Ask any question you want about Physics

originally posted by: Arbitrageur
a reply to: Choice777

The short answer is:

Post-Quantum Correlations: Exploring the Limits of Quantum Nonlocality

Despite advances in quantum research, physicists still don’t fully understand the fundamental nature of nonlocality.

That article goes on to describe how some experiments refine our understanding of nonlocality.

It's a stretch to say that "information" is being exchanged, since there is no faster than light communication possible in entanglement experiments so far. I think it would be more accurate to say it's a "correlation".

When it comes to nonlocal correlations, some correlations are more nonlocal than others. As the subject of study for several decades, nonlocal correlations (for example, quantum entanglement) exist between two objects when they can somehow directly influence each other even when separated by a large distance. Because these correlations require “passion-at-a-distance” (a term coined by physicist Abner Shimony), they violate the principle of locality, which states that nothing can travel faster than the speed of light (even though quantum correlations cannot be used to communicate faster than the speed of light).

What if we could make two antennas of entangled particles ? Instant communication across the planet, solar system, etc.

a reply to: Choice777
I'm not going say it's "impossible", but what we can say is that no experiments so far have indicated faster than light communication is possible. There is a theorem about this:

no-communication theorem

In physics, the no-communication theorem is a no-go theorem from quantum information theory, which states that, during measurement of an entangled quantum state, it is not possible for one observer, making a measurement of a subsystem of the total state, to communicate information to another observer. The theorem is important because, in quantum mechanics, quantum entanglement is an effect by which certain widely separated events can be correlated in ways that suggest the possibility of instantaneous communication. The no-communication theorem gives conditions under which such transfer of information between two observers is impossible.

The challenge is open to anyone to prove this theorem false by demonstrating "Instant communication" via any means they choose including "two antennas of entangled particles" or any other design. So if you can do it, who knows, you might get a Nobel prize for that accomplishment. I'm sure there are researchers trying to perform FTL communication, but nobody has succeeded, and for numerous reasons I doubt anyone will create instant communication which violates this theorem, but, I could be wrong. Someone will need to prove it though.

a reply to: Arbitrageur

What is the leading theory as to the physical interaction between entangled particles, that provides the correlation at a distance, with an as of yet known cause, that was thought to be due to some mystery non locality, but now it is known there must be some logical mechanism, as regardless of distance, the correlation between entangled particles must occur at the speed of light or less, so what I am asking for as a theory, is what is the theory of the now hidden variables, that is the physical/material/energetic structure which supports the entanglement of particles theory?

originally posted by: ImaFungi
now it is known there must be some logical mechanism, as regardless of distance, the correlation between entangled particles must occur at the speed of light or less

How is this known? How many times do we need to say that nature is under no obligation to behave in a manner that humans would deem "logical"?

so what I am asking for as a theory, is what is the theory of the now hidden variables, that is the physical/material/energetic structure which supports the entanglement of particles theory?

I'm not a researcher in this field and since it's an area of active research I'm sure an active researcher would have a better answer. But as far as I know, the hidden variables theory doesn't appear to be true because the results don't satisfy Bell's inequality.

Quantum entanglement

A possible resolution to the apparent paradox might be to assume that the state of the particles contains some hidden variables, whose values effectively determine, right from the moment of separation, what the outcomes of the spin measurements are going to be. This would mean that each particle carries all the required information with it, and nothing needs to be transmitted from one particle to the other at the time of measurement. It was originally believed by Einstein and others (see the previous section) that this was the only way out, and therefore that the accepted quantum mechanical description (with a random measurement outcome) must be incomplete. ...

The hidden variables theory fails, however, when we consider measurements of the spin of entangled particles along different axes (for example, along any of three axes which make angles of 120 degrees). If a large number of pairs of such measurements are made (on a large number of pairs of entangled particles), then statistically, if the local realist or hidden variables view were correct, the results would always satisfy Bell's inequality. A number of experiments have shown in practice, however, that Bell's inequality is not satisfied. This tends to confirm that the original formulation of quantum mechanics is indeed correct, in spite of its apparently paradoxical nature.

So the observed behavior conforms to quantum mechanics theory, without hidden variables.

You said you don't like the Many Worlds interpretation (I don't either) but this paper claims it can explain this apparently paradoxical behavior locally (meaning without exceeding the speed of light):

Locality in the Everett Interpretation of Heisenberg-Picture Quantum Mechanics

Bell's theorem depends crucially on counterfactual reasoning, and is mistakenly interpreted as ruling out a local explanation for the correlations which can be observed between the results of measurements performed on spatially-separated quantum systems. But in fact the Everett interpretation of quantum mechanics, in the Heisenberg picture, provides an alternative local explanation for such correlations. Measurement-type interactions lead, not to many worlds but, rather, to many local copies of experimental systems and the observers who measure their properties. Transformations of the Heisenberg-picture operators corresponding to the properties of these systems and observers, induced by measurement interactions, "label" each copy and provide the mechanism which, e.g., ensures that each copy of one of the observers in an EPRB or GHZM experiment will only interact with the "correct" copy of the other observer(s). The conceptual problem of nonlocality is thus replaced with a conceptual problem of proliferating labels, as correlated systems and observers undergo measurement-type interactions with newly-encountered objects and instruments; it is suggested that this problem may be resolved by considering quantum field theory rather than the quantum mechanics of particles.

To me, that creates an even bigger paradox (proliferating labels) than the one it tries to solve (the locality paradox), but nature is under no obligation to conform to my preferences either, so I try to keep an open mind

originally posted by: Choice777

originally posted by: Arbitrageur
a reply to: Choice777

The short answer is:

Post-Quantum Correlations: Exploring the Limits of Quantum Nonlocality

Despite advances in quantum research, physicists still don’t fully understand the fundamental nature of nonlocality.

That article goes on to describe how some experiments refine our understanding of nonlocality.

It's a stretch to say that "information" is being exchanged, since there is no faster than light communication possible in entanglement experiments so far. I think it would be more accurate to say it's a "correlation".

When it comes to nonlocal correlations, some correlations are more nonlocal than others. As the subject of study for several decades, nonlocal correlations (for example, quantum entanglement) exist between two objects when they can somehow directly influence each other even when separated by a large distance. Because these correlations require “passion-at-a-distance” (a term coined by physicist Abner Shimony), they violate the principle of locality, which states that nothing can travel faster than the speed of light (even though quantum correlations cannot be used to communicate faster than the speed of light).

What if we could make two antennas of entangled particles ? Instant communication across the planet, solar system, etc.

You are onto something there mate

a reply to: Nochzwei

Problem becomes how to transfer information you still have to transport the entangled particles and that would be at light speed. However may be away around this i read an experiment that seemed to show entangled pairs can communicate back in time so there could be a loop hole.

originally posted by: Arbitrageur
How is this known? How many times do we need to say that nature is under no obligation to behave in a manner that humans would deem "logical"?

When you say, 'nature does not have to behave logical'. What is your understanding of the term 'logic' being used here, that you deny being appropriate?

I'm not a researcher in this field and since it's an area of active research I'm sure an active researcher would have a better answer. But as far as I know, the hidden variables theory doesn't appear to be true because the results don't satisfy Bell's inequality.

The term 'hidden' in the concept hidden variables only applies to hidden from our awareness. It is saying there are variables that we are ignorant of. If non locality is true, if entanglement is true, there still must be variables as to HOW non locality and entanglement is physically working. This ties into my understanding of logic, that there must be a physical reason as to why something occurs, even if you dont think there is, even if you dont know what it is.

Quantum entanglement

A possible resolution to the apparent paradox might be to assume that the state of the particles contains some hidden variables, whose values effectively determine, right from the moment of separation, what the outcomes of the spin measurements are going to be. This would mean that each particle carries all the required information with it, and nothing needs to be transmitted from one particle to the other at the time of measurement. It was originally believed by Einstein and others (see the previous section) that this was the only way out, and therefore that the accepted quantum mechanical description (with a random measurement outcome) must be incomplete. ...

The hidden variables theory fails, however, when we consider measurements of the spin of entangled particles along different axes (for example, along any of three axes which make angles of 120 degrees). If a large number of pairs of such measurements are made (on a large number of pairs of entangled particles), then statistically, if the local realist or hidden variables view were correct, the results would always satisfy Bell's inequality. A number of experiments have shown in practice, however, that Bell's inequality is not satisfied. This tends to confirm that the original formulation of quantum mechanics is indeed correct, in spite of its apparently paradoxical nature.

So the observed behavior conforms to quantum mechanics theory, without hidden variables.

I think if there were hidden variables there would be the same results as are received. I think what matters is what is actually occurring when an entangled pair of particles is created. Hidden variables suggests they must be in some exact state (upon measurement we can deduce, opposite states). QM suggests each particle is in at the same time, 2 opposite quasi states.

So hidden variables is suggesting a real physical way to receive the equal and opposite particle property from each entangled particle, so the results are equal with QM results, it is merely the interpretation that is different. QMs interpretation thus far is magic. Hidden variables interpretation is our ignorance.

Locality in the Everett Interpretation of Heisenberg-Picture Quantum Mechanics

Bell's theorem depends crucially on counterfactual reasoning, and is mistakenly interpreted as ruling out a local explanation for the correlations which can be observed between the results of measurements performed on spatially-separated quantum systems. But in fact the Everett interpretation of quantum mechanics, in the Heisenberg picture, provides an alternative local explanation for such correlations. Measurement-type interactions lead, not to many worlds but, rather, to many local copies of experimental systems and the observers who measure their properties. Transformations of the Heisenberg-picture operators corresponding to the properties of these systems and observers, induced by measurement interactions, "label" each copy and provide the mechanism which, e.g., ensures that each copy of one of the observers in an EPRB or GHZM experiment will only interact with the "correct" copy of the other observer(s). The conceptual problem of nonlocality is thus replaced with a conceptual problem of proliferating labels, as correlated systems and observers undergo measurement-type interactions with newly-encountered objects and instruments; it is suggested that this problem may be resolved by considering quantum field theory rather than the quantum mechanics of particles.

To me, that creates an even bigger paradox (proliferating labels) than the one it tries to solve (the locality paradox), but nature is under no obligation to conform to my preferences either, so I try to keep an open mind

Yes it depends what it means. I have felt at times it has meant that a single system, say a person sitting in a chair in their room holding an apple, every single quantum action that takes place 'doubles' into an entirely new real universe, or that the entire universe is always physically multiplying. But the past few times I have come in contact with this theory, I feel it seems it might be instead suggesting that, merely the universe, or the sections and intimate systems within the universe are not entirely checked and captured and solidified in terms of all else, that the immediate relations of particles while they are not in contact with all the rest, it is as if they exist in another world, unto themselves. So then when particles are separated from this system, it is a part of that old system traveling into new territory, like an entire new world, a new system, but it still has the signatures, the breeding if you will, of the old system it was a part of. And perhaps they are suggesting this sort of thing happens or can happen all the time, mixing and matching and withholding signatures, and still be connected by some informational aspect even at a distance. Just like if you moved to south east asia, even though you would be away from the system you started and grew much in, you would still have some 'attachment' and relation to that old system. but this is me spitballing.

a reply to: ImaFungi

As far as I know there isn't any deeper theory. Personally I think this means that locality is a classically emergent property, a persistent illusion, but at the core, quantum mechanical state evolves in a stupendously complex Hilbert space (space of functions) that can't be intuitively comprehended.

And the experiments show over and over that something in quantum mechanics isn't entirely local. Intuitive? Heck no, but it's time for us to take the experiments seriously. Whenever make-senseness and locality fight against quantum mechanics, quantum mechanics always wins.

Give up your need for locality. It ain't happening.

a reply to: Arbitrageur

Is there a locality paradox?

My position:

At the core, Einsteinian relativity is about imposing symmetry & transformation constraints on the underlying laws of physics. And quantum field theory obeys this 100%.

Those constraints, when applied to a *classical* field theory with differential operators only, for example, fluid mechanics or acoustics, result in light-cone locality restrictions on cause and effect. These just happen to be the types of physics which humans live in and experience day to day.

So, it's the expectation of locality which ought to be adjusted.

originally posted by: mbkennel
a reply to: Arbitrageur

Is there a locality paradox?

My position:

At the core, Einsteinian relativity is about imposing symmetry & transformation constraints on the underlying laws of physics. And quantum field theory obeys this 100%.

Those constraints, when applied to a *classical* field theory with differential operators only, for example, fluid mechanics or acoustics, result in light-cone locality restrictions on cause and effect. These just happen to be the types of physics which humans live in and experience day to day.

So, it's the expectation of locality which ought to be adjusted.

But is there even any conceivably hypothetical, rhetorical, theoretical blurb of a thought can offer as to how possibly in formation can travel instantly across any distance?

That is what you are suggesting, even if you say we cant read that information faster than light, you are suggesting that at an infinite distance between 2 entangled particles, when one is observed, the other automatically reverts to the exact opposite state.

Now all this means, is there is another physical dimensional structural aspect of the universe, that we did not and could not take into account, while developing einstein speed of light is the fastest speed rule.

You now think you know that is a fact, that there is a systematic potential relationship between what are thought to be separate parts of a system, which when moved about relative to its system, and to the local whole, and the next local whole, and so on, eventually at every increment upwards to the total whole of all system, the system of all systems, that allows these thought to be separate parts interact in a way faster than how we know light can interact from emitter to receiver, + the time it takes to take in the light, and mechanical processes to store and record that light in the receiver.

You are saying, there is no even tiny thought of an idea, how possibly this new dimensional relationship between particles, could possibly be connected, in the greater spatial extent of things? You think all quantum quantas, exist in a realm that is 'MUCH!' 'smaller, tinier, compact, 'closer'' and so when we move two that are intimately related together away from each other, this is moving them 'very far' from one another, in their tiny close knit realm, but relatively to us, in this big realm, we are not moving them that far, hmmm, no I dont think this makes sense...which is why I am asking if there is any sort of constructional idea as to how the system and field or such exists, that allows entanglement to function?

All I could think of would be computer analogies, how the laws of physics are fake, and everything is a computer simulation, and the quanta reality is the closest thing to the real real reality, as perhaps the electrons in a circuit are the most 'grounded' hard' reality when compared to the projections their actions create on the screen.

a reply to: ImaFungi

First i think you misunderstand entangled particles you do realize we cant change one and magically have the other change dont you? An entangled system means both systems no matter how far we separate them act the same, when we measure one we know the state of the other no matter where it is. In other words the other particle acts just as if we measured it even if we didnt. Because we know that quanta behave differently when measured for example the double slit experiment. But lets say we change say an electron in an entangled pair what happens to the other nothing at all. So basically what entanglement shows us is we can measure anything like spin etc and the other system will be the same id their any communication id have to say no. But as i said earlier there does appear to be a time independence that opens up some strange possibilities for communicating across different frames of reference, If that article i read was correct but again we arent making changes to the system just measuring it.

originally posted by: dragonridr
a reply to: ImaFungi

First i think you misunderstand entangled particles you do realize we cant change one and magically have the other change dont you? An entangled system means both systems no matter how far we separate them act the same, when we measure one we know the state of the other no matter where it is. In other words the other particle acts just as if we measured it even if we didnt. Because we know that quanta behave differently when measured for example the double slit experiment. But lets say we change say an electron in an entangled pair what happens to the other nothing at all. So basically what entanglement shows us is we can measure anything like spin etc and the other system will be the same id their any communication id have to say no. But as i said earlier there does appear to be a time independence that opens up some strange possibilities for communicating across different frames of reference, If that article i read was correct but again we arent making changes to the system just measuring it.

Either you are misunderstanding entangled particles, or when considering the description you just gave me, you can tell me why the concept of 'non locality' has ever been thought of to be related to entanglement if what you just said is true? You just explained a perfectly classical description of 'entanglement'.

But is there even any conceivably hypothetical, rhetorical, theoretical blurb of a thought can offer as to how possibly in formation can travel instantly across any distance?

Well I prefer not to think we live in a computer, but the best explanation I have read is the following:

Entangled particles are not in fact separate entities but rather a projection of the same single entity within the computer. A shared memory area from which different manifestations of the same entity or information are created. Faster than light signaling is thus an illusion.

Taken from this video:

originally posted by: ImaFungi

originally posted by: mbkennel
a reply to: Arbitrageur

Is there a locality paradox?

My position:

At the core, Einsteinian relativity is about imposing symmetry & transformation constraints on the underlying laws of physics. And quantum field theory obeys this 100%.

Those constraints, when applied to a *classical* field theory with differential operators only, for example, fluid mechanics or acoustics, result in light-cone locality restrictions on cause and effect. These just happen to be the types of physics which humans live in and experience day to day.

So, it's the expectation of locality which ought to be adjusted.

But is there even any conceivably hypothetical, rhetorical, theoretical blurb of a thought can offer as to how possibly in formation can travel instantly across any distance?

Well of course, it's called quantum mechanics. The initial and final states are close by in the Hilbert space which is the target of the functional operators which govern the quantum mechanical equations of motion. (Have you learned enough real analysis to learn about functional spaces and metrics on them?)

These just happen to be projected to further distances in physical space, but that's the classically emergent property.

When you have the decoherence and randomization from large macroscopic bunches of particles (this is the classical limit) then you DO get the behavior of classical physics that stuff outside the light-cones doesn't have any causative influence on stuff inside. So you don't have Schroedinger's entangled felines---his point was that there has to be some transition from quantum to classical in practical nature because actual cats are always classical and not entangled/mixed states in our experience.

That is what you are suggesting, even if you say we cant read that information faster than light, you are suggesting that at an infinite distance between 2 entangled particles, when one is observed, the other automatically reverts to the exact opposite state.

That's what the experiments persistently say.

Now all this means, is there is another physical dimensional structural aspect of the universe, that we did not and could not take into account, while developing einstein speed of light is the fastest speed rule.

Yes, it's called quantum mechanics which is pretty difficult & confusing.

Einstein derived symmetry relationships. The 'speed of light' being the fastest speed is a consequence of applying Einstein's modification of Newton's laws to the classical mechanics of particles with mass. Historically relativity was developed from 1905 through 1917 or so (special to general). Modern, i.e. correct, quantum mechanics wasn't developed until 1925 through 1929, with Bohr & Heisenberg and then Schroedinger & Pauli. It took a few more years with Dirac to apply special relativity (meaning the Lorentz transformation properties) to wavefunctions. And then for Einstein and others to recognize the consequences of QM axioms to observations across light-cones.

You now think you know that is a fact, that there is a systematic potential relationship between what are thought to be separate parts of a system

Things which are physically separated in 3-d space may turn out to be close or mutually interacting in Hilbert space of quantum mechanical interactions when they're entangled.

The point is that the fundamental physical time-evolution of stuff happens in an abstract functional space (the primary discovery of Heisenberg), not something easily parameterized exclusively by x,y,z,t. This is the difference between quantum and classical physics.

a reply to: Arbitrageur

The no communication theorem depends on the realization of a quantum mechanical measurement as a projection operator.

That's the tricky part of quantum mechanics which in Copenhagen interpretation I believe hides plenty of "sin".

Clearly, it is an experimentally justified fact, which I think is an approximation to the microscopic truth, like Fermi's golden rules. It comes up when you mix a small quantum mechanical system with something 'outside' it, the observing apparatus which is a hypothetical classical device. In real reality measuring devices are themselves made out of atoms which obey quantum mechanics. If you integrate the Heisenberg equation of motion for the system and measuring device, when does it "stop" for somebody to insert a projection operator? Never of course, so somehow 'projection' itself has to be an emergent consequence of plain old quantum mechanics (minus projection).

So I think it has to do with the classical limit---the decoherence of thermodynamically large numbers of particles. And getting around that is like reversing the 2nd law of thermodynamics, probabilistically an infinitesimal chance of temporarily happening in a fluctuation, but in any practical real life, no human will ever see it to make any difference.

We can't prepare and maintain in a deep quantum mechanical way two different macroscopic measurment apparatuses separated beyond light cones.

So, FTL communication is impossible to the degree that we are 60 kilogram meatbags of jillions of atoms at a positive temperature.

The technology of quantum computers is to slow down this decay from decoherence from its typical level, enough that useful computations may be done using full quantum mechanical states.


On quantum measurement from Wikipedia

en.wikipedia.org...

n quantum mechanics, einselection, short for environment - induced superselection, is a name coined by Wojciech H. Zurek[1] for a process which is claimed to explain the phenomenon of wavefunction collapse and the emergence of classical descriptions of reality from quantum descriptions. In this approach, classicality is described as an emergent property induced in open quantum systems by their environments. Due to the interaction with the environment, the vast majority of states in the Hilbert space of a quantum open system become highly unstable to entangling interaction with the environment, which in effect monitors selected observables of the system. After a decoherence time, which for macroscopic objects is typically many orders of magnitude shorter than any other dynamical timescale,[2] a generic quantum state decays into an uncertain state which can be decomposed into a mixture of simple pointer states. In this way the environment induces effective superselection rules. Thus, einselection precludes stable existence of pure superpositions of pointer states. These 'pointer states' are stable despite environmental interaction. The einselected states lack coherence, and therefore do not exhibit the quantum behaviours of entanglement and superposition.
Advocates of this approach argue that since only quasi-local, essentially classical states survive the decoherence process, einselection can in many ways explain the emergence of a (seemingly) classical reality in a fundamentally quantum universe (at least to local observers). However, the basic program has been criticized as relying on a circular argument (e.g. R. E. Kastner [3]). So the question of whether the 'einselection' account can really explain the phenomenon of wave function collapse remains unsettled.

Einstein would have been much happier with this explanation, as it is true that the orthodox axioms of QM of his time did have conceptual difficulties that his peers were not so willing to admit.

Something else new, Quantum Darwinism.

en.wikipedia.org...

a reply to: mbkennel

So hilbert space refers to the spatial domain in which the most fundamental quanta and forces operate? The effects of which, their interactions, are deemed 'the emergent classical world'?

So are you saying the emergent classical world is 'less real' than the most fundamental hilbert space quanta interacting?

Is hilbert space not also 3d space?

You said 'These just happen to be projected to further distances in physical space, but that's the classically emergent property.'

Can you say, how might locally 'close actions' (real quanta acting closely in hilbert space) are projected further distances in physical space? Say I have a quantum mechanical system on the moon, and I have entangled particles within it, and you take some and leave the solar system. You are saying, the physical classical act of bodies of atoms and such, obeying the speed of light and gravity making the classical and maybe quantum systems to take some entangled particles from mine on the moon and bring them outside the solar system, is an act, as all of our acts are, which takes place in a projected classical world, that to our big bodies appears to be big and large, however the most fundamental quanta that makes all things up, are really much closer together than they appear, so even if you bring your particle outside of the solar system, and this is a relatively classically comparatively large distance and expenditure of energy to do so, the quanta will relatively not have traveled the same distance? What you are saying is the hilbert space and the quanta may 'scale up nicely' as all things that exist may be comparable in some sort of scale, but the scale is 'obviously' tremendously distant in terms of units, when compared to the classical projections the quanta world creates. Are you saying the classical world is a persistent illusion created by the quantum world? If the illusion aspect is unavoidable, that is to say, it is just as much as an aspect as the quanta world existing, that there must be effects of the quantum world existing, and these effects must be the interactions between the quantum which must result in classical structures, which then must interact classically, wouldnt this suggest that the classical world is just as real as the quantum world? Or is this like saying the letters you are seeing on this screen are just as real as the electrons that are making them appear?

originally posted by: ImaFungi
a reply to: mbkennel

So hilbert space refers to the spatial domain in which the most fundamental quanta and forces operate? The effects of which, their interactions, are deemed 'the emergent classical world'?

So are you saying the emergent classical world is 'less real' than the most fundamental hilbert space quanta interacting?

Yes.

Is hilbert space not also 3d space?

No!

The notion of 'spaces' in mathematics extends far beyond Euclidean space or finite dimensional space and was/is a major subject since the middle of the 19th century.

It's time for you to stop bugging people here and actually work and learn real physics. You'll get some answers to your questions more reliably and with deeper understanding.

The persistent illusion of the classical world is also real because the physics of decoherence and thermodynamics of large numbers of particles is just as real and unavoidable in our universe, even if it is an emergent property of microscopic dynamics.

Just as fluid mechanics is an emergent property of the underlying kinetic theory of particles---does that make the existence of things which behave like fluids, nearly universal in Earthly experience---unreal or invalid? Surely not. Even though we know the equations of fluid mechanics aren't always valid. For instance in a vacuum tube shooting electrons.

originally posted by: mbkennel

"Is hilbert space not also 3d space?"


No!

The notion of 'spaces' in mathematics extends far beyond Euclidean space or finite dimensional space and was/is a major subject since the middle of the 19th century.

If quanta can relatively move up-down, left-right, back-forth; how is the hilbert space no 3d? (and 4d for time)

I dont care about 'in mathematics', I care about 'in reality'. If your mathematics says reality must be a way, that reality cannot hypothetically possibly be, then what your mathematics is telling you, is false. Or what you are telling yourself about it.

The persistent illusion of the classical world is also real because the physics of decoherence and thermodynamics of large numbers of particles is just as real and unavoidable in our universe, even if it is an emergent property of microscopic dynamics.

This is a superbly interesting statement. Because my first thought was to think, 'but cant large clusters, as a large conglomeration of emergent property' effect the fundamental non emergent but immediately real, quanta? And then I thought, if they can, still what it means is that the original notion of reality is always operating at the tiniest level first, and the tinniest level receives all information which cause changes at the tinniest level, which cause changes at the emergent level. Because the tinniest is the closest to fundamental real substance, while all thinks larger then the tiny quanta, are results of the tiny quantas effects, how what it fundamentally is causes the surrounding topographical, field -like environment to react, this is what is meant by emergent. The fact a quanta, or group of quanta, can create EM radiation, or gravity, or and/and form a bond at a semi distance in 'some kind of real space'.

What I thought that was so interesting then, is that your statement implies that the nature of the mind must be intimately quantum, as your statement implies that nature of nature, the nature of all things! must always at first and most fundamental, be quantum phenomenon, and so the 'cause' or 'will' must start from the quantum realm, because it is the quanta that is always immediately acted on, while the classical mechanisms are the 'built up illusions' of 'the exact and 'more simpler? (mehbye)' ways in which the quanta are moving. This is why the first life forms had to start out so semi unfathomably small, and why the brilliant means of encoding genes was almost established and worldly agreed upon in stone at the small but still impressive level of DNA molecule. Reality is always a 'bottom up process', is what you are saying?

Just as fluid mechanics is an emergent property of the underlying kinetic theory of particles---does that make the existence of things which behave like fluids, nearly universal in Earthly experience---unreal or invalid? Surely not. Even though we know the equations of fluid mechanics aren't always valid. For instance in a vacuum tube shooting electrons.

What about our visual delay, or because the speed of light is so fast our imagery of fluid dynamics, is quite objectively accurate? there is really liquid that is really substance that is really moving in a really containment really just like that as I see it and its doing that exactly because this is like this and this is like this. I have thought of these things before and have played with the idea that it might fail due to the existence of stability, when an atom is relatively stable, and when it combines with other pretty stable atoms to make a stable molecule, in an undeniably real way, this system of stability as a 'sum of its parts' real effect, that acts as a solitary object, even though it is a collective. As if to express that where stability can exist, where matter can more and more materialize, this is also now a new quantum level, or the way I would look at it, this is a classical level, as even the most fundamental quanta is a classical level. Sure sometimes quantum may overrule classical from time to time, but classical molecules also have their real collective power over a quantum quanta, because as an object the molecule can play on the quantums playing field, it is as if nature does not draw a line or makes no distinction, there is no projection, it is all real, what the quantas build is a building of quantas, it still unavoidably exists in the quantum realm, at the quantum level, as does all things always but it has established its area and means of stability.

originally posted by: ImaFungi

originally posted by: Arbitrageur
How is this known? How many times do we need to say that nature is under no obligation to behave in a manner that humans would deem "logical"?

When you say, 'nature does not have to behave logical'. What is your understanding of the term 'logic' being used here, that you deny being appropriate?

In this case I'm specifically denying that there's a requirement as you stated that "the correlation between entangled particles must occur at the speed of light or less" which is apparently your logic. As I said the MWI (Many worlds Interpretation) would allow this to happen, but I know of no absolute reason why "the correlation between entangled particles must occur at the speed of light or less", so I don't feel any compulsion to accept the MWI just because it allows a local explanation.

The term 'hidden' in the concept hidden variables only applies to hidden from our awareness. It is saying there are variables that we are ignorant of.

Yes but Bell's inequality doesn't require us to know what the hidden variables are, it's only testing for whether such variables may exist.

If non locality is true, if entanglement is true, there still must be variables as to HOW non locality and entanglement is physically working. This ties into my understanding of logic, that there must be a physical reason as to why something occurs, even if you dont think there is, even if you dont know what it is.

I think there is a deeper explanation for entanglement behavior, and we don't know what that is, but again, I don't make any assumption that this deeper explanation must include locality. It may, or it may not, or I could be wrong and maybe there isn't a deeper explanation.

I think if there were hidden variables there would be the same results as are received. I think what matters is what is actually occurring when an entangled pair of particles is created. Hidden variables suggests they must be in some exact state (upon measurement we can deduce, opposite states). QM suggests each particle is in at the same time, 2 opposite quasi states.

How do you rationalize this with Bell's inequality?

Yes it depends what it means. I have felt at times it has meant that a single system, say a person sitting in a chair in their room holding an apple, every single quantum action that takes place 'doubles' into an entirely new real universe, or that the entire universe is always physically multiplying. But the past few times I have come in contact with this theory, I feel it seems it might be instead suggesting that, merely the universe, or the sections and intimate systems within the universe are not entirely checked and captured and solidified in terms of all else, that the immediate relations of particles while they are not in contact with all the rest, it is as if they exist in another world, unto themselves. So then when particles are separated from this system, it is a part of that old system traveling into new territory, like an entire new world, a new system, but it still has the signatures, the breeding if you will, of the old system it was a part of. And perhaps they are suggesting this sort of thing happens or can happen all the time, mixing and matching and withholding signatures, and still be connected by some informational aspect even at a distance. Just like if you moved to south east asia, even though you would be away from the system you started and grew much in, you would still have some 'attachment' and relation to that old system. but this is me spitballing.

The physicist in the OP video, Sean Carroll likes it, and while he may be in the minority, I think the minority may be growing. The way he puts it, it's just assuming the Schrodinger equation is actually correct, but it seems like a messy explanation. That doesn't mean it's necessarily wrong.

originally posted by: mbkennel
Give up your need for locality. It ain't happening.

That was addressed to imafungi and I don't have a need for it, but I was curious...Do you agree with the paper I posted saying that the many worlds interpretation is local so one wouldn't need to give up locality with that interpretation? For me, giving up locality is easier than accepting the many worlds interpretation, but I'd still like to know if that assertion is correct.

originally posted by: mbkennel
Is there a locality paradox?

I didn't choose the word "paradox" very carefully. The source I quoted called lack of locality a "conceptual problem", is that better? I'm not sure if it's really a problem though, which is why I don't feel compelled to buy into MWI just because it claims to provide a local explanation.

My position:

At the core, Einsteinian relativity is about imposing symmetry & transformation constraints on the underlying laws of physics. And quantum field theory obeys this 100%.

Those constraints, when applied to a *classical* field theory with differential operators only, for example, fluid mechanics or acoustics, result in light-cone locality restrictions on cause and effect. These just happen to be the types of physics which humans live in and experience day to day.

So, it's the expectation of locality which ought to be adjusted.

I tend to agree. Thanks for contributing your thoughts. I started the thread on this topic but we never really discussed it much in depth until now but I'm glad to see we returned to it to discuss it in more depth.

originally posted by: ChaoticOrder
Well I prefer not to think we live in a computer, but the best explanation I have read is the following:

So you don't agree with the video but you're citing it anyway, is that what you mean?

originally posted by: mbkennel
So you don't have Schroedinger's entangled felines---his point was that there has to be some transition from quantum to classical in practical nature because actual cats are always classical and not entangled/mixed states in our experience.

So, Cats are macroscopic meatbags and that explains why they can't be in a superposition of dead and alive states...makes sense to me.

originally posted by: mbkennel
We can't prepare and maintain in a deep quantum mechanical way two different macroscopic measurment apparatuses separated beyond light cones.

So, FTL communication is impossible to the degree that we are 60 kilogram meatbags of jillions of atoms at a positive temperature.

I didn't think that was the main problem. I thought even if we weren't macroscopic entities with macroscopic measurement devices, the problem is that it's simply a correlation. You need to do more than just measure the state, you'd need to set it somehow, and you can't do that because the outcome of the measurement seems to be probabilistic, unless you're saying it's not really probabilistic.

originally posted by: mbkennel
The notion of 'spaces' in mathematics extends far beyond Euclidean space or finite dimensional space and was/is a major subject since the middle of the 19th century.

It's time for you to stop bugging people here and actually work and learn real physics. You'll get some answers to your questions more reliably and with deeper understanding.

No doubt a lot of ImaFungi's questions could be answered in physics courses. However this question of how to interpret Quantum Mechanics wasn't answered in any of the courses I took nor was such a course even offered to my knowledge. Also as the OP video states there is quite a divergence of opinion even among professional physicists.