Bell Definition and 230 Threads

I quoted these post from other thread. I don't want to distract discussion in other thread so I'm starting a new one about statements in these posts. Basically the question is if we can violate Bell inequalities by two separated but correlated systems that can be as non-classical as we like (as...

Did they manage to do a loopholes free Bell test ? The best I got from google was an article from february that says no , they only did one where 2 out of 3 loopholes were eliminated in one test.

Hi, In all the discussions about EPR, Bell's inequality and interpretations of QM locality seems to be a property that nobody likes to drop light-heartedly. This is somehow understandable since SR is an extremely successful theory. But SR only says that we cannot transmit information faster...

Homework Statement A cyclist with a bell ringing with a frequency of 659.7 Hz drives towards a wall with a speed of 8.15 ms-1. Just before colliding with the wall the cyclist hears beats, due to the bell itself and the reflection of the sound from the wall. What is the frequency of beats...

Homework Statement A cylindrical diving bell with open bottom and closed top 12.0m high is lowered into a lake until water within the bell rises 8.0m from the bottom end. Determine the distance from the top of the bell to the surface of the lake. Homework Equations I actually solved this...

i found the following proof of Bell's theorem : we measure spin in 3 different directions a b c we can note the counting of events N1=n(a+,b+,c+) N2. + + - N3. + - + N4. + - - N5. - + + N6. - + - N7. - - + We have N3+n4<=n7+n3+n4+n2 With n3+n4=p(+a,-b)...

if we consider a separable measurement operator $$(A+A')\otimes (B-B')$$ then quantum mechanics predict the result is in [-2;2] Whereas going to classical results would give in [-4;4] This could indicate that going from measurement operator in the quantum realm to measurement results is maybe...

In section IIIA (p11) Max Tegmark tries to prove that the integrated information Φ of a bell state is zero. The definition of Φ that Tegmark uses is given by the mutual information I minimized over all possible factorizations. The bell state has I=2 when written in the usual basis. Tegmark...

I believe length contraction always makes more sense when integrated with reminders of relativity of Simultaneity. Let's say the engines are at the back end of each rocket. For the viewer "A" in the initial frame, they begin moving and continue accelerating simultaneously, and clocks next to...

I was trying to understand Bells theorem and I found this site http://www.upscale.utoronto.ca/PVB/Harrison/BellsTheorem/Analogy.html easy to understand. I found the "The Second Analogy: More Boxes" in it easy to grasp. But one thing I didn't understand in it, where it uses the word random...

Although he is primarily an astrophysicist, Dirac medal-winning Oxford Professor James Binney has taught a Quantum Physics course to second-year students at the university for years. A series of 27 of his lectures for the course is featured on the university's official website. Binney's take on...

http://arxiv.org/pdf/1308.5290v2.pdf I'll just highlight some stuff " "We submit: Doesn’t quantum theory itself, which is a local theory, account for its own predictions? As the authors of this quote know very well, experi- mental data contradict Bell’s theorem [22,23], which im- plies that —...

Is here any progress on explaining Bell's Inequality? I do not mean explaining what it is, I mean how it works.

Hi All, I'm in the beginning stages of writing a quantum computer emulator, primarily to get all the concepts down. I've got an excellent Bloch sphere with a Bloch vector that I can duplicate as many times as I like. However, I'm now tackling entangled states. I'm struggling with identifying...

I went through a paper last week about the Bell inequality and how it is incompatible with QM. Something along the lines of probability in classical regards being 1/3 but in quantum mechanics it is 1/4. It went into some basic principles of how this is determined through quantum entanglement to...

Hey I am new here and not exactly sure how it works. I am stuck on this problem from my professor and would love any help anyone has!When one thinks of the normal distribution the first thing that comes to mind is the bell curve and grades. While this is one example of a normal curve that is...

Are there any equations you can use for the bell jar experiment? Any answer would be appreciated thanks

If we start with a Bell state 1/Sqrt(2)(|00>+|11>) and (after moving the second qbit a significant distance away) apply the interferometer transformation |0> -> 0.5(|0>+|1>) |1> -> 0.5(|0>-|1>) to the first qbit, we get 0.5/Sqrt(2)((|0>+|1>)|0>+(|0>-|1>)|1>) =0.5/Sqrt(2)(|00>+|10>+|01>-|11>)...

i have the following questions: Bell inequalities use spin 1/2 matrices and experiments use photons. Is then the electric field horizontal or vertical after the measurement with a polarizer in other words can we assimilate the orientation of the field with a vector in the hilbert space ? How...

Seriously, a 5 year old asked me whether entanglement information survives/escapes a black hole. Specifically, he asked me (in only slight paraphrase) whether if one of the particles (headed in different directions) fall into black holes on either end, does the other one know it?

A cylindrical diving bell 3.4 m in diameter and 4.5 m tall with an open bottom is sub- merged to a depth of 148 m in the ocean. The temperature of the air at the surface is 22C, and the air’s temperature 148 m down is 6.3C. How high does the sea water rise in the bell when the bell is...

Raw data sample source: http://people.isy.liu.se/jalar/belltiming/ 999 detections parsed in .txt format: http://www.mediafire.com/download/1pi64hrydzs7r7h/bell999.zip This below is the first 99 detections. It's unmatched raw data, so A-B pairs on the right are going to be different once the...

There have been quite a few Bell threads lately, so I have been looking at them and various other sources. I'm missing something... any guidance appreciated. Per Dr. Chinese's, "Once any photon passes through a polarizer lens, its polarization will be aligned exactly with the lens thereafter...

There are several threads on the Bell paradox, plus the article in the FAQ forum, but I must be missing something here. Forget for a moment about 2 ships. Let's take one ship, which an observer at the front and the other at the rear. The ship is undergoing a constant 1G acceleration. The...

As a high schooler, what I can deduce from Planck's distribution's bell shape is that the majority of the atoms of a body above 0k possesses a certain K.E which is the average K.E which leads to the presence of a peak point in the distribution. While the minority posses higher or lower K.E...

I was searching the internet for information on Bell tests, when I found an article entitled "Taco Bell tests grilled stuffed nacho." Does anyone know how the stuffed nachos are used in Bell tests? http://www.huffingtonpost.com/2013/10/11/taco-bell-grilled-stuft-nacho_n_4086345.html...

Are there any modern interpretations of QM that predict the correlations in a Bell Inequality violation ? Preferably a local non realistic model based on mechanisms.

Hi, I was just writing another thread when I stumbled upon something strange: What if I now make a slight change and replace ##\bf{b}\rightarrow-\bf{b}##? The expectation values containing ##\bf{b}## change signs and I get $$\left|\frac{1}{\sqrt{2}}-0\right|=\frac{1}{\sqrt{2}}\leq...

This form of a Bell inequality: n[x-y+] + n[y-z-] ≥ n[x+z+] is derived from spin measurements at A and B when detector settings are aligned. If it is correct that when a particle is measured at detector A and is spin up in the y direction , then its entangled twin at B is in superposition...

Invariably in the lay literature when it comes time to show that EPR hidden variables are incompatible with QM, Bell's Theorem is invoked (e.g. Greene's "Fabric of the Cosmos", Zeilinger's "Dance of the Photons", Rosenblum's "Quantum Enigma", ...). I don't see why a simple application of...

Kochen-Specker rules out non-contextual hidden variable theories and Bell's theorem rules out local theories. I thought this was an interesting paper, particularly the authors' conclusions: Simultaneously testing the Kochen-Specker and Bell theorems http://arxiv.org/pdf/1308.6336.pdf

I look at wikipedia.org/wiki/Bell_state and use the same notations. The article says that there are just 4 Bell states. Is not |\xi^+\rangle = \frac{1}{\sqrt{2}} (|0\rangle_A \otimes |+\rangle_B + |1\rangle_A \otimes |-\rangle_B) another maximally entangled state? The Schmidt decomposition...

Bell theorem say that there is a contradiction between the locality principle in special relativity theory and quantum mechanics.So one theory must be incomplete describable theory.Then which theory(special relativity or quantum theory) is incomplete describable theory?

The Bell theorem (and its variations) suggests that either locality or reality is wrong. The PBR (Pusey-Barrett-Rudolph) theorem (and its variations) suggests that quantum state is real (ontologic). So what do they tell us together? Do they suggest that eventually it is only locality which...

I was looking to the definition of the Bell curve, and the Gaussian distribution, but I don't see any difference when we represent them in a graph. Both have the same Bell curve. What is the difference between the Bell curve and the Gaussian distribution?

Given two spin-1/2 particles, the overall spin of the pair decomposes into a spin singlet and a spin triplet. Using the Clebsch-Gordon series and referring to the z-axis, we find the spin singlet is: ##|\Psi^- \rangle = \frac{1}{\sqrt{2}}(|\uparrow_z \downarrow_z \rangle - |\downarrow_z...

I have a question regarding the paper by John Bell (www.drchinese.com/David/Bell_Compact.pdf‎ ) in which he shows that a certain hidden variable approach cannot reproduce the expectation values predicted by QM for a pair of particles in the singlet state. After eqn 15 on page 4, I don't...

Homework Statement Basically, in a homework question, I'm presented with the definition of bell states and asked to show some elementary properties. I've been able to show they form an orthonormal basis, and express them in terms of the usual basis, |00>, |01> |10> |11>. I am then asked...

Hi I have three states (I believe bell states) and want to find the density matrix, am I right in thinking: 1) \frac{|00> + |11>}{\sqrt{2}} \rightarrow \rho = \left( \begin{array}{cc} \frac{1}{\sqrt{2}} & 0 \\ 0 & \frac{1}{\sqrt{2}} \\ \end{array} \right) (because it is pure) 2)...

Is this possible? If I have, say a photon and two non-orthogonal polarizations \mid0\rangle and \mid1\rangle, can I create a Bell state \mid10\rangle+\mid 01\rangle If not, what is the reason? Thank you :)

I imagine that some topics and questions keep reappearing since it is hard to track through all past posts even with the query tool. So apologies if this has been covered before (as it probably has). I just want to check my intuitive understanding of the Bell experiment, having heard an...

Morrobay suggested we split off this discussion from another thread. I will post my summary of the EPR definition a bit later today.

I keep looking at these experiments that demonstrate violation of Bell's inequality and I really can't figure out why anyone cares. The scenario always seems wrong in some way. For example the EPR paradox. The argument goes like this, if you start out with a source of entangled "photons"...

Regarding the polarization correlation studies generated using parametric down conversion. All the studies appear to be done correlating the polarization of linearly polarized photons. Has any experiment been done showing the same effect with circularly polarized light? 1) If this...

Consider the following thought experiment. Two spaceships are initially floating in a region of space far removed from other matter. They are at rest with respect to each other, and with respect to some inertial reference frame F. There is a distance L between them. At some time, t=0, as...

Our math Teacher asked us to find how many equivalence relations are there in a set of 4 elements, the set given is A={a,b,c,d} I found the solution to this problem there are 15 different ways to find an equivalence relation, but solving the problem, i looked in Internet that the number of...

After reading a bit about Bell's theorem and various hidden variable theories, I thought a little about the detection loophole, and how it gets around Bell's theorem while still allowing a pretty much 'local' Universe. The main argument against this, as I understand it (correct me if I'm wrong)...

Lately I was studying the Bell and CHSH inequalities on Wikipedia (it has proven to be a good source to get an quick idea about everything). The articles are detailed and even provide the core of the proof in a mathematical derivation that is easy to understand. But it leaves me still with a...

describe how an electric bell operates (HINT: the make break contact dose not move; the hammer, however, moves bath and forth very quickly as it rings the bell) my solution An electric bell is a mechanical bell that functions by means of an electromagnet. When an electric current is...

Hi, I have a question regarding quantum teleportation. I understand that Alice starts of with a photon A whose state she wants to teleport. Alice and Bob share an entangled pair of photons, B and C. Then Alice does something called a Bell measurement which entangles A and B and the result...