Recent content by Badvok

Where is the border between the quantum system and the macro world?

I'm only a novice with this stuff but I'd guess that it is when the photon is detected, i.e. when it interacts with the detector and thus the energy transforms into an electrical signal.

Thanks again for all your help with this. If anyone is interested I've knocked up a little JavaScript model to play with the various assumptions so you can see the effects they have (though of course nothing allows you to get closer to the quantum predictions/real test results). You can even...

OK, it doesn't matter what factors affect the measurements so long as they are the same for both and not linked to the observer setting. If they were slightly different, e.g. magnetic field strength, then that would simply affect how close to perfect correlation the experiment could get but it...

Thanks, but Bell then goes onto express an expectation value as the integral with respect to λ of the product of A, B, and the probability distribution of λ. Again, I'm unsure how that can work when there are different λs.

Sorry, I guess this is maths that I don't understand, how can A(a,λ)=a+Q+R not include S when S is part of λ.

I don't understand that text, if λ can include factors that are 'local' to each of the measurement devices how can you get a function A(a,λ) that doesn't depend in some way on b? He also says that "our λ can then be thought of as initial values of those variables at some suitable instant", but...

So there isn't just one set of variables λ then? i.e. in the two functions A(a,λ) and B(b,λ) the λ isn't actually the same thing?

I haven't a clue! What I don't get though is how Bell proves that it would be impossible to do so. My understanding of his formulae seems to indicate that they don't take account of possible LHVs that are part of the measuring devices, i.e. why is there just one λ and not a λa and λb? Telling...

But that is exactly what I don't understand, how can I completely ignore that? Haven't we known for ages that a photon polarised at θ will only pass a polarisor set at angle α with a probability proportional to cos2(α - θ)? So it is possible that one device would influence in one direction and...

Yes, I see that. However, is it not true that in a case like testing photon polarisation A(λ,a) would depend in part on something in the measurement device, i.e. λ would be likely to include a LHV from the measurement apparatus?

OK, I still seem to be having a problem expressing the points that I'm stuck on, here's another attempt. (Please note that I have no doubts whatsoever that QM predictions tally with experimental results - that sort of thing is unquestionable for someone at my level.) EPR talks about...

This is a step that I have trouble understanding. Why are we reducing it to + and -? Why is there a preset limit for saying it is + or -? I don't see how that comes from EPR. The + and - are simply limits imposed by the experimental apparatus and I can't see how they are in themselves elements...

You actually hit the nail on the head with that statement about the measurement. In all the examples the possible outcomes of a measurement are taken to be the 'elements of reality', this is the same assumption I think Bell makes? In the EPR paper it says: "If, without in any way disturbing a...

Thanks all for your assistance with this but it looks like I'm falling between two stools. On the one hand I see simplified explanations that make assumptions that I can't clearly see the validity of, on the other hand my mathematical ability is not up to the required level to read and fully...