This famously complex experiment gets explained simply

  • @kromem
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    1 year ago

    No, it gets explained poorly.

    I’m guessing his first video had more glaring issues that got called out, but this one tries to right the ship around whatever that error was by mangling the entire point of the original experiment.

    The fact that the ballistic vs interference pattern on D1 is being separated out by researchers based on the entangled correlation is besides the point.

    The point of the experiment is that the entangled photon hitting D1 does so before it hits the half-silvered mirror determining if the “which path” information of its pair is kept (continues straight to a detector that can only be reached by one slit) or is lost (sent to a detector that could be reached by either slit).

    So the question is how does the detection of the entangled pairs hitting D1 fall into a ballistic pattern or an interference pattern when the other photon hasn’t yet ‘selected’ if it’s going to fall into a ballistic or interference pattern.

    Retrocausality remains a concern no matter what the aggregate pattern on D1 looks like, as the whole point is the behavior of the subsets of entangled pairs. The only way this somehow changes the experiment and its interpretation is if the researcher filtering of D1’s subsets introduced bias in the observed pattern of those subsets.

    The nuance that the subset patterns on D1 are observed at the end of the experiment can be relevant depending on one’s QM interpretation, particularly ones along the lines of consciousness collapse (where it is the researcher review of the results that is the point of effective collapse thus there is no retrocausality), but are not particularly relevant for a Copenhagen interpretation of the experiment.

    This video is effectively misinformation. The correction of the original video was likely someone correcting a misrepresented facet of the presented details, but the OP seemed to get confused about what was being called out and now made this video further muddying the waters by making the entire video about the correction, which is irrelevant to the original underlying experiment (particularly through the lens of Copenhagen which is the stated interpretation in the video), and was only relevant to OP’s 2019 video that mistakenly presented D1’s aggregate pattern as changing during the experiment.

    Edit: In case it’s confusing in the above, it is correct that there’s no evidence for retrocausality. But the ‘refutations’ of retrocausality are misrepresenting the case as if retrocausality is disproven. It’s more accurate to state that nothing can be said about retrocausality because there’s no “which way” information at D1 in the first place to be retroactively ‘changed’. I’ve always hated this experiment as the much more interesting details of the quantum eraser behavior in the first place is generally lost in the discussion over temporal order. And for those that find the question of quantum consistency interesting, there’s more recent experiments that are much more interesting.