bangstrom

6 hours ago, NTuft said:

As to how you figure a ratio cannot be a speed

Speed IS a ratio of distance over time so a ratio can be a speed. But not all ratios of distance over time are necessarily a speed. Some say c is the speed of causality.

6 hours ago, NTuft said:

Granted, c should be the constant speed of light in a vacuum so I doubt what I'm alluding to previously means much, but I do think there's more to argue there.

That last point is an understatement. I know from experience.

One issue is that the true speed of light is unknown and unknowable. Our units of distance, time, and the value of c are all mutually defined. The length of a meter is defined the distance light travels in 1/c seconds and a second is defined as the time it takes light to travel a c number of meters. 

Consider the absurdity of trying to measure the speed of light over the distance of a light year. This is the conundrum of trying to measure the speed of light.

5 hours ago, MigL said:

Of course it's not science.
It is an interpretation of the science into 'common' deterministic ideas.
( which are more familiar to us than quantum paradigms )

Do you think the other popular interpretation, that a cat in a box can be dead and alive, simultaneously before wave function collapse, IS real science ????

The cat is a macro object so QM does not apply but something similar happens at the particle level.

9 hours ago, joigus said:

The correlations are initial!!!

So no non-locality. No superluminal signals.

1) The spin states are indeterminate

2) The correlations are initial

Got it now?

Where were you when we discussed this before?

I can agree that the correlations are initial and the spin states are indeterminate.

But are the spin states fixed from the start like a pair of gloves or are they in a state of alternate flux like two pendulums swinging in alternate directions? You never made this clear despite my asking.

I favor the alternate flux view even over the conventional view of superposition.

9 hours ago, joigus said:

Gosh! Y'all pop-science people seem to be equally stubborn, if nothing else. And now I can absolutely tell that you guys got nothing else.

Does the word "projection" sound familiar?

9 hours ago, joigus said:

Oh, by the way, I keep waiting for that superluminal signal.

You got it. Are you saying that entanglement where two remote particle are connected as if they were side so that an action upon one instantly affects the other, is not a superluminal connection?

5 hours ago, NTuft said:

I'd also like some explication of S. Hossenfelder's argument, not just your bare synopsis and a video link, seeing as you insist on tilting at MWI with such vigor. Occam's razor can be formulated to say that complexity of phenomenon dictates necessary complexity of explanation, and MWI is not comparable to Leprechauns wrangling rainbows with pots o' gold. 

 

I agree with Ernst Mach that the invention of ad hoc conjectures "metaphysicals" to explain physical events should be avoided if at all possible. It is better to leave the "unknowns" unknown if we want to progress. The danger is that conjectures tend to become "reality" with time and conjectures tend to compound over time. Conjectures are used to explain more conjectures.

Do you have anything specific in mind?

2 hours ago, joigus said:

You couldn't tell locality from non-locality in a model if either one of them hit you in the face at 1000 miles a second.

That much I have proven here.

As to experiments, I'll give you ten years from now to point me to the experiment where any non-local effect of QM is proven. You can point me to anything from the past too, of course.

There isn't. And my guess is that there never will be. If otherwise, QM would have to be fundamentally wrong.

There's your experimental argument from silence, but a very solid one at that.

I'll be waiting. 

Thank you for the encouraging words Here is a quote about an old experiment from one of the books in my personal collection.

“THE NON-LOCAL UNIVERSE” by Robert Neadau and Menas Kafattose

Oxford University Press 1999 p.4

“The “observed” phenomena in the Aspect and Gisin experiments reveal correlations between properties of quanta, light or photons, emanating from a single source based on measurements made in space-like separated regions. What cannot be measured or observed in this experimental situation, however, is the total reality that exists between the two points whose existence is inferred by the presence of the correlations.

When we consider that all quanta have interacted at some point in the history of the cosmos in the manner that quanta interact at the source of origins in these experiments and that there is no limit on the number of correlations that can exist between these quanta, (4) this leads to another dramatic conclusion- nonlocality is a fundamental property of the entire universe.”

The experiment by Aspect and Gisin was an experiment testing Bell’s Inequality in 1972 at the University of California, Berkley

2 hours ago, joigus said:

This must be a joke. So where they able to send signals? No. They were able to check the correlations that I told you and proved to you based on QM, are there all along. (Sigh)

Were Alice and Bob able to send a signal? No. The non-local signal was not between Alice and Bob it was from one quantum particle to its entangled partner. Forget Alice and Bob.

Your thinking is totally anthropomorphic if you think a signal can only be a signal if it sends a message from one person to another. The signal under consideration was between two entangled particles. Whether it was understood by two humans is irrelevant.

When one particle was measured to be spin-up the other particle instantly responded by becoming spin-down. Both particles “got” the message instantly. The signal was non-local at the quantum level. It could only be observed to have been non-local at the macro level by means of an after analysis of the events.

I suspect we may be discussing two different signals? One was non-local at the quantum particle level and the other was local between macro participants, Alice and Bob.

16 hours ago, MigL said:

There is nothing 'over the line' about the Many Worlds Interpretation; it is just as valid as the Copenhagen Interpretation.
Quantum Mechanics is NOT classical, or macro, mechanics

Naturally, QM is NOT classical.

One provision of Occam’s Razor is that it cautions against the addition of unknown and unobserved entities like Leprechauns or worlds beyond our own to explain a hypothesis.

In this video Sabina Hossenfelder explains why MWI is not science.

“The Multiverse: Science, Religion, or Pseudoscience?”

https://www.youtube.com/results?search_query=sabine+hossenfelder+multiverse

And for @joigus, Hossenfelder cautions against confusing math with reality.

I am a gadget person. My gold standard for truth is if a hypothesis can be reproducibly tested or observed.

The non-local and super superluminal nature of entanglement has been demonstrated at CERN and a number of other laboratories around the world so that works for me.

https://www.technologyreview.com/2013/03/07/179528/chinese-physicists-measure-speed-of-spooky-action-at-a-distance/

22 hours ago, NTuft said:

If we don't have constant speed of light I would undercut SR by extension and question whether we're discussing faster or slower or variable speed but other than that I am unarmed for this fight.

I don’t see instant action at a distance as a violation of anything in SR with the single exception of Einstein’s second postulate where nothing can travel faster than the speed of light. 

The second postulate is a provisional statement and it does not work as a law of physics. Faster-than-light need not extend into the main body of SR if we recognize c as a dimensional constant of space and time rather than as a speed. The value of c serves as a universal constant for converting between units of distance and units of time. The constant c is essentially the length of a standard meter expressed in seconds.

It is a ratio and not a speed, and in SR, c works perfectly well as dimensional constant but it acts nothing like a speed. This is why c is the same for all observers independent of their own velocities. Nothing can go faster than c because c is a ratio and NOT a speed. Nothing can go faster than a ratio just as nothing can go faster than 1.6 km per mile. If c were a speed c +/- v should be possible.

Whether we choose to call c the “speed of light “ or a “dimensional constant” the numerical values are identical so none of the math is changed. This change in perspective simplifies SR and it eliminates the paradoxes such as the “Pole in the Barn”. A slight modification to the wording of the second postulate could set everything right.

Olaf Roemer observed the planet Jupiter and its moons and discovered c as the constant ratio between units distance and units of time and he mistakenly called it a “speed”. Unfortunately the misnomer has carried into SR.

8 hours ago, swansont said:

One issue is that there is no “flip” or “change” since the states are not determined. “flip” implies going from one state to the other. 

The “flip” involves going from an indeterminate state of superposition to a determinate state.

10 hours ago, joigus said:

Is something 'real' if it can be explained away depending on interpretation ?

Yes, something is "real" if it can be explained by interpretation. But, what is 'real' for one may not be 'real for another'.

On 9/15/2022 at 6:01 PM, MigL said:

"I show that quantum nonlocality is an artifact of the assumption that observers obey the laws of classical mechanics, whereas observed systems obey quantum mechanics. Locality is restored if observed and observer both obey quantum mechanics"

Do you know the interpretation of this quote from "MigL"?

If not, read the article or other articles about MWI and see if you agree.

The interpretation holds that entangled particles are in superposition as are their observers. An observer in one world is in superposition with an observer in another world. But in a universe other than our own. When one observer measures his particle to be spin-up, his entangled Doppelganger in another world measures his particle as spin-down.

In an instant, entanglement is lost between both worlds and they become separate entities. However, the events appear entirely local from the perspective of each world.

I like speculation but that is a little over the line for me.

29 minutes ago, Ned said:

The ''rods'' between entangled particles are the quantum fields of the particles that are in essence an extension of the particle into space ! 

The connecting particle fields interact non-locally such that the particles are essentially side-by-side.

33 minutes ago, Ned said:

I think you are forgetting that wave energy passing from a to b is what affects any other particle in entanglement .

The connecting waves are not energy bearing so there is no energy passing from a to b. An energy exchange may be possible but that gets into a real can of worms.

1 hour ago, NTuft said:

I do not think I understood indeterminancy, as I conceive of the observables as having a value capable of being described but that it is in superposition until actually observed; that the state(CSCO n,l,m_s,m_l?) was in existence  before observation but was indeterminate only insofar as it was unknown.

I like to think indeterminacy as a coin spinning in the air. We cant give it a call until it lands.

I think superposition can better explained but the idea works so I’m not about to dispute it.

1 hour ago, NTuft said:

I can't get the math in here properly

It’s an omen but watch for the little black tag at the bottom that reads “ Paste as plain text instead” when you enter a quote.

2 minutes ago, Ned said:

No, because you can't force light to travel faster than c ! 

Entangled particles are connected non-locally and by a likely Schroedinger wave-like connection. The loss of this connection is instant for both particles. This is not a light signal.

1 hour ago, NTuft said:

Is that entanglement, or is it non-locality? I read the thread to come to that non-locality implies faster than light information exchange. My question is, if one of two entangled electrons undergoes an interaction/evolution to flip , is this change conducted to the other electron to induce a change in ,or , supraluminally?

Entanglement is non-local and non-local interactions are superluminal. That means that two entangled particles can interact instantly as if side-by-side no matter what the distance between them. If one flips up the other instantly flips down and the change takes place superluminally.

This never happens in the macro world. In the macro world, two observers are always have a “space-like” separation. That means that if they are separated by space they are also separated by a c/d amount of time... “spacetime”. This makes superluminal communication at the macro level absolutely impossible.

1 hour ago, NTuft said:

 Or is the "strict" entanglement broken, and now needing consideration as part of the density matrix alluded to since it is not a closed or unperturbed system and has "evolved"?

Once entanglement is lost, the particles become independent of each other so that any change to one has no effect on the other.

1 hour ago, NTuft said:

On 9/14/2022 at 6:38 AM, joigus said:

Then you certainly don't understand the question. 12√(|↑↓〉−|↓↑〉) independently of the space-time factor of the state. In fact, the space-time factor of the state is completely omitted. Don't you find that peculiar?

No telling if it's the suggestion at play, but yes I found it peculiar; isn't that pointing at the entanglement having a non-local character? I need to re-read, I can figure, I did not understand the whole discussion.

I don’t understand it either. I think eliminating the space-time factor would make any interaction non-local.

That is what non-locality is- no spacetime between. “joigus” has yet to explain how this is local.

9 hours ago, MigL said:

Is something 'real' if it can be explained away depending on interpretation ?

On the question of local versus non-local decoherence 
( because there is no non-local interactions )

Quantum nonlocality does not exist | PNAS

Two questions. Why would you pick an article from such a sketchy source as a Many-Worlds Interpretation article to support your opinion.

And what is your opinion of the MWI.

I am aware of two cosmologies where non-locality is not possible. One is the Many-Worlds Interpretation MWI and the other is Superdeterminism.

I vaguely recall the nature of these cosmologies, but as I recall, in the MWI when one of a entangled pair of particles is measured to be in the spin-up position, there is an identical entanglement in one of the many alternate universes -remote from our own- where an identical particle is measured to be in the spin-down position. So one particle is spin-up and another is spin-down but in alternate universes.

I also clearly recall an article by John Cramer in which he thoroughly trashed the Many Worlds Interpretation.

In the Superdeterminism cosmology, the present and past are like a movie running in the projector and our reality is the scene that is playing out so there is nothing we can to change events since our reality is that movie.

11 hours ago, joigus said:

So far, I'm the only one of us that's shown you the calculations and basic principles (conservation laws, observables, quantum evolution, maximally entangled systems) at play, in a way that seems to be to, at least to a certain extent, to the satisfaction/agreement of everybody else but you.

The main calculation you gave me is the same calculation physicists give to explain non-locality. The same maths that work for non-locality also work for locality.

11 hours ago, joigus said:

You've shown nothing but your unconditional adhesion to a well-known silly and incorrect interpretation that's been running around for decades to the desperation of many renowned physicists.

That means the many renowned physicists may be right.

11 hours ago, joigus said:

Then I give you a simple problem in classical physics to illustrate how if you try to solve a "paradox" by using words instead of writing down the maths, you can be easily mislead.

You don't even understand that simple problem (the cyclists are not pedalling downhill; rather, they're falling downhill, etc.) You misinterpret every single thing I say. That was designed as a test for your attention span. And the key to why you misinterpret the physics is in your own words:

12 hours ago, bangstrom said:

The quote below is what I said.

12 hours ago, bangstrom said:

I find the bicycle story to be intuitively simple even without any math.

A heavy rider is at a big disadvantage when climbing a hill because he has to input so much more energy to get to the top. When he is at the top, he has more potential energy with which to overcome the friction when going down. Therefore he can go faster.

The acceleration is not that different because of the force of friction. The heavier rider has even more wind friction because of his speed. The potential energy of the riders is the dominating factor.

And here is what you said.

22 hours ago, joigus said:

If you listen to the argument like that, in words, it sounds like he was right. But,

Because he couln't be bothered with writing a simple equation, he was incapable of understanding why I was right. In the first case, the acceleration is the same because the force is proportional to the mass. In the second case --with friction-- the force of gravity is still proportional to the mass --necessary for acceleration to be the same in the 1st case--, while the force of friction is not. That's why the acceleration is different. The things that are independent of mass are different things. 

The problem is, if you just follow the words, you're incapable of understanding the reasoning. Words in physics, by themselves, are very deceptive.

Show me where I failed to understand the problem, misinterpreted your words, or came to the wrong conclusion.

11 hours ago, joigus said:

 

11 hours ago, joigus said:

 

It takes a lot more than a quick view of the literature to understand physics.

It doesn’t take long to look up what the current authorities are writing or saying about commonly discussed topics such as non-locality or entanglement. Naturally, understanding takes longer.

11 hours ago, joigus said:

So now I think it's your turn. What is non-locality?

You never responded when I asked you the question… so now its my turn?

Einstein’s view of non-locality works for me. “Spooky action at a distance.”

Non-locality is a non-observable time interval between an action and a reaction because the timing is either instant or far too fast to measure. It is instant action at a distance.

10 hours ago, joigus said:

Is that any better?

Not at all and you side-stepped my question.

10 hours ago, joigus said:

Yes, but you're interpreting incorrectly, and drawing wrong conclusions!

I don't find your explanation of the bicycle story to be an example of of either interpreting correctly or reaching the right conclusions. Here is your explanation.

10 hours ago, joigus said:

If you listen to the argument like that, in words, it sounds like he was right. But,

Because he couln't be bothered with writing a simple equation, he was incapable of understanding why I was right. In the first case, the acceleration is the same because the force is proportional to the mass. In the second case --with friction-- the force of gravity is still proportional to the mass --necessary for acceleration to be the same in the 1st case--, while the force of friction is not. That's why the acceleration is different. The things that are independent of mass are different things. 

I find the bicycle story to be intuitively simple even without any math.

A heavy rider is at a big disadvantage when climbing a hill because he has to input so much more energy to get to the top. When he is at the top, he has more potential energy with which to overcome the friction when going down. Therefore he can go faster.

The acceleration is not that different because of the force of friction. The heavier rider has even more wind friction because of his speed. The potential energy of the riders is the dominating factor.

As for the rest of our discussion:

I don’t see where you have been addressing the problems at hand with much more than unsupported personal opinions.

Why do the same math examples you give not work with non-locality as well as with locality?

How do you define non-locality?

I think a quick view of the literature will show your views to be to be long out of date.

Things like the non-locality of entangled particles, and the super position state of entangled particles prior to their measurement are the commonly accepted, mainstream views. Not that that makes it right.

And, can you support your views with anything more than just personal opinions?

9 hours ago, joigus said:

16 hours ago, bangstrom said:

I don’t find that “well-defined at all times” applies to quantum identities which are an entirely different matter.

Then you certainly don't understand the question. 12√(|↑↓〉−|↓↑〉) independently of the space-time factor of the state. In fact, the space-time factor of the state is completely omitted. Don't you find that peculiar?

What you are saying is largely what I am saying so I do find it peculiar because what you are saying sounds like non-locality.

"Independently of the space-time factor of the state. In fact, the space-time factor of the state is completely omitted".

That sounds like what I would call non-locality.

If two entangled particles are moving in opposite directions and beyond the range of light speed communication, Observing the identity of particle A as spin-up instantly fixes the identity of its partner B as a predictable spin-down. How does particle B “know” what has happened to particle A?

Or, how would you explain it without non-locality.

9 hours ago, joigus said:

OK. Let me stop you right there, because it is plainly obvious you don't understand quantum mechanics here. Quantum particles have no identity. They are indistinguishable, and they are in a way much more profound than macroscopic objects can be made extremely difficult to tell apart. Not even Nature "knows" which electron is which. There is no "which electron." They're just instantiations of a quantum field. It's actually more profound than instances of a computer program, for example, which have a process tag and a time stamp. Electrons have no tags.

This appears to be an overly broad a generalization that may apply to entangled particles or entangled particles in quantum computers but normally particles have a largely predictable nature otherwise there would be nothing but chaos. All electrons may look alike but Nature at least "knows" where they are.

10 hours ago, swansont said:

16 hours ago, bangstrom said:

Since particles A and D are always anti-correlated, this means that particle A must change its identity half the time to conform to the later ABCD pairing.

A doesn’t “change” its identity, since it doesn’t have one in the first place. Its spin is not determined until the measurement

That is a valid point but when A was entangled with AB its spin could have been either up or down.

But when the particles are in a three way entanglement D-CB-A and particle D is observed to have a spin-down, that collapses the wave function for all the particles which fixes the observation of A to a predictable spin-up.

This is why your gloves in boxes model does not work for entangled particles. Gloves have a fixed identity before observation but entangled particles do not.

3 hours ago, joigus said:

And do QM calculations for ten years as a punishment for making the widespread foolishness that Gell-Mann talked about, even more widespread.

I have a lot of respect for Gell-Mann but two things made me suspect his views. One was that they appeared to be based on the long discredited EPR paper and mainly because I find non-locality to be a long established reality.

4 hours ago, joigus said:

The gloves example serves the purpose of showing that initial correlations don't require spooky action at a distance. Nothing more.

 I can agree with that.

4 hours ago, joigus said:

They differ --very importantly-- in that left or right-handedness, colour, material, etc., are well-defined at all times. Contrary to quantum mechanical systems, for which the mere assumption that these properties have a definite value would lead you to untenable assumptions like non-locality or existence of negative probabilities, or both.

I don’t find that “well-defined at all times” applies to quantum identities which are an entirely different matter.

4 hours ago, joigus said:

Because we think quantum mechanics is correct, we don't need to assume such foolish things. Do you see my point?

 I don’t see your point. What principles of QM make quantum identities constant at all times or rule out the possibility of non-locality? Have you heard of “identity swapping” where entangled particles non-locally swap identities? Quantum teleportation is an example.

Consider this possibility. One can generate two entangled particles A and B. Later they can generate two more entangled particles C and B. Then if they entangle particles B and C, the result is a four-way entanglement ABCD. As with single entanglements, the pairs are all anti-correlated.

A multiple ABCD entanglement is called a GHZ state named after the first experimenters to study multiple entanglements Greenberger, Horne, and Zeilinger. If one measures just the identity of particle D as spin-up, they can predict the identity of particle A as spin-down.

Since particles A and D are always anti-correlated, this means that particle A must change its identity half the time to conform to the later ABCD pairing.

This and several other experiments suggest that quantum identities are not fixed at the moment of their origin but they only become fixed at the first measurement. This is why entangled particles are considered to be in a state of superposition prior to observation. In QM, the cat is neither dead nor alive until examined.

13 hours ago, joigus said:

No. The singlet state is totally trivial under rotations. Rotations act on it trivially: they don't change it at all. That's why it looks like (up)x(down)-(down)(up) in any representation you choose. It does not code any orientation in it. The matrix that rotates it is the identity matrix. It is blind to rotations. I can try to rephrase this over and over... That's all I can do, I'm afraid.

I think we are largely in agreement about the impossibility of rotating a signet state.

Swansont mentioned something about contemplating a rotation of the signet state so I mentioned Kracklauer’s paper where he described entanglement as a rotation through Q-bit space just to indicate that I had given rotation some thought but I also thought I made it clear that I did not share Kracklauer’s view.

On other matters, if I understand correctly, your view is that that there is nothing superluminal about entanglement? Could you explain?

Also, I mentioned that the general consensus about entanglement is that the particles involved are in a state of superposition prior to their first measurement. I qualified this statement with my view that it could be better explained.

I got some contrary opinions about this but a quick Google search should indicate that the main stream, hyper peer reviewed, everybody knows it, consensus of opinion is that entangled particles are in a state of superposition prior to their first measurement and this has been the case for many years.

I don’t always agree with Don Lincoln but his video below is one I can agree with from start to finish.

https://www.youtube.com/watch?v=JFozGfxmi8A

He explains why entanglement is superluminal, why the gloves/ balls in a box analogy is not valid, and rather than saying the particles are in superposition, he says their spin directions can be in any possible direction governed by their common wavefunction. This is essentially the same thing but better than saying they are in a superposition of both spin directions at the same tine.

3 hours ago, joigus said:

If you know some Pauli-matrix and angular momentum algebra, it's an interesting exercise to write down the singlet state and rotate it. People normally write it as

|up, down> - |down, up>  

with a normalisation factor, and referred to the z direction. As if the z-direction played some kind of role in it. I doesn't. The states really are indeterminate. You can use any axis you want and it has the same form:

|up_x, down_x> - |up_x, down_x> = |up_y, down_y>- |downy, up_y> = |up_n, down_n>- |down_n, up_n> = etc.

It's all a whole quantum state with like "no parts in it", "no internal arrows", so to speak. That's entanglement for you.

Try it, it's very illuminating.

I have read (not that I follow it) a paper by A.F. Kracklauer where expresses something similar where he claims entanglement can be explained as rotations through Q-bit space. I think rotations are looking at events in reverse. The initial orientation of the detectors is all that matters.

There is a speculation I find favorable that any electron can spontaneously entangle with any, and likely several, other electrons existing on the same light cone.

There is a precise orientation where one electron, and likely under the influence of other electrons nearby, can share a common Schroedinger wave function with another electrons such that strong interactions can occur with the result that remote electrons can function as if side by side no matter what the distance between them. That is entanglement.

Because the interaction is instant and non-local, there is no time between the signal and its reception to alter the orientation of a detected result so that it is anything other than anti-correlated.

Because the entangled electrons are found at different locations on the light cone, we observe a light related time delay. Our observations have a “space like” time delay because the observed events are simultaneous but separated by space rather than happening at different times, in which case the delay would be “time like.”

4 hours ago, joigus said:

As I said: The correlations are there when the singlet is prepared, they're there a minute later, they're there until you perform another measurement. And no experiment that I know of contradicts this.

So yes, it's like the gloves in the sense that the correlations are initial. No superluminal action at a distance. Period.

It is my understanding that the general consensus is that entangled particles are in a state of superposition prior to their first measurement, in which case, the correlations are not necessarily fixed at the moment of preparation. Rather, they are fixed a the the instant of first measurement.

I don”t favor the idea of superposition but I think it can be better explained without the magic.

https://www.quantum-inspire.com/kbase/superposition-and-entanglement/

13 hours ago, joigus said:

 

4 hours ago, joigus said:

The evidence of that interaction would be reflected in what we call the density matrix, which essentially consists of statistical weights: the probabilities 1/2, 1/2 that I mentioned before (and constitute the diagonal elements of the density matrix: those would not change) plus the relative phases between the states "up" and "down" (which constitute the non-diagonal elements: those would change). But those coherences are a part of the wave function that is affected by the interaction, and they would take some time to reach Bob. Nevertheless, after enough time has passed, Bob would be able to tell (in principle, I repeat) that someone's been messing with the state. Nothing more. In fact, he wouldn't be able to tell whether it was Alice, or a gust of wind, or what the output of the experiment was unless he measured the same projection of spin they agreed to measure.

This makes no sense. QM does not care if the message is understood by Bob or when it arrives at his level. The loss of entanglement is a signal from one particle to its entangled partner and the partner receives the interaction instantly and non-locally and responds accordingly. Alice and Bobs perception of the timing may be delayed but it is irrelevant to what is happening at the particle level. The message is for the paired particle and not for Bob.

12 hours ago, joigus said:

Then you absolutely have missed the point of what's going on, and are still living in the confusion. This is what Murray Gell-Mann calls the "widespread foolishness associated with the EPR effect."

The EPR effect was first demonstrated to be invalid in the early sixties by the experiments performed by Bell and Aspect. I think I understand what you and Gell-Mann are saying but I can’t say I agree with either. I will try to point out items where I find we disagree.

12 hours ago, joigus said:

Go back to the example of the gloves that MigL was talking about. One glove goes to Australia and the other stays with me. I open the box and find out that it's LH. I thereby know immediately that hoola got the RH one. Would you think for a moment that one glove corresponds to the right hand and the other to the left hand because some "spooky action at a distance" has taken place between them? That's what's foolish to say. The gloves are perfectly anti-correlated just because the correlation was there from the beginning.

I can repeat the point over and over if you wish, but I can't make it any more clear.

That is perfectly clear so no need to repeat it.

The correlation with the gloves was there from the beginning, but with entangled particles, their quantum identities are indeterminate until the first measurement is made. Some say they are in a state of superposition prior to the first measurement so the glove analogy does not apply. I thought we had agreed on this.

12 hours ago, joigus said:

The story of the argument is somewhat contorted, because Einstein thought of a different example, with position and momentum, and then David Bohm proposed one with spins. But you got the story wrong too.

That's for another post, though.

 As I recall, Niels Bohr claimed there were no hidden variables while Einstein claimed there were and Bell’s inequality was a test to decide between the two and Bell’s results favored Bohr’s view.

3 hours ago, noha said:

 

I would interpret the statement as saying that the virus is not the direct cause of liver cancer. Instead it damages a gene in a liver cell that tells the cell when to stop growing so the cell keeps growing out of control and that is cancer.

15 hours ago, joigus said:

So, as I said earlier, each one of them is as indeterminate as it can be, but the quantity formed by the addition of both is sure zero every single time we measure.

Does that clarify the discussion?

That answers my question concerning your statement about when correlations take place. You said, “All the correlations are initial. Quantum correlations were there when the state was prepared.” It was not clear from this when the correlations began.

If you are saying that the correlations are initiated at the instant when the first measurement is made and for both particles, that is something I can agree with..

My other question was about the timing of the correlation. If the measurement of one entangled particle instantly fixes the identity of its partner particle, no matter how far the distance, how can that not be considered to be a non-local interaction?

As I understand the Bell test, Einstein proposed the existence of a hidden variable that maintained a constant correlation between the two particles thus maintaining the appearance of locality.

Bell’s test was to identify if there was such a hidden variable and he found none suggesting that the correlation was truly non-local without the help of any hidden variable. Identifying a single identity of one particle instantly fixes the identity of the other at any distance and that is what I would call non-locality.
 

On 9/9/2022 at 4:07 PM, joigus said:

No, there is nothing superluminal going on between both parts of the bipartite state in Bell's theorem.

All the correlations are initial. Quantum correlations were there when the state was prepared.

 

Could you clarify this part?

As I understand it, the quantum correlations of the entangled particles are indeterminate prior to the first observation rather than fixed at the moment of their preparation. They are neither-spin up nor spin-down unlike a pair of gloves that must have a fixed identity as either left handed or right handed prior to observation. The particles are in a state of superposition prior to the first observation.

Also, if particle A is observed to be in a spin-up position at position A, then the extremely remote particle B must be observed to be in the spin-down position even if a second observation at location B is made a nano second later.

This appears to be an example of one measurement having an instant affect on the other. How is that not a superluminal going on? Or properly called a non-local interaction?

On 9/10/2022 at 2:23 AM, hoola said:

I basically am asking if something could be added to the box, as a deliberate modification or addition to what is there, without excessive disturbance to the function of the box.

This can be accomplished with experiments known as “quantum teleportation” but the modifications can not be made deliberate.

For example, Alice can generate a pair of entangled electrons A and B and send electron B to Bob at a remote location while placing electron A in a “box”. She can then create another entangled pair of electrons C and D and direct electron D into the same box with A. Anton Zeilinger calls this a four-way or ABCD entanglement. Zeilinger is best known for his early experiments with quantum teleportation which is why he is called “Mr Beam”.

After the insertion of electron D into the box with electron A, Alice can then observe her remaining electron C. If electron C is spin up, the electron D that she put in the box is now spin down making its partner A spin-up and its away partner B that she sent to Bob spin down.

The overall observation is that the spin direction of the second particle she puts in the box will always be the same as the the spin direction of the particle at Bob’s location making it appear that she placed one particle in the box and it instantly appeared at Bob’s location. No particles have been physically teleported from one location to another but the quantum identity of the second particle placed in the box has been teleported to Bob’s location.

The modification can not be made deliberate because Alice has no way of knowing the random identity of any of the particles she generates prior to the experiment. If an observation is made of any one particle, none of the particles are allowed to remain in a superposition state and entanglement is lost..

It definitely looks like a mixed population of bacteria. Dead or alive is another question. On a minor note, morphology terms should not be capitalized. The capitalized terms are used if the genus is known. For example, many streptococcal shaped bacteria are not necessarily members of the genus Streptococcus or bacilli of the genus Bacillus. Some of the organisms could be small algae or fungi.

As a former medical technologist, I don’t recognize the structure as any of the usual crystals or hyaline casts found in urine and it doesn’t look microbial. Unless there are more similar structures, I would guess it is a bit of foreign material that drifted into the sample. Technically known as microscopic junk.

https://laboratoryinfo.com/types-of-crystals-in-urine/

2 hours ago, Danijel Gorupec said:

If I choose a galaxy near the edge of the observable universe, and I send a ray of light toward this galaxy, will the light ever reach the galaxy?

Let me rephrase the question. If I send a ray of light in a direction exactly opposite this galaxy, will the light ever reach the galaxy? The universe is curved so it has no "edge".

Enne Malus discovered another difference between light reflected from a smooth surface and a rough surface in about 1800. Light reflected from a smooth surface is both circularly and linearly polarized while light from a rough surface is not.

This is how polarized glasses are able to eliminate the glare reflected from smooth surfaces. Also, if circularly polarized light is reflected from a smooth surface, the direction of polarization is rotated by 90 degrees. Light polarized to the right becomes polarized to the left etc..

With linear polarization, the light is polarized in either a horizontal or vertical position, but with circular polarization, the “electro” part of the electromagnetic light wave runs slightly behind the “magnetic” part and how far it is behind makes the wave appear to rotate to either the left or the right.

The glasses used to view 3D movies use both linear and circular polarization. Both right and left lenses are linearly polarized the same as sun glasses but the right and left lenses have opposite circular polarization as does the movie projector. This way the projector can project different images for the viewer’s left and right eyes so they see the image in 3D.

There is a surprising effect if you look at your reflection in a mirror while wearing 3D movie glasses. If you look at your reflection with just one eye. Say your right eye. The light from your right eye can’t return because the mirror reverses the circular polarization so your right lens appears totally opaque while the left lens appears clear. You can see your closed left eye but not your open right eye.

1 hour ago, Markus Hanke said:

He perceives both A and B to be dilated (slower), because he finds himself in relative motion with respect to both those frames.

He may calculate B's clock to be slower because of time dilation but his perception should be that B's clock is running faster because of the Doppler effect.

11 minutes ago, MPMin said:

To exaggerate the the question, imagine that all clock are synched before C departs from A, and imagine that from B’s perspective, it takes C 1 minute move from A to B, and C happens to move at 50% of the speed of light for the whole trip. Would that mean that when C arrives at B that clock B would be 30 seconds ahead of clock C? And if so, how is that clock B ticked 30 more seconds than C when C had been observing clock B to be ticking slower than C?

Acceleration in velocity slows time exactly as acceleration in a gravitational field slows time so clock C should be running behind A and B as you explained.