Joncon said:I've also heard a suggestion that the "first" measurement may send a signal backwards in time to when the entangled particles were first produced, ensuring that the spins are always opposite.
This seems to solve the issue about the ordering of the , and removes a bit of the "spookiness" involved with the particles being spatially separated.
I'm not sure what other issues this might create though. And I can't think of an which could test for this.
Interesting though ...
mfb said:No. In every frame, there is a description which does not involve any propagation backwards in time. And all frames give the same measurements.
Both reference frames have their own time-order of the events - you cannot transmit information with those measurements, so you do not need a unique ordering of those events.myshadow said:Could you please elaborate? From one reference point, A collapses the system and as a result B has a defined spin. From another reference point, the measurement of B seems to happen first and collapses the system. As a result, A takes a defined spin.
Look up Bell's theorem. It has, and it is a very interesting experiment.As a side question, has it been proven empirically (somehow) that the spins are actually undefined before measurement? I'm guessing this is impossible. btw, I'm an engineer not a physicist so I'm sorry if the answers are obvious. Thanks.