Quantum Eraser and Delayed Choice Quantum Eraser

[thenewmans]

I have read that these experiments have been successful and do not cause a disagreement with QM. But I can’t quite determine what was learned. So what did they prove or disprove? Is there a simple explanation? I thought they were designed to determine if wave collapse breaks either locality or causality? (Non-Locality – instant action at a distance. Non-Causality – action goes back in time. I think I have that part right.) It should be one or the other, right?

 

[thenewmans]

(Oops, I hope I didn’t ask a question that was answered in that other Quantum Eraser thread. Sorry if I committed a PF faux pas.)