I know this has been discussed in so many ways on this forum, but it is hard for me to separate interpretations, fact, speculation, and inaccuracies. You can probably just skip the next two paragraphs that I describe the EPR/Aspect experiment and go right to my question. In an EPR experiment like the one Alain Aspect performed with entangled photons being measured by respective polarizers, Quantum Mechanics treats the experiment as a system where the probability for the polarization of the photons leaving the polarizers is determined to be cosine squared of the difference between the polarizer angles. Say one of the polarizers, call it polarizer B, is far away relative to polarizer A and the photon source. Say it is so far away that by the time photon A hits polarizer A, there is no possible way by instant communication (faster than the speed of light) that photon B, heading towards polarizer B has any idea of what it might interact with in the future. QUESTION: So if all the components in the system have no idea what photon B will interact with in the future, how can QM math give the correct result? The only two logical possibilities that come to mind are: 1) That QM happens to give the correct probability, but the reason it does is because there is an underlying mathematical algorithm that describes how photon A collapses some of its state to photon B when it interacts with polarizer A. 2) That QM works because the system is actually everything in the entire universe and somehow every particle in the universe knows the state of every other particle in the universe and can follow the rules of QM math.. At least in my eyes, #1 seems the simplest, most likely explanation, and it is easy enough to simulate and get the correct result in this specific scenario with linear polarized photons. Would #1 be called a collapse or Copenhagen interpretation of QM? Is this the most popular interpretation by QM experts? Do most QM experts who subscribe to this interpretation think there is a deeper realistic (i.e. based on rules of math) theory that gives an explanation for the collapse that is not just some random probability generator? If not, are there any strong reasons why this interpretation is a dead end? #2 seems unlikely to me. QM has very simple rules, you add probability amplitudes when a state can change in multiple ways, but otherwise you multiply; then you square the result for the probability. These simple rules seem to have a local basis and so I have a hard time equating these rules with the state of the entire universe. Is there a name for this type of interpretation? How popular is this interpretation with QM experts? Thanks.