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In the hidden variables case (yours), it was predetermined which marble was in the bag before you opened it. In the retrocausal case, the information about whic
by Twisol 9y ago
In the hidden variables case (yours), it was predetermined which marble was in the bag before you opened it. In the retrocausal case, the information about which marble is in the bag simply isn't part of reality until you've checked. With macroscopic objects like bags and marbles, this is ridiculous, because someone had to put the marble in the bag (a "shared cause"). However, Bell's Theorem shows that entanglement isn't a sufficient "shared cause" to explain his experiment. Thus, we either need superdeterminism (the "shared cause" is the origin of the universe!), spooky action at a distance, or retrocausality.
- RobertoG 9y ago>>" the information about which marble is in the bag simply isn't part of reality until you've checked" It seems to me that the universe uses lazy evaluation (1). (1) https://en.wikipedia.org/wiki/Lazy_evaluation https://en.wikipedia.org/wiki/Lazy_evaluation
- Twisol 9y agoIt's even weirder than that, though, because with lazy evaluation you still have a complete description of the state involved; it's just a matter of unpacking it by executing the description. That's more analogous with a hidden variables theory. With retrocausality, it seems that performing an observation fundamentally adds information to that which has been observed. If retrocausality can be likened to a computational mechanism, I'd be really interested to know what it is! Like I said in another comment, it seems like there's some element of monotonic computation involved, but the brand of monotonicity is quite unusual.
- deleted 9y ago[deleted]
- RobertoG 9y ago>>"it seems that performing an observation fundamentally adds information to that which has been observed." disclaimer: I have not idea what I'm talking about. Is it not that the "adds information" that you mention, it's like sampling a probability distribution? Of course, then your program, the universe, it's not deterministic anymore (but I think that it's already the case when quantum physics is involved). So, your lazy function, don't do anything until is required and then it returns a sample from a probability mass function (not a pdf because we are talking quantum here).
- cma 9y agoNo. See the Kochen-Specker theorem. You can choose which way to measure in ways that sort of interact with one another statistically even after two particles are far separated.
- neolefty 9y agoCan anything be "forgotten" once it's been determined? For example--can two entangled particles be created, then forced to interact in a way that collapses their wave functions, then sucked into a black hole, without having been observed by anything that isn't sucked into that black hole--does their collapse matter? Does the universe forget it? If so, then could the whole universe be a reversible computation, once it's summed up from big bang to big ... whatever happens at the end?
- lurquer 9y agoThis makes me think of dangling pointers and memory leaks.
- marcosdumay 9y agoThat can also be called "retro causality".