djo@pbhyc.UUCP (05/26/87)
In article <19028@ucbvax.BERKELEY.EDU> kube@cogsci.berkeley.edu.UUCP (Paul Kube) writes: > >So, everybody, what do you want to give up: the impossibility of FTL >information transfer, that the particle was spinning happily left all >along, or the relevance of mathematics for physics? Oakes sounds like >he might opt for doing without the last, but it's interesting to note >that the Bell inequalities don't depend on the formalism of quantum >mechanics at all (though QM does correctly predict the observed >probabilities). Actually, we can accept a much weaker condition -- the inadequacy of our [current] mathematical model to describe the physical reality. That is perfectly consonant with scientific method, whereas the dogmatic and anthropomorphic insistence that the universe conform to our mathematics is not. State equations are not a description of a particle; they are a description of what we know about a particle. The ontological confusion which allows physicists to believe -- effectively -- that "We can narrow things down to A or B, but can't determine which; therefore both are equally true" never ceases to astonish me. Why are you all so afraid to admit that there are things you just don't and can't know? Dan'l Danehy-Oakes
kube@cogsci.berkeley.edu.UUCP (05/27/87)
In article <651@pbhyc.UUCP> djo@pbhyc.UUCP (Dan'l Oakes) writes: >In article <19028@ucbvax.BERKELEY.EDU> kube@cogsci.berkeley.edu.UUCP (Paul Kube) writes: >> >>So, everybody, what do you want to give up: the impossibility of FTL >>information transfer, that the particle was spinning happily left all >>along, or the relevance of mathematics for physics? > >Actually, we can accept a much weaker condition -- the inadequacy of our >[current] mathematical model to describe the physical reality. Fine, though it's nice to have a reason for doing so. Most everyone feels uncomfortable with noninstrumentalist interpretations of quantum mechanics. I am suspicious of anyone who says they understand them. Einstein thought it obvious that reality couldn't be strangely indefinite in the way required by these interpretations of QM. It would be nice if there were a way to decide the question; and that, in fact, is exactly what experiments based on Bell's inequality are designed to do. Keep in mind that Bell's inequality doesn't depend on a choice of interpretation of quantum mechanics. It's just an exercise in elementary applied probability theory; given the assumption that certain random variables are independent (representing absence of superluminal linkages) and that certain conditional probabilities are either zero or one (representing that given a value of particle state--WHATEVER IT HAPPENS TO BE--and an apparatus configuration, experimental outcome is determined) you get the inequality (representing relationships among probabilities of outcomes conditioned on apparatus configuration). As it turns out, relative frequencies of outcomes observed in certain experiments violate the inequality. This prima facie shows that either there are superluminal signals or there's a strange indefiniteness to particle state (coincidentally of the type required by a noninstrumentalist interpretation of QM). To argue for rejecting both of these conclusions, someone should either point out an error in the derivation of the inequality (pretty unlikely), some failing of the experiments (they've been repeated), or some particular infelicity in the application of the former to the interpretation of the latter. I would like to see this. But it's not enough just to say that it's always possible that our mathematics fails to correspond to reality (especially in this case where the mathematics was developed to describe, in a very general way, what should be observable in case there is some definite reality for our classical state variables to correspond to). --Paul kube@berkeley.edu, ...!ucbvax!kube