Editorial Note

This is a canonocal question meant to cover all possible specific questions that fit the schema, as well as the fully general "Can quantum entanglement be used for FTL communications?"

If a question fits the schema, close it as a duplicate of this one.

Generic Question

So I came up with this concept for FTL communication with quantum entanglement"‰/"‰EPR"‰/"‰spooky action at a distance:

I have one or more pairs of entangled particles, with Alice and Bob holding one of each pair.

My Very Clever Idea™ is to"¦

Blah blah blah, the details are irrelevant. This might be a well crafted highly speficic scenario, or it might be rather muddy and unclear. It may involve any or all of

• changing one particle and expecting its partner to change too
• measuring a chosen observation one one particle and expecting any measurement on its partner to yield any information about that without comparing notes via normal communication
• assuming that the actions of Alice and Bob, who are outside of each other's light cones, have an absolute time ordering

Constraints

This applies to real-universe physics, though may require unobtainium or engineering so advanced as to seem like magic.

If you want to postulate a change to the laws of QM, it would take a hard-science question to ask someone to work out the details to see if these results still apply. But, a reality-check science-based question can be posted to simply assess whether the postulated change will break all of physics or might conceivably result in a universe like ours but with FTL communication

posted about 7 years ago

Mephistopheles‭

6 reputation 146 0 1 0