- #1
peter0302
- 876
- 3
Hello all -
New to the forums so let me start by saying hi to everyone. ;)
Something has always bugged me about considering entanglement effects as "instantaneous." As we all know from SR, moving observers do not agree on simultaneity between two space-separated events.
If we consider the entanglement effect to be "instantaneous" do we not have a problem when we consider the relativistic observer in the following thought experiment?
Say we have two entangled electrons (E1 and E2) moving in opposite directions, each at .9c relative to the lab. Observers A and B, however, are riding the particle accelerator with E1 and E2, respectively, matching their speeds perfectly. When A performs a measurement on E1, the "influence" is "instantaneously" felt by E2. But instantaneous for whom?? A? B? A stationary observer in the lab? All of the above?
And at the time A makes a measurement, believing it to travel "instantaneously" to B, in B's frame that measurement has not yet occurred. Thus, will the "influence" travel backwards in time for B? If B made a measurement BEFORE (in his frame) A did, will the Bell correlations hold? If not, can we not infer a "speed limit" for the quantum influence? If so, can we conclude anything other than non-causality or retro-causality?
Would love to hear your thoughts!
Peter
New to the forums so let me start by saying hi to everyone. ;)
Something has always bugged me about considering entanglement effects as "instantaneous." As we all know from SR, moving observers do not agree on simultaneity between two space-separated events.
If we consider the entanglement effect to be "instantaneous" do we not have a problem when we consider the relativistic observer in the following thought experiment?
Say we have two entangled electrons (E1 and E2) moving in opposite directions, each at .9c relative to the lab. Observers A and B, however, are riding the particle accelerator with E1 and E2, respectively, matching their speeds perfectly. When A performs a measurement on E1, the "influence" is "instantaneously" felt by E2. But instantaneous for whom?? A? B? A stationary observer in the lab? All of the above?
And at the time A makes a measurement, believing it to travel "instantaneously" to B, in B's frame that measurement has not yet occurred. Thus, will the "influence" travel backwards in time for B? If B made a measurement BEFORE (in his frame) A did, will the Bell correlations hold? If not, can we not infer a "speed limit" for the quantum influence? If so, can we conclude anything other than non-causality or retro-causality?
Would love to hear your thoughts!
Peter