Why don't entanglement and relativity of simultaneity contradict each other?

[swansont]

1 hour ago, Matterga said:

After the measurement, because of entanglement, electron 1 has, say, z up and thus the second z down. On electron 2 we measure, say x right. Then electron 1 has x left. All at the same time. Don't both then have z and x determined at the same time?

Only one component can be determined. Whether you measure spin up or down (z), the x and y components are undetermined. Measurement of any two components does not commute

[bangstrom]

On 7/31/2021 at 4:49 PM, TheVat said:

 Once I know one member of the pair is left-hand then I instantly know the other is right-hand.   If this is wrong or simplistic, someone LMK.

What you described is a classical connection since the handedness of the gloves is unchanging from start to finish. Entanglement is different in that the handedness of the gloves (quantum identity) is truly indeterminate and not fixed prior to the first observation. Prior to observation, entangled particles are in a Bell state of superposition meaning that they are in neither in one quantum state nor another but are mixed. Their quantum states simultaneously become fixed in all reference frames at the instant of the first observation.

Bell’s inequality is a statistical test to determine if the quantum identities were fixed and unchanging from the beginning, as with a pair of gloves, or if they were indeterminate until the instant of the first observation on either end. With entangled particles, the outcome of an observation is random prior to the first observation.

[studiot]

5 hours ago, bangstrom said:

What you described is a classical connection since the handedness of the gloves is unchanging from start to finish. Entanglement is different in that the handedness of the gloves (quantum identity) is truly indeterminate and not fixed prior to the first observation. Prior to observation, entangled particles are in a Bell state of superposition meaning that they are in neither in one quantum state nor another but are mixed. Their quantum states simultaneously become fixed in all reference frames at the instant of the first observation.

Bell’s inequality is a statistical test to determine if the quantum identities were fixed and unchanging from the beginning, as with a pair of gloves, or if they were indeterminate until the instant of the first observation on either end. With entangled particles, the outcome of an observation is random prior to the first observation.

I don't think so.

Entangled electrons in an orbital are most definitely in one quantum state or another prior to observation, according to QM.
However prior to observation the observer does not know which is which.

[Genady]

A state of two electron system is either factorizable into tensor product of the individual electron states, or it is not. In the former case, they are not entangled and each one has a definite state. In the latter, they are entangled and don't have individual states.

Measurement of any of them changes the state of the system: it becomes factorizable, they become unentangled, and each gets an individual state.

[studiot]

1 hour ago, Genady said:

A state of two electron system is either factorizable into tensor product of the individual electron states, or it is not. In the former case, they are not entangled and each one has a definite state. In the latter, they are entangled and don't have individual states.

Measurement of any of them changes the state of the system: it becomes factorizable, they become unentangled, and each gets an individual state.

 

I can't agree with this.

[bangstrom]

9 hours ago, studiot said:

I don't think so.

Entangled electrons in an orbital are most definitely in one quantum state or another prior to observation, according to QM.
However prior to observation the observer does not know which is which.

Entangled electrons, whether in an orbital or not, are in a state of superposition having a shared quantum state including an indeterminate location. That is, they have no determinate quantum state or position. We can’t say one electron with a spin up state is here and another in a spin down state is there. It is all random and indeterminate until one or the other is observed.

This may be counter intuitive and Schroedinger pointed out the absurdity of quantum entanglement with his dead/alive cat but it appears that the dead/alive state of entangled particles is something we have to live with in QM.

5 hours ago, studiot said:

 

I can't agree with this.

Observation favors Genady’s view. The dominate interaction of electrons in the electron cloud surrounding the nucleus of an atom is one of collective interaction, rather than the configuration of particular locations. Charges move about such that their behavior is consistent with that of all the other charges.

The majority of electrons in the cloud either appear to be entangled or at least arranged in Cooper pairs with no factorizable properties or individual actions. Electrons in the cloud have no degrees of freedom or identities of their own. Their degrees of freedom are those of the collective degrees of freedom of the electron cloud and their collective interaction can extend well beyond the atom itself. This is most noticeable with such things as Bose-Einstein condensates and with low temperature properties such as super fluidity and superconductivity.

Electrons in an atom act more like collective wave functions rather than little planets about a star.

 

[studiot]

3 hours ago, bangstrom said:

Entangled electrons, whether in an orbital or not, are in a state of superposition having a shared quantum state including an indeterminate location. That is, they have no determinate quantum state or position. We can’t say one electron with a spin up state is here and another in a spin down state is there. It is all random and indeterminate until one or the other is observed.

This may be counter intuitive and Schroedinger pointed out the absurdity of quantum entanglement with his dead/alive cat but it appears that the dead/alive state of entangled particles is something we have to live with in QM.

Observation favors Genady’s view. The dominate interaction of electrons in the electron cloud surrounding the nucleus of an atom is one of collective interaction, rather than the configuration of particular locations. Charges move about such that their behavior is consistent with that of all the other charges.

The majority of electrons in the cloud either appear to be entangled or at least arranged in Cooper pairs with no factorizable properties or individual actions. Electrons in the cloud have no degrees of freedom or identities of their own. Their degrees of freedom are those of the collective degrees of freedom of the electron cloud and their collective interaction can extend well beyond the atom itself. This is most noticeable with such things as Bose-Einstein condensates and with low temperature properties such as super fluidity and superconductivity.

Electrons in an atom act more like collective wave functions rather than little planets about a star.

 

 

Really ?

Well you go with your Physics and I will stick with Schroedinger and Pauli.

 

I look forward to your mathematical derivation of this fanciful description.

S and P and many others have already provided many different derivations of their version to the world.

 

[bangstrom]

6 hours ago, studiot said:

Well you go with your Physics and I will stick with Schroedinger and Pauli.

 

I look forward to your mathematical derivation of this fanciful description.

The mathematical support for my fanciful description is the experimental violation of ‘Bell’s inequality theorem’ which supported the EPR version of entanglement where the observation of one of an entangled pair has no affect on its remote partner, especially, not simultaneously in all reference frames.

The experiments of John Bell and Alain Aspect demonstrated an inequality not permitted by the EPR effect where the quantum identities of the entangled must have been statistically in a state of correlation prior to observation. This invalidated Einstein’s insistence of ‘no spooky action at a distance’ but it did support Schroedinger’s calculations suggesting that entangled particles are in a state of superposition where both share a common quantum identity.

Schroedinger doubted the correctness of his own calculations resulting in his thought experiment with the dead/alive cat.

20 hours ago, studiot said:

Entangled electrons in an orbital are most definitely in one quantum state or another prior to observation, according to QM.
However prior to observation the observer does not know which is which.

This is where I don't agree. Entangled particles are in a state of superposition which means they share mix of both possible identities rather than having individual quantum states.

Prior to observation, the observer does not know which is which or which is where because they are in a mixed state of identities and their locations are indeterminate until observed.
 

[studiot]

4 hours ago, bangstrom said:

This is where I don't agree. Entangled particles are in a state of superposition which means they share mix of both possible identities rather than having individual quantum states.

Prior to observation, the observer does not know which is which or which is where because they are in a mixed state of identities and their locations are indeterminate until observed.

It is not a question of agreement it is a question of understanding QM and its definitions.

Entanglement is not a state, which has a particular axiomatic definition in QM.

Again it is not entanglement that says an observer does not know (in fact cannot know) exactly where a particle is, but Heisenberg.

But this veering off topic now.

 

In order to have a contradiction, it is necessary for the equations that define and measure relativity of simultaneity and the equations that define quantum entanglement to have at least one common variable that produce different contradictory results when some common variable is calculated from their respective defining equations.

 

Edited January 25, 2022 by studiot

[bangstrom]

11 hours ago, studiot said:

Again it is not entanglement that says an observer does not know (in fact cannot know) exactly where a particle is, but Heisenberg.

I had a salient point in mind when I mentioned the uncertainty of location and it had nothing to do with Heisenberg. I failed to explain my view in a way that anyone could follow but I find it relevant to the topic so I will try to explain it now with the following example.

Suppose you mail two letters at the same time. One contains a payment addressed to the utility company and the other contains a note addressed to a friend. If the utility company receives your personal note and your friend receives the utility payment, you know you made a mistake and sent the wrong item to the wrong address because the laws physics do not conspire to swap the contents of your letters while in transit.

But suppose the laws of QM can conspire to swap the identity of the contents, then you can never be certain which item went where and that is the uncertainty of location I had in mind.

If quantum superposition is a reality, then the latter scenario is possible with the resulting uncertainty of locations. Entangled particles can not physically swap places prior to their observation but they can swap identities which is the observational equivalent.

Quantum teleportation is an example where an operator on one end of an entangled pair can alter the outcome on the other end with the resulting uncertainty.

On 1/24/2022 at 4:17 AM, studiot said:

Entangled electrons in an orbital are most definitely in one quantum state or another prior to observation, according to QM.

 

How do you reconcile this view with Schroedinger’s "superposition" where entangled particles are in a mixed quantum state until observed?

 

[studiot]

14 hours ago, bangstrom said:

But suppose the laws of QM can conspire to swap the identity of the contents, then you can never be certain which item went where and that is the uncertainty of location I had in mind.

Thank you for explaining that and +1 for understanding classical entanglement which is based on the idea that the two entangled entities are distinct and distinguishable at all times and in all locations.
Note however that there are no 'states' in the scientific meaning involved.
Classically the only way for your contents to change places is by a mix up (error) in the original packaging.

This also nicely brings out the fact that classically the one letter could never change or be changed into the other one.
That is neither letter could ever take the place (serve the function) of the other one.

So the big difference between quantum entanglement and classical entanglement is that in the quantum case either particle can perform whatever function is required whereas in the classical case each of the entities can only perform one of the functions.

14 hours ago, bangstrom said:

How do you reconcile this view with Schroedinger’s "superposition" where entangled particles are in a mixed quantum state until observed?

Discussing the scientific concept of a 'state' will bring me back on topic which is the possibility of a conflict between Relativity and QM.

Why do you never mention this in your posts ?

OK so scientifically a state is governed by ' state variables', which are required to be single values.

A state is fully defined when the individual values of all the state variables are known.

For a state to exist all the values must exist and be unique, but they do not need to be known.

Applying this to quantum states, it is an axiom of QM that the state variables are the variables involved in equations like that of Schroedinger (there are others) including their boundary conditions.
So a specific quantum state is defined uniquely by a complete set of values of these variables. (The quantum numbers)

Underlying the Physics of this is the Mathematics of existence and uniqueness of such equations and variables.

This is why I say that even though we do not know the values of the spin quantum numbers of two electrons entangled in an orbital, they must each have a spin number.
Furthermore Pauli says that these numbers must be of opposite signs.
 

A 'mixed state' , by definition, therefore has no actual meaning.

Furthermore, the idea of a single well defined quantum 'state' for an object as large, complex and diverse as a cat, has even less meaning as it were.

 

On to Relativity.

There are no 'states' in Relativity.

I also noted that there in order for a conflict to be established we must be able to calculate different values for the same variables in QM and Relativity.

Can you do this ?

[bangstrom]

On 1/26/2022 at 6:06 AM, studiot said:

Discussing the scientific concept of a 'state' will bring me back on topic which is the possibility of a conflict between Relativity and QM.

Why do you never mention this in your posts ?

I don't mention a conflict because I see no real conflict.

[studiot]

8 minutes ago, bangstrom said:

I don't mention a conflict because I see no real conflict.

So why are you posting off topic material and ignoring on topic material ?

[bangstrom]

On 1/26/2022 at 6:06 AM, studiot said:

This is why I say that even though we do not know the values of the spin quantum numbers of two electrons entangled in an orbital, they must each have a spin number.
Furthermore Pauli says that these numbers must be of opposite signs.

Apparently entangled electrons need not have opposite signs if they are both in superposition.

The Pauli exclusion principle can be used determine if the entangled states are mixed or defined. If you have one of a pair of entangled particles at hand and its partner is at a remote location, there is no way of observing the spin state of the at-hand particle without breaking the entanglement but you can observe it indirectly.

You can create another entangled pair and combine one of the entangled particles with the at-hand entangled partner creating a three way entanglement so you now have four entangled particles. You still know nothing about their entangled states except that the combined pair of old and new particles will have opposite signs when observed as Pauli said.

Observing the pair would give you no useful information but you can observe the state of the remaining particle from second entanglement. If the partner is spin-up, you know the particle you combined with the at-home entangled particle is now spin-down and making the at-home particle spin-up, and finally the remote particle spin-down.

By the same sequence, if the particle from the second entanglement combined with the at-home particle is spin down, the remote particle will also be spin down. In general, the spin of the particle from the second entanglement combined with the at-home particle will always have the same as the spin of the remote particle when the sequence is observed. A spin-up particle introduced into the at-home- combination results in a spin-up particle out at the location of the remote entangled particle.

The observation of one particle going into a combination in one location and a particle instantly appearing at a remote location with the same spin has the outward appearance of si-fi teleportation but nothing is physically transported. Only the quantum identity of one particle has been transported to another particle and the observation can take place with only one quantum identity at a time. One q-bit of information has been exchanged.

This exchange of quantum identities is called 'quantum teleportation' and it is possible because entangled particles are in a mixed state of superposition rather than fixed before they are observed. 

14 minutes ago, studiot said:

So why are you posting off topic material and ignoring on topic material ?

The OP asked, "If two electrons are entangled and change spin (for example) how can these two events occur regardless of reference frame? "

The answer can be found in both QM and SR. This obviously takes some 'splainen and understanding the principle of superposition is essential to the understanding how the mentioned event can happen.

[studiot]

15 minutes ago, bangstrom said:

Apparently entangled electrons need not have opposite signs if they are both in superposition.

 

How can electrons be in superposition ?

The wavefunctions of the electrons may be in superposition, but not the electrons themselves.

[bangstrom]

6 minutes ago, studiot said:

 

How can electrons be in superposition ?

The wavefunctions of the electrons may be in superposition, but not the electrons themselves.

Electrons and their wave functions are part of a whole. Entangled electrons have shared identities when not observed so what observation can make that distinction?

Are you suggesting that superposition is a bogus concept?

[studiot]

40 minutes ago, bangstrom said:

Are you suggesting that superposition is a bogus concept?

Of course not.

Superposition means "in exactly the same place"

Later mathematicians generalised this to mean "in exactly the same mathematical space", which is the meaning adopted in QM.

 

 

44 minutes ago, bangstrom said:

Electrons and their wave functions are part of a whole. Entangled electrons have shared identities when not observed so what observation can make that distinction?

 

I have no idea what you mean by a 'shared identity' or 'part of a whole  or indeed the rest of your statement.

Please explain in (preferably mathematical) detail.

 

1 hour ago, bangstrom said:

The observation of one particle going into a combination in one location and a particle instantly appearing at a remote location with the same spin has the outward appearance of si-fi teleportation but nothing is physically transported. Only the quantum identity of one particle has been transported to another particle and the observation can take place with only one quantum identity at a time. One q-bit of information has been exchanged.

This is nonsense.

Particles never instantaneously appear at remote locations or anywhere else.

[bangstrom]

7 hours ago, studiot said:

Superposition means "in exactly the same place"

Later mathematicians generalised this to mean "in exactly the same mathematical space", which is the meaning adopted in QM.

 

Something of description below should look familiar because it has appeared in other threads in this forum.

electron|〉 = (1/√2)|spin up〉 + (1/√2)|spin down〉

This represents the mixed spin state of two entangled electrons.

7 hours ago, studiot said:

This is nonsense.

Particles never instantaneously appear at remote locations or anywhere else.

No one is saying particles can suddenly appear out of nowhere but two entangled particles can swap quantum identities nonlocally (instantly and across any given distance.) Even extra galactic distances.

Quantum teleportation is not new and experiments are ongoing around the world. Are you familiar with the work of Anton Zeilinger “Mr. Beam” or what the Chinese have done recently?

https://news.yahoo.com/chinese-scientists-successfully-teleported-particle-190234249.html?fr=yhssrp_catchall

Our observation of the events is largely limited to observing a single particle’s quantum identity at a time so teleportation is never observed at the macro level.

 

[studiot]

1 hour ago, bangstrom said:

Something of description below should look familiar because it has appeared in other threads in this forum.

electron|〉 = (1/√2)|spin up〉 + (1/√2)|spin down〉

This represents the mixed spin state of two entangled electrons.

No one is saying particles can suddenly appear out of nowhere but two entangled particles can swap quantum identities nonlocally (instantly and across any given distance.) Even extra galactic distances.

Quantum teleportation is not new and experiments are ongoing around the world. Are you familiar with the work of Anton Zeilinger “Mr. Beam” or what the Chinese have done recently?

https://news.yahoo.com/chinese-scientists-successfully-teleported-particle-190234249.html?fr=yhssrp_catchall

Our observation of the events is largely limited to observing a single particle’s quantum identity at a time so teleportation is never observed at the macro level.

 

 

And all this unverified ytube nonsense is mainstream Physics ?

But, I forgot you have already made it quite clear, the site rules don't apply to you.

Since no one else seems to care and the OP hasn't been back since posting, I will leave you to your musings.

[bangstrom]

41 minutes ago, studiot said:

 

And all this unverified ytube nonsense is mainstream Physics ?

But, I forgot you have already made it quite clear, the site rules don't apply to you.

Since no one else seems to care and the OP hasn't been back since posting, I will leave you to your musings.

Can you cite an example of what the "mainstream" understanding of superposition, quantum entanglement, and/or quantum teleportation is so I can be properly informed. Again, are you familiar with the experiments of Anton Zeilinger and would you consider him to be mainstream or not?