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Of course I ask for it. Because I want to clarify what you mean. For you obviously 'theory' means 'any opinion somebody has'. I know about a lot of thoughts and thought constructs that are called 'theories'. But we need to clarify what you mean with it. (And of course, as academic philosopher, I know what philosophical theories are). I am also pretty good in recognising unsubstantiated ideas, and distinguish them from empirically justified ideas. This is just plain wrong. I won't discuss this with you anymore. You can only convince me by linking to reliable sources. But I already know. No physicist will agree with you. Ask here. Enough physicists around. 'Controlled randomness' is an oxymoron. The only two possibilities I know of are 'pseudo randomness' and 'real randomness': latter category is the domain of QM. That is not what we are discussing here. We are discussing if there is real randomness. And exotic interpretations of QM aside (Bohm's implicate order, or Everett's many worlds interpretation), there are QM events that are really random. Your unsubstantiated idea has no roots in actual physics. Made the important abbreviation bold. Your opinion contradicts experiment.

Philosophy already has that covered. No need for redundancy. No, no, philosophy does not cover 'truth'. At most it is concerned with the concept of truth, which is something different. Philosophy does not find true propositions about the world. That is science' business. But it does formulate true propositions about our thinking about the world. So it can clarify about methods, concepts, etc of our thinking, also the thinking in science. So my 2 cents as philosopher: the concept of 'truth' suggests as if it something 'out there'. But it isn't. It is a relationship between propositions and praxis (that can be empirical, or ethical, maybe even aesthetical). In the case of science these propositions refer to empirical facts. But as mentioned above, the model behind the facts is just that: a model. Its success lies in the possibility to make predictions, not in that it is a perfect image of reality. No better illustration than the succession of scientific theories, which empirical predictions become more and more comprehensive. But 'The Truth' is a mirage we should get rid of.

... and we have based technology based on it. And you, Randolpin, are using it now. The models made in science make empirical predictions that can be tested. That does not necessarily mean that these models are 'The Truth': but the empirical conclusions from it are confirmed experimentally. That means you can trust these empirical results. Of course you need belief. You must belief that thousands of physicists are not lying; that they did their work correctly. And one reason is what Phi for All so clearly stated: experiments are repeated, especially when they are nearly unbelievable, like Bell tests. Remember cold fusion: many groups tested Fleischmann's and Pons' claims, because if it were true the chances for our civilisation would be enormous. It was not enough just to say: "We don't believe it because it does not fit to our present models". So there is a 'cleansing mechanism' in science, especially in the hard sciences. It may not take effect immediately always, but in the end false claims will be unmasked or corrected. Throwing over a general accepted central theory in science will guarantee you a Nobel-price. (Oh so different in ideologies and religion...)

Of course. I did not say such a thing. I said that you can expect that when posting on a science forum people interpret 'theory' as 'scientific theory'. And so that you should be clear in your language. Take an electron as example: measuring the spin of individual neutrinos is notoriously difficult, as measuring neutrinos itself is already extremely difficult. The point is that we know that the absolute value of the spin of an electron is always 1/2. But dependent on the circumstances we will find different directions. If we measured it before in the up direction, and it was +1/2, then we know we will measure +1/2 again if we do it again in the up direction. But if we measure it exactly 90⁰ left, we will have no idea what we will measure. Chance of +1/2 is 50%. So in that case it really is completely random. And the Bell theorem shows that there are no properties of the electron that will determine if the value will be +1/2 or -1/2. So any local variable theory is doomed to fail. There is order in the universe. QM predicts very precisely in which limits there is a bit of randomness. I still don't understand why you conclude from 'a bit of randomness' to 'no order at all'. I have no idea what you are asking. So to guess a little: we have a lot more knowledge than zero. But there are some limits in the domain of QM, and we know exactly what these limits are.

Here you are again. If you want to philosophise, you must use your terms clearly. As you are posting in science forums, you can expect that people think about a scientific theory. I criticised you weeks ago already for ambiguous use of words ('effect'). If you want to have a discussion about a viewpoint of yours, then you must present it clearly. 'The theories' are obvious just opinions of people. Well, whatever people may think about local (hidden) variables, they are wrong: because science has proven that there are no local hidden variables. You cannot agree with Bell's theorem, and say that there are local hidden variables. This idea is scientifically proven wrong. If you have any other reasons, bring them in. It does not bring much if you just say something like that, and then keep silent about it.

What you fail to understand is that the empirically proven knowledge of physicists is that not any theory (already thought of or not) that contains local variables, hidden or not, can replicate the predictions of QM. It simply is not the case that some ideas, pet- or good theories, were falsified by Bell's theorem: any theory with local variables is ruled out definitely. Do you understand this? And if so, why do you still hold to the opposite?

Just as I thought. And here is the problem. QM does not comply to common sense. I find it OK if you have troubles with that. But it is a pity that you move to remarks as 'I provided these links already' or that I would understand little of QM and Bell's theorem,

Reliable sources of: - Which concrete theories were refuted by Bell's theorem? - that Bell's theorem says 'the theorem states we can't explain QM with our knowledge of physics'? Please refer to the post(s) where you gave these links.

Well, if you could support your ideas with reliable sources, then it would be OK, but otherwise... wise decision.

Again: which hidden variable theories? Name them! (But of course if there are any, they are unscientific. Because we have already proof that they cannot work. You are contradicting yourself.) Here you go again: the theories. You are fantasizing some story about the history of QM, but you fail to mention the theories. Which theories were proposed that contain local variables? What a bare nonsense. Name the theories that explicitly were disproved by Bell's theorem. Who was proposing them? When and how where they refuted? Why does Bell's theorem proved these wrong? And where is the link that says that 'the theorem states we can't explain QM with our knowledge of physics'? Slowly you are beginning to look like a troll. You evade my questions, and you do not give scientific sources that support your position.

You said: I asked: You answered: So you give a in my eyes wrong interpretation of Bell's theorem, and if I ask you for a link that supports your interpretation, you cannot give one. I am also wondering what you mean with 'The local hidden variable theories'. Which ones? Can you name a few?

Please give some more or less authoritative link for this. THX

You do not understand how strong Bell's theorem is. It is valid for any particle that behaves according QM. If it is possible to create entangled pairs, you can create Bell like situations: local variables cannot explain the correlations between measurements. (Or QM is false...) It doesn't matter if they would be made of smaller components. There is no presupposition about the precise buildup of the particles in Bell's inequalities. The only presupposition is that some attribute of the particle itself (e.g. one of its constituents, or of an attribute we not yet know of) determines what we will measure. As QM is not consistent with Bell's inequalities, we can conclude that there are no such local attributes.

I think it is pretty clear what is meant with local variables. In the case of polarised photons the question would be: is there some physical attribute of the photon that determines for a certain angle of the measuring device what polarisation will be measured? It means that when a polarised photon pair is created, both photons already have this attribute. Bell's theorem proves that if this were the case, we cannot get the predictions that QM makes. In experiments where this can be tested it turns out that QM's predictions are correct. So it proves that in these situations there are no local variables that determine exactly what the measurement will be. Of course that does not mean there is no determination at all. E.g. when both measurement devices are oriented exactly the same, I can predict for 100% sure that if I detect a photon on one side, I will also detect the photon at the other side. But on average, for random angles, QM's predictions differ from any possible theory that assumes that the measurement depends on any attribute the photons already have before measurement. This is even a finer example. Another source: MinutePhysics

Bell's theorem proves that not any possible theory that contains local variables can reproduce the predictions of QM. If you think it doesn't, then show us the error in Bell's theorem. You really should read the article Mordred linked to, I had a small glance at it. Here is its central statement: No physical theory of local Hidden Variables can ever reproduce all of the predictions of Quantum Mechanics. Follow his argumentation, and tell us where the author makes an error.

Until you prove that Bell's inequality is wrong, your words are empty. Go ahead, and get your Nobel-price. Really, the inequality is not difficult to understand, so it must not be too difficult to disprove it, and show why thousands of physicists are deluded. You argue from ill faith.

You are incredible. You show that you still do not understand Bell's theorem. Maybe I was a little ambivalent when I wrote ' Local variable theories comply to Bell's inequalities' here. So I'll try once again: Any possible theory (even a theory we haven't thought up yet) that contains local variables per definition obeys Bell's inequalities. The predictions of QM do not obey Bell's inequalities. The predictions of QM turn out to be correct in Bell test experiments. Conclusion: It is impossible that there are local variables in Bell like situations. Corrolarium: if it is impossible that there are local variables, then it is also impossible that there are hidden local variables. The interesting thing is that number 1. is the easiest to understand, if you put some concentration in it. You do not need any knowledge about mechanics, quantum or not, to understand it. Just google. Mordred's 'Chapter 4' surely explains it all, but it is not aimed at lay persons, as you obviously are one. After you understood point 1 you must believe the points 2 and 3. Of course, if you are really at it, you could learn QM, and then understand that 2 is correct too. Then you only have to believe number 3, but I am pretty sure after understanding number 2 you do not really doubt that the experiments done show exactly what they did: confirm QM, and therefore rule out the possibility of local variables. But if you do not even try to understand number 1, I can only say that your standpoint is done from ill faith. So your task, if you want to stick to your view point, is to refute number 1. If you can't, you must logically accept that it is proven that there are no local hidden variables. Any belief or opinion of yours is empty if you do not take the bull at the horns. Of course there is! We can measure when a photon arrives at a detector, we can measure the projection of its polarisation, but what we cannot do is measure its polarisation as it really was before measuring: simply because there is no local reality behind the scenes. Again, you do not understand QM enough, otherwise you would not say this. Again, only ill faith can explain you saying such things again and again. Again, a hidden variable theory might be possible: it is not ruled out by Bell's theorem. But local hidden variables logically cannot reproduce the empirically proven correct results of QM. I can only say: groundless metaphysical considerations, free flowing from any physics.

Blueyedlion, I suggest your read this small Wikipedia article on soundness. This should help you to understand what logic is, and how logical arguments (in the logic sense of the word!) differ from true statements. Oh, and, validity adds some more simple examples.

So, Itoero, when Mordred is correct: then you are just citing papers without understanding them. No hidden variables.

Randolpin, I would suggest that you start reading here. This was a topic in this forum already. But of course, if you have other insights or questions, feel free, but I for myself do not want to repeat the whole discussion.

Yes. Because the predictions of QM turn out to be correct. Must I spell it out for you? 1. Local variable theories comply to Bell's inequalities 2. The predictions of QM do not comply to Bell's inequalities. 3. The predictions of QM turn out to be correct in Bell test experiments. Conclusion: There are no local variables in Bell like situations. Corrolarium: if there are no local variables, then there are neither hidden local variables. On quantum level there is a tiny bit of 'disorder'. No idea why you think that. As you obviously do not understand the Bell theorem and its consequences, you say things that are far over your head. Let me know if it is interesting. Seems above my head. But at least I have the strong impression that has not much to do with local hidden variables.

Bell's theorem shows that no local hidden variable theory can reproduce the predictions of QM. If you leave out the word 'local', then the discussion is open. But I really doubt that we can look behind the scenes of what we observe. There are no observations we can do below the level of quantum events: we measure photons, or electrons arriving at screens or in counters. Do you suggest that there is some mechanism in photons and electrons?

No, because we have empirical proof that local hidden variable theories impossibly can reproduce the predictions of QM. You simply do not understand Bell's inequalities and the fact that QM violates them.

Yes. No.

It is mathematically proven that the predictions of QM are inconsistent with theories with local variables. It is empirically proven that QM's predictions are correct. You behave like a creationist who cannot accept scientifically proven facts. So you did not learn anything. Your opinion is against established science.