I In Bell's Theorem, communication

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The discussion centers on the implications of Bell's Theorem and the concept of "spooky action" at a distance versus faster-than-light (FTL) communication. It highlights the reluctance to accept FTL communication due to its potential to disrupt traditional understandings of cause and effect, where effects could precede their causes. The conversation emphasizes that any violation of the speed of light limit would necessitate a fundamental reevaluation of these concepts. The mention of the "tachyonic anti-telephone" illustrates the complexities and paradoxes associated with FTL communication. Overall, the consensus is that maintaining the light speed limit is crucial for preserving our current understanding of causality.
ndvcxk123
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i.e., excluded in Bell's circuit is only an unknown precondition at splitting time that would bias the spin toward an examined value.
If correct, as non-physicist, I wonder why the vast jump to "spooky action" is seen as more plausible as some new type of particle faster than the speed of light. Consider the time long before the discovery of radio communication, how weird it must have been to theorize about that. The speed of light limit extends here to even unknown objects, perhaps ones smaller, lighter than photons, and confidence in this limit is so high that we completely change our conception of cause and effect. Gravity does tug at photons, but only at light speed.
 
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ndvcxk123 said:
The speed of light limit extends here to even unknown objects, perhaps ones smaller, lighter than photons, and confidence in this limit is so high that we completely change our conception of cause and effect.
You have it backwards. It is any violation of the light speed limit that would require us to completely change our conception of cause and effect, and that is why we are so reluctant to accept explanations based on violation of that limit.

FTL communication creates the possibility that effects appear before causes and even that a message might be received before it is sent - and that the recipient of the message is then able to stop the message from being sent if and only if it has been received. These possibilities are utterly incompatible with our conception of cause and effect.

You might want to Google for “tachyonic anti-telephone” to get a sense of some of the difficulties.
 
For the quantum state ##|l,m\rangle= |2,0\rangle## the z-component of angular momentum is zero and ##|L^2|=6 \hbar^2##. According to uncertainty it is impossible to determine the values of ##L_x, L_y, L_z## simultaneously. However, we know that ##L_x## and ## L_y##, like ##L_z##, get the values ##(-2,-1,0,1,2) \hbar##. In other words, for the state ##|2,0\rangle## we have ##\vec{L}=(L_x, L_y,0)## with ##L_x## and ## L_y## one of the values ##(-2,-1,0,1,2) \hbar##. But none of these...