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Thread: Entanglement

  1. #1 Entanglement 
    Moderator Moderator Markus Hanke's Avatar
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    https://phys.org/news/2017-09-entang...ality.html#jCp

    This is just to stimulate traffic and discussion on the forum a little - I've no particular point to make, other than that I hope it might develop into a bit of a debate, or might evoke interesting questions and answers from people.

    Enjoy !


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    the mechanism of quantum entanglement is simple. the force between any 2 charged particles f=Ke x qp/rr is the carrier of energy/information/moving electric force. it is an invisible physical rod with zero mass that always connected 2 particles as 1. if 1 particle is energized, that energy instantly transferred to another. from f=ma, m=0, so energy instantly moved from 1 particle to another. we call it QE.


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    Cannot entanglement be thought of an extension to the Pauli exclusion principle to unbound quantum entities?
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    Quote Originally Posted by Markus Hanke View Post
    https://phys.org/news/2017-09-entang...ality.html#jCp

    This is just to stimulate traffic and discussion on the forum a little - I've no particular point to make, other than that I hope it might develop into a bit of a debate, or might evoke interesting questions and answers from people.

    Enjoy !
    Check this out, why they deleted a lot of comments? https://phys.org/news/2017-09-supern...rk-energy.html Deleted comments at Fucked Science
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    Quote Originally Posted by isawit View Post
    What I thought.
    Do NOT post in the hard science sub-fora again.
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    Quote Originally Posted by Dywyddyr View Post
    Quote Originally Posted by isawit View Post
    What I thought.
    Do NOT post in the hard science sub-fora again.
    That's where the missing comments are. Do you want to see the original comments? Do you want to find out why phy.org deleted those comments? Do you want to learn the truth?
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    Quote Originally Posted by isawit View Post
    Check this out, why they deleted a lot of comments?
    Probably because they were made by ignorant morons like you.

    It also has nothing to do with the topic.
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    Quote Originally Posted by isawit View Post
    drivel
    I expect Markus is very disappointed that the first response to this very interesting article was crap like this. Ho hum.
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  10. #9  
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    Quote Originally Posted by isawit View Post
    That's where the missing comments are. Do you want to see the original comments? Do you want to find out why phy.org deleted those comments? Do you want to learn the truth?
    You appear to be having comprehension problems so I'll repeat it: Do NOT post in the hard science sub-fora again.
    Any future comments from you will be moved to the Trash sub-forum.
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    Quote Originally Posted by isawit View Post
    is this a science forum or a science church?
    It is a science forum. That is why your crap isn't welcome.
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  12. #11  
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    Maybe should be renamed I's a twat...
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    Quote Originally Posted by isawit View Post
    the mechanism of quantum entanglement is simple. the force between any 2 charged particles f=Ke x qp/rr is the carrier of energy/information/moving electric force. it is an invisible physical rod with zero mass that always connected 2 particles as 1. if 1 particle is energized, that energy instantly transferred to another. from f=ma, m=0, so energy instantly moved from 1 particle to another. we call it QE.
    You should post this on Cosmoquest Forum - you will get a much more exciting response.
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    I expect Markus is very disappointed that the first response to this very interesting article was crap like this. Ho hum.
    You bet
    But I guess I should have known - quantum physics seems to attract the...ahem...less savoury characters like flies. This is something that will never change.
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    Quote Originally Posted by Markus Hanke View Post
    I expect Markus is very disappointed that the first response to this very interesting article was crap like this. Ho hum.
    You bet
    But I guess I should have known - quantum physics seems to attract the...ahem...less savoury characters like flies. This is something that will never change.
    I wish I had something more insightful to contribute than: it's very interesting and I wonder where it will lead ...
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    Forum Radioactive Isotope zinjanthropos's Avatar
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    Although the full proof is very detailed, the main idea behind it is simply that any theory that describes reality must behave like classical theory in some limit. This requirement seems pretty obvious, but as the physicists show, it imparts strong constraints on the structure of any non-classical theory.
    Never know how to word these questions but....Does this mean there is a good chance that there are no other realities except the one were in?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
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    Quote Originally Posted by zinjanthropos View Post
    Although the full proof is very detailed, the main idea behind it is simply that any theory that describes reality must behave like classical theory in some limit. This requirement seems pretty obvious, but as the physicists show, it imparts strong constraints on the structure of any non-classical theory.
    Never know how to word these questions but....Does this mean there is a good chance that there are no other realities except the one were in?
    Or, if there are other realities, they must have some things in common, such as a quantum nature with entanglement.

    (But I'm not quite sure whether this reality exists, never mind others! )
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  19. #18  
    Forum Radioactive Isotope zinjanthropos's Avatar
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    Quote Originally Posted by Strange View Post
    Or, if there are other realities, they must have some things in common, such as a quantum nature with entanglement.

    (But I'm not quite sure whether this reality exists, never mind others! )
    Not sure what you mean about this or other realities not existing, is that like a hallucination or it's a reality but not the one we sense? So if I'm interpreting you correctly, and just in case our reality doesn't exist in any way, then is it fair to say that any non existing reality must also include a quantum nature with entanglement? Sounds like sci-fi or philosophical problem
    Last edited by zinjanthropos; September 29th, 2017 at 10:49 AM.
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    Quote Originally Posted by zinjanthropos View Post
    Quote Originally Posted by Strange View Post
    Or, if there are other realities, they must have some things in common, such as a quantum nature with entanglement.

    (But I'm not quite sure whether this reality exists, never mind others! )
    Not sure what you mean about this or other realities not existing, is that like a hallucination or it's a reality but not the one we sense? So if I'm interpreting you correctly, and just in case our reality doesn't exist in any way, then is it fair to say that any non existing reality must also include a quantum nature with entanglement? Sounds like sci-fi or philosophical problem
    Oooh. You're getting a bit too deep me ...
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  21. #20  
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    Quote Originally Posted by Strange View Post


    Oooh. You're getting a bit too deep me ...
    Like NOTHINGNESS having a quantum nature...lol
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    Quantum Entangle is interesting. Instantaneous effect proves that physically world is one & events may not be local.
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    Quote Originally Posted by Mahesh khati View Post
    Quantum Entangle is interesting. Instantaneous effect proves that physically world is one & events may not be local.
    Quantum entanglement is actually just a statistical correlation between measurements outcomes; there is no action at a distance involved in this.
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  24. #23  
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    I'm a newbie here, and have a desire to tread carefully. There's been a fair bit of mud-slinging on this thread but better that than nothing said, for this is a subject demanding examination and it's one of many principles of physics that, in my humble opinion, can't be confined to experiment or formula. We live in a quantum world, with its entanglements, forces and dimensions, and the issues raised here are the kinds of issues I was hoping to find brought to life on this forum. Some areas of philosophy and science are naturally compatible, as has always been the case, never more so than when the Everett and Copenhagen interpretations went head-to-head. There's no reason why things like entanglement shouldn't be sensibly discussed with such arguments in mind.
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    Quote Originally Posted by Quantumologist View Post
    There's been a fair bit of mud-slinging on this thread
    Examples?

    it's one of many principles of physics that, in my humble opinion, can't be confined to experiment or formula.
    In which case those "aspects" aren't exactly science, are they?

    We live in a quantum world
    Not really. We tend to live in the macro world.

    There's no reason why things like entanglement shouldn't be sensibly discussed with such arguments in mind.
    Sure: that's why the loon's posts were moved to Trash - because we wanted a sensible discussion.
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    Quote Originally Posted by Dywyddyr View Post
    Quote Originally Posted by Quantumologist View Post
    There's been a fair bit of mud-slinging on this thread
    Examples?

    Well, using words like "crap" and "twat" might qualify...

    it's one of many principles of physics that, in my humble opinion, can't be confined to experiment or formula.
    In which case those "aspects" aren't exactly science, are they?

    Scientists like Einstein, Schroedinger, and Planck attested to their theories being outside currently acceptable frameworks of the day, and certainly there are quotes out there from the aforementioned which admit that principles like entanglement are philosophical by nature as much as they are academic - if not more so. I can provide examples of such quotes but they are easily found in the public domain.

    We live in a quantum world
    Not really. We tend to live in the macro world.

    We are made of quarks. That's good enough for me. How we live with them, and what they do, together with what our electrons do, and how these particles react and interact with each other and with other contenders in the Particle Zoo is surely what these discussions are all about?

    There's no reason why things like entanglement shouldn't be sensibly discussed with such arguments in mind.
    Sure: that's why the loon's posts were moved to Trash - because we wanted a sensible discussion.
    Look forward to it. Thank you for replying.
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    I am a layman but this sentence from the link does puzzle me. I have high lighted the bit that does cause me concern. I hope that Marcus can enlighten me.
    " In a new study, physicists have mathematically proved that any theory that has a classical limit—meaning that it can describe our observations of the classical world by recovering classical theory under certain conditions—must contain entanglement. So despite the fact that entanglement goes against classical intuition, entanglement must be an inevitable feature of not only quantum theory but also any non-classical theory, even those that are yet to be developed."

    Read more at: https://phys.org/news/2017-09-entang...ality.html#jCp
    Last edited by Dave Wilson; October 6th, 2017 at 01:15 PM. Reason: spelling.
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    My current guess(probably wrong) about entanglement is this; When certain particles are in a aystem, because of Paulis Exclusion Principle they must have different quantum states. So that when the state of one particle is measured the other particle is known to have the other state. Or is it that when an entangled particle is measured the other entangled particle also changes state and then the entanglement is broken?
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    Quote Originally Posted by GiantEvil View Post
    My current guess(probably wrong) about entanglement is this; When certain particles are in a aystem, because of Paulis Exclusion Principle they must have different quantum states. So that when the state of one particle is measured the other particle is known to have the other state. Or is it that when an entangled particle is measured the other entangled particle also changes state and then the entanglement is broken?
    Wouldn't the latter explanation need the action at a distance that Markus says does not happen ? (post #22)

    How many simultaneous measurements of entangled particles are possible within a system? Can the state of a whole group of particles be known by measuring a set of entangled pairs?

    Not just one pair at a time?

    Would there be applications for this?(if I was clear)
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  30. #29  
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    Quote Originally Posted by Dave Wilson View Post
    even those that are yet to be developed."
    Why is this puzzling ?
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    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by Mahesh khati View Post
    Quantum Entangle is interesting. Instantaneous effect proves that physically world is one & events may not be local.
    Quantum entanglement is actually just a statistical correlation between measurements outcomes; there is no action at a distance involved in this.

    "spooky action at distance" ,by einstein
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    Forum Radioactive Isotope zinjanthropos's Avatar
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    Just thinking from a layman's perspective......If I had an entangled pair of particles contained inside a box then would the particles occupy every cubic inch within? I mean would super positioned particles not under direct observation occupy the entire volume of the box? Have an idea where I'm going with this but I'll stop here because I'm probably way out to lunch already.
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    Quote Originally Posted by Mahesh khati View Post
    "spooky action at distance" ,by einstein
    Einstein (wrongly) described it like that because he didn't like it.
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  34. #33  
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    Quote Originally Posted by zinjanthropos View Post
    Just thinking from a layman's perspective......If I had an entangled pair of particles contained inside a box then would the particles occupy every cubic inch within? I mean would super positioned particles not under direct observation occupy the entire volume of the box? Have an idea where I'm going with this but I'll stop here because I'm probably way out to lunch already.
    In general, yes. A particle has some probability of being anywhere in the box until detected (depending on the particle and the nature of the box, it could be an equal probability of being anywhere or it might be more likely to be on one sidebar example).

    In the case of entangled particles, it also depends what properties are entangled. For example, it is possible to entangle position information such that if one particle is on one side of the box, then the other one will be too. (I read something about this in passing the other day, so don't know much more about it...)
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  35. #34  
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    Quote Originally Posted by Mahesh khati View Post
    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by Mahesh khati View Post
    Quantum Entangle is interesting. Instantaneous effect proves that physically world is one & events may not be local.
    Quantum entanglement is actually just a statistical correlation between measurements outcomes; there is no action at a distance involved in this.

    "spooky action at distance" ,by einstein
    Yes, Einstein did use this term during the early days of quantum mechanics; but he was wrong in his assumption that an action takes place. We know today that there is in fact no “action at a distance”, it’s just a statistical correlation between measurement outcomes.
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  36. #35  
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    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by Mahesh khati View Post
    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by Mahesh khati View Post
    Quantum Entangle is interesting. Instantaneous effect proves that physically world is one & events may not be local.
    Quantum entanglement is actually just a statistical correlation between measurements outcomes; there is no action at a distance involved in this.

    "spooky action at distance" ,by einstein
    Yes, Einstein did use this term during the early days of quantum mechanics; but he was wrong in his assumption that an action takes place. We know today that there is in fact no “action at a distance”, it’s just a statistical correlation between measurement outcomes.
    I thought only 2 measurements were involved.Where does the statistics come into it?

    Also ,am I right that distance is not a factor in the outcome?
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    [QUOTE=Strange;608138]
    Quote Originally Posted by zinjanthropos View Post

    In general, yes. A particle has some probability of being anywhere in the box until detected (depending on the particle and the nature of the box, it could be an equal probability of being anywhere or it might be more likely to be on one sidebar example).

    In the case of entangled particles, it also depends what properties are entangled. For example, it is possible to entangle position information such that if one particle is on one side of the box, then the other one will be too. (I read something about this in passing the other day, so don't know much more about it...)
    My next question was going to be if wherever one half of the pair was super positioned then why wouldn't the other particle be there too? IOW should superposition allow for each particle of an entangled pair to be in the same place or at the same point?

    Let's say they can be and if I then impart motion to the box (ie...shake it or twirl it) then what happens inside the box? I'm thinking nothing changes with respect to the entangled pair, they remain as they are, still everywhere within the box. If nothing really changes to the pair even if motion is applied to their container then does the super positioned entangled pair recognize the motion? IOW is motion irrelevant to super positioned particles?
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    Quote Originally Posted by zinjanthropos View Post
    My next question was going to be if wherever one half of the pair was super positioned then why wouldn't the other particle be there too? IOW should superposition allow for each particle of an entangled pair to be in the same place or at the same point?
    If the entanglement includes their position, then that is true (nearby, at least, if not the same place - the uncertainty principle comes in to it their - limiting how precisely the position can be defined).

    But if it is some other property (typically spin) that is entangled then they can be separated by arbitrary distance and the entanglement remains.
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by zinjanthropos View Post
    My next question was going to be if wherever one half of the pair was super positioned then why wouldn't the other particle be there too? IOW should superposition allow for each particle of an entangled pair to be in the same place or at the same point?
    If the entanglement includes their position, then that is true (nearby, at least, if not the same place - the uncertainty principle comes in to it their - limiting how precisely the position can be defined).

    But if it is some other property (typically spin) that is entangled then they can be separated by arbitrary distance and the entanglement remains.
    It is this separation I'm trying to get to. I figure super positioned particles do not care what perceptible environment they're in. They could be hurtling through space or doing a slow boil, doesn't matter, as far as entangled particles go they are in the same place. It's a stretch perhaps, but could we go as far to say spatial dimensions and perhaps even time mean nothing between entangled pairs. Why would these dimensions mean anything if each particle can be everywhere at once, including the position of their twin?

    Edit: Does it mean that when I observe one particle of an entangled pair that the other particle is also sharing the same position, just not observed?
    Last edited by zinjanthropos; October 9th, 2017 at 09:42 AM.
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  40. #39  
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    Quote Originally Posted by zinjanthropos View Post
    It is this separation I'm trying to get to. I figure super positioned particles do not care what perceptible environment they're in. They could be hurtling through space or doing a slow boil, doesn't matter, as far as entangled particles go they are in the same place.
    Entangled particles are described by a single wave function. If a pair of photons are created by the annihilation of a particle-antiparticle pare then they will have opposite spins (when measured) and they will also be heading in opposite directions (to conserve momentum). So they won't be in the same place, physically. However, entangled particles are described by a single wave function and this will become increasingly spread out as the particle move apart (until the entanglement is broken).

    But maybe this isn't much different from the wave function for a single particle which only describes the position in terms of a probability where the particle might be.
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    [QUOTE=zinjanthropos;608144][QUOTE=Strange;608138]
    Quote Originally Posted by zinjanthropos View Post

    S: "In general, yes. A particle has some probability of being anywhere in the box until detected (depending on the particle and the nature of the box, it could be an equal probability of being anywhere or it might be more likely to be on one sidebar example).

    In the case of entangled particles, it also depends what properties are entangled. For example, it is possible to entangle position information such that if one particle is on one side of the box, then the other one will be too."

    Z: Let's say they can be and if I then impart motion to the box (ie...shake it or twirl it) then what happens inside the box? I'm thinking nothing changes with respect to the entangled pair, they remain as they are, still everywhere within the box. If nothing really changes to the pair even if motion is applied to their container then does the super positioned entangled pair recognize the motion? IOW is motion irrelevant to super positioned particles?
    As the entangled pair have a relatonship, and the question here is whether they recognise the aspects of their environment (in order to exchange the relevant information?) by what means could the particles be said to be observing their environment? And for what reason, hypothetically, would particles separated by distance maintain such a relationship in the first place?
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    Brassica oleracea Strange's Avatar
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    Quote Originally Posted by Quantumologist View Post
    As the entangled pair have a relatonship, and the question here is whether they recognise the aspects of their environment (in order to exchange the relevant information?) by what means could the particles be said to be observing their environment? And for what reason, hypothetically, would particles separated by distance maintain such a relationship in the first place?
    I'm not sure what you mean by "recognise aspects of the environment". The particles will interact with the environment and this, usually, destroys the entanglement.

    The 'reason" for entanglement? See the first post in this thread. It seems it is kind of inevitable.
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    As quoted by Z: "Does the superpositioned entangled pair recognise the motion?" I know it's very difficult to talk about physical processes without using words that might be ascribed to conscious processes when talking about such things, but that's the point, really. Engineers talking about machine tools don't have those kinds of problems. They don't ask whether the bore mechanism can recognise the steel plate, because someone already programmed it that way.

    There's the line that says once entangled always entangled, and I understand that decoherence through environmental interaction is an entropic process although appreciate that this is a debated aspect. The superpositoned state breaking down on observation How Big Can Entanglement Get? - The Nature of Reality — The Nature of Reality | PBS suggests the relationship between quantum states and macro-reality is a jack-in-the-box reactionary one, and I asked for views on the "reason for entanglement" because I wanted to know more on what people thought regarding why particles achieve entanglement in the first place and the purpose behind it. I don't read equations so the first post on this thread isn't an answer for me, and "it just is" might not be the only view, there might be other ideas as to why it happens.
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    Quote Originally Posted by Quantumologist View Post
    There's the line that says once entangled always entangled
    I don't know where that is from, but it is wrong.

    I don't read equations so the first post on this thread isn't an answer for me
    There are no equations in the first post (or the linked article). It just explains how entanglement is a necessary part of any quantum system that also behaves classically (i.e. any possible description of our world).
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    I'll try to summarize my layman's perspective, which means I am not trained in the science of the topic and realize I am more likely to misinterpret wording and observation. IOW be wrong

    To me, a super positioned particle or anything that is everywhere at once has no need to go from Point A to B since it's already there even if iits environment (I used the box here) is in a constant state of motion. I asked then if a super positioned particle would recognize (not consciously as if alive) the elements of motion such as time and distance only because it doesn't make sense to me why everywhere involves distances and why at once involves time.. IOW what part of distance and time is required for everywhere at once?

    I'm also puzzled as to whether the entangled particles in the super positioned state share the same spaces. I think that's about it from a guy laying in bed tapping an iPad
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    Quote Originally Posted by zinjanthropos View Post
    ITo me, a super positioned particle or anything that is everywhere at once has no need to go from Point A to B since it's already there even if iits environment (I used the box here) is in a constant state of motion. I asked then if a super positioned particle would recognize (not consciously as if alive) the elements of motion such as time and distance only because it doesn't make sense to me why everywhere involves distances and why at once involves time.. IOW what part of distance and time is required for everywhere at once?
    You ask some questions that are beyond my understanding and may relate to the whole problem of how classical behaviour derives from quantum behaviour.

    If a particle is in the superposition of two different locations that means there is a probability that will be detected in either of those positions. Presumably with a 50/50 chance of being in either. So it doesn't need to "go" from A to B because it isn't (yet) in either position. As with most quantum properties, the position just isn't defined until it isn't measured.

    There are situations where this can lead to odd effects, such as tunnelling. In this case, there is some sort of barrier (perhaps a literal one like a layer of insulating material between two conductors) and the wave function (probability distribution) of an electron can be large on one side of the barrier, zero in the barrier (it is an insulator) and then not quite so large on the other side. This means that even if the electron starts out none side, it can appear on the other side as if it had gone through the insulator (it doesn't go through - there is just a finite chance of its next interaction with an atom being on the other side).

    As to why quantum particles are "aware" of time and space, I assume this is because time and space are included in quantum field theory - which includes special relativity. (Of course, this is not the "reason" they behave as they do; it is our description of the reason!)
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
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    Thank you, these replies are illuminating. The relationship between particles also alludes to their relationship with spacetime and this is clarified in context by your posts.
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    I thought only 2 measurements were involved.Where does the statistics come into it?

    Also ,am I right that distance is not a factor in the outcome?
    There is a minimum of two measurements involved, but you can also entangle more complex systems that have more than two components. Either way, entanglement becomes apparent only when the outcomes are being compared - which is possible only via classical communication between the parts.

    Yes, distance is not a factor in the outcome, because the parts of the system are described by just one wave function, regardless of how far they are apart.
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    Quote Originally Posted by Markus Hanke View Post

    There is a minimum of two measurements involved, but you can also entangle more complex systems that have more than two components. Either way, entanglement becomes apparent only when the outcomes are being compared - which is possible only via classical communication between the parts.

    Yes, distance is not a factor in the outcome, because the parts of the system are described by just one wave function, regardless of how far they are apart.
    If a complex system is entangled are the measurements that are made of the sets of pairs (right terminology and understanding?) made simultaneously or is it a further task to construct the related system from a set of component measurements that are separated in time?
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by zinjanthropos View Post
    ITo me, a super positioned particle or anything that is everywhere at once has no need to go from Point A to B since it's already there even if iits environment (I used the box here) is in a constant state of motion. I asked then if a super positioned particle would recognize (not consciously as if alive) the elements of motion such as time and distance only because it doesn't make sense to me why everywhere involves distances and why at once involves time.. IOW what part of distance and time is required for everywhere at once?
    You ask some questions that are beyond my understanding and may relate to the whole problem of how classical behaviour derives from quantum behaviour.

    If a particle is in the superposition of two different locations that means there is a probability that will be detected in either of those positions. Presumably with a 50/50 chance of being in either. So it doesn't need to "go" from A to B because it isn't (yet) in either position. As with most quantum properties, the position just isn't defined until it isn't measured.

    There are situations where this can lead to odd effects, such as tunnelling. In this case, there is some sort of barrier (perhaps a literal one like a layer of insulating material between two conductors) and the wave function (probability distribution) of an electron can be large on one side of the barrier, zero in the barrier (it is an insulator) and then not quite so large on the other side. This means that even if the electron starts out none side, it can appear on the other side as if it had gone through the insulator (it doesn't go through - there is just a finite chance of its next interaction with an atom being on the other side).

    As to why quantum particles are "aware" of time and space, I assume this is because time and space are included in quantum field theory - which includes special relativity. (Of course, this is not the "reason" they behave as they do; it is our description of the reason!)
    Just glad many people find this topic interesting. I kind of know where my mistakes are before I hit the enter button but nothing ventured, nothing gained. Wouldn't it be great if something penned on this forum actually led to an amazing discovery. It would be awesome.

    Ever notice how some of the more imaginative science fiction works its way into some conversations. I was thinking we could clear a lot of this entanglement and FTL stuff up if we had a Star Trek Subspace. ​Here's one official definition from a Star Trek site:

    "a spacial continuum with significantly different properties from our own." Okay, how about this: a region of space that coexists with our own universe but is disconnected in some way. A lot of Star Trek gizmos work only when accessing subspace. Warp-drive spaceships, for example, travel through subspace at the speed of light. Messages are transmitted via subspace. Lots of stuff in subspace is different from our stuff. Never read about subspace in science class? That's because Star Trek's writers made it up.

    What are the chances of a Subspace actually existing? I wonder if science has checked it out.
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
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    Quote Originally Posted by geordief View Post
    Quote Originally Posted by Markus Hanke View Post

    There is a minimum of two measurements involved, but you can also entangle more complex systems that have more than two components. Either way, entanglement becomes apparent only when the outcomes are being compared - which is possible only via classical communication between the parts.

    Yes, distance is not a factor in the outcome, because the parts of the system are described by just one wave function, regardless of how far they are apart.
    If a complex system is entangled are the measurements that are made of the sets of pairs (right terminology and understanding?) made simultaneously or is it a further task to construct the related system from a set of component measurements that are separated in time?
    Not sure if I understand you correctly, but the measurements are taken in different places and potentially at different times; the data as to their outcome is then communicated, brought together, and compared.
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    Quote Originally Posted by Markus Hanke View Post
    Not sure if I understand you correctly, but the measurements are taken in different places and potentially at different times; the data as to their outcome is then communicated, brought together, and compared.
    How is the comparison carried out in effect? The numbers corresponding to the states of the measured particles are added together in a simple arithmetical operation and divided by the number of measurements?
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    Quote Originally Posted by geordief View Post
    Quote Originally Posted by Markus Hanke View Post
    Not sure if I understand you correctly, but the measurements are taken in different places and potentially at different times; the data as to their outcome is then communicated, brought together, and compared.
    How is the comparison carried out in effect? The numbers corresponding to the states of the measured particles are added together in a simple arithmetical operation and divided by the number of measurements?
    No, it’s a simple comparison. For example, if you have two entangled identical fermions, then one spin measurement might come out as “spin down”, meaning the other one must come out as “spin up”. However, the fact that these outcomes are always opposites becomes apparent only when you compare the two measurements - each one taken on its own is completely random to the respective observer.
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    Quote Originally Posted by Markus Hanke View Post
    Quote Originally Posted by geordief View Post
    Quote Originally Posted by Markus Hanke View Post
    Not sure if I understand you correctly, but the measurements are taken in different places and potentially at different times; the data as to their outcome is then communicated, brought together, and compared.
    How is the comparison carried out in effect? The numbers corresponding to the states of the measured particles are added together in a simple arithmetical operation and divided by the number of measurements?
    No, it’s a simple comparison. For example, if you have two entangled identical fermions, then one spin measurement might come out as “spin down”, meaning the other one must come out as “spin up”. However, the fact that these outcomes are always opposites becomes apparent only when you compare the two measurements - each one taken on its own is completely random to the respective observer.
    And if there were multiple observations(very many pairs) how would one set of "pair halves" be related to the other set? (am I making sense?)
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