tag:blogger.com,1999:blog-3891434218564545511.post5378738707549907509..comments2024-03-28T19:56:42.305-05:00Comments on Alexander Pruss's Blog: EntanglementAlexander R Prusshttp://www.blogger.com/profile/05989277655934827117noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-3891434218564545511.post-34802544465692408252019-07-31T14:08:13.474-05:002019-07-31T14:08:13.474-05:00The difficulty in explaining Bell-type correlation...The difficulty in explaining Bell-type correlations with superluminal causal influence is to account for the direction of the causality and take into account the symmetry in the setup. We have two measurements at distant locations. There is a correlation between the outcomes of the measurements. But how to explain that correlation? Which of the two measurements triggered the collapse?<br /><br />On the model in my post, the system randomly chooses one of the two measurements as the trigger.<br /><br />It now occurs to me that a simpler and more elegant solution would be overdetermination. Alexander R Prusshttps://www.blogger.com/profile/05989277655934827117noreply@blogger.comtag:blogger.com,1999:blog-3891434218564545511.post-23016645555582205692019-07-31T09:50:06.881-05:002019-07-31T09:50:06.881-05:00First off, I think it's better to just leave t...First off, I think it's better to just leave terms like "direction of time" out of it, since so much nonsense is said about that. It's better to just say that states of affairs evolve or that events happen one after another.<br /><br />And, in any case, I don't think it's difficult to come up with a causal explanation for the Bell-type correlations, as long as you permit superluminal (perhaps even instantaneous) causal influence. My point about GTR before is that it doesn't seem to me to make any reference at all to reference frames (pun intended). Sure, none is privileged in the trivial sense that there aren't any and therefore aren't any privileged ones.... But, then, this is all way above my pay-grade. LolMichael Gonzalezhttps://www.blogger.com/profile/05279261871735286117noreply@blogger.comtag:blogger.com,1999:blog-3891434218564545511.post-57237656754934908292019-07-27T15:47:12.471-05:002019-07-27T15:47:12.471-05:00I think the direction of time comes from the predo...I think the direction of time comes from the predominant direction of causation. <br /><br />The causal problem arises in the Bell inequality setting, where there is a correlation between the choice of which quantity to measure at, say, location A, the result of the measurement at A, and the result of the measurement at B. This correlation is difficult to explain causally.Alexander R Prusshttps://www.blogger.com/profile/05989277655934827117noreply@blogger.comtag:blogger.com,1999:blog-3891434218564545511.post-29269187177175671512019-07-27T02:34:27.603-05:002019-07-27T02:34:27.603-05:00For this approach to work, time would have to have...For this approach to work, time would have to have an intrinsic direction – the messages would have to be excluded from the backward (but not the forward) light cone. This may or may not worry you, since collapse style interpretations of QM seem to require a direction of time in any case.<br /><br />Do you need any new story to preserve causal explanation? Isn’t the experimental setup that produced the entanglement and arranged the measuring apparatus sufficient explanation of the correlations? Note that even without non-locality, QM “explains” e.g. a detector’s propensity to click, but not why it clicked or did not click on any particular occasion. Non-locality merely makes it weirder.<br /><br />As you say in D, with more than two entangled systems, things get complicated. Most things are entangled, if only very slightly, with many other things. So in reality, there would be a lot of complication.IanShttps://www.blogger.com/profile/00111583711680190175noreply@blogger.comtag:blogger.com,1999:blog-3891434218564545511.post-9391246300467589172019-07-25T16:07:36.099-05:002019-07-25T16:07:36.099-05:00GTR doesn't have a privileged simultaneity eit...GTR doesn't have a privileged simultaneity either. The "cosmic time" is, as far as I know, not well-defined at the local level.Alexander R Prusshttps://www.blogger.com/profile/05989277655934827117noreply@blogger.comtag:blogger.com,1999:blog-3891434218564545511.post-32898162382758753812019-07-25T12:56:30.259-05:002019-07-25T12:56:30.259-05:00I've always wanted to ask someone who knows th...I've always wanted to ask someone who knows this stuff better than I do: why are we so concerned with STR's rejection of preferred reference frames when GTR supersedes STR and it doesn't care about reference frames?<br /><br />I did ask Tim Maudlin about a Bohmian view of QM coupled with a Neo-Lorentzian view of STR, and he gave me some very interesting things to think about. But, I guess I just don't understand why STR is such a concern when GTR replaces it and doesn't have its same issues.... In other words, why not take the so-called "cosmic time" of GTR, and say that the causation is super-fast but still always forward in cosmic time?Michael Gonzalezhttps://www.blogger.com/profile/05279261871735286117noreply@blogger.com