I have some questions about quantum entanglement 1 - Why is this phenomenon considered so surprising, if it just states conservation of quantities (e.g. spin, momentum) and we are already accostumed with conservation of quantities in classical physics 2 - Suppose we have, say, a hydrogen molecule, which means we have two entangled electrons. Suppose further we do not have made yet any measurement of the spin of any of the two electrons, but we know one has to be up while the other is down. Given that, we separate the two hydrogen atoms... and now we measure the spin of one of the electrons to be up... the other will certainly be down. Now... Why is this considered bizarre? Why can't we just realize that the two electrons had their spins already set up in the state we later would find them to be in? To be more precise, I will give an example Before destroying the molecule: Electron 1 has spin up in z direction Electron 2 has spin down in z direction Of course, calling "Electron 1" and "Electron 2" is just to keep things clear, afterall they are indistinguishable particles. Suppose further we don't know these are their spin states. When the electrons got separeted, it seems obvious that their spin states will keep in that way. In other words, there is nothing bizarre happening, it is just we did not know what their spin state were.