I'm sorry if this is a stupid question. I'm a novice at physics.
I have read the article about entanglement and EPR paradox. The spin of two particles is measured when they are very far apart, and they always make opposite choices. It seems that they must be correlating faster than light, which would be spooky.
I also read the article about many worlds. And I think it solves the faster-than-light paradox. Am I correct? Has anyone already noticed this? (I tried to google it and didn't find anything).
This is why I think it solves the paradox: In order to observe the spin of the two particles you need two observers, one for each particle. To correlate the answers, the two observers need to communicate with each other (either traveling together or by sending light-speed messages to each other). According to the many worlds interpretation, both spins (clockwise and counterclockwise) are always observed by both observers. Therefore there are actually four observers. However, not all observers can communicate to each other. Only pairs of observers that exist in compatible universes are able to detect one another's communications. The discrepancies are only enforced when the two observers are near enough to each other, or enough time has past, for them to communicate. Therefore, there is no spooky faster-than-light paradox when using the many worlds interpretation.
Answer
The MWI explains the EPR experiment without invoking any non-local influences. Each observer measures one particle. The measurement affects only the particle being measured and the measurement device. Each measurement device differentiates into two versions, one for each measurement outcome. The correlations are established only after the results are compared locally. Until that comparison is done there is no fact of the matter about the correspondence between measurement results.
This can all be described explicitly in the Heisenberg picture as explained by David Deutsch in these papers:
http://arxiv.org/abs/quant-ph/9906007
http://arxiv.org/abs/1109.6223.
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