I have thought of an experiment to test for statistical significance in a quantum entangled system. The proposed experiment is as follows:

Suppose there are 3 entities all in a straight line from each other, as a graph Z is at 0,0 B is at 44,44 and C is at 90,90. B is emitting quantum entangled particles to both Z and C. Z and C have both decided on a system where C has a polarized filter that only allows up or down, and Z measures the particles until it has obtained spin up or down 3 times in a row, then it rotates a polarized filter 90° for the next 5 particles to send a binary code where up would equal 1 and down would equal 0. C then knows if it receives 3 up or 3 down in a row followed by 5 particles absorbed by the filter and therefore not observed, that it got a 1 or 0. C measures every particle slightly later than Z as it is slightly further away from B. Would that send a statistically significant amount of data across Spacetime faster than light, or is it still random?

I ask wondering if this is definitively disproven by other experiments or theories, or if it is worth performing the experiment to find the results? Were this to be attempted how would one run the experiment on a technical level and what current technology/techniques could be used to perform it.

I am less interested it the actual results and more interested in whether this experiment is fundamentally flawed. If not how would one would preform it in the real world.

If I am not being clear enough, I am not making sense at all, or if this question doesn't belong here, please let me know in the comments. Simply down voting tells me nothing. Thank you.

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    $\begingroup$ Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. $\endgroup$
    – Community Bot
    Commented May 24 at 14:25
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    $\begingroup$ "Simply down voting tells me nothing." I think the downvotes are telling you something. $\endgroup$
    – hft
    Commented May 24 at 15:47
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    $\begingroup$ Every few weeks we get someone trying to suggest a way of using entanglement for FTL information transmission. The downvotes are probably folks tired of this flawed way of thinking being asked over and over again. Usually the "faster-than-light" tag is added to questions that are on their way to being closed. $\endgroup$
    – Hokon
    Commented May 24 at 15:55
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    $\begingroup$ @hokon I honestly don't believe that this will be ftl communication at all, I'm more curious about what methods could be used to actually run the experiment. $\endgroup$ Commented May 24 at 16:00
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    $\begingroup$ The title does not mention entanglement, which would be helpful to any reader. You have to read the question first to pick that up. Some people would not be interested if they knew that in advance. $\endgroup$
    – DrChinese
    Commented May 24 at 17:40

1 Answer 1


There are a number of things to discuss about your experimental setup and your discussion around that (and I didn't downvote).

  1. You have placed Z closer to B than C is to B. This distinction is completely meaningless to every experimental test you may perform, if your idea is that the first particle measured leads to some difference in the outcomes. There is not the slightest evidence this is the case, and there is no particular element of quantum theory that says there should be either.

  2. You mention something about Z getting spin up 3 times in a row. Since each detection leads to a random outcome for Z, there is no difference here with flipping coins. There is a 1 in 8 chance of seeing 3 spin ups in a row, just like there is a 1 in 8 chance of seeing 3 heads in a row. The important point here is that ALL results Z sees are random. Always. And ALL results C sees are random. Always. And there is no connection between one pair (going to Z and C) and any other pair.

  3. You mention something about Z rotating a polarizer 90 degrees. Fine, but that will have no observable effect on whether the particles C measure will go through a polarizer or not. Keep in mind that real Bell tests normally use Polarizing Beam Splitters rather than Polarizers, because they record whether the outcome is explicitly up or down (or H or V, depending on particle type).

In summary: all C ever sees is a random stream of ups and downs. Nothing Z does will ever change that. There is obviously no useful information to be seen in a random set of bits. The effects of entanglement are only evident when the results from Z ande C are combined. That requires classical communication.

And yes, hopefully you have picked up that this is a basic Bell test and has been performed many times, with many variations. I might suggest reading some actual experimental papers on Bell tests to gain a better understanding of entanglement basics. Here is one I recommend, which is as real world as it gets:

Entangled photons, nonlocality and Bell inequalities in the undergraduate laboratory

  • $\begingroup$ Thank you. I appreciate the link, and the explanation. This paper is honestly exactly what I was looking for. Obviously I'm no expert in the subject, which makes it hard to find papers since I don't really know what I'm actually searching for. Do you have any advice for what to actually search for on resources like the arXiv if you don't already know the keywords? $\endgroup$ Commented May 25 at 3:13
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    $\begingroup$ @DakotaWharton Great question, I wish I could give a better answer. But there are SO many papers, it’s not easy. I use ARXIV extensively so I’ve learned authors and keywords, and have saved many links. But the time spent on this over the years would not be practical for most. If you look at a few of the citations in a good paper and find it in the arxiv (which is free of course, and is nearly complete for about 30 years back), that is often fruitful. I will drop a couple of summary papers in a separate comment which are both good themselves, and also feature great references by top scientists. $\endgroup$
    – DrChinese
    Commented May 25 at 13:38
  • $\begingroup$ This one from Zeilinger, who shared a Nobel for his groundbreaking work on entanglement: courses.washington.edu/ega/more_papers/zeilinger.pdf and also this one from Aspect, who also shared that Nobel: semanticscholar.org/paper/… $\endgroup$
    – DrChinese
    Commented May 25 at 14:36

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