I remember years ago, back in highschool, when I studied quantum mechanics, our professor suggested this idea (he used a blue and a red ball in two briefcases)

I remember years ago, back in highschool, when I studied quantum mechanics, our professor suggested this idea (he used a blue and a red ball in two briefcases) as a comparison to entanglement and then disproved it explaining that it's not quite the same. Unfortunately, too many years passed and I don't remember the counter-argument that explains why you can't apply that logic to entanglement but it involved Bell's theorem[1] and the EPR Paradox[2]. Actually I think Einstein himself made a counter-argument similar to that (just not with stones/balls but with actual particles) and was disproved later on. Sorry if I can't give more details, I'm not a physicist. [1] https://en.wikipedia.org/wiki/Bell%27s_theorem https://en.wikipedia.org/wiki/Bell%27s_theorem [2] https://en.wikipedia.org/wiki/EPR_paradox https://en.wikipedia.org/wiki/EPR_paradox