Bell Definition and 223 Threads

Moved from https://www.physicsforums.com/showthread.php?t=590249&page=3 to avoid confusion with the classical example in its OP. ThomasT and I are mainly discussing Bell (1964) here. The example discussed relates to 2 spin-half particles in the original EPR-Bohm example, see Bell (1964). The...

Imagine a bell that has only 3 ideal resonant frequencies (no damping) and I am hitting it with a point like ideal hammer, does this mean that all of the energy of the hammer is distributed among those 3 resonances? I think not, i.e. the energy stored in the resonant modes are less than the...

Suppose that IQ scores have a bell shaped distribution with a mean of 104 and a standard deviation of 14. Using the empirical rule what percentage of IQ scores are less than 76? Please do not round your answer. So far this is what i have 76 -104= -28 -28 __ = -2 14 *How do I...

I am confused by the role of photon polarisation in Bell inequality experiments. The original logic of EPR as I understand it is based on the HUP such that QM predicts that measurement of momentum on one particle should affect the measurement of position of the other particle. Yet across...

So I've been reading a lot about Bell tests. I have a question that I can't seem to find an answer to. The tests indicate that a photon decides to be horizontally or vertically polarized at the moment of detection. What are they basing this on? To make such a counter-intuitive assumption seems...

what did bell show concerning the existence of a local hidden variable model for quantum physics?

If you follow some of my posts, you probably already know that I am a big advocate of Bell's Theorem. I thought I would share a little exercise that shows another aspect of why it is important. Deposited today in the preprint archive was the following article: Waves, Particles, and...

It is said that experiment which unproves Bell's unequation does not unprove Bohm hidden variables. To me Bohm's interpratation seem rather unbeliveable. But it should exist experiment which could unprove it. Which is this experiment? Maybe it is enough that Bohm equation does not work in...

Two years ago an intriguing paper of De Raedt's team concerning Bell's Theorem appeared in Europhysics Letters (http://arxiv.org/PS_cache/arxiv/pdf/0907/0907.0767v2.pdf). Now (officially next month), an elaboration on those ideas has been published: Hans De Raedt et al: "Extended...

Hi All, I'd be interested in your thought on this classical Bell test by Hans de Vries. http://www.physics-quest.org/Bell_inequality.pdf" Cheers

This topic came up in another discussion and I said I’d start a new thread for it. I had speculated that to experimentally demonstrate Bell violations, you needed particles in the spin singlet state; in particular, photons in the spin triplet state would not be especially distinguishable from...

Taken from an earlier thread: "If the two devices are aligned in matching orientations (in opposite directions to allow for the initial state), then QM says that 100% of the results should match. If either of the two devices is turned at 90 degrees to the original orientation, then QM says...

Hi Can anyone direct me to a recent review article of tests of Bell's inequalities. As recent as possible Thank you

Brian Greene describe an experiment in his book "The fabric of the cosmos" pretending to illustrate the Bell test experiment. I spent hours trying to understand it until I decided to write a small simulation to finally realize that the experiment is completely flawed ! After doing some...

I will be going to university next year and I've really fell in love with the idea of working somewhere like the old Bell Labs. What I want to know is... Is there a modern day equivalent to Bell Labs (anywhere in the world) or have I created an unattainable dream, rooted in a long forgotten...

Hi, I was reading Heinz Pagels' description of the nail gun experiment in the chapter about "Bell's Inequality" from his book, The Cosmic Code: Quantum Physics as the Langauge of Nature, 1982, pp. 160-176. He describes the record of hits and misses after "turning polarizer A clockwise by...

How do you do a Bell measurement on a state that doesn't have a power of 2 number of qubits? I've got GHZ states like this: |GHZ_{ijk}> = \frac{|0_{i}0_{j}0_{k}> + |1_{i}1_{j}1_{k}>}{\sqrt{2}} And I'm trying to Bell measure the following state at qubits 2 and 3...

Is it true that the fast food restaurants Taco Bell, KFC, Pizza Hut, Wingstreet, Long John Silver's restaurants are operated by one single company called Yum!? This would mean that if one is going to boycott Pizza Hut for some policy, then they should also boycott other brands as well to make...

I wanted to point out some links I found hugely useful and mind expanding. Apologies if this has been posted before (I did search for GHZM). I've always found my eyes glazing over when trying to follow the derivation of Bell's Inequality, so I was very impressed when I saw this Sidney Coleman...

I just purchased a condo built in 1992. The door bell is fine in that I get the ding-dong sound. However, attached to the door bell is a small box with DIP switch selectable music. This box has wires labeled FRONT, REAR, and TRANS. The wires were attached to the to the corresponding wire on...

Towards the end of http://www.youtube.com/watch?v=IAgV-LKTiMI&feature=channel" video at 54:55, the professor defines the four possible states of two entagled electrons as follows: singlet |0,0> = |u,d> - |d,u> triplet |1,1> = |u,u> |1,0> = |u,d> +...

I am opening a new thread to continue discussion of some interesting ideas around EPR and Bell. Specifically, this is about the idea of realism, and whether it is tenable in light of Bell and other HV no-go theorems. Note: I usually use Hidden Variables (HV) and Realism interchangeably...

I apologize for the vagueness of my question, but a more specific version would not fit in the thread title box: How widely accepted is the rejection of local realism due to violations of Bell's theorems? I also have two follow-up questions: How does a rejection of local realism...

I am writing a system that collects values from our devices (CRAH, Generators, etc) compute the trend of the data, and determine if an alarm should be raised. For testing I have a point generator and I want it to follow fairly realistic norms. Currently I generate a new point as: p.Y = p'.Y...

For several years Joy Christiaan has been publishing about the disproof of Bell in a typical EPR setup, his latest (?) publication being http://arxiv.org/PS_cache/arxiv/pdf/0904/0904.4259v3.pdf" . In a nutshell his argument is that Bell uses an invalid topology for the EPR elements of...

Hi guys, first post, sorry if it's in the wrong place. Frequent visitor, you seem to help pretty comprehensively. I'm using mathematica to calculate a bell inequality, with a general noisy quantum state. However, when I evaluate it, I get a sequence with an a in the result.. which isn't a...

Does the Bell inequality confirms the quantum mechanics? If answer is yes, why the violation of Bell inequality is more famous?

I'm slowly working my way through what I need to really understand the Bell papers. Everyone says that a good start is the EPR paper. I understand that Einstein may not have read the final version before publication and may not even have wanted his name appended (sort of convoluted logic and...

I have trouble finding the following information on the coincidence counting in a Bell experiment: - Is there a fraction of single photons (not entangled) produced in the experiment and how are the final results corrected for this? - No-hits on both side can never be counted (nothing is...

Hi all ! What chronology of Bell inequalities testing ( their violation ) ? What positive and negative aspects of each experiment ? What experiments have been spent latest years ? Some material: http://arxiv.org/PS_cache/quant-ph/pdf/0310/0310192v1.pdf Thanks.

The Fair Sampling Assumption, as commonly discussed, is implicit in Bell tests: As long as detection efficiency is less than 100%, the observed photon pairs are a representative sample of the total universe of emitted pairs. At this time, no Bell test has satisfactorily closed both the Fair...

A bell of diameter 3m and bulk modulus of 14x1010N/m2 is toss into the ocean. By how much did the diameter decrease as it sank to a depth of 10km? The bell is assumed to be a sphere of diameter 3m. Well o what i did was to calculate the pressure at the depth of 10km so P=Po+\rhogh which gives...

1. Are there any tests done actually show Bell inequality is NOT violated? 2. What are the different kinds of things the Bell inequality experiment test? I know most tests are testing spins of electrons, what are the other Bell tests, what they test?

Hey guys, hope your all well. Was wondering what people make of the claims made in the paper 'Disproofs of Bell, GHZ, and Hardy Type Theorems and the Illusion of Entanglement' by Joy Christian ( http://arxiv.org/abs/0904.4259 ) where he claims ''An elementary topological error in Bell's...

Hi I am looking at Quantum Computation by Neilsen and Chuang at the CHSH inequality. Looking at the spin singlet state they make measurements of for example the observable Z1 and Z2-X1 and then find the expectation value of the product. I am slightly confused here because a) Z and X are...

Homework Statement At the surface, where the temperature is 27 °C, the volume of air in Dan’s diving bell is 2 metres cubed. When he descends to a depth of 10 m the pressure doubles and the temperature drops to 7 °C. What volume of air does Dan have in his diving bell now? Homework...

I recently read about the pilot wave theory and the Bohm interpretation, and I must say I really like the idea. The only of my confusions it leaves unchanged are those concerning the EPR paradox. The Bohm interpretation does not seem to answer the question of the dreaded spokhafte Fernwirkung...

This is not true. If the coins are designed in such a way that they are biased to produce those results at 120 degrees apart, it would not be at odds with probability. The problem with bells theorem which many people still fail to realize to their own undoing is that it is only valid within...

How do I calculate the frequency of an 8.5 cm diameter bell ? The bell is cast brass for resonance, but I intend to activate it with a buzzer so sound will last for more than a few seconds. Does the weight affect anything other than volume ? I intend to use it inverted, supported near the "top".

Homework Statement A large bell is hung from a wooden beam so it can swing back and forth with negligible friction. The center of mass of the bell is 0.65m below the pivot, the bell has mass 37.0 Kg, and the moment of inertia of the bell about an axis at the pivot is 19.0 kg*m^2. The clapper...

So first off, Ill admit I've forgotten most of the finer details of the bell inequality so I apologize if I've gotten something wrong. From how I remember it, the bell inequality is a test of any local hidden variable theory vs. QM. It uses the fact that the inequality measured if a classical...

http://blog.wired.com/gadgets/2008/08/bell-labs-kills.html" Six Nobel-prize worthy research came from that lab, including the invention of the silicon transistor, and the laser! It was a business decision by the parent company but, I think it's a very myopic business decision to abandon...

[SOLVED] Fluid Mechanics Homework Statement You are designing a diving bell to withstand the pressure of seawater at a depth of 230. a) What is the gauge pressure at this depth? (You can ignore changes in the density of the water with depth.) got 2.32x10^6 Pa - masteringphysics said...

Two questions about Bell that relate to things that I learned in philosophy and subsequently make it difficult to understand Bell's claims. First, Bell says he has 3 assumptions and that one of them failed because his inequality was violated. I gathered that proof by negation was invalid in...

Homework Statement During a test dive in 1939, prior to being accepted by the U.S. Navy, the submarine Squalus sank at a point where the depth of water was 73.0 m. The temperature at the surface was 27.0 C and at the bottom it was 7.0 C. The density of seawater is 1030 kg./m^3. A diving bell...

I have the next theoretical-practical problem. I have to build a tubular bell array (like that at symphonic orchrestas) with tubes (not rods) of aluminium or copper. The principal problem I have is I don't know how to state the wave equation for a tube (I have done it for a string). How I do it...

This is not a homework problem, I hope I am in the right forum. Suppose a magnetic field is applied long enough so that the spin up particles acquire a phase of Pi/2 expressed as i=squareroot(-1). How does each of the four bell states transform under this phase gate. What is exactly...

...but they just didn't call it such. :rolleyes: Interesting story: http://scienceblogs.com/catdynamics/2007/08/schisler.php

We have a local telephone company complaining to our utility that they have noise on their system. We have investigated and found a fairly significant 9th harmonic on the power line. This seems to play havoc with phone systems. What is a likely cause of a 9th harmonic? We are a rural utility...

Hey, I was wondering about a scenario, perhaps you can help me. Imagine a bell hung from an arbitrary pole in which the friction of the bell-pole junction is known. Assume this bell and pole are in a clean room of known atomospheric density and pressure. Orthogonal to the plane of the pole...