In the experiment where there are two electrons, and one is shot out to a person, the experiment depends on the two having opposite spins, one up one down, though which has which is not determined until observation. So person 1 looks at theirs and sees it's an upward spin. This collapses person 2s to downward imediantly. So even if the other person was 2 billion lightyears away at that time, it would still effect instantly. This experiment makes sense, aside from one thing. How do they know that one is up spin, and one is down spin to begin with? I think I may have learned in chemistry that on the same valance level, electrons must have opposite spins or something, is that it or am I completely off?