scerir wrote:
If A and B are two wings of a typical Bell apparatus, i the observable to be measured in A and x its possible value, j is the observable to be measured in B and y its possible value, and if Lambda are hidden variables, we could write Locality Condition p_A,Lambda (x|i,j) = p_A,Lambda (x|i) p_B,Lambda (y|i,j) = p_B,Lambda (y|j) Separability Condition p_A,Lambda (x|i,j,y) = p_A,Lambda (x|i,j) p_B,Lambda (y|i,j,x) = p_B,Lambda (y|i,j) There is (or was) some agreement that a (phantomatic) deterministic theory (i.e. one in which the range of any probability distribution of outcomes is the set: 0 or 1) reproducing all the predictions of QM, can not violate the Separability Condition, (the specification of Lambda, i, j, in principle determines completely the outcomes x, y, then any additional conditioning on x or y is superfluous, having x and y just one value allowed, so they cannot affect the probability, which - in a deterministic theory - can just take the values 0 or 1) and must violate the Locality Condition. Following the above reasoning, MWI (if it is a truly deterministic theory) should violate the Locality Condition. --------------- ### Since the Everett faq gives the following ..... "To recap. Many-worlds is local and deterministic. Local measurements split local systems (including observers) in a subjectively random fashion; distant systems are only split when the causally transmitted effects of the local interactions reach them. We have not assumed any non-local FTL effects, yet we have reproduced the standard predictions of QM. So where did Bell and Eberhard go wrong? They thought that all theories that reproduced the standard predictions must be non-local. It has been pointed out by both Albert [A] and Cramer [C] (who both support different interpretations of QM) that Bell and Eberhard had implicity assumed that every possible measurement - even if not performed - would have yielded a single definite result. This assumption is called contra-factual definiteness or CFD [S]. What Bell and Eberhard really proved was that every quantum theory must either violate locality or CFD. Many-worlds with its multiplicity of results in different worlds violates CFD, of course, and thus can be local." So, I should say that ..... MWI (if it is a truly deterministic theory, reproducing all thepredictions of QM) should violate the Locality Condition but, in fact, it violates CFD only :-). -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
