bangstrom

On 11/18/2022 at 5:12 AM, Eise said:

I said, an example without entanglement. Oh man...

Your question made no sense.

“Really? A real signal, i.e. transferring information (and therefore at least a minimum amount of energy)? Or will you beg the question, and will give entanglement as example? So, please, give an example of such a signal, but not concerning entanglement.”

Your question is asking for, a real signal transferring information and energy but not entanglement. That is any ordinary signal. It could be a signal with a bell or a postal letter or a signal with flags.  That can't be what your asking for.

If you are asking for a signal without a transfer of energy, I gave you one and that is entanglement. If you want a signal with entanglement and a transfer of energy, I gave you one.

If you want an example of a signal without a transfer of energy, I can't think of any example except entanglement.

And if you want an example with exactly what you asked for, I just gave you three. And this post via computer is four.

4 hours ago, Lorentz Jr said:

Didn't Hensen's 2015 experiment* show that the state of Bob's electron is correlated with the final state of Alice's electron after she measures two mutually non-commuting properties (spin states along different axes), even though (a) the state of Bob's electron must have been correlated with the intermediate state of Alice's electron between the two measurements she made, and (b) the final measurements were made at spacelike intervals?

Henson’s experiments were made beyond light-like which means they were made beyond the reach of a light signal in order to close ‘locality loop’. In reverse of the usual practice, the emitters were beyond reach of a light signal with a single detector near but not exactly in the center.

I am not confident enough to describe how Henson’s experiment works except to say that it involves a single photon detector to detect photons from two stationary sources that contain entangled electrons embedded in a diamond material. When illuminated by a laser, the diamonds emit streams of photons and vary rarely they emit a pair of entangled photons from a pair of entangled electrons. One photon simultaneously from two remote sources.

A coincidence detector identifies the entangled photons and sends a ‘ring’ signal to the detector to start recording for a narrow window of time when the photons arrive. As I recall the spin states of the electrons is interpreted from the interference pattern of the photons since the photons are also entangled with the electrons. It’s complicated.

4 hours ago, Lorentz Jr said:

I'm struggling to fit that into the socks-and-widows analogy.

 Don't bother, the socks don't fit the widows.

On 11/17/2022 at 7:12 AM, studiot said:

On 11/15/2022 at 2:10 PM, Ghideon said:

Maybe not intended but I see this as yet an analogy for entanglement. Assume a couple is married and then separated by some (great) distance. When one (random) individual of the married couple dies we immediately know that the other party has become a widower or a widow. The immediate change from wife to widow (or husband to widower) does not need a signal.

I agree this is a superb example. 

That was the worst explanation of entanglement I have ever seen. If that is entanglement, then Aspect and Clauser got the Nobel for discovering that entanglement is a matter of changing the names on particles.

On 11/17/2022 at 7:12 AM, studiot said:

On 11/17/2022 at 5:16 AM, bangstrom said:

The question is, if an electron on one end of an entanglement is found to be spin-up, how does it's former partner in the entanglement instantly 'know' it should be spin-down?

It doesn't know, why should It ?

The quantum properties of both entangled particles are random and changing on both ends of the entanglement until one property of the two is measured. The particles can be widely separated, and because of the distance between them, one particle shouldn’t ‘know’ what is happening to its partner without some form of communication between them and time for the communication to reach it.

On 11/17/2022 at 7:12 AM, studiot said:

Can you provide an actual example of the circumstances for these two electrons ?

If a pair of entangled electrons is generated and a one sent in one direction and the other is sent in another direction the measurement of a single property of one electron, the spin direction for example, instantly establishes the identity of both separated electrons and quantum properties of the two will be found to be anti-correlated. Even if the the electrons are far apart and before a light signal has time to reach the second electron to get the message and ‘know’ which property was observed and how it should be oriented.

https://www.tudelft.nl/en/dossiers/loophole-free-bell-test-tu-delft-crowns-80-years-old-debate-on-nature-of-reality-einsteins-spooky-action-is-real

“Quantum mechanics states that a particle such as an electron can be in two different states at the same time, and even in two different places, as long as it is not observed. This is called ‘superposition’ and it is a very counter-intuitive concept”, says lead scientist Professor Ronald Hanson. Hanson’s group works with trapped electrons, which have a tiny magnetic effect known as a “spin” that can be pointing up, or down, or - when in superposition - up and down at the same time. “Things get really interesting when two electrons become entangled. Both are then up and down at the same time, but when observed one will always be down and the other one up. They are perfectly correlated, when you observe one, the other one will always be opposite. That effect is instantaneous, even if the other electron is in a rocket at the other end of the galaxy”, says Hanson. 

19 hours ago, Eise said:

20 hours ago, bangstrom said:

The entanglement experiment is grounded in the local reference frame of the experiment itself.

Again use of vague concepts. What does 'grounded' mean here? That the experiment happens to be done in an inertial frame?

How is that statement vague? 'Grounded' in the local reference frame means it is based upon the local reference frame or it uses the local reference frame. And don't you have the same usage in German 'auf gegrundet'? 

19 hours ago, Eise said:

OK, obviously you need reading glasses. So in a large font, specially for you:

Nobody claims that observers that are in other inertial frames of reference affect the experiment.

That is a bit of confusion that kept things going. I kept saying that outside observations have no effect on the results of the experiment while "joigus" and others kept saying that outside observers see events in a different order so no one can say which came first. I was thinking of the experiment only while "joigus" and some others were discussing an Alice and Bob type scenario where SR matters.

That was an unfortunate confusion that never should have happened but it did.

19 hours ago, Eise said:

The rest of your argument is BS. Observers in other inertial frames, like in Joigus' drawing, Carla and Daniel, see the space-like separated measurements, assuming they were simultaneous in the frame of reference of the experiment, in opposite timely order. Still they must agree on the physical interpretation of the measurements. A signal from one measurement to the other cannot fulfill this condition.

My arguments were based on the experiment and the particles involved so I kept insisting that the SR differences of outside observers have no effect on the results.

19 hours ago, Eise said:

It is so simple. According to SR there is no preferred inertial frame of reference. But you take the FoR of the experiment as such. I think that is also the reason why you keep sticking to this stupid idea that we think that other observers somehow change the order of events. 

It is not so simple. For one thing, as I have explained before, you have the wrong idea about what a "preferred frame of reference" is and why it is prohibited by SR. Can you define what you mean by a preferred frame of reference?

Also consider this, if Alice is next to the detector on the far left and Bob is next to the detector on the far right and the entangled particles reach both detectors at measurably the same instant relative to their origin at the center. Alice will say the particle arrived at her detector first and Bob will say the particle arrived his detector first. This should indicate that they, like all outside observers, are not in exactly the same reference frame as the experiment itself so they are in no position to say which particle was detected first.

Others, and if I recall you are among them, say it is impossible to say which came first because the observation is relative. This is essentially saying outside observers can affect the order of events. I say there has to be a first by some tiny amount of time and the particles know which was observed first. It is not for outside observers to decide.

16 hours ago, MigL said:

If the experimenter can see ( or receive information from ) both right and left detectors, they are not space-like separated. 

Yes, the detectors are space-like separated even if they are both visible.  If they are beyond the range of a light signal, they are light-like separated.

See the definitions from physics.stackexchange.com/questions below.

Spacelike separation means that there exists a reference frame where the two events occur simultaneously, but in different places.

Timelike separation means that there exists a reference frame where the two events occur at the same place, but at different times.

Lightlike means that, well, light could travel between those points.

16 hours ago, MigL said:

On 11/17/2022 at 1:49 PM, MigL said:

How exactly do they decide, or synchronize if you will, without super-luminal communication ?
Please explain the process for space-like separated experiments/observations.

You seem to be avoiding quite a few questions put to you, and just repeating the same things over and over again.

Your question was strange but I did answer it. The detectors may be space-like separated but they are not light-like separated for the operators so nothing superluminal was required.

The detectors are only light-like separated when the signal between them is superluminal. There are ways of changing the detectors at superluminal speeds like for experiments involving Wheeler’s delayed choice but that was not one of them.

If anyone thinks I didn’t answer their question their response should be- as was yours, ‘You didn’t my question about...’ And if they didn’t like my answer they should explain why and not just repeat the same question expecting a different answer. That would save a lot of miscommunication. And don't complain, 'You didn't answer my question,' without explaining what it was and expect me to guess.

1 hour ago, Eise said:

And that is exactly what I am saying. However, you use the inertial frame of reference of the experiment as a preferred frame of reference. Which is prohibited by SR, exactly as you say.

No, a 'preferred frame of reference' is an unworkable cosmological reference frame. That is the kind of "preferred" frame that is prohibited. It's an unfortunate and confusing use of the word 'preferred'.

1 hour ago, Eise said:

And, oh, by the way, I am still waiting for an example:

 This example should be non-controversial enough. https://newscenter.lbl.gov/2010/05/10/untangling-quantum-entanglement/

Previous experiments led by Graham Fleming, a physical chemist holding joint appointments with Berkeley Lab and UC Berkeley, pointed to quantum mechanical effects as the key to the ability of green plants, through photosynthesis, to almost instantaneously transfer solar energy from molecules in light harvesting complexes to molecules in electrochemical reaction centers. Now a new collaborative team that includes Fleming have identified entanglement as a natural feature of these quantum effects. When two quantum-sized particles, for example a pair of electrons, are “entangled,” any change to one will be instantly reflected in the other, no matter how far apart they might be. Though physically separated, the two particles act as a single entity.

1 hour ago, Eise said:

So what is the difference between the entanglement experiment and the Alice and Bob scenario? 

The entanglement experiment is grounded in the local reference frame of the experiment itself. The Alice and Bob scenario involves the SR observations of two outside observers. Their observations have no affect on the timing or calculations of the local reference frame and the experimental setup is blind to both classical and SR variations in timing by its perfectly symmetrical design so SR variations need not be considered.

1 hour ago, Eise said:

What? SR is the theory of how observers in different inertial frames of reference see physical events. It is the theory about how events are seen across different reference frames.

I agree, SR works differently in individual references frame so we can compare.

1 hour ago, Eise said:

How often must I repeat this? No order of events is 'changed'. Observers in different inertial frames of reference just see them in different timely order, when events are space-like separated. So this is blatantly false:

That is what I have been saying all along. Observations outside the local reference frame do not change the local reference frame.

2 hours ago, joigus said:

Only problem is that's not true. If a person can't handle addition, any silly mistake they see as easy-peasy. It's easy for you because you've got the wrong picture.

Apparently we have been discussing two different pictures.

I have been discussing the entanglement experiment the whole time and you appear to have been discussing an Alice and Bob scenario and that is a disconnect that appears to have lead to some major confusion.

To go back to the beginning, I said the first particle observed decides the quantum properties for both entangled particles.

Someone asked. “How do you know which particle was observed first?” A sensible question.

I said there is rarely a need to know which came first but the experimenters can decide which particle they choose to measure first.

That means they can choose to measure the particle that went to the left first- or- they can measure the particle that went to the right first. It all depends on how they setup the experiment prior to each run.

You said I know nothing about SR because I failed to consider the SR observations from outside observers. I explained that SR may work but it does not work across reference frames. SR can not change the order of events in the experiment so SR is irrelevant to the experiment and its calculations. The setup of the experiment itself decides the order of events.

I don’t know where Alice and Bob came from but that was never my view. Does that clarify things?

14 hours ago, Eise said:

The inertial frame of the experiment has no 'special authority': that would mean it would be a preferred inertial frame of reference, which is against SR. So different observers do not agree upon which measurement was first, and therefore about the direction of a signal.

A “preferred inertial frame of reference” has a specific meaning in physics (look it up) and it is prohibited by SR.

But nothing in SR prohibits designating your local frame as your center of discussion to the exclusion of all others.

7 hours ago, MigL said:

19 hours ago, bangstrom said:

That's what I said. If it matters to know which measurement came first, the experimenters can decide which to measure first.

How exactly do they decide, or synchronize if you will, without super-luminal communication ?
Please explain the process for space-like separated experiments/observations.

What I said is in reference to the experiment itself. The experimenters can decide which particle to measure first as part of the setup of the detectors in the experiment.

7 hours ago, MigL said:

Again, 'first' depends on your FoR.

My FoR was always the local RF of the experiment itself.

7 hours ago, MigL said:

But the actual signal ( if there was one ) could only go one way.
You cannot have different physical outcomes from frame dependent observations.

The signal (if there is one) is an important consideration. If there is one, it would likely be two, as with Cramer's or Wheeler-Feynman's advanced and retarded waves extending both forward and backward in time.

11 hours ago, joigus said:

There you go again. There is no "first." None of them comes first, and then the other. It'd better not.

There is rarely any need to know which measurement came first but it is possible to do so. One entangled particle goes to a detector on the left and another goes to the right. The experimenters can decide to move one detector closer to the source so that side becomes the first particle to be measured because the particle with the shortest distance to travel is the first to reach a detector. Easy-peasey.

12 hours ago, joigus said:

That's why Ghideon's analogy is so brilliant. There's no speed at which the woman becomes a widow. Or it's infinite, whatever way you want to say it. It's a logical fitting between both ends. Nothing travels. No Cramer, I'm sorry.

You are just giving a person or particle a different name. That is by no means entanglement.

2 hours ago, Eise said:

Really? A real signal, i.e. transferring information (and therefore at least a minimum amount of energy)? Or will you beg the question, and will give entanglement as example? So, please, give an example of such a signal, but not concerning entanglement.

Information has no energy and a signal need not be energy bearing. The question is, if an electron on one end of an entanglement is found to be spin-up, how does it's former partner in the entanglement instantly 'know' it should be spin-down?

2 hours ago, Eise said:

Simultaneous according which observer? Simultaneity is not even agreed upon by different observers for time-like separated events. Only the timely order is.

Simultaneous within the reference frame of the experiment itself and its measurements. Or, simultaneous relative to the origin of the entangled particles if you want to be really precise.

The detectors are ideally widely spaced so the events will never be simultaneous to all observers but that has no relevance to the experiment or its measurements since outside observations can not change the results.

19 hours ago, joigus said:

The experimenters decide who does the measurement: One of them, the other, or both. And they also decide when that happens, in their respective local reference frame.

That's what I said. If it matters to know which measurement came first, the experimenters can decide which to measure first.

19 hours ago, joigus said:

OTOH, observers moving with respect to them, see the measurements happen in different temporal order, depending on their state of motion. Will you at some point understand this?

I have explained many, many times I understand this. What are you saying I don't understand?

16 hours ago, Eise said:

It is obvious what I mean: again you are obfuscating the discussion. Of course I mean it in the context of SR: all inertial reference frames are equally valid; none is privileged, not even the inertial frame where entanglement source and measuring devices are at rest. So if we have two events, e.g. two measurements, that are space-like separated, there is no fixed timely order. 

Agreed, a purely space-like separation has no timely order.

Also, the term 'privileged reference frame' is specifically a cosmological term and one that I would not use in reference to an ordinary reference frame so your claim that I did had me confused.

16 hours ago, Eise said:

You are moving the goal posts. Yes, it is easy, just setup the experiment so that the measurements are time-like separated. But that was not what we are talking about. You are evading the point we are making.

I understand the point you were making but, in reality, when two different measurements are made in the 'real' world it has to be nearly impossible to make both measurements at absolutely and precisely the same femtosecond or less so there will always be a first measured.

17 hours ago, Eise said:

As you know, we say there is no message.

 I know you say there is no message. But I say there does appear to be evidence of a signal and response and that is suggestive of a message being sent and received so I am not convinced.

17 hours ago, Eise said:

And one of the ways of seeing that is that when the two measurements are space-like separated, the timely order is different for different observers. Signals have a direction. But a signal going into one direction for one observer, but in another direction for another observer makes no sense physically.

Different observers seeing signals going in different directions is a well understood phenomenon of SR. It may be counter intuitive but I don't understand how it means there is no signal.

It also makes no difference to the measurements at the local level of the experiment itself.

.

14 hours ago, Ghideon said:

On 11/16/2022 at 12:59 AM, bangstrom said:

In the actual experiment, the first particle observed instantly makes the other particle the second particle to be observed.

That seems incompatible with Special Relativity.

Clarification: I'm sure the actual experiment is consistent with Special Relativity, your explanation is not.

Agreed, changing the names to first observed and second observed or to widow and widower has nothing to do with SR.

Also, the experiments with entanglement are consistent with SR because they are designed with SR in mind.

They are perfectly symmetrical with pairs of entangled particles originating in the precise center between two measuring devices so the measurements on both ends are made simultaneously. This eliminates any time variations due to either classical or relativistic variations.

16 hours ago, MigL said:

I have to agree with INow; this is just going around in circles.

Very much so- right from the start.

16 hours ago, MigL said:

But while the states themselves are not realized, the correlation between them is, and is defined by the common wave function.

A correlation does not have to be 'maintained' in any way, it simply is, or isn't; no 'signalling' required. All this points to 'non-relity' being the root cause of the behaviour of entangled pairs, certainly not 'non-locality', as there is no need for it after 'non-reality' is taken into consideration.

Could it be that the common wave function that “defines” the correlation is a form of ‘signal’ that maintains correlation?

I don’t find the view that a correlation is because “it simply is” as explanatory when the quantum identities are indeterminate until observed and entangled particles always appear anti-coordinated even when separated by a great distance.

23 hours ago, Eise said:

On 11/14/2022 at 11:40 PM, bangstrom said:

I never claimed the inertial frame of the experiment was a ‘privileged’ frame.

Yes, you did:

23 hours ago, Eise said:

I never claimed the inertial frame of the experiment was a ‘privileged’ frame.

Sorry, the first part or this was omitted so I will repeat it in the next comment.

My underline.

In physics, the term ‘preferred frame’ or ‘privileged frame’ has a specific meaning much different from the common usage of the word meaning favored or selected. It has a cosmological meaning unrelated to anything we were discussing. So I never claimed my frame was ‘privileged’.

Using a local reference frame to the exclusion of others is a normal and accepted practice. It is absolutely not the same as a ‘preferred frame’.

A ‘preferred frame’ is a global reference frame that unifies all reference frames. Various preferred frames, such as the CMBR, have been proposed but so far they have all been proved unworkable so there is really no such thing as a preferred frame.

This is from Wikipedia,

"In theoretical physics, a preferred frame or privileged frame is usually a special hypothetical frame of reference in which the laws of physics might appear to be identifiably different (simpler) from those in other frames.

In theories that apply the principle of relativity to inertial motion, physics is the same in all inertial frames, and is even the same in all frames under the principle of general relativity."

23 hours ago, Eise said:

there is no way that on basis of a measurement one can know if the other was already measured or not. If you think you can, then show us how.

If it is necessary to know which measurement came first, the experimenters can decide which measurement to make first. Easy-peasy.

Usually it is not necessary to know which came first and the measurements may not be able to determine which was first but that only means that the timing was below the device's threshold of measurement.

On the other hand, when one particle is measured, the other responds correctly by being predictably anti-coordinated so the second measured particle apparently ‘got the message’ no matter how quickly or beyond measure the timing was.

23 hours ago, Eise said:

On 11/14/2022 at 11:40 PM, bangstrom said:

If you understand SR, you should know that observers from outside a single reference frame can not go back in time and change events that have already happened to conform to their various outside observations.

I nowhere said such a thing. If you think I did, cite the relevant text passage.

That was one of MY explanations for why SR considerations are neither relevant nor used in the the calculations. I made no claim that you said that. You would have been right if you did.

23 hours ago, Eise said:

Here you take the inertial frame of the entanglement source and the measurement devices as a preferred frame. There is no change in order of events. With space-like separated events there is no objective order of events. For one observer measurement 1 might be first, for another measurement 2. Nothing changes. It is only a change of perspective. 

My underline.

In physics, the term ‘preferred frame’ or ‘privileged frame’ has a specific meaning much different from the common usage of the word meaning favored or selected. It has a cosmological meaning unrelated to anything we were discussing. So I never claimed my frame was ‘privileged’.

Using a local reference frame to the exclusion of others is a normal and accepted practice. It is absolutely not the same as a ‘preferred frame’.

A ‘preferred frame’ is a global reference frame that unifies all reference frames. Various preferred frames, such as the CMBR, have been proposed but so far they have all been proved unworkable so there is really no such thing as a preferred frame.

This is from Wikipedia,

"In theoretical physics, a preferred frame or privileged frame is usually a special hypothetical frame of reference in which the laws of physics might appear to be identifiably different (simpler) from those in other frames.

In theories that apply the principle of relativity to inertial motion, physics is the same in all inertial frames, and is even the same in all frames under the principle of general relativity."

18 minutes ago, bangstrom said:

 

23 hours ago, joigus said:

The statistics of such properties is hardwired in the state without them being "real" properties of the individual entities. The entangled state is the entity as far as the current theory understands it.

It is more like they are soft-wired since we know nothing about the properties of entangled particles until observed and then it all comes together.

11 hours ago, Ghideon said:

The immediate change from wife to widow (or husband to widower) does not need a signal.

In the actual experiment, the first particle observed instantly makes the other particle the second particle to be observed. You should write a paper.

20 hours ago, Eise said:

So that means your argument is not relevant. That particles at different locations have a space distance is a tautology. That two measurements are space-like separated in a space-time diagram is not. This is just one example of you confusing, or better, obfuscating, the discussion again and again. (Calling' non-locality' 'not realist' is another one.)

I was discussing two objects in ordinary space. You assumed I was discussing a diagram. I was not discussing a diagram so the confusion was on your end.

20 hours ago, Eise said:

As repeatedly said, the inertial frame of the entanglement source and the measurement devices is not a privileged frame. There is no 'objective now', and no absolute timely order for space-like separated events, so no objective first.

I never claimed the inertial frame of the experiment was a ‘privileged’ frame. As usual, it was a frame of its own.

20 hours ago, Eise said:

There is no way, even for the measurements themselves, to 'know' if its entangled partner has been measured. There is no flipping of the wave function before it is measured: there are only measurements.

I said the particles ‘know’ which was measured first. That was a teleological statement but how better to say it?

20 hours ago, Eise said:

It takes so long because you do not see the relevance of it. You only show again and again that you do not understand SR, and therefore you do not understand the relevance. 

If you understand SR, you should know that observers from outside a single reference frame can not go back in time and change events that have already happened to conform to their various outside observations.

5 hours ago, joigus said:

You cannot just say "oh, but this is not SR," and get away with it.

About "bickering,"

If people tell you there are non winged lions, that's not bickering. That's stating something that's very likely to be true. It's for your own intellectual good when people tell you so.

 

The "people" in this case were telling me SR applies across reference frames. I was saying that ain't so.

11 hours ago, joigus said:

21 hours ago, bangstrom said:

Are you implying that entanglement itself is a cohort?

This sentence doesn't make sense gramatically, let alone physically.

A cohort is a set.

An ‘entanglement’ is a ‘set’ of two or more particles that may be widely separated in space but they act as if they were side-by-side.

21 hours ago, joigus said:

That's exactly the point. Quantum systems do not have "internal cohorts." No internal cohort of elements with attributes can explain their correlations. Read it again, and you may finally understand this.

There are no cohorts among quantum properties but there is a non-local connection among entangled particles that maintains correlation.

Are you implying that entanglement itself is a cohort?

21 hours ago, joigus said:

If you insist on these properties to arise from any kind of internal cohort, whatever the wave function represents --either our knowledge of the system or some "real wave" carrying our knowledge of the system-- would have to be updated non-locally. "The internal cohorts" would have to change their composition in a coordinated way, at a distance, even when separated by space-like intervals.

Non-local updating of the system without ‘hidden variables’ is a generally accepted principle of QM. The non-local updating of the system is what Einstein objected to as, “Spooky action” but it has been routinely verified as a real effect ever since it was first demonstrated by Bell.

21 hours ago, joigus said:

But none of this represents any interaction.

Why is this not an interaction?

21 hours ago, joigus said:

It represents updating of your knowledge of the system. You now know more about the system than you knew before, that's all.

It represents an updating of the system itself. Your observation tells you that the system has been updated but the system was updated whether you are aware of it or not.

21 hours ago, joigus said:

The fact that the position variables play no role, and you can conduct the experiment at one small region of space, and the results would be exactly the same, should give it away.

Experiments involving entanglement work over both large or small distances and there are no 'hidden variables' in position.

18 hours ago, Eise said:

 If you would draw a simple space diagram, yes, then there is a space distance between particles at different locations.

I don’t know if you noticed but the first part of my statement was self contradictory because I inadvertently omitted a word. I intended to say interacting particles can not have a space-like separation.

In the second part, where I said that any two particles in different locations have a space-like separation, I was referring to different locations in the usual sense of ‘different locations’ not to locations on a diagram. So your comments about diagrams do not apply.

18 hours ago, Eise said:

Nobody here defended that there are observers that see time-like separated events in a different timely order.

I made a statement that, with entangled particles, the “first particle observed” breaks the entanglement for both particles simultaneously.

The result was that everyone, including yourself as I recall, were claiming that different observers see space-like events differently so no one could say which observation came first therefore I was ignorant of SR because I ignored SR in my explanation.

I agreed that remote observers may not know which came first but the “particles know” which was ‘first observed’ and no outside SR observations could change the order of events.

I don’t know if anyone got the message that SR was irrelevant to the problem because the bickering about my omission of SR continued for much longer than it should have.

18 hours ago, Eise said:

All this confusion arises because you are so sloppy with what a space-time diagram depicts, namely events, not physical objects. A physical object A in a space-time diagram is a chain of events, A being at x₁ at t₁, at x₂ at t₂, etc. Drawn all infinitesimal positions and times, the physical object A will show as a world-line, never as an individual point.

I was not aware that a space-time diagrams should plot events and not physical objects. You can't have events without physical objects so I would would think plotting one would be redundant to plotting the other.

All the light cones I have seen, do plot physical objects and they plot them as world-lines. Never as points.

18 hours ago, Eise said:

Again, your use of the concepts in your arguments are so vague, that they are, well, not even wrong. They miss the matter under discussion completely.

 

I was not aware that my arguments are so vague. Could you point which of my depictions of a space-time diagram got you so confused, or in the future, let me know when my arguments are vague.

18 hours ago, joigus said:

On 11/11/2022 at 2:52 AM, bangstrom said:

What is so wrong about this statement? Essentially it says that every particle, given enough time, will eventually interact with another particle. I don't find that to be so controversial.

It is simply not true that every particle, given enough time, will eventually interact with another particle. Two photons that are being lost beyond the cosmic horizon in opposite directions, eg, will never meet again, or interact in any way.

You are reading something into it that isn't there. Each photon will eventually strike another particle. Not necessarily the other photon or any specific particle.  Just another particle.

18 hours ago, joigus said:

False, shockingly ignorant statement. Entanglement always occurs as a consequence of local interactions. Particles must be brought together for them to entangle. Here. Simple Google search of "what causes particle entanglement":

I don’t agree that a local interaction is required to initiate entanglement although that is necessary for experimental sources. Any non-local, two-way interaction among particles, usually electrons, such as Cramer’s advanced and retarded potentials constitutes an entanglement.

18 hours ago, joigus said:

You're misquoting here, or just plain lying. Point to me where anybody said that "the ambiguous nature of SR events for different observers can reverse the order of time-like (separated) events." This, most likely, is a new half-digested regurgitation from your mind of what others have actually said.

If you can have numerous observers in different inertial reference frames all claiming a different timing and different orders of the same event, I call that “ambiguous”. That may not be the best word but it appeared to be a fit regurgitation at the time and it was mine.

18 hours ago, joigus said:

Missing the point again. I will rephrase correctly your gazpacho of words and, with any luck, you will see what you said wrongly:

The observation of one quantum property cannot indicate the possible outcome of any other incompatible quantum property.

That sounds like a line from my gazpacho in support of Bell’s analysis. To continue:

18 hours ago, joigus said:

The observation of one quantum property completely determines the possible outcome of the compatible quantum property that's tied to it by a conservation law.

I say the observation of one property determines nothing about the possible outcome of any of the others, with the one exception of the same property to be observed with the other entangled particle.

I think our difference in opinion is with quantum properties having cohorts. Classical objects have cohorts but quantum particles do not so any of the combinations in your “Collectivity (2)” are possible.

No quantum properties necessarily go together. If you have a quantum coin that is heads on one side and tails on the other- and red on one side and blue on the other- you can get Heads- Red one time and Heads-Blue the next. Quantum properties do not cohort and that is the Bell test.
 

20 hours ago, joigus said:

What's wrong is that, for space-like separated events, time ordering is ambiguous. So the thing that's "happening" before or after, as the case may be, has to be completely ineffectual (for all intents and purposes, just a re-definition of the wave function,) and only in your mind, really. Eise has just explained how the ordering is ambiguous. If it had any consequences --measurable ones, interactions, etc.-- it would be very bad for SR. It doesn't happen.

Yes, for space-like separated events, timing is ambiguous but the ambiguous nature of SR events for different observers can not reverse or even slightly affect the order of time-like events. You and others were trying to tell me some discussions ago this is possible but I still say outside observations can not go back in time and reverse the order of events that have already happened. I thought this was eventually understood but you raised the issue again.

16 hours ago, joigus said:

IOW, there is no way that you can obtain both statistical behaviours at the same time with any reasonable assumption of cohorts that hold these properties as real.

That's my reverse-engineering of Bell's theorem --or its violation by QM, to be more precise-- for you.

I agree with Bell that the many kinds of variations such as those found in your "Collectivity (2)" are observed with observations involving entangled particles. The observation of one quantum property can not indicate the possible nature of any other of the several quantum properties. They can all vary independently and this indicates that they are not fixed from the start. 

There are no cohorts among quantum properties as there are among classical properties and every observation is random.

22 hours ago, Eise said:

This shows you do not even understand what SR is about. The 'objects' in a space-time diagram are events, not physical objects of any kind, so not particles either. Important to note is that the measurements (that are events) both lie in (e.g. when using electrons) or on (when using photons) the future light cone of the event in which the entangled particles were created.

The outer bounds of a space-time diagram are the propagation distance of a light flash and the inner contents of a light cone can include anything within the entire visible universe. The light cones themselves are imaginary constructs and it is legitimate to populate the cones with any ‘objects’ relative to the discussion.

The contents of a light cone are not limited to events alone and other contents frequently include particles, world world lines, smaller cones, and even space travelers as with illustrations of the twin paradox so your assertion that the addition of anything other than events alone in not kosher with SR is without merit.

19 hours ago, joigus said:

On 11/11/2022 at 2:52 AM, bangstrom said:

Essentially it says that every particle, given enough time, will eventually interact with another particle.

No. Two photons parting away from each other will never meet.

OK, but that is not what I said.

19 hours ago, joigus said:

No, there's no "remarkable exception." Again, you ignored something I said later. I made a significant addition because I fell in the trap of your ambiguous language of referring to "a light cone" without specifying the generating event, which of course, is meaningless:

The generation of an entanglement event is like the generation of a light flash. It can be anywhere an origin is possible and it makes no difference where the origin may be if you are just speaking of entanglement or light flashes in general.

A major difference with entanglement is that it can begin at a single point when two particles are generated from a common source or it could be generated at more than one point as when two electrons in different locations spontaneously entangle. In that case, it would be the origin of two separate light cones but with electrons sharing a common non-local wave-like connection.

Your second picture of light cones illustrates that sort of an event.

On 11/9/2022 at 3:09 PM, joigus said:

No. It is simply not true that every particle is within the absolute future light cone of another. This proves an absolute ignorance of the principles of special relativity. You know nothing about SR, that's clear enough for everybody here.

This isn't what I said but close enough. What is so wrong about this statement? Essentially it says that every particle, given enough time, will eventually interact with another particle. I don't find that to be so controversial. This statement had something to do with how a thrown stone has an impact site in its future light cone but that doesn't mean it is entangled.

Also, I learned nothing from your excellent discussion about light cones because it was nothing I didn't know before. We appear to be in general agreement but you missed the points where our views part company.

One minor point is that particles can not have a space-like separation. I say that any two particles in different locations have a space-like separation.

The only major disagreement I see is the one below.

17 hours ago, joigus said:

Space-like separated events are never, --repeat, never-- on the same light cone.

There is one remarkable exception to the rule and that is with entanglement. When two similar charged particles, usually electrons, establish a two-way resonant connection and act as if they were side-by-side, even though they may be galaxies apart, that is entanglement.

Their connection is non-local and you could say they even reside in different light cones because they have no ordinary classical connection.

On 11/9/2022 at 8:38 AM, joigus said:

Do we have to go to the basics of SR every time you say something?

As I recall there are some basics of SR that you never explained if I may go back and review.

For one, if you have a source of entangled photons (usually a down converter) exactly in the middle of two synchronized clocks, so that two photons are generated simultaneously and they reach opposite detectors at exactly the same time, how do the observer-dependent views of outside observers affect the timing of the events.

I say they have no effect on the the timing at all.

Secondly, with the same setup, if one timer is closer to the source than the other so a measurement is made on the closer particle before the farther particle, that makes the closer particle the ‘first observed’ and the difference in the timing of the measurements both time-like as well as space-like.

Then, as before, if an observer closer to the farther particle sees the farther particle as the ‘first observed’, how does this change the order of events and make the farther particle the actual ‘first observed’ and the closer particle the ‘second observed’?

I would say the local view where the closest particle is the first particle observed still holds true and the view of an outside observer has no effect on the local observation of which came first.

What is wrong with these scenarios?

12 hours ago, swansont said:

Because you asked “Are you saying they are fixed from start to finish?” 

Now you admit to knowing that I was not. One wonders why you asked the question.

 

I asked the question because your explanations of why the particles always appear anti-coordinated only work when one assumes that they are unchanging as with the 'gloves in boxes' example or how the particles are always anti-correlated with no signal between them. I wasn't asking about the quantum properties while they were entangled.

12 hours ago, swansont said:

You’ve not shown an example of a system that has a “before” state that could be identified.

Knowing the “before” state is not necessary to observe that changes in the quantum properties of entangled particles are taking place.

It is NOT necessary to know the ‘before’ state with the Bell test. The Bell test demonstrates that there are more possible outcomes of an ‘after’ observation when more than a single quantum property is observed than are possible with the classical model where the quantum properties are fixed and unchanging from the start.

Are you implying the Bell test is faulty?

Also, knowing the ‘before’ identity is also NOT necessary for quantum teleportation because a second entanglement can change the observation of a remote entangled particle from indeterminate to determinate.

If you understand how quantum teleportation, works you should know that the instant teleportation of a single quantum property from one particle to that of a remote entangled particle is only possible if the quantum property under observation is capable of being instantly changed (teleported) from one particle to a distant particle.

You may not know what the quantum property of the particle may have been without teleportation but you can reliably predict what it will be after teleportation because it will always be identical to the identity of the particle whose property you teleported. This requires some kind of instant signaling between the particles.

Experiments demonstrate that the quantum properties of entangled particles are random and anti-coordinated on both ends of an entanglement and become determinate when the first particle is observed. So how does a particle on one end of a remote entanglement 'know' it should be anti-coordinated with its partner when its distant partner is observed without some kind of an instant signaling?

12 hours ago, swansont said:

 

5 hours ago, swansont said:

8 hours ago, bangstrom said:

Energy, spin and all other properties are conserved but are the quantum properties unchanging? Are you saying they are fixed from start to finish?

Are you incapable of determining whether or not I said that? Or that I’ve repeatedly confirmed that the states are undetermined?

I guess reading comprehension is one of the issues here. 

We both know entangled particles are indeterminate before the first observation is made so why tell me they are indeterminate?

Quantum particles have observable properties BEFORE and or AFTER entanglement and you say they are coordinated or anti-coordinated after entanglement.

The Bell test and quantum teleportation experiments tell us that any AFTER property is not necessarily the same as the BEFORE. Do you agree with this observation or not?

5 hours ago, joigus said:

See my point? With this degree of carelessness it's gonna be hard. When one event is within the absolute future light-cone of another, you don't need to invoke non-locality/violation of relativistic causality to explain it. Maybe thowing a stone would suffice.

It's with spacelike-separated events that you do.

Do we have to go to the basics of SR every time you say something?

Entanglement is not SR and think about what you said in the above.

Every particle large or small is “within the absolute future light-cone of another.” If that is your understanding of ‘entanglement’ then every interaction is an entanglement so entanglement is no different from throwing a stone.

I don’t know if that is what you mean but that is what you appear to have been saying the whole time.

Do you recognize that there is a difference between entanglement and classical interactions?

5 hours ago, joigus said:

Yeah, sure. You're waiting. It takes half a minute to dismiss other people's careful arguments with no arguments of your own. But it takes a bit longer to prepare a carefully-thought argument.

I know the problem well so take your time.

On 10/31/2022 at 2:16 PM, joigus said:

But again, no need for causation at a distance to explain the overall correlations. The quantum state has all you need, and it was prepared at one small region of space, and at one time.

Again, are you saying the quantum properties of entangled particles are ‘fixed’ at the start and unchanging? This is contrary to the Bell test and Zeilinger’s teleportation experiments would be impossible if it were so.

This should be a yes or no question. More examples with macro objects will not answer the question since the question is about entangled “particles” and not macro objects after separation.

On 10/31/2022 at 9:40 AM, swansont said:

Energy is going to be conserved, too. But nothing has be “constantly maintained” in order for that to happen. 

Energy, spin and all other properties are conserved but are the quantum properties unchanging? Are you saying they are fixed from start to finish?

On 10/31/2022 at 2:16 PM, joigus said:

I'm working on an example that's so transparent that even you will have to agree with it. Let's see what happens.

I'm waiting.

On 10/29/2022 at 4:33 AM, joigus said:

What people (sometimes, quite loosely, quite sloppily) call "quantum non-locality) is not that. Quantum theories allow you to prepare states that have no definite value of these locally-conserved quantum numbers Q, and then measure their value at the boundary. So you force the quantum state to "decide" (select, einselect) what particular value of the quantity Q it --for lack of a better word-- "encapsulates."

 

"So you force the quantum state to "decide" (select, einselect) what particular value of the quantity Q it --for lack of a better word-- "encapsulates."

How does that 'force to decide' not involve some kind of a signal?

On 10/29/2022 at 4:33 AM, joigus said:

You can do pairs of measurements for space-like separated events (so no light ray can join them) or for time-like separated events (so the time ordering between the events is observer-independent: the later one is in the light cone of the previous one). That really doesn't make that much of a difference. And it doesn't because all the alternatives that were coded in the quantum superposition in some sense disappear.

The individual quantum properties are binary, either one state or another, and they don’t disappear with the loss of entanglement. They become determinate. What happens with the others is unknown because we can only observe one property and that causes entanglement to be lost.

On 10/29/2022 at 4:33 AM, joigus said:

You can do pairs of measurements for space-like separated events (so no light ray can join them) 

Would you say space-like separated particles interacting on the same light cone are local or non-local?

I would call that a non-local interaction. If that is 'local,' what would you call non-local? Or, are you saying nothing is non-local? 

On 10/29/2022 at 6:47 AM, swansont said:

Correlation is not an interaction, and the correlation is present at the beginning.

I will leave it to you to speculate about how a correlation is not an interaction?

The correlation may be present from the beginning but the quantum properties have been demonstrated to be random at the first observation and instantly predictable at the second observation. If the observed properties were unchanging from the first, then the instant correlation could have a simple classical explanation but it has been determined that this is not the case.

This makes it difficult to explain how a correlation can be constantly maintained from one end of the connection to the other, no matter what the distance between, without some kind of an instant signal common to both ends of the entanglement.

The conventional explanation is that the quantum properties are random, indeterminate and superimposed prior to the first observation. This explains the random nature of the observation but it doesn’t explain the correlation.

Some have described the connection between the two or more entangled particles as a Schroedinger wave-like connection and that implies some kind of a circular undulation like the one depicted with “Hoola’s” wave a few posts ago. If the two particles are always at opposite points of the wave function such that, when one particle is at a point that could be considered the ‘peak’ of the wave, the other particle will be at a point that could be considered the ‘trough’. This could explain how the entangled particles remain anti-correlated where opposite positions on the common wave function represent opposite quantum properties.

N. “Viv” Pope explained the connection as “swapping stools” much like two persons in a game of musical-chairs with two chairs. When the music stops, each one grabs a chair but they will always be anti-correlated.

The first observation is the thing that breaks the entanglement and the loss of a connecting wave function instantly ‘stops the music’ on both ends and this signals each particle to take on an identity that is appropriate for whichever its position on the wave function calls for at the time.

In this scenario, the connecting wave function is what maintains the correlation and the instant loss of entanglement is the signal that ‘stops the music’ and ends the entanglement leaving the particles on both ends of the former entanglement with the appropriate anti-correlated quantum properties.

4 hours ago, joigus said:

I've found what's confusing you. The reason is this: This doesn't happen if you don't re-entangle the boxes.

The point I was trying to make is that the results are random whether you make the observation once or a dozen times.

4 hours ago, joigus said:

Don't dwell on the confusion: They are always random, always!

Agreed, they are always random.

4 hours ago, joigus said:

Particles that become entangled need to do so by means of local interactions. If you study field theory, this becomes obvious. That's why all field theorists, Weinberg, Salam, Gell-Mann, 't Hooft, etc., have always been so little impressed by these claims of non-locality.

What do they consider to be "local interactions"? If one electron entangles with any other electron on their common light cone, would that be considered 'local'? One peculiarity of entanglement is that the particles appear to be without any space-like separation between them. Their properties are superimposed and that may be as local as anything can get.

2 hours ago, joigus said:

The anticorrelations are built into the state, very much like the Pythagorean theorem is built into the relations of a right triangle, for example --a similar example to the one he is proposing. He is proposing that infinitely many possible values of an angle can be associated to a given value of a trigonometric function.

Agreed that the anti-correlations are built into the state. I question how they are maintained after entanglement when the Bell test has ruled out the possibility that the quantum properties of the entangled particles are not static.

To go back to the old gloves in boxes scenario. If you open your entangled box and find a RH glove you know the other box is LH. If you could close the box and somehow re-entangle the boxes the handedness of the gloves again becomes random.

If you open the box a second time and find your glove to be LH  the handedness of the glove in your box has changed and you know the other box contains now contains the RH glove. How did the glove in the distant box 'know' it should be LH on your first observation and RH on your second observation?

8 minutes ago, swansont said:

The predictable reaction is a correlation that was already present. That’s all that the experiment demonstrates.

Where is the demonstration of a signal that does not rely on this correlation?

 

Then the correlation has become the signal.

1 hour ago, studiot said:

I find the rudeness of the dismissal the most suprising part in your reply to someone who has offered sources of genuine help for your consideration.

I am sorry if that offended you and I thank you for the suggestion. I meant no offense.

1 hour ago, studiot said:

You clearly do not understand the most fundamental point about entanglement at all.

The entangled properties are set for both particles at the moment of entanglement.

The entangled properties are not 'set' they become random, The conventional explanation is that they are superimposed and indeterminate until the first observation is made and then they become set again until something disturbs them.

1 hour ago, studiot said:

In order to create entanglement you require very close proximity  -  not spooky action at a distance.

Close proximity is only necessary for generating entangled particles for experimental purposes but spontaneous entanglement at a distance among charged particles (especially electrons) is normal and common. Carver Mead is THE authority on entanglement among electrons and he claims that any electron can spontaneously become entangled with any other electron on its light cone. He explains this in detail in his book, "Collective Electrodynamics" Part 5 Electromagnet Interaction of Atoms.  

2 hours ago, studiot said:

I'm a little hydrogen atom,
You're a little hydrogen atom
I've got one electron
You've got one electron
Let's get spin entangled and form a hydrogen molecule.

At this point we know that one electron is spin up and the other is spin down

But we don't know which is which until we observe one of them.

 

Electrons in a molecule are entangled as are the electrons in an atomic cloud of electrons and a electron in one atom can entangle with an electron in a distant atom.

"In a time-symmetric universe, an isolated system does not exist. The electron wave function in an atom is particularly sensitive to coupling with other electrons; it is coupled either to far-away matter in the universe or to other electrons in a resonant cavity or other local structure."- Carver Mead

1 hour ago, swansont said:

You claim to have the answer. But how can you demonstrate that there is a signal?

1 hour ago, swansont said:

You claim to have the answer. But how can you demonstrate that there is a signal?

There is a demonstrable action and a predictable reaction. That is a demonstration of some kind of connection.