Entanglement (split from Using entanglement to achieve...)

[bangstrom]

A non-local, faster-than-light correlation involves a non-local, faster-than-light communication when the transaction between the particles is correlated rather than random. Correlation requires a comunication even if it is a “spooky" action at a distance.

Also, a time-symetric transaction is simultaneous in time on both ends. It only appears to be either forward or backward in time when viewed from one end or the other.

https://arxiv.org/pdf/2006.11365

“Article: Symmetry, Transactions, and the Mechanism of Wave Function Collapse

"Abstract: The Transactional Interpretation of quantum mechanics exploits the intrinsic time-symmetry of wave mechanics to interpret the ψ and ψ* wave functions present in all wave mechanics calculations as representing retarded and advanced waves moving in opposite time directions that form a quantum “handshake” or transaction. This handshake is a 4D standing-wave that builds up across space-time to transfer the conserved quantities of energy, momentum, and angular momentum in an interaction. Here, we derive a two-atom quantum formalism describing a transaction.” John Cramer and Carver Mead 2020

[Markus Hanke]

6 hours ago, bangstrom said:

A non-local, faster-than-light correlation involves a non-local, faster-than-light communication

No, not necessarily. While all causation automatically involves some form of correlation, the reverse isn’t true - not all correlation implies causation, in the sense of something “acting” non-locally.

[bangstrom]

4 hours ago, Markus Hanke said:

No, not necessarily. While all causation automatically involves some form of correlation, the reverse isn’t true - not all correlation implies causation, in the sense of something “acting” non-locally.

Is entanglement possible without correlation and what causes particles to become entangled?

 With entangled particles, where the interacting particles begin with anti-coordinated quantum identities- for example, one is spin up and the other spin down- when the common wavefunction is lost, the particles may be observed as having quantum identities opposite that of their original conditions. It is as if something has caused the particles to swap places. The original identities of entangled particles is always unknown but the odds of finding the particles anti-coordinated after the collapse of the wavefunction is greater than even as demonstrated by tests of Bell’s Inequalities indicating that a casual event has taken place. The same sort of coordination is best demonstrated in experiments involving quantum teleportation where something causes two remote particles to appear to swap locations with neither particle traveling through the space between. The only thing passing through space is ‘information.’ The spin-up particle is informed to spin-down and the spin-down particle is simultaneously informed to spin up.

With light, the same principle applies except the quantum identities of the paired electrons that swap places are the locations of the electrons within the atoms rather than something like spin as with my previous example. An electron in one atom has an energy level above its ground state while its entangled partner has an energy level below its ground state. When their common wavefunction collapses, the wavefunction allows the higher energy electron to drop to a lower energy orbit while its partner simultaneously rises to a higher energy orbit. ‘Information’ is the only thing that passes through the space between. Energy is conserved in this transaction rather than flying through the void looking for a place to land.  In this view, the non-local entanglement among charged particles allows remote particles to swap energy levels simultaneously with no need for a local transfer of energy through the space between. This is the cause of what we observe as light.

[swansont]

14 minutes ago, bangstrom said:

With entangled particles, where the interacting particles begin with anti-coordinated quantum identities- for example, one is spin up and the other spin down- when the common wavefunction is lost, the particles may be observed as having quantum identities opposite that of their original conditions. It is as if something has caused the particles to swap places

No. In entanglement, you don’t know the individual states. If you start out knowing, something must happen in the entangling interaction so that you lose track. 

21 minutes ago, bangstrom said:

With light, the same principle applies except the quantum identities of the paired electrons that swap places are the locations of the electrons within the atoms rather than something like spin as with my previous example. An electron in one atom has an energy level above its ground state while its entangled partner has an energy level below its ground state. When their common wavefunction collapses, the wavefunction allows the higher energy electron to drop to a lower energy orbit while its partner simultaneously rises to a higher energy orbit. ‘Information’ is the only thing that passes through the space between. Energy is conserved in this transaction rather than flying through the void looking for a place to land

The atoms would be in a superposition, rather than one in a higher and one in a lower state (and “below the ground state” is nonsense)

[bangstrom]

10 hours ago, swansont said:

No. In entanglement, you don’t know the individual states. If you start out knowing, something must happen in the entangling interaction so that you lose track. 

The atoms would be in a superposition, rather than one in a higher and one in a lower state (and “below the ground state” is nonsense)

As I said, it is impossible to know the original states of entangled particles but tests of the Bell’s inequality demonstrate that the quantum identities in the after states are not necessarily the same as in the original states as if the entangled particles had nonlocally swapped locations. This possibility is demonstrated directly with experiments involving quantum teleportation where entangled particles swap identities nonlocally without either particle physically passing through the space between.

This swapping places is never seen at the macro level but it is observed at the quantum level with entangled particles. We know the Eiffel Tower is in Paris and the Leaning Tower is in Pizza but, in the quantum world, we could find the Leaning Tower in Paris and instantly know that the Eiffel Tower must now be in Pizza. We don’t know the identity of either entangled particle until after it is observed.

The energy state of entangled particles is unknown and unknowable until after the collapse of the wavefunction- not during which, as you say, is nonsense.

[swansont]

2 hours ago, bangstrom said:

As I said, it is impossible to know the original states of entangled particles but tests of the Bell’s inequality demonstrate that the quantum identities in the after states are not necessarily the same as in the original states

Which is a meaningless observation, since they must interact in order to become entangled, and interactions affect the states of particles.

Quote

This possibility is demonstrated directly with experiments involving quantum teleportation where entangled particles swap identities nonlocally without either particle physically passing through the space between

It’s not the identity that‘s swapped - e.g. an electron doesn’t become another kind of particle, and electrons are identical particles. The state of the particle is what is teleported.

Quote

This swapping places is never seen at the macro level but it is observed at the quantum level with entangled particles. We know the Eiffel Tower is in Paris and the Leaning Tower is in Pizza but, in the quantum world, we could find the Leaning Tower in Paris and instantly know that the Eiffel Tower must now be in Pizza. We don’t know the identity of either entangled particle until after it is observed.

If you think this is a good analogy it suggests you don’t know all that much about quantum teleportation. 

[Markus Hanke]

16 hours ago, bangstrom said:

Is entanglement possible without correlation

No. Entanglement is correlation between measurement outcomes.

16 hours ago, bangstrom said:

what causes particles to become entangled?

They need to interact first (in some ordinary way, not at a distance), which establishes the entanglement relationship. There are different ways to do this, but they all involve an initial causal interaction of some kind; they then remain entangled afterwards, right up until a measurement is performed on them; once any entangled part collapses into a definite state, the entanglement relationship is broken.

[Eise]

@bangstrom: starting the same chain of misunderstandings again? 

See:

If you have any new ideas, let us know otherwise this discussion is meaningless. The other thread was closed because we were running in circles.

 

[bangstrom]

3 hours ago, swansont said:

Which is a meaningless observation, since they must interact in order to become entangled, and interactions affect the states of particles.

Naturally, they must interact to become entangled. I said, “It is impossible to know the original states of entangled particles.” Not knowing the original states does not make interaction impossible.

 

3 hours ago, swansont said:

It’s not the identity that‘s swapped - e.g. an electron doesn’t become another kind of particle, and electrons are identical particles. The state of the particle is what is teleported.

How is the “state” of a particle different from the “quantum identity” of a particle? Electrons have the same intrinsic properties (that is, state-independent) properties that make them indistinguishable. An electron does not become another kind of particle. I have read that entangled particles can transpose their quantum identities, such as spin or orientation, so "quantum identity" is what I call it. You may call it “state” but I call it “identity”. I see the difference as semantic.

 

3 hours ago, swansont said:

If you think this is a good analogy it suggests you don’t know all that much about quantum teleportation. 

I admit the towers analogy was a bit over the top but it was an exaggeration to make a point, as analogies often are, if you know all that much about analogies.

[exchemist]

3 hours ago, swansont said:

Which is a meaningless observation, since they must interact in order to become entangled, and interactions affect the states of particles.

It’s not the identity that‘s swapped - e.g. an electron doesn’t become another kind of particle, and electrons are identical particles. The state of the particle is what is teleported.

If you think this is a good analogy it suggests you don’t know all that much about quantum teleportation. 

And the Leaning Tower of Pizza is what you get when your Deliveroo courier stacks them too high.

[bangstrom]

1 hour ago, Markus Hanke said:

No. Entanglement is correlation between measurement outcomes.

Agreed.

1 hour ago, Markus Hanke said:

They need to interact first (in some ordinary way, not at a distance), which establishes the entanglement relationship. There are different ways to do this, but they all involve an initial causal interaction of some kind; they then remain entangled afterwards, right up until a measurement is performed on them; once any entangled part collapses into a definite state, the entanglement relationship is broken.

Agreed, with the exception of (at a distance). In non-photon models, such as John Cramer's, any two electrons having a common resonate frequency and with the space between permitting among other conditions, can become entangled.  

Correction: John Cramer's model includes photons as quanta of energy involved in light-related events. He does not consider photons to be real in the conventional sense as space-traveling particles carrying energy from place to place. Similar models have banned the word 'photon' from their lexicon to avoid confusion with considering photons as particles.

34 minutes ago, exchemist said:

And the Leaning Tower of Pizza is what you get when your Deliveroo courier stacks them too high.

Good observation! I noticed the city in Italy is Pisa too late.

Edited Monday at 07:43 AM by bangstrom
Cramer's model is not a photon as a particle model.

[swansont]

6 hours ago, bangstrom said:

How is the “state” of a particle different from the “quantum identity” of a particle? Electrons have the same intrinsic properties (that is, state-independent) properties that make them indistinguishable. An electron does not become another kind of particle. I have read that entangled particles can transpose their quantum identities, such as spin or orientation, so "quantum identity" is what I call it.

You can’t tell which electron is which by what state they are in, so you can’t say that anything has swapped. “Swapping” would imply that you knew what state each was in.

An electron is a spin 1/2 lepton with a mass of .511 keV and charge -e. To me that’s its identity, but it’s the identity of any electron.

6 hours ago, bangstrom said:

You may call it “state” but I call it “identity”. I see the difference as semantic.

If you don’t use physics terminology then there’s a good chance nobody will know what you mean.

[bangstrom]

11 hours ago, swansont said:

You can’t tell which electron is which by what state they are in, so you can’t say that anything has swapped. “Swapping” would imply that you knew what state each was in.

You can tell something has happened when an abrupt change in the quantum state of a particle is observed. Swapping is assumed when a probable cause for the change is known but lies beyond the limits of a classical connection. For example, observations of entanglement, quantum teleportation, or as with quantum encryption, where a change can indicate that a message has been hacked.

11 hours ago, swansont said:

 An electron is a spin 1/2 lepton with a mass of 2511 keV and charge -e. To me that's its identity, but its the identity of any electron.

If you don’t use physics terminology then there’s a good chance nobody will know what you mean.

The properties you have listed are the ‘intrinsic’ properties of an electron but not its "quantum identity". My term, “quantum identity” is commonly found in the literature as a variable property synonymous with, quantum state, Bell state, or eigenstate of a particle. These states or identities can change without changing the particle. More specifically, 'information' leading to an apparent swapping is what is transported in entanglement. 

[swansont]

13 minutes ago, bangstrom said:

You can tell something has happened when an abrupt change in the quantum state of a particle is observed. Swapping is assumed when a probable cause for the change is known but lies beyond the limits of a classical connection. For example, observations of entanglement, quantum teleportation, or as with quantum encryption, where a change can indicate that a message has been hacked.

But we’re talking about entanglement, where the states are unknown, so you can’t tell there is a change in state. You only know the states when you make the measurement. “Change” implies two measurements (initial state, final state)

 

[bangstrom]

3 hours ago, swansont said:

But we’re talking about entanglement, where the states are unknown, so you can’t tell there is a change in state. You only know the states when you make the measurement. “Change” implies two measurements (initial state, final state)

The initial states with entanglement are unknowable. However, assumptions can be made about change and hypotheses can be tested by repeated experiments. Reasonable assumptions can be made by observing the final results alone. If I find a dead and flattened cat on the road I can assume it was once alive and got run over.

Edited yesterday at 05:38 AM by bangstrom
added a missing word

[swansont]

6 hours ago, bangstrom said:

The initial states with entanglement are unknowable. However, assumptions can be made about change and hypotheses can be tested by repeated experiments. Reasonable assumptions can be made by observing the final results alone. If I find a dead and flattened cat on the road I can assume it was once alive and got run over.

A typical cat is not a quantum object. It has a definite state beforehand.

If it’s Schrödinger’s cat, in a superposition of alive and dead, and you flatten the box it’s in, did you kill the cat or was it already dead? Can you say for sure that you changed its state?

[studiot]

@bangstrom

 

Here is a question for you to think about in relation to knowable and unknowable states.

 

Consider the formation of a covalent chemical bond : This involves the entanglement of two electrons.

What are the possibilities for the states before and after the bond formation ?

[exchemist]

14 minutes ago, studiot said:

@bangstrom

 

Here is a question for you to think about in relation to knowable and unknowable states.

 

Consider the formation of a covalent chemical bond : This involves the entanglement of two electrons.

What are the possibilities for the states before and after the bond formation ?

Does it? I suppose in the case of a 2 electron bond it typically involves 2 electrons sharing a molecular orbital but with opposed spin orientations. We have no way of knowing which is which, nor does it have any significance. 

[bangstrom]

5 hours ago, studiot said:

@bangstrom

 

Here is a question for you to think about in relation to knowable and unknowable states.

 

Consider the formation of a covalent chemical bond : This involves the entanglement of two electrons.

What are the possibilities for the states before and after the bond formation ?

I have never thought of a covalent bond as an entanglement but I suspect you are right.

As for the states before and after, if the electrons are in opposite states, as I understand from Cramer, Mead and Kastner, the electrons are rapidly swapping states as suggested by their sharing a common wavefunction rather than the more conventional view that they are in a state of superposition. I agree with “exchemist” that none of this is observable nor does it matter.

[studiot]

1 hour ago, exchemist said:

Does it? I suppose in the case of a 2 electron bond it typically involves 2 electrons sharing a molecular orbital but with opposed spin orientations. We have no way of knowing which is which, nor does it have any significance. 

 

Just now, bangstrom said:

I have never thought of a covalent bond as an entanglement but I suspect you are right.

As for the states before and after, if the electrons are in opposite states, as I understand from Cramer, Mead and Kastner, the electrons are rapidly swapping states as suggested by their sharing a common wavefunction rather than the more conventional view that they are in a state of superposition. I agree with “exchemist” that none of this is observable nor does it matter.

I really thought I was being clear.

 

1 hour ago, studiot said:

What are the possibilities for the states before and after the bond formation ?

 

...before and after...

 

So before bond formation there are two electrons in separate obritals, each with two spin possibilities, making a total of four possible configurations.

After the bond formation there is one orbital holding both electrons and the possible configurations reduce.

 

And no , I do not think it is irrelevant, I think it is vitally important and demonstrates that our knowledge is not as limited as made out.

It is important because the available combinations determine the probabilities.

 

[exchemist]

3 hours ago, bangstrom said:

I have never thought of a covalent bond as an entanglement but I suspect you are right.

As for the states before and after, if the electrons are in opposite states, as I understand from Cramer, Mead and Kastner, the electrons are rapidly swapping states as suggested by their sharing a common wavefunction rather than the more conventional view that they are in a state of superposition. I agree with “exchemist” that none of this is observable nor does it matter.

They can't share the same quantum state because they are fermions (Pauli Exclusion Principle). They have 3 quantum numbers that are the same, which are the 3 that define what we call in chemistry an orbital. But the 4th is the spin orientation quantum number and that is opposite sign for the two. So they don't have the same wave function in full, if you include spin.

I've never heard of them swapping states. Where do you get that from? 

[bangstrom]

4 hours ago, studiot said:

I really thought I was being clear.

You were perfectly, clear that covalent bonds are an entanglement and I find the idea quite valid but it was just novel to me.

 

4 hours ago, studiot said:

And no , I do not think it is irrelevant, I think it is vitally important and demonstrates that our knowledge is not as limited as made out.

It is important because the available combinations determine the probabilities

 It may prove to be important but as of now, I find it to be speculative but worthwhile to keep in mind among other possibilities.

 

3 hours ago, exchemist said:

I've never heard of them swapping states. Where do you get that from? 

The idea of swapping states has been around for many years, even before what we normally think of as states were known. When I first learned of entanglement I thought such a bizarre phenomenon must be of some enormous importance but I had no idea what. Later I discovered the nonlocal, swapping of energy states among charged particles was a possible mechanism behind the transmission of light.

The possibility was first proposed by Hugo Tetrode in “Zeitschrift fur Physik” vol.6 1922. Here is a quote from Tetrode’s article as translated by A. F. Kracklauer. Kracklauer advised the reader that Tetrode’s mention of atoms should best be understood as electrons. Electrons were unknown in Tetrode’s time.

“Suppose two atoms in different states of excitation are located near each other, normally it is to be expected that they would have little influence on each other; however, under special conditions with respect to positions and velocities, possibly also in the vicinity of a third atom, it might be that strong interactions occur, Such a situation could well lead to an energy transfer between atoms such that their excited states are exchanged. The energy loss of one and the gain of the other could occur in a time interval corresponding to their separation; that is, we would have an instance of emission from one atom and absorption by the other. While according to classical understanding, emission is a random event leading to radiation that also randomly might somewhere at some time be adsorbed; here in this theory, the source and sink of a radiative interaction are virtually predetermined paired events.

That is, in effect, the sun would not shine at all were there no other charged bodies in the universe to adsorb its radiation.”-Hugo Tetrode 1922

The model of swapping energy states among entangled particles is an important part of N.”Viv”Pope and Anthony Osborne’s “Angular Momentum Synthesis” POAMS and later in John Cramer’s “Transactional Interpretation Of Quantum Mechanics” TIQM. An excellent discussion of TIQM can be found in Chapter 5 of Carver Mead’s book “Collective Electrodynamics” and also in a 2020 collaborative article between Cramer and Mead. https://arxiv.org/pdf/2006.11365

Here is a quote from the article,

“As illustrated schematically in Figure 1, the process described involves the initial existence in each atom of a very small admixture of the wave function for the opposite state, thereby forming two-component states in both atoms. This causes them to become weak dipole radiators oscillating at the same difference-frequency ω0. The interaction that follows, characterized by a retarded-advanced exchange of 4-vector potentials, leads to an exponential build-up of a transaction, resulting in the complete transfer of one photon worth of energy ̄hω0from one atom to the other. This process is described in more detail below”-Cramer and Mead 2020

Figure 1 and the quote can be found on p.4 of the article cited above.

Cramer and Mead consider the energy states between entangled electrons to be oscillating rather than in superposition until the wavefunction collapses fixing the energy levels where they are found at the instant of collapse.

 

[swansont]

58 minutes ago, bangstrom said:

You were perfectly, clear that covalent bonds are an entanglement and I find the idea quite valid but it was just novel to me.

 

 It may prove to be important but as of now, I find it to be speculative but worthwhile to keep in mind among other possibilities.

 

The idea of swapping states has been around for many years, even before what we normally think of as states were known. When I first learned of entanglement I thought such a bizarre phenomenon must be of some enormous importance but I had no idea what. Later I discovered the nonlocal, swapping of energy states among charged particles was a possible mechanism behind the transmission of light.

The possibility was first proposed by Hugo Tetrode in “Zeitschrift fur Physik” vol.6 1922. Here is a quote from Tetrode’s article as translated by A. F. Kracklauer. Kracklauer advised the reader that Tetrode’s mention of atoms should best be understood as electrons. Electrons were unknown in Tetrode’s time.

The electron had been discovered 25 years prior to this publication, so no, that claim about electrons being unknown in his time isn’t correct.

58 minutes ago, bangstrom said:

“Suppose two atoms in different states of excitation are located near each other, normally it is to be expected that they would have little influence on each other; however, under special conditions with respect to positions and velocities, possibly also in the vicinity of a third atom, it might be that strong interactions occur, Such a situation could well lead to an energy transfer between atoms such that their excited states are exchanged. The energy loss of one and the gain of the other could occur in a time interval corresponding to their separation; that is, we would have an instance of emission from one atom and absorption by the other. While according to classical understanding, emission is a random event leading to radiation that also randomly might somewhere at some time be adsorbed; here in this theory, the source and sink of a radiative interaction are virtually predetermined paired events.

That is, in effect, the sun would not shine at all were there no other charged bodies in the universe to adsorb its radiation.”-Hugo Tetrode 1922

The model of swapping energy states among entangled particles is an important part of N.”Viv”Pope and Anthony Osborne’s “Angular Momentum Synthesis” POAMS and later in John Cramer’s “Transactional Interpretation Of Quantum Mechanics” TIQM. An excellent discussion of TIQM can be found in Chapter 5 of Carver Mead’s book “Collective Electrodynamics” and also in a 2020 collaborative article between Cramer and Mead. https://arxiv.org/pdf/2006.11365

Here is a quote from the article,

“As illustrated schematically in Figure 1, the process described involves the initial existence in each atom of a very small admixture of the wave function for the opposite state, thereby forming two-component states in both atoms. This causes them to become weak dipole radiators oscillating at the same difference-frequency ω0. The interaction that follows, characterized by a retarded-advanced exchange of 4-vector potentials, leads to an exponential build-up of a transaction, resulting in the complete transfer of one photon worth of energy ̄hω0from one atom to the other. This process is described in more detail below”-Cramer and Mead 2020

Figure 1 and the quote can be found on p.4 of the article cited above.

Cramer and Mead consider the energy states between entangled electrons to be oscillating rather than in superposition until the wavefunction collapses fixing the energy levels where they are found at the instant of collapse.

 

There’s nothing in these snippets that indicates entanglement is involved.

 

[bangstrom]

3 hours ago, swansont said:

The electron had been discovered 25 years prior to this publication, so no, that claim about electrons being unknown in his time isn’t correct.

You are right, the electron was discovered long prior to 1922. I was relying on my faulty memory of a paper I haven’t reviewed in several years. Kracklauer’s actual quote was, “At the time of the writing, ‘electron’ appears to have been virtually a synonym for ‘charged massive particle.’

I was also wrong about the Journal volume of the source. The complete name of the source was “Uber den Wirksamzusamenmmenhang der Welt. Eine Erweiterung der Klassichen Dynamic.  Z. Phys. 10, 317-328 (1922)

 

 

3 hours ago, swansont said:

There’s nothing in these snippets that indicates entanglement is involved.

 

 Nonlocal action at a distance, aka entanglement, can be found in other parts of Tetrode’s article but, of course, not by the name 'entanglement.'

“When solar radiations emitted and then eight minutes later absorbed on Earth, in the intervening time interval, according to classical physics, it is found each moment at a distinct location as field energy. This new theory, however, does not recognize fields, so in its terms in the interval the energy is nonexistent, although it will appear at the moment of absorption. This leads to no observable differences.”-Tetrode.

In my previous quote, Tetrode explains the time interval we always observe in light-related events as “ A time interval corresponding to their separation.” This is consistent with Special Relativity where we always find light-related events separated by distance to also be separated by time at the constant ratio of one second for every 300,000 km of distance. This view considers the commonly called ‘speed of light’ to be a spacetime dimensional constant rather a speed of any kind. This is why we can't have c+/-v because c is a ratio of time/distance and not a speed. You can't go faster than a ratio anymore than you can't go faster than 1.6 km per mile.

The numerical for c in Special Relativity is the same whether you call it a speed or a dimensional constant so there is no difference in the body of SR. The only difference is with Einstein's Second Postulate where c is considered a speed.

 

 

 

[Eise]

12 minutes ago, bangstrom said:

This view considers the commonly called ‘speed of light’ to be a spacetime dimensional constant rather a speed of any kind.

Funny enough, this 'dimensional constant' has the dimension of speed. Today it is interpreted as the maximum speed of causality. EM waves in vacuum and gravity have exactly this speed.

17 minutes ago, bangstrom said:

Nonlocal action at a distance, aka entanglement

Nope, no action. It is correlation. The no-communication theorem shows that even in QM there are no none-local actions. 'Action' implies energy transfer, and there is none. 

You start repeating the same misunderstandings as in the closed 'crowded quantum information' thread.