Recent content by RespectableCheese

I'm not familiar with the intricacies of Bohm's theory, but I don't think doing away with the requirement of strict local causality necessarily entails that particular interpretation. If you admit inherent stochasticity it could be the case that the potential observables are totally...

Right, I think I understand now. The thought experiments in the Bell and EPR cases are not identical but are pretty similar conceptually I think - in the EPR experiment, the systems I and II can be represented by two distinct wavefunctions w1(x1, x2) = a(x1)*p(x2) or w2(x1, x2) = b(x1)*q(x2)...

My main gripe with the EPR argument, just to re-summarize, is that it seems to contain redundancies. They describe a theoretical scenario in which it is possible, under the assumption of causal locality, to predict with absolute certainty and without disturbing the target system, the values of...

It seems like you might be circling back to my initial point - it's not their criterion of reality alone that's the issue, it's how it fits into their broader argument regarding complete theories and entanglement. Can you elaborate on how the existence of a particle's spin "in physical...

I think they just mean that it has the ontological status of existing in the objective physical world? Maybe that sounds like a circular definition. They were reasoning metaphysically, that is, prior to any particular scientific theory or empirical observation, with their definition of...

I think this already pretty tangential, but I'm not sure what you're getting at; their criterion of reality is that a value being predictable with certainty is sufficient for the corresponding element to exist in physical reality. So I don't think that situation violates their criterion, i.e. by...

I think their initial criterion of reality (that a quantity's being predictable with absolute certainty without disturbing the system of the corresponding element entails that element's physical reality) could still hold even given Bell's results, which imply that local hidden variable theories...

I mean that's a true enough statement about Bell's theorem but I don't see what it has to do with this paper.

I don't think that really addresses the concern - in that excerpt the authors refute a potential objection to the criterion of reality they had assumed (that is, that an element of a system is physically real if it can be predicted with absolute certainty without disturbing the system). The...

Oh, I see what you're saying - that's referring to the latter part of their argument. Given that both values are physically real, this line of reasoning: "From this follows that either (1) the quantum-mechanical description of reality given by the wave function is not complete or (2) when the...

I'm not sure I understand this - what is the "something" that actually can be predicted with certainty but is not "in the theory"?

No, you second point is backwards. "... [the theory] would contain these values; these would then be predictable. This not being the case, we are left with the alternatives stated." This chain of reasoning is immediately preceded by: "More generally, it is shown in quantum mechanics that, if...

"For if both of them had simultaneous reality - and thus definite values - these values would enter into the complete description, according to the description of completeness. If the wave function provided such as complete description of reality, it would contain these values; these would then...

That's exactly what I mean, that's the issue with their argument. It would have to be the other way around for their logic to hold together.

Yes, that is correct. I mean they had the right idea in noting the tension between QM and locality; they assume locality and derive contradictory results.