quantum mechanics: Kastner\'s brilliant blog (Introduction)

by rekastner , Sunday, July 21, 2013, 23:03 (3933 days ago) @ Balance_Maintained
edited by unknown, Sunday, July 21, 2013, 23:10

Let me clarify: by 'event', I mean a single actualized transaction. That is always well-defined in terms of a specific emitter and a specific absorber. I'm not using 'event' to refer to large-scale processes made up of myriads of events among different observers. In the latter, each observer will have his/her own set of experiences. But they are always reducible to collections of objectively real transactions, and can be corroborated.-You say:-"Knowledge of an objective reality has the pre-requisite of a complete data set."-I'm not claiming that anyone has complete, exhaustive knowledge of an objective reality, so I don't see why this very strict criterion would apply to my claims.-All I claim is that the structure of QM can reasonably be taken as referring to an objectively real structure in the world that can be said to transcend the spacetime domain, since the mathematical structure of the basic objects in the theory (quantum states) does not fit into a spacetime structure. If you take these objects as real, then that's their objective nature IF the theory is correct. That's why I call this provisionally correct knowledge. QM is very likely to be at least approximately correct, since it is so well-corroborated. -On the other hand, if you think that QM does not describe anything real, then you're going with an anti-realist interpretation: the doctrine that QM is only about subjective knowledge. Perhaps that's your view; I reject this approach to physical theory because I think it fails to explain the success of the theories, especially the fact that pet theories can be found to be wrong and new theories discovered that would not have been arrived at without anomalous evidence from nature (e.g. QM). But ultimately of course no realist can disprove the doctrine that physical theory is not about an independent reality but only about our subjective "knowledge" (meaning the kind of assumptions made about sense data based on previous experience and concepts, a la Kant) -- that theories are only about subjective impressions, biases, and so forth. But there's the 'reflexive' problem in which the subjectivists' own statements, by his own criterion, are mere statements of his own subjective impressions and views -- which deprives them of force. So I think this kind of approach is ultimately self-defeating. If we're going to do science, as a means of finding out about the world, then to assume in advance that no non-subjective knowledge about the world is impossible is to prejudge the issue. -I understand that subjectivism can be compelling. The post-modern world has done a good job of calling into question the idea that science can yield any kind of objective knowledge about the world. But (due to the 'reflexivity' problem) it's a self-defeating position because any statement made by a proponent of such a view is nothing more than a statement of their own subjective views, based on their own subjective impressions, all tied together with logic that is heavily dependent on definitions that are endlessly debatable.-As I said before, of course the phenomena we can observe and measure are intersubjectively created and corroborated based on what we choose to measure and how our experiments are set up. However, the fact that certain wrong theories were discarded (classical physics, flat earth theory) certainly is at least good evidence that unexpected aspects of reality can force changes in putative knowledge. The other point is that the structure of those new theories can point to aspects of reality not previously suspected. To say that a theory may provide a basis to think that there is more to reality than what we can sense with our 5 senses is certainly not a claim of total knowledge of such an objective reality, and does not require a 'complete data set'. -The bottom line: one can adhere to a doctrine that all knowledge is subjective, and I can't disprove that, although I have argued that it can be self-defeating. I can adhere to the view that well-corroborated theories can provide a way to gain knowledge of an objective reality; of course I can't prove that claim, but it can't be disproven either. It is certainly possible that there are objects described by quantum theory and that they can be involved in processes independently of a agent's subjective perceptions - e.g., a photon emitted from the sun and absorbed by a leaf. In fact this was happening millenia before agents with subjective impressions arrived on the scene, and they didn't need those agents for their existence.