from http://en.wikipedia.org/wiki/Quantum_entanglement" [Broken](adsbygoogle = window.adsbygoogle || []).push({});

so far so good. makes sense. the maximum number of mismatches (between A and C) can only be (1/100) + (1/100) = 2% A simple limit of Bell's inequality has the virtue of being completely intuitive. If the result of three different statistical coin-flips A, B, and C have the property that:

A and B are the same (both heads or both tails) 99% of the time

B and C are the same 99% of the time

then A and C are the same at least 98% of the time. The number of mismatches between A and B (1/100) plus the number of mismatches between B and C (1/100) are together the maximum possible number of mismatches between A and C.

yet in Quantum Entanglement (QE) the number of mismatches is, say, = 4%

however if there were hidden variables (in QE) the mismatch rate would be only 2% as calculated above. thus the hidden variable hypothesis weakens.

This is a chance for folks like me to understand it better. i thought the spin value is plus 1/2 or minus 1/2. In quantum mechanics, by letting A, B, and C be the values of the spin of two entangled particles measured relative to some axis at 0 degrees, θ degrees, and 2θ degrees

how is another value possible?

Let's assume x-axis. We measure spin at 0 degrees, 40 degrees and 80 degrees say.....we can only get -1/2 or +1/2 how are other values possible? what does the above mean?

between entangled photons: is the correlation not the same in all directions? does only one direction, generally, have 100% correlation? Choosing the angle so that ε = 0.1, A and B are 99% correlated, B and C are 99% correlated and A and C are only 96% correlated.

what would be the actual (relative) value of the angle where A and B would be 99% correlated?

however can we entangle photons such that say along both x-axis and y-axis (separately) the correlation (between entangled photons) is 100%?

. Imagine that two entangled particles in a spin singlet are shot out to two distant locations, and the spins of both are measured in the direction A. The spins are 100% correlated (actually, anti-correlated but for this argument that is equivalent). The same is true if both spins are measured in directions B or C. It is safe to conclude that any hidden variables that determine the A,B, and C measurements in the two particles are 100% correlated and can be used interchangeably.

If A is measured on one particle and B on the other, the correlation between them is 99%

Why does the correlation drop from 100% to 99%?

so say at some angle (and we call it 0 degrees) along some axis there is 100% correlation but as we change the angle the correlation drops? why? anything to do with Malus law?

also here we have considered only one axis. if the correlation between two photons along, say x-axis, was 100%, what correlation can we expect along y and z axis?

this is conceptually understandable from the statistical coin-flips example above. If B is measured on one and C on the other, the correlation is 99%. This allows us to conclude that the hidden variables determining A and B are 99% correlated and B and C are 99% correlated. But if A is measured in one particle and C in the other, the results are only 96% correlated, which is a contradiction. The intuitive formulation is due to David Mermin, while the small-angle limit is emphasized in Bell's original article.

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# Questions about Bell's Theorem

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