Does Quantum Entanglement Imply Faster-Than-Light Interaction?

[DrChinese]

DrChinese - I still don't see why I need "lots of hidden variables" - all I need is a hidden in plain sight principle, found in Maxwell's views of electromagnetism

Somehow I think you have not yet read and understood Bell Theorem. It is almost pointless to discuss in absence of that, but I will explain a bit about hidden variables.

Imagine we have entangled Alice and Bob (polarizations clones of each other). If I measure both at 0 degrees I get the same answer. If I measure both at 10 degrees I get the same answer. If I measure both at 20 degrees I get the same answer. Etc.

If I measure Alice at 0 degrees and Bob and 90 degrees, I get different answers every time. If I measure Alice at 10 degrees and Bob and 100 degrees, I get different answers every time. If I measure Alice at 20 degrees and Bob and 110 degrees, I get different answers every time. Etc.

Now, obviously, if there was some simple arrangement to explain this - such as 1 set of variables to cover from 0 to 90 degrees, another from 90 to 180 - then the coincidence rate would never match the cos^2(theta) rule. You can work this out for yourself (I hope).

So perhaps there are hidden variables at every 10 degrees. Then we would need 36 sets of variables in both Alice and Bob for everything to work out. Of course, if I change the resolution to 1 degree, I need 360 sets of hidden variables.

So a lot of hidden variables.

 

[Delta Kilo]

Delta Kilo - can you provide a link to a high resolution graph plot for coincidence rate vs. angle

Yeah, sure, http://images.lmgtfy.com/?q=bell+coincidence+count"

Also this: (http://www.sciencefile.org/SciFile/forum/Foundations/164390-Alain-Aspect-EPR-Lecture" )

 

[afstgl]

Oh yeah, that cosine curve, I really expected something fancier, with multiple plots, like this one:
http://www.nature.com/nphys/journal/vaop/ncurrent/carousel/nphys1996-f2.jpg

I guess the smooth cosine curve came from ... how do you call it in English... averaging of results, similar to the point plots in the image above...

I took this one off wikipedia and did some mirroring to give a visual representation of the degree of asymmetry, with 180 degree being the center, RED is right superimposed on left, GREEN is left with mirror transformations superimposed on left.
[PLAIN]http://img64.imageshack.us/img64/5021/cosine.png[/URL]

As it is obvious, a very neat, almost perfect symmetry is observed, and the small differences probably fall well within the margin of error when averaging dot plots to a single curve.
In that case, this graph (supplied to me with the hint that I am a moron to the extent I don't know how to google) seems to be consistent with my moronic idea - we observe anti-correlation increasing with the increase of symmetry in the transformations of entangled particles and what is MORE IMPORTANT - we also observe correlation when measured at 180 degree relative, which is CRUCIAL to my idea - we start with anti-correlated particles, we apply mirror transformations to both particles and get anti-correlated particles as result, BUT measuring at 180 degree applies mirror transformation only to one of the particles, if we have two mirror particles and rotate one at 180 degree, we end up with two identical particles. And that is not all, the cosine graph shows a very neat relationship between correlation shifting at equal steps of 90 degree. It makes perfect sense to me, I can visually imagine the whole process with its logical outcome, and [B]you are telling me that I am able to grasp the mechanics of the experiment because I don't understand something, which if I DID UNDERSTOOD, I wouldn't be able to explain the mechanics of the experiment[/B]...

DrChinese - I understand your last post perfectly, it seems that it is you who cannot understand how I understand the mechanics of this experiment, perfectly logical without any hidden variables at all.

Pardon the nonconformity of my expression in regard to academic nomenclature, I am not a member of academia, not to mention not a native English speaker, that is why I feel a pictorial explanation might bridge that gap and make things clear - keep in mind this is a photochop file - no precision at all, just explaining my concepts in a visual way:

[PLAIN][PLAIN]http://img232.imageshack.us/img232/9229/entanglement.png[/URL]
Note - disregard the "transformation boundary" in the legend at the end, I accidentally forgot to delete it from a previous idea. Arrows do not represent physical direction of rotation but spin + or -, up or down or whatever.

 

[SpectraCat]

@afstgl

Look, you are really making this very difficult. You are shouting so loudly about what you think you understand (but actually don't), that you cannot hear the helpful suggestions and explanations being provided to you. That last post of yours is almost entirely non-sensical in the context of what is already known about entanglement, and how measurements are made in quantum mechanics. You probably won't take my advice, but you need to slow down, back up, review basic QM, and carefully re (or re-read) the Mermin paper I linked, which goes through the issues with what you are describing in patient detail, in a fashion that is designed to be accessible to non-academics.

Some key points you are missing:

1) entangled pairs do not have to be anti-correlated .. they can also be correlated. In other words, you can create entangled pairs such that both particles always have the same spin (or polarization) when measured at the same angle.

2) entangled pairs are quantum mechanical superpositions.

For correlated pairs you have: $\Psi_I=\frac{1}{\sqrt{2}}[|U>|U> + |D>|D>]$

For anticorrelated pairs you have: $\Psi_II=\frac{1}{\sqrt{2}}[|U>|D> + |D>|U>]$

where U and D denote up and down, and the notation |U>|D> means that particle A is up and particle B is down.

3) there is no preferred polarization angle. In other words, if you have a correlated state, and particle A is measured at 45º, and particle B is measured at 135º, you will observe zero coincidences (a coincidence being defined as both particles having the same state). If you measure particle A at 67º, and particle B at 247º, you will also observe zero coincidences. What I am saying is that the coincidence rate does not depend on the polarization angles of the photons as they come out of the source. It ONLY depends on the relative angle ($\theta$) between the measurements, and the dependence (as shown in the plot you posted) is given by $cos^2\theta$.

 

[afstgl]

So you claim that I don't understand something you don't understand yourself and last time I checked no one really does, is that right? If that is the case, I don't really think you have a case here, and if not, perhaps you will be the first one to provide a plausible explanation of the mechanics behind those "predictions"?

If anything, you obviously missed the bottom of my image, where it says "cause of "randomness" due to relative angle between (measurement of) A and B", otherwise you wouldn't repeat the statement "It ONLY depends on the relative angle (θ) between the measurements" since it was implied I am well aware of that.

My example would be equally valid with correlated "entangled" particles as well, do you really fail to understand my idea, which perfectly explains the results of the experiment in a way even a kid would probably get it right away? Why is that I feel a kind of "it cannot be that simple" attitude. Don't get me wrong, the image I made is just a very rough concept - it would take me way too long to do it all in 3D animation so that it can be perfectly clear what happens with photons upon their polarization, I think you should be able to do that in your mind fairly easy.

Again, my concept is based on the ideas of Maxwell and not really compatible with stuff like GR which came later on. But I smell a closed loop here - Einstein was clearly displeased to say the least with the very notion of FTL since it violated his theories, but it is potentially his theories which led to the very concept of entanglement due to the fundamental disability to explain the mechanics of certain processes. What if Maxwell was right and Einstein was wrong - he would be happy in his grave there is no "spooky" action at a distance, no FTL interactions to violate his theory, but in the same time this would prove his theory as wrong, since it was GR's inability to bridge the gap between classical and quantum mechanics and left QM in obscurity to the point no man can explain how it works through the prism of Einstein's scientific legacy. And just to make sure - I am not proposing pseudo science here - Maxwell is NOT a pseudo scientist, not by a long shot, I merely propose some of his "discarded" ideas were actually worth keeping, since they can easily be quantized and explain QM in a laughably simple way. That would however make about a century worth of science pretty much obsolete, which is a tough pill to swallow, especially since that science consists the academic baggage scientist base their credentials on. And sure, there is always the argument "Science could not have been wrong for over a century, look at all the technology we've come up with" - however, everything from the world electric grid through logic gates and the chips they make, radio communications, robotics and practically the very backbone of modern technology traces its origin to one, named Nikola Tesla - a person who not only denied, but heavily criticized, even ridiculed Einstein's ideas, and as famous as Einstein is, the number of his practical inventions is zero, and I for one believe science is not a popularity contest, science is about practical implications... I really do hope this doesn't get interpreted as "scientific blasphemy" as it often happens. I am just being objective.

Sure, I feel you, you - a PhD in science have a really hard time believing a nobody could get something no man of science has managed to, just as I as a Muaythai instructor have a hard time believing a 5 year old can just come and beat me up...

 

[Joncon]

afstgl,

Let's say we have two entangled, polarization correlated particles. Both pass a polarizer set at 0 degrees to the vertical.

How would you explain them giving the same results i.e both 0 or both 1?

Because the way I understand it (and I may well be wrong, I'm only starting to learn this stuff), either the polarization is undetermined, in which case each particle has a 50/50 chance of passing the polarizer, or the particles have definite unknown polarizations, in which case they should follow Malus' law.

 

[SpectraCat]

My example would be equally valid with correlated "entangled" particles as well, do you really fail to understand my idea, which perfectly explains the results of the experiment in a way even a kid would probably get it right away? Why is that I feel a kind of "it cannot be that simple" attitude.

It doesn't explain anything, for reasons that have already been explained to you several times on this thread. It starts from a premise that is known to be false, namely that the individual particles in entangled states have well-defined properties. Everything in your "model" falls apart unless you can assume that. Furthermore, you assume a mathematical relationship between the results and the measurement angles without any justification or mathematical derivation. Until you have read and appreciated Mermin and Bell, there is really nothing left to talk about.

 

[afstgl]

Joncon - Yes, particles may fail to pass the polarizer and get absorbed by it, but in case they are the right polarization to pass the filter their quantum correlation will be +1 - they should remain correlated.

In my view there isn't any entanglement to begin with. Good old electromagnetism all the way.

SpectraCat - just as well you start with the premise it is a phenomenon, making it unexplainable, I simply state it is a phenomeNOT which renders it explainable in a classical way. Also, I am not a mathematician, perhaps you or someone else could translate my simple idea in a complex language, so that smart people can get it too :)

 

[Joncon]

Joncon - Yes, particles may fail to pass the polarized and get absorbed by it, but in case they are the right polarization to pass the filter their quantum correlation will be +1 - they should remain correlated.

But they don't need to be the "right polarization" do they? As long as the difference between their polarization and the polarizer is less than 90 degrees, they have a chance of passing through. And if there is no entanglement, then the results of the measurements won't correlate 100% of the time.

 

[afstgl]

Even so, if you want to confirm the result, you will have to it to both particles, both will still be subjected to the same transformation and measured at 0 degree relative to each other, thus correlation is +1

My questions is what would happen if both particles get polarized in a different manner and still measured at the same degree, if that is even possible, and if it is, what will the correlation be, +1 or 0?

 

[Joncon]

Even so, if you want to confirm the result, you will have to it to both particles, both will still be subjected to the same transformation and measured at 0 degree relative to each other, thus correlation is +1

Which transformation is this?
Here's an example: -
Two particles, A and B, are entangled. Let's suppose they are polarized at 45 degress to the vertical. A goes to Alice, B goes to Bob. Both measure at 0 degrees (how do I do a "degrees" symbol anyway?) so each has a 50/50 chance of passing the polarizer.

So the possible results are
A B
1 1
1 0
0 1
0 0

But in experiments the results are always one of the following: -
A B
1 1
0 0

So what happened to the other possible results?

My questions is what would happen if both particles get polarized in a different manner and still measured at the same degree, if that is even possible, and if it is, what will the correlation be, +1 or 0?

Well if they had different polarizations they wouldn't be entangled would they?

 

[afstgl]

Well, as far as I am familiar with, experiments rarely use single measurement, lots of measurements are taken and summarized in a statistical way. In case any, and naturally both particles fail to pass, you get nothing or garbage data that is irrelevant, both particles have to pass through to return a result, and if both pass that result will always be quantum correlation of +1. What happens to the other possible results - well, you simply have no way to come up with a result unless both particles pass through and get detected. It is practically impossible to get correlation -1 - all those get "selected" out by the test equipment...

 

[Joncon]

Well, as far as I am familiar with, experiments rarely use single measurement, lots of measurements are taken and summarized in a statistical way. In case any, and naturally both particles fail to pass, you get nothing or garbage data that is irrelevant, both particles have to pass through to return a result, and if both pass that result will always be quantum correlation of +1. What happens to the other possible results - well, you simply have no way to come up with a result unless both particles pass through and get detected. It is practically impossible to get correlation -1 - all those get "selected" out by the test equipment...

Of course. I'm not talking about single measurements. What I'm saying is that the measurements at the same angle, regardless of how many you do, always correlate.

And it isn't always necessary that the particles pass the polarizer. Alain Aspect has done experiments using two-channel polarizers, whereby the particle goes one way or the other, so it is always detected - http://arxiv.org/ftp/quant-ph/papers/0402/0402001.pdf"

Again, the results match QM predictions.

 

[Delta Kilo]

afstgl,

You appear to be working down the list I gave previously. At the moment you are at the second-last point of it.

Yes, a classical model of it, like the one on your photoshop slide, is possible. Here is a simple example: when the particles are created one gets random polarisation and another gets the exact opposite of it. The outcome of the measurement is +1 if the angle between particle polarisation and detector is < 90 and -1 otherwise: result=sign(cos(Aparticle-Adetector)). This model will describe the process qualitatively: You get perfect correlation when the detection angles are the same, completely random results when they are at 90 degrees and something in between for all other angles.
But, as I said, this is not the weird bit.

The trouble is, this model produces linear dependency between angle and coincidence rate while QM predicts and experiments confirm cosine-squared dependency. And then Bell tells us that NO classical theory can possibly produce cosine-squared law and on the other hand Aspect puts actual experimental error bars on the graph which fit QM predictions nicely and are far away from the classical limit.

So the problem, the weird bit, is just this difference between the two curves on the graph. It may seem like a minor technical detail but it got people like Einstein all worked up.

Of course, to get to this point, it is not sufficient to just "visualize the process". One has to get their hands dirty with math to see the conflict here. On the positive side, both EPR and Bell's papers are quite readable.

 

[afstgl]

Well, that is just the thing, QM prediction are derived 100% experimentally, there is absolutely no math involved in the derivation of the cosine curve, abstract math is only used to formulate the predictions, not to derive them.

Going back to the slide shot you attached to your last post - it says "No ... theory (in the spirit of Einstein's ideas) can reproduce QM predictions..." - I put the critical aspect of it in bold - it is that potentially flawed spirit of Einsteinian ideas which suggests a linear curve. Maxwellian view of spacetime fabric and EM radiation's mechanics of mediation along it do not. In this case the nonconformity of the result is direct evidence against the validity of Einstein's work - his theory is INCOMPLETE at its foundation, experiments obviously prove the dependency is NOT linear, and if that cosine curve proves Einstein's theory wrong, well then it is only natural for that theory to fail to explain why it is a cosine curve and not a linear one. Ironically or not, but it was Einstein's work, which somehow managed to swing mainstream science away from the concept of AETHER while still partially relying on it, but starting with Newton, passing through Maxwell, Lorentz, including mr. Tesla I mentioned previously and potentially many more I don't know of - those have been incorporating the concept of AETHER, and it is a fundamental property of aether which is responsible for the non-linear curve of QM predictions. You say like you mean it, but you hardly expect a common Joe like me to prove this concept to you in academic nomenclature, it would take a large scale effort to verify my claims, and effort that for SOME reason has never been attempted the last century, again, it is blind directional belief in the rightness of the doctrine that has place only in theism is observed in the scientific community, like there is no possible way for Einstein's legacy to be wrong, in the face of the fact it fails at the quantum scale and as a result "mystifies" it. What IF people like Maxwell were on the right track and people like Einstein "accidentally" derailed science from this track for the sake of simplification or whatever? You demand of me, a non-mathematician to explain in math something mathematicians fail to do... well la-de-da :)

 

[Delta Kilo]

Going back to the slide shot you attached to your last post - it says "No ... theory (in the spirit of Einstein's ideas) can reproduce QM predictions..." - I put the critical aspect of it in bold - it is that potentially flawed spirit of Einsteinian ideas which suggests a linear curve.

You do realize Einstein had quite a few ideas during his career. Many of them were brilliant, a few of them turned out to be incorrect.

it is a fundamental property of aether which is responsible for the non-linear curve of QM predictions.

Oh no. Please, no. If it is locally-realistic in EPR sense then it violates Bell's inequality, aether or no aether.

You demand of me, a non-mathematician to explain in math something mathematicians fail to do... well la-de-da :)

No, I expect you to at least read the works you are trying to disprove. I believe DrChinese has them all on his web site.
While I agree that QM uses rather fancy math, there are several derivations of Bell's inequality out there that do not require anything beyond simple arithmetics.

 

[afstgl]

First of all, I really doubt nature cares about math, people like you say nature works in math but the truth is math is written in attempts to formulate nature, more or less... Then... nature probably cares little about Bell's inequality as well, the quantum correlation curve is smooth and proportional, showing an obvious relation between relative angles and outcome.

Let me ask you this, is the curve for reflection/refraction vs angle a LINEAR ONE? If so, I withdraw my statements, but from what I was able to find on google, angle of incidence vs reflectance and refractance was not linear.

Also, doesn't Occam's razor demand the fewest assumptions as possible?

 

[DrChinese]

DrChinese - I understand your last post perfectly, it seems that it is you who cannot understand how I understand the mechanics of this experiment, perfectly logical without any hidden variables at all.

It is somewhat humorous to see someone relish in their ignorance as if it is a virtue.

Your ideas are useless because they do not describe the results of experiments correctly. Of course, they may work in the limited ones you happen to pick, but there are probably a thousand others that they fail. As long as you don't want to take the time and effort to understand those, you will return to the same point as I predicted in an earlier post.

So let me know when you want to learn about Bell. Not that hard.

 

[dlgoff]

What IF people like Maxwell were on the right track and people like Einstein "accidentally" derailed science from this track for the sake of simplification or whatever? You demand of me, a non-mathematician to explain in math something mathematicians fail to do... well la-de-da :)

Okay. I'm a lowly QM learner. I need references. If you don't have math savvy, how can you possibility show an accidental derailment of science:

First of all, I really doubt nature cares about math, people like you say nature works in math but the truth is math is written in attempts to formulate nature, more or less...

Is that so? Give me a break. Wait. Didn't you just say "You demand of me, a not-mathematican to explain in math..."?

 

[DrChinese]

Well, that is just the thing, QM prediction are derived 100% experimentally, there is absolutely no math involved in the derivation of the cosine curve, abstract math is only used to formulate the predictions, not to derive them.

This is completely wrong, as per usual with your recent statements. But we all know you wouldn't want to be burdened with learning facts before forming opinions.

 

[afstgl]

This is completely wrong, as per usual with your recent statements. But we all know you wouldn't want to be burdened with learning facts before forming opinions.

Aren't you getting a little personal and offensive here? Of course that I care, but not about each and every "fact" especially when it is potentially a wrong one. Why would I force myself to learn something which would make me understand less?

I see a way that explains the outcome of the Bell experiment in a simple and classical way, without any "quantum magic", and you tell me this is because I don't understand and agree with a theory, which if I did agree with, I wouldn't be able to explain the experiment and instead settle for it being not a product of logic and reason, but "predictions" based on experiments...

DrChinese - you say a hidden variable theory would need a separate hidden variable for every angle. Yet experiments return a PERFECT squared cosine function, obviously no separate hidden variable is needed for every angle, since there is an obvious relation between angle and correlation, symmetrical, proportional and so on, thus only ONE SINGLE hidden variable is needed - a squared cosine function that determines odds in the picture example I posed on the previous page of the discussion.

We have a comparison between two results at a relative angle, and the outcome is a simple matter of reflection and refraction indexes for those angles in aether spacetime "fabric". I specifically asked if the relation between reflectance/refractance vs incident angle is linear, which would produce the linear result, but no one answered that question.

However, I found graphs which demonstrate not only that the relation is not linear, but closer to exponential, which makes it in agreement with my idea. At lower angles there is very little chance of -1 correlation and it progressively goes to 50/50 at 90 degree

The reason entanglement seems to be destroyed upon measurement, even if there is no such thing as entanglement, is that measurement physically affects particles and induces a change from their initial state. Measuring at different relative angles practically induces changes or transformations at those angles. In fact recently published papers proved 'Quantum Magic' without any 'Spooky Action at a Distance' in a system where entanglement was not possible and results still could not be interpreted classically
http://www.sciencedaily.com/releases/2011/06/110624111942.htm

Particles are not entangled, they are simply "synced", they are not in an undetermined quantum superposition state, they are defined from the moment of their creation, no matter whether they are correlated or anti-correlated, and it is simple, classical mechanics which determine the "quantum" correlation result according to relative angle. When particles are measured, no collapse occurs, no FTL process takes place to define their already defined at creation states, particles only get disturbed so that they are no longer in sync with each other.

Maxwell's original quaternion equations were later reduced and vectorized, and along this his concepts of ELECTROMAGNETIC TOPOLOGY were DRAMATICALLY REDUCED, eventually leading to a theory of modern classical physics which cannot explain the cosine relation between angle of measurement and quantum correlation and requires "quantum magic". That is what Bell says - modern classical physics cannot explain the squared cosine relation, but that is because of the fact modern classical physics does not account for the actual EM topology, Bell is right because he looks through a wrong prism, but without it there is nothing strange, mysterious or weird about it, those "predictions" are perfectly explainable in a classical way, without damaging the potential implication and practical benefits of this fundamental universal principle. This however, would hurt the over 70 years spent on QM, rendering a large portion of that work obsolete and unnecessary, and from my experience, science seem to have gotten overconfident and incapable of admitting an eventual wrongness. Better keep it complex and mysterious, to justify the 70+ years of research and the many millions spent, and what is more important, ensure many more millions in the future rather than falling back to a simple, classical interpretation which relies on a CERTAIN fundamental principle of physics, which will also have it benefits if applied to regular physics, not to mention finally achieve a UNIFIED physics theory and its potential benefits.

So no hidden variables, just a "hidden in plain sight" and "vastly ignored" fundamental principle...

 

[unusualname]

afstgl, these things have been discussed hundreds of times on this forum alone, you ideas are really ruled out by modern science experiments, if you don't like Bell inequalities then there are GHZ states for example which don't require an inequality to refute classical realism.

In post 1 you present a simplistic argument that is normally referred to as Bertlmann's socks after a paper by John Bell himself. That is NOT the way QM works, and this has been proved beyond doubt by many experiments in the last 2 or 3 decades.

 

[afstgl]

there are GHZ states for example which don't require an inequality to refute classical realism.

Care to elaborate?

 

[unusualname]

Care to elaborate?

This stuff is so well-known that you really shouldn't be posting here if you are not aware of modern science results, do a google search, read this article:

Going Beyond Bell's Theorem

and read DrChinese's site, he has made painstaking efforts to explain all this for several years.

 

[Doc Al]

I see a way that explains the outcome of the Bell experiment in a simple and classical way, without any "quantum magic", and you tell me this is because I don't understand and agree with a theory, which if I did agree with, I wouldn't be able to explain the experiment and instead settle for it being not a product of logic and reason, but "predictions" based on experiments...

DrChinese - you say a hidden variable theory would need a separate hidden variable for every angle. Yet experiments return a PERFECT squared cosine function, obviously no separate hidden variable is needed for every angle, since there is an obvious relation between angle and correlation, symmetrical, proportional and so on, thus only ONE SINGLE hidden variable is needed - a squared cosine function that determines odds in the picture example I posed on the previous page of the discussion.

The hidden variables denied by Bell's theorem are local hidden variables. The cosine of the angle between measurements is explicitly non-local and thus irrelevant. (We already know that cosine squared relationship--the trick is to explain it using local variables.)