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

[bangstrom]

6 hours ago, KJW said:

On 12/10/2024 at 3:14 PM, bangstrom said:

I don't recall ever seeing anything about entangled neutrinos.

This indicates a misunderstanding of not only how particles become entangled, but also why particles become entangled.

Neutrinos are unique animals, in the particle world. Have you ever heard of entangled neutrinos?

[bangstrom]

4 hours ago, KJW said:

The no-communication theorem says that entanglement can't be used to communicate information. Presumably, if entangled particles did communicate their states, then this could be exploited to provide communication between people, in violation of the no-communication theorem.

As I said earlier, it is my understanding that ‘no-communication’ applies only to classical communication . Communication via entanglement can be observed when the particle coordination is reversed from its original condition indicating that ‘something has happened’ before and after entanglement. This is observed as quantum swapping.

Entanglement can be used to communicate but it is impossible to observe such a communication as faster than light.

 

4 hours ago, KJW said:

If this is being considered from a metaphysical perspective, then you need to consider why it is necessary for the correlation due to entanglement to be the result of communication, rather than accept that correlation can occur without communication.

Coordination occurs both with and without communication . The two are not mutually exclusive.

4 hours ago, KJW said:

Entanglement is observed but the non-local interaction is not observed, and it is the non-local interaction that runs afoul of Occam's razor.

 

Non-local interaction is the simplest form of interaction. Occam’s razor is violated when we insert what Mach called “unobserved metaphysicals” to explain events.

Milo Wolff “When an energy exchange occurs between, say, two molecules one wonders what is traveling between them. If we don’t know, we say it is a “photon” Giving it a name doesn’t add any knowledge, but it allows us to feel better and we can pretend we know what travels.”

 

 

 

[swansont]

3 hours ago, bangstrom said:

Neutrinos are unique animals, in the particle world. Have you ever heard of entangled neutrinos?

Yes. 

[bangstrom]

On 12/12/2024 at 4:04 AM, Eise said:

Now the other constants can be either derived, or measured according the new units. Your 'problem' simply does not exist.

The problem remains. When you measure the speed of light in units of length based on how far light travels in a given time and in units of time determined by the number of wavelengths of a cesium emission (or pick another emission) within your previously determined length, the value you get when you try to measure the speed of light will be the same as the value for c that you used in determining your values for length and time. Our units of distance, time, and c are all mutually determined.

This is difficult to understand when measuring the speed of light over short distances but it becomes more clear when you consider the difficulty of measuring the speed of c over the distance of a lightyear. Light travels the distance of a light year in a year at the rate of c. So the rate of c can only be measured as the same as the value of c you used for calculating units of distance and time. This makes it impossible to measure c as anything other than it was decided to be by convention.

On 12/12/2024 at 4:04 AM, Eise said:

Nope. What this is about is that it makes no sense to ask 'which path information' between the 2 events. So yes, there is information exchange in this example, and energy is sent from one atom to the other. But this is not entanglement.

You are describing the classical view which is not entanglement. There is no time interval to insert a block or a double slit between an entangled event. Entanglement is not possible unless the space between is open so a block would prevent entanglement in the first place.

 

On 12/12/2024 at 4:04 AM, Eise said:

Then you have always been wrong. It is not an interaction, it is a correlation. So no violation of causality. No information or energy exchange.

Entanglement is a violation of causality therefore also a violation of the EPR effect. It is described as a "violation of normal realism" but that is essentially causality to me. Entanglement is a correlation, but when the correlation is observed to have 'swapped' quantum locations in the before and after entanglement, that indicates an interaction.

 

On 12/12/2024 at 4:04 AM, Eise said:

Wot? This is energy transfer (see above). And instantly? How so, when we could measure that there is a time of d/c (d=distance between the atoms)? How does SR account for that, where in fact it forbids energy exchange faster than c?

 We can never observe the events as instant. Cramer and Mead describe them as simultaneous. As follows from SR, any two simultaneous events separated by distance will always be observed to also be separated by an interval of time at the rate of one second for every 300,000 km of distance. This makes c a spacetime dimensional constant rather than a speed of any kind.

Einstein's Second Postulate was a provisional statement that was instrumental in his formulation of SR but whether we call c a speed or a dimensional constant makes no difference to the body of SR since the numerical value remains the same no matter what we call it.

On 12/12/2024 at 4:04 AM, Eise said:

Below the ground state? How is that possible?

 The "ground" state is the ambient energy level of the electron's environment. It is not an absolute zero.

[Eise]

1 hour ago, bangstrom said:

When you measure the speed of light...

You don't understand: as c is defined as an exact value, there is no need to measure the speed of light anymore. 

1 hour ago, bangstrom said:

Our units of distance, time, and c are all mutually determined.

Yep. By fixing 2 of them the third rolls out automatically. The invariance of c makes it the perfect constant to define a distance unit, the fact that all atoms of one element are identical makes such atoms perfect to base the definition of the second on. 

1 hour ago, bangstrom said:

This makes it impossible to measure c as anything other than it was decided to be by convention.

Yep. See above.

1 hour ago, bangstrom said:

There is no time interval to insert a block or a double slit between an entangled event.

Of course there is: just make the distance between the detectors big enough. Let the photons pass, then block any communication between the detectors, and then measure the polarisations. It is not that different from Alain Aspect's experiment, where the choice of polariser is done after the photons left their source.

1 hour ago, bangstrom said:

Entanglement is a violation of causality therefore also a violation of the EPR effect.

First you only state that entanglement is a violation of causality, you give no argument. Second, with EPR you have it upside down. E P, and R believed that nature could not be so absurd. Bell tests proved them wrong. 

1 hour ago, bangstrom said:

Entanglement is a correlation, but when the correlation is observed to have 'swapped' quantum locations in the before and after entanglement, that indicates an interaction.

What has 'swapped'? Two entangled photons measured parallel both pass the polarisation filter. What has 'swapped'? And exactly under 90^o, always one passes, then the other doesn't. What has 'swapped'?

1 hour ago, bangstrom said:

We can never observe the events as instant. Cramer and Mead describe them as simultaneous.

Simultaneity is often not observed, but concluded from time and distance measurements. If I get a light signal from an event close by, and a signal from another event at 300,000 km exactly one second later, I know the events were simultaneous. SR is not about signal delay.

1 hour ago, bangstrom said:

The "ground" state is the ambient energy level of the electron's environment. It is not an absolute zero.

The ground state of an atom is the state where no electron can change its orbital to a lower energy state.

You do not understand enough about QM and SR to have a meaningful opinion about these matters.

Edited Friday at 02:55 PM by Eise

[bangstrom]

On 12/11/2024 at 5:17 AM, swansont said:

They don’t claim that this is entanglement (which is good, because it’s not). They state that it’s a description of a “quantum jump”

It is a description of a "quantum jump" but they also said the two electrons later become entangled.

In my quote, they used the term,”...a retarded-advanced exchange of 4-vector potentials ” to describe entanglement. Entanglement is a 4-vector event with three space-like vectors and a time-like vector extending both forward and backward in time. (advanced and retarded waves)

This was my quote,

“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 ̄hω0 from one atom to the other. This process is described in more detail below”

 The last sentence is where they describe an entanglement.

 

[swansont]

4 hours ago, bangstrom said:

It is a description of a "quantum jump" but they also said the two electrons later become entangled.

No, they don’t. They never say entanglement in that description.

4 hours ago, bangstrom said:

In my quote, they used the term,”...a retarded-advanced exchange of 4-vector potentials ” to describe entanglement. Entanglement is a 4-vector event with three space-like vectors and a time-like vector extending both forward and backward in time. (advanced and retarded waves)

This was my quote,

“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 ̄hω0 from one atom to the other. This process is described in more detail below”

 The last sentence is where they describe an entanglement.

 

!

Moderator Note

Nope. It’s clear you don’t understand what entanglement is, and have resisted all attempts to correct your misunderstanding. Since there’s no new ground to cover, this is closed. Don’t bring it up again.