Forum Replies Created
-
Posts
-
Mark,
Well, I guess the fact that evidence continues to point to the impossibility of HVs. Every time someone thinks they find a loophole that allows for HVs, it is usually fairly rapidly closed.
Ken,
The multiverse *could* be a BW (or a BU, I guess). There’s no reason it couldn’t be. In any event, I still see the “future events as HVs” scenario as being just a fancy way of saying everything is simply pre-determined.
Either way, let’s look at it this way. Suppose you are right and future events are simply hidden variables (or “governed by HVs” might be a more proper way of putting it). Under that scenario the apparent randomness of the universe corresponds to a lack of knowledge on our part. But if they are truly HVs then they are impossible to fully know. Hence the theory is untestable, i.e. there’s no way to prove such a theory is the correct theory of future events. If they’re not necessarily truly hidden, then where are they and how does a BW theory predict them experimentally?
So, in short, either give me something physically testable or else it’s just philosophy in my book. I’m sure that makes me look like an operationalist but I’m really not because I do believe that Occam’s razor can be employed to root out the simplest but broadest theoretical explanations whereas true operationalists don’t care.
Mark: well, I see two options here. Either randomness is merely a representation of our lack of knowledge (after all, the probability distributions you describe are only meaningful in the context of gaining knowledge, i.e. experiment), which would seem to suggest hidden variables are required to invoke a BW, or the multiverse exists in order to account for all possible outcomes simultaneously. The BW assumes that everything simply exists, i.e. time doesn’t flow, there’s no sense of “becoming” as Ken puts it. The only way I can see to reconcile that with quantum randomness is either hidden variables or the multiverse. Neither is particularly appealing to me.
Funny you should mention Eddington. I have gone back and re-examined some of his stuff and have come to the conclusion that he was actually an operationalist at heart. I don’t think he bought the ontological status of spacetime. In fact it is quite clear he didn’t. I just never thought about it in depth until last week’s RQI-N meeting.
Regarding the block universe, I am still at a loss as to how randomness can be accounted for in such a description. So more than the sense of “becoming” it seems to fly in the face of the way things actually work.
Ken,
You are going to have to sell me on the block universe (again) next weekend when we tape the inaugural episode of Quantum Conversations. I can buy retrocausality on the micro level so I do not think the two ideas are necessarily connected. I think the block universe is merely a way to make retrocausality seem palatable on the macro level, or, rather, to make better sense of the quantum-classical contrast. But it assumes that space and time have some ontological status beyond mere relations.
Ian
