Understanding Quantum Entanglement: Debunking Common Misconceptions

In summary, the phenomenon of quantum entanglement is surprising because it contradicts classical physics' understanding of conservation of quantities. In a hypothetical scenario where two entangled electrons are separated and the spin of one is measured, the other's spin is guaranteed to be the opposite. This is considered bizarre because it challenges the idea that the spins of the two electrons were already set at creation. However, experiments have shown that quantum mechanics accurately predicts the results of measurements at different angles, supporting the concept of entanglement.
  • #36
Quandry said:
This one is bending my mind (it is probably supposed to). If you are to get information from the something else, you need to know what the something else is and probably where it is (which puts us into red green sock territory). Presumably if a particle is entangled with something else, and is going to respond when the state of that something else changes, there must be something in the particle that 'knows' which something it is entangled with.

You really don't get any information. It's random and essentially redundant.
 
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  • #37
DrChinese said:
You really don't get any information. It's random and essentially redundant.
I don't immediately agree with that: when data from 'the other side' is added, we have information about the relative orientation of the detectors, right?
 
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  • #38
I should not have used the term 'information', I was addressing the post that I quoted. Certainly 'you' don't get anything. The second part was really my 'philosophical' question which is that if a particle is going to respond to something that happens to its entangled particle 'it' must 'know' which particle to respond to.
But that's probably getting off topic.
 
  • #39
entropy1 said:
Non-CFD/non-realism might be one I guess.

Yes since the inequalities are derived from CFD: From spin 1/2 particles the strict anti correlations along parallel settings enables you to deduce
A+B- , A-B+ for one pair of particles and
A+C-, A-C+ for another pair. Leading to this general form of Bell inequality: N(A+B-) + ≤ N(A+C-) + N(B-C+)

And for the CHSH inequality : (AB) + (AB') + (A'B) - (A'B') ≤ 2 A,A' B,B' = ± 1
However in the just closed thread; Quantum entanglement information. Post # 43 ,
@Mathematech states that CFD is an invalid assumption when there are more than two variables.
Quote: (selected) "The point of particular importance is the idea of combining counterfactual results with factual results gives the same statistics. It is a mathematical fact that when the counterfactual results are possible alternate results that were not obtained due to an incompatable experiment being performed instead, then when more than two variables are involved, the statistics need not be the same as a scenario where the counterfactual results were not obtained "

I would like to see an elaboration on the above claim that CFD is not valid for
the two inequalities above that results in the violations
 
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  • #40
Take a look at https://www.researchgate.net/publication/51931411_Hidden_assumptions_in_the_derivation_of_the_Theorem_of_Bell the discussion on pages 3 - 4. They don't use the terminology "counterfactual definiteness" but what they mention relates. See also Ray Streaters comments in his book https://www.researchgate.net/publication/253090359_Lost_Causes_in_and_beyond_Physics in section 6.3
 
  • #41
morrobay said:
What are the alternative explanations for the correlations between spacelike separated entangled particles that do not include a superluminal signal ?
morrobay said:
I would like to see an elaboration on the above claim that CFD is not valid for
the two inequalities above that results in the violations
What I ment was that, as long as one of the two measurements is not examined, there is no need for a superluminal signal. If and when that other measurement will be examined, it will already be a non-superluminal course of events.
 
  • #42
Mathematech said:
Take a look at https://www.researchgate.net/publication/51931411_Hidden_assumptions_in_the_derivation_of_the_Theorem_of_Bell the discussion on pages 3 - 4. ...

While I have great respect for Hess and Michielsen and the teams they are a part of: a) this is not a suitable reference; and b) it is far off-topic. The primary objective of their work is to produce mathematical models that can reproduce local realism in various respects.

This is a "B" level threat about quantum entanglement, not about arguing for or against local realism. You should start a new thread if you wish to go in that direction.
 
  • #43
This thread has run its course and is now closed.
 

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