lol, you're focused on observations but at this level isn't it the observer that determines what is observed as there's no objective reality? Anyway, have fun trying to define all the "observations". If there's no travel, there's no speed of light. Maybe the "spin" is all in your head - instantaneous. I don't know.ScienceIsCool said:I'm climbing that Dunning-Kruger curve (people with a bit of knowledge can't recognize that they aren't experts...) as we dip into string theory, metaphysics and the like, so I will only give a partial answer.
Entanglement binds two particles together in a fundamental way. Let's say one has spin "up", then the other *must* have spin "down". The problem is that each particle behaves as though it has both spins simultaneously until you measure one of them. Then the spin is determined for both particles. One up and one down.
Now let's say you entangle two particles and then separate them to opposite sides of the continent. When you measure one to be spin up, the other instantaneously becomes spin down. Instantaneous as in faster than the speed of light, no time at all, it becomes spin down. That is what is referred to as "spooky action at a distance".
The thought was maybe there's some hidden variable we don't know about that gets set (i.e., particle becomes spin up or down) at the time of entanglement. We just can't observe that variable until we observe the particle. In other words, the spin was predetermines at entanglement. Well, that was ruled out. So what's left? Instantaneous, faster than light communication? That is, errr... problematic.
This all becomes great fodder for the philosopher at meta-physicist, but there's still plenty of objective reality based physics left to test before we get to the "weird" stuff. Plus, we know that the standard model of particle physics is incomplete (dark matter, gravity, etc) and we can't resolve quantum gravity, so it might just very well be that this will all shake out once we get a new model of the universe.