quantum mechanics: answers? (Introduction)

by dhw, Saturday, September 14, 2013, 17:29 (3878 days ago) @ David Turell

Dhw: Thank you. Sadly I remain just as confused. Now the authors seem to be saying that if Alice sends Bob m bits of information about her quantum experiment, Bob can't gain more than m bits of information about the non-quantum world. Is it not possible for Bob to see connections that Alice doesn't see? After all, the authors think that every construct is subjective (see below). And I still don't know what is meant by "information causality". Perhaps you can define it and explain why it is so important.-DAVID: I interpret this to mean that Bob cannot receive any more information than Alice sends.-So if Alice sends him a dollar, he can't receive more than a dollar. Hardly worth making a song and dance about. And I still don't know what "information causality" means, or why you find it so important that you put it in bold.-DAVID: Your confusion is because these folks are ignoring Ruth. [...] These folks keep trying to interpret quantum phenomena as if they are fully within our reality and they are not.
 
Dhw: On the contrary, these folks REJECT the idea that all of this represents "something real out in the world", and insist that the constructs are subjective! Ruth regards quantum states as "ontologically real possibilities existing in a pre-spacetime realm [...] These possibilities are taken as real because they are physically efficacious, leading indeterministically to transactions which give rise to the empirical events of the spacetime theatre." And the problem of subjectivism "evaporates" because the transaction "is simply observed differently by the different observers" (which in my book = subjectivism). Yes, I am mightily confused.-DAVID: I think most people still want quantum characteristics to act as if they are totally part of our reality. They are not. I still think of the dividing wall as a semi-permiable membrane. Some comes through, some doesn't, but it all makes sense if we could reside on the other side.-I like the image of the semi-permeable membrane, which is far more comprehensible than what seem to me to be contradictory and often nebulous arguments that even you obviously find difficult to clarify. Your syntax above is misleading. Perhaps it WOULD all make sense if we could reside on the other side, but we can't, so it doesn't. I was genuinely eager to follow Ruth's theories and your defence of them, because it may well be that the quantum world contains solutions to some of the mysteries of our own world ... I'm thinking especially of consciousness and psychic experiences, which from your point of view might shed light on your God theory. But the arguments have to be coherent. So far they aren't, and although I acknowledge that my confusion may be due to my own lack of scientific training, I'm beginning to suspect that the scientists themselves quite literally don't "know" what they're talking about.