-at-a-distance itself on the other. We explain why it is different 
from these options, and why it has clear advantages, in both cases.*

- pt

 

> My own idea is that we need to think about how to interpret time 
> evolution, instead of making all this fuss about superpositions. Without 
> collapse, the time evolution of a system can be interpreted as a simple 
> change of basis. You still have access to the initial state, at least in 
> theory. But if the system collapses (in the MWI this is then an 
> effective collapse due to you getting entangled with the system), you 
> cannot access the initial state anymore (in practice, you might not have 
> been able to do that anyway). 
>
> This all suggests to me that we live in a multiverse where each moment 
> of time defines a different universe, memories of the past refer to 
> alternative universes. We need to keep in mind that in experiments we 
> can only ever directly measure the present state. If you dig up a bone 
> of a dinosaur, what you are seeing is a result of processes in your 
> brain right now. These are then the result of photons interacting with 
> your eye and ultimately you can draw an inference about life on Earth, 
> say, 150 million years ago. But an explanation for the presence of the 
> bones is ultimately just information compression, we can account for 
> information in our universe "today" in terms of information present in 
> an alternative "past" universe. 
>
> According to classical physics, information is conserved in a one to one 
> way between the past and present, and this allows for an interpretation 
> of time evolution that says that our universe is evolving in time. in QM 
> this naive interpretation breaks down, information is not conserved 
> after collapse when you consider only one term of a superposition. But 
> there is no problem if you just stick to the view where each moment in 
> time defines a universe. The idea that all information present in one 
> universe can be accounted for in terms of a single past universe", is 
> false. 
>
> Another aspect of this is how a particle can tunnel through a potential 
> barrier. Here there is no intermediary state where the particle is in 
> the "classically forbidden region". So, we have a final state, an 
> initial state, but no intermediary state. Clearly this fits in much 
> better with the idea that time evolution is not real, it just allows you 
> to account for information in some universe in terms of information in 
> other universes. 
>
> Saibal 
>

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Re: Interpretation of Superposition

[smitra]

On 15-10-2018 12:40, agrayson2...@gmail.com wrote:

On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:


On 14-10-2018 15:24, agrays...@gmail.com wrote:

In a two state system, such as a qubit, what forces the

interpretation

that the system is in both states simultaneously before

measurement,

versus the interpretation that we just don't what state it's in

before

measurement? Is the latter interpretation equivalent to Einstein
Realism? And if so, is this the interpretation allegedly falsified

by

Bell experiments? AG


It is indeed inconsistent with QM itself as Bell has shown.
Experiments
have later demonstrated that the Bell inequalities are violated in
precisely the way predicted by QM. This then rules out local hidden

variables, therefore the information about the outcome of a
measurement
is not already present locally in the environment.

Saibal


What puzzles me is this; why would the Founders assume that a system
in a superposition is in all component states simultaneously --
contradicting the intuitive appeal of Einstein realism -- when that
assumption is not used in calculating probabilities (since the
component states are orthogonal)? AG


It may look like one can re-interpret QM as being consistent with 
Einstein realism, but Bell disproved this (if you assume locality). Note 
also what Bruce said about "simultaneously".


My own idea is that we need to think about how to interpret time 
evolution, instead of making all this fuss about superpositions. Without 
collapse, the time evolution of a system can be interpreted as a simple 
change of basis. You still have access to the initial state, at least in 
theory. But if the system collapses (in the MWI this is then an 
effective collapse due to you getting entangled with the system), you 
cannot access the initial state anymore (in practice, you might not have 
been able to do that anyway).


This all suggests to me that we live in a multiverse where each moment 
of time defines a different universe, memories of the past refer to 
alternative universes. We need to keep in mind that in experiments we 
can only ever directly measure the present state. If you dig up a bone 
of a dinosaur, what you are seeing is a result of processes in your 
brain right now. These are then the result of photons interacting with 
your eye and ultimately you can draw an inference about life on Earth, 
say, 150 million years ago. But an explanation for the presence of the 
bones is ultimately just information compression, we can account for 
information in our universe "today" in terms of information present in 
an alternative "past" universe.


According to classical physics, information is conserved in a one to one 
way between the past and present, and this allows for an interpretation 
of time evolution that says that our universe is evolving in time. in QM 
this naive interpretation breaks down, information is not conserved 
after collapse when you consider only one term of a superposition. But 
there is no problem if you just stick to the view where each moment in 
time defines a universe. The idea that all information present in one 
universe can be accounted for in terms of a single past universe", is 
false.


Another aspect of this is how a particle can tunnel through a potential 
barrier. Here there is no intermediary state where the particle is in 
the "classically forbidden region". So, we have a final state, an 
initial state, but no intermediary state. Clearly this fits in much 
better with the idea that time evolution is not real, it just allows you 
to account for information in some universe in terms of information in 
other universes.


Saibal

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Re: Interpretation of Superposition

[Philip Thrift]

On Monday, October 15, 2018 at 12:29:30 PM UTC-5, John Clark wrote:

> On Mon, Oct 15, 2018 at 12:51 PM Philip Thrift  > wrote:
>
> > *There is not one method of calculation.*
>
>
> There is always more than one way to make a calculation in physics, but at 
> the end of the day they all end up with the same number. And if that number 
> doesn't match the number experiment told us about then either somebody made 
> a mathematical error in the calculation or the theory the calculation was 
> based on is wrong. 
>  
>
>> *> The "just calculate" interpretation is filled with "computational" 
>> interpretations. *
>>
>
> Use whatever interpretation you like and you're still going to come up 
> with the same number as everybody else even if their interpretation is 
> radically different from yours. If this was not true we would not have had 
> a 90 year old controversy over which interpretations were better than 
> others because we'd know, we'd know that some produced the same numbers 
> that experiment did and some didn't; but unfortunatly we don't know because 
> all interpretations produce the same numbers and they are all equally close 
> to the numbers experiment provides.  
>  
>
>> > *There is not one method of calculation. Each method of calculation 
>> has within it some sort of "programmatic model":*
>>
>
> And if the model the calculation is based on comes up with a different 
> number than the one experiment does then the model is wrong, the trouble is 
> in quantum mechanics there are lots of very different models that come up 
> with the same number and they all agree with experiment, so you're free to 
> embrace any model you like.
>
> John K Clark
>
>
 

That is true in all sciences (not just QM). Look at all he different models 
of evolution (punctuated equilibria, ...). The data is the same (the fossil 
record).

This goes back to the pragmatists (Quine, Rorty, ...), 
"underdetermination", Kant (naturally),  

*Many models for the same data.* *It's the curse of science.*

- pt

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Re: Interpretation of Superposition

[John Clark]

On Mon, Oct 15, 2018 at 12:51 PM Philip Thrift 
wrote:

> *There is not one method of calculation.*


There is always more than one way to make a calculation in physics, but at
the end of the day they all end up with the same number. And if that number
doesn't match the number experiment told us about then either somebody made
a mathematical error in the calculation or the theory the calculation was
based on is wrong.


> *> The "just calculate" interpretation is filled with "computational"
> interpretations. *
>

Use whatever interpretation you like and you're still going to come up with
the same number as everybody else even if their interpretation is radically
different from yours. If this was not true we would not have had a 90 year
old controversy over which interpretations were better than others because
we'd know, we'd know that some produced the same numbers that experiment
did and some didn't; but unfortunatly we don't know because all
interpretations produce the same numbers and they are all equally close to
the numbers experiment provides.


> > *There is not one method of calculation. Each method of calculation has
> within it some sort of "programmatic model":*
>

And if the model the calculation is based on comes up with a different
number than the one experiment does then the model is wrong, the trouble is
in quantum mechanics there are lots of very different models that come up
with the same number and they all agree with experiment, so you're free to
embrace any model you like.

John K Clark



>

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Re: Interpretation of Superposition

[Philip Thrift]

On Monday, October 15, 2018 at 11:01:32 AM UTC-5, John Clark wrote:
>
> On Mon, Oct 15, 2018 at 6:40 AM > wrote:
>
> *> What puzzles me is this; why would the Founders assume that a system in 
>> a superposition is in all component states simultaneously -- contradicting 
>> the intuitive appeal of Einstein realism*
>>
>
> Because in physics experiment is king, and however intuitive naive realism 
> may be something conflicts with it, We know from experimental results that 
> Bell's Inequality is violated, therefore we know for certain that if the 
> universe is deterministic then it can't be both local and realistic, at 
> least one of those 2 things must be false. I don't see how locality could 
> be wrong. If things were non-local a change anywhere would instantly change 
> everything everywhere and the effect would be undiminished by distance, so 
> before you could understand anything you'd have to understand everything. 
> We certainly don't know everything but we do know something and I don't see 
> how we could if things were non-local. And if things are not realistic then 
> the moon doesn't exist when nobody is looking at it, and that seems like 
> too high a price to pay for determinism.
>
> Actually if Everett is right then you could have all 3 to the multiverse's 
> point of view because it evolves according to the wave equation and that is 
> completely deterministic, but that's a bit of a cheat because you can't 
> have an observer outside of the multiverse looking in at it.
>  
>
>> >*when that assumption is not used in calculating probabilities*
>>
>
> It doesn't matter what your favorite quantum interpretation is or what 
> your philosophical ideas about determinism locality and realism are, we all 
> calculate the same way and get the same probability. Everybody agrees about 
> how the world behaves but disagree about why it behaves that way. However 
> nobody has performed an exparament that can decide which of the various 
> interpretations is correct, and most working physicists aren't very 
> interested in philosophy, and that's why most favor the "shut up and 
> calculate" quantum interpretation. 
>
>  John K Clark 
>


The "just calculate" interpretation is filled with "computational" 
interpretations. There is not one method of calculation. Each method of 
calculation has within it some sort of "programmatic model":

*Computational Quantum Mechanics*
  
  
http://research.physics.illinois.edu/electronicstructure/498cqm/498gen-info.html

e.g. "finding the ground state of the many-body Schrödinger equation by 
propagation in imaginary time using Monte Carlo methods"

- pt

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Re: Interpretation of Superposition

[John Clark]

On Mon, Oct 15, 2018 at 6:40 AM  wrote:

*> What puzzles me is this; why would the Founders assume that a system in
> a superposition is in all component states simultaneously -- contradicting
> the intuitive appeal of Einstein realism*
>

Because in physics experiment is king, and however intuitive naive realism
may be something conflicts with it, We know from experimental results that
Bell's Inequality is violated, therefore we know for certain that if the
universe is deterministic then it can't be both local and realistic, at
least one of those 2 things must be false. I don't see how locality could
be wrong. If things were non-local a change anywhere would instantly change
everything everywhere and the effect would be undiminished by distance, so
before you could understand anything you'd have to understand everything.
We certainly don't know everything but we do know something and I don't see
how we could if things were non-local. And if things are not realistic then
the moon doesn't exist when nobody is looking at it, and that seems like
too high a price to pay for determinism.

Actually if Everett is right then you could have all 3 to the multiverse's
point of view because it evolves according to the wave equation and that is
completely deterministic, but that's a bit of a cheat because you can't
have an observer outside of the multiverse looking in at it.


> >*when that assumption is not used in calculating probabilities*
>

It doesn't matter what your favorite quantum interpretation is or what your
philosophical ideas about determinism locality and realism are, we all
calculate the same way and get the same probability. Everybody agrees about
how the world behaves but disagree about why it behaves that way. However
nobody has performed an exparament that can decide which of the various
interpretations is correct, and most working physicists aren't very
interested in philosophy, and that's why most favor the "shut up and
calculate" quantum interpretation.

 John K Clark

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Re: Interpretation of Superposition

[agrayson2000]

On Monday, October 15, 2018 at 11:17:56 AM UTC, Bruce wrote:
>
> From: >
>
>
> On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote: 
>>
>> On 14-10-2018 15:24, agrays...@gmail.com wrote: 
>> > In a two state system, such as a qubit, what forces the interpretation 
>> > that the system is in both states simultaneously before measurement, 
>> > versus the interpretation that we just don't what state it's in before 
>> > measurement? Is the latter interpretation equivalent to Einstein 
>> > Realism? And if so, is this the interpretation allegedly falsified by 
>> > Bell experiments? AG 
>>
>> It is indeed inconsistent with QM itself as Bell has shown. Experiments 
>> have later demonstrated that the Bell inequalities are violated in 
>> precisely the way predicted by QM.  This then rules out local hidden 
>> variables, therefore the information about the outcome of a measurement 
>> is not already present locally in the environment. 
>>
>> Saibal 
>>
>
> What puzzles me is this; why would the Founders assume that a system in a 
> superposition is in all component states simultaneously -- contradicting 
> the intuitive appeal of Einstein realism -- when that assumption is not 
> used in calculating probabilities (since the component states are 
> orthogonal)? AG
>
>
> I think the problem arises with thinking of a superposition as an 
> expression of a fact of the system being in all components of the 
> superposition simultaneously. 
>

*This is precisely what I argued here as recently as last summer, whereupon 
those who claim knowledge of quantum computers asserted that qbits assume 
exactly that, that qbits are in both states simultaneously. AG*

This mistaken interpretation leads to the Schrödinger cat paradox, which 
> you have worried about for a while.
>
> But this is a mistake. A superposition is just an expansion of a wave 
> function in some basis or the other -- the choice of basis is arbitrary, so 
> it makes no sense to think of this expansion as representing anything that 
> happens in "reality" (in Einstein's sense of "reality").
>

*I agree and argued the same last summer.  I quoted Dirac, which quote 
appears in the Wiki article on quantum superposition, who makes the mistake 
you reference, which IMO Schroedinger falsified. Some claim Schroedinger 
didn't falsify the error (show it was an error) because he was unaware of 
decoherence. I disagree with this analysis. AG*

The state is still the original state until decoherence kicks in and then, 
> because of einselection of a preferred basis, we can say that the separate 
> states are "real" -- namely orthogonal, so that one other other is chosen. 
> Until that time, the only state around is the original state, as can be 
> demonstrated by the possibility of recoherence, in which case you recover 
> just the initial state and nothing else.
>

*Aren't the component states orthogonal prior to decoherence? IIUC, they 
must be if they have distinct eigenvalues. AG*

>
> So for Schrödinger's cat, for example, if you could recohere the system 
> after one hour, say, you would find the cat alive in the box and the vial 
> of cyanide unbroken with the radioactive atom undecayed -- exactly as you 
> set the system up. It is only because the cat and apparatus are large warm 
> classical objects that this recoherence is not possible FAPP. To think of 
> the cat at some intermediate time as being both dead and alive is just a 
> confusion -- it is at all times either one or the other.
>
> Bruce
>

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Re: Interpretation of Superposition

[Bruce Kellett]

From: mailto:agrayson2...@gmail.com>>


On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:

On 14-10-2018 15:24, agrays...@gmail.com wrote:
> In a two state system, such as a qubit, what forces the
interpretation
> that the system is in both states simultaneously before
measurement,
> versus the interpretation that we just don't what state it's in
before
> measurement? Is the latter interpretation equivalent to Einstein
> Realism? And if so, is this the interpretation allegedly
falsified by
> Bell experiments? AG

It is indeed inconsistent with QM itself as Bell has shown.
Experiments
have later demonstrated that the Bell inequalities are violated in
precisely the way predicted by QM.  This then rules out local hidden
variables, therefore the information about the outcome of a
measurement
is not already present locally in the environment.

Saibal


What puzzles me is this; why would the Founders assume that a system 
in a superposition is in all component states simultaneously -- 
contradicting the intuitive appeal of Einstein realism -- when that 
assumption is not used in calculating probabilities (since the 
component states are orthogonal)? AG


I think the problem arises with thinking of a superposition as an 
expression of a fact of the system being in all components of the 
superposition simultaneously. This mistaken interpretation leads to the 
Schrödinger cat paradox, which you have worried about for a while.


But this is a mistake. A superposition is just an expansion of a wave 
function in some basis or the other -- the choice of basis is arbitrary, 
so it makes no sense to think of this expansion as representing anything 
that happens in "reality" (in Einstein's sense of "reality"). The state 
is still the original state until decoherence kicks in and then, because 
of einselection of a preferred basis, we can say that the separate 
states are "real" -- namely orthogonal, so that one other other is 
chosen. Until that time, the only state around is the original state, as 
can be demonstrated by the possibility of recoherence, in which case you 
recover just the initial state and nothing else.


So for Schrödinger's cat, for example, if you could recohere the system 
after one hour, say, you would find the cat alive in the box and the 
vial of cyanide unbroken with the radioactive atom undecayed -- exactly 
as you set the system up. It is only because the cat and apparatus are 
large warm classical objects that this recoherence is not possible FAPP. 
To think of the cat at some intermediate time as being both dead and 
alive is just a confusion -- it is at all times either one or the other.


Bruce

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Re: Interpretation of Superposition

[agrayson2000]

On Sunday, October 14, 2018 at 5:08:42 PM UTC, smitra wrote:
>
> On 14-10-2018 15:24, agrays...@gmail.com  wrote: 
> > In a two state system, such as a qubit, what forces the interpretation 
> > that the system is in both states simultaneously before measurement, 
> > versus the interpretation that we just don't what state it's in before 
> > measurement? Is the latter interpretation equivalent to Einstein 
> > Realism? And if so, is this the interpretation allegedly falsified by 
> > Bell experiments? AG 
>
> It is indeed inconsistent with QM itself as Bell has shown. Experiments 
> have later demonstrated that the Bell inequalities are violated in 
> precisely the way predicted by QM.  This then rules out local hidden 
> variables, therefore the information about the outcome of a measurement 
> is not already present locally in the environment. 
>
> Saibal 
>

What puzzles me is this; why would the Founders assume that a system in a 
superposition is in all component states simultaneously -- contradicting 
the intuitive appeal of Einstein realism -- when that assumption is not 
used in calculating probabilities (since the component states are 
orthogonal)? AG 

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Re: Interpretation of Superposition

[Philip Thrift]

On Sunday, October 14, 2018 at 8:24:29 AM UTC-5, agrays...@gmail.com wrote:
>
> In a two state system, such as a qubit, what forces the interpretation 
> that the system is in both states simultaneously before measurement, versus 
> the interpretation that we just don't what state it's in before 
> measurement? Is the latter interpretation equivalent to Einstein Realism? 
> And if so, is this the interpretation allegedly falsified by Bell 
> experiments? AG
>


Interpretations of quantum computing (QC) follow interpretations of quantum 
mechanics (QM) itself.

Here's two:

1. *An introduction to many worlds in quantum computation*
- https://arxiv.org/pdf/0802.2504.pdf

2. *The sum-over-histories formulation of quantum computing*
- https://arxiv.org/pdf/quant-ph/0607151.pdf

If one is familiar with these two interpretations in QM, one can at least 
follow how they would work in a semantics for QC.

As far as I know it's a matter of personal preference which one you might 
like (but I wouldn't choose door #1!).
 
- pt

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Re: Interpretation of Superposition

[smitra]

On 14-10-2018 15:24, agrayson2...@gmail.com wrote:

In a two state system, such as a qubit, what forces the interpretation
that the system is in both states simultaneously before measurement,
versus the interpretation that we just don't what state it's in before
measurement? Is the latter interpretation equivalent to Einstein
Realism? And if so, is this the interpretation allegedly falsified by
Bell experiments? AG


It is indeed inconsistent with QM itself as Bell has shown. Experiments 
have later demonstrated that the Bell inequalities are violated in 
precisely the way predicted by QM.  This then rules out local hidden 
variables, therefore the information about the outcome of a measurement 
is not already present locally in the environment.


Saibal

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