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Message: <blockquote data-quote="Umbran" data-source="post: 5893392" data-attributes="member: 177">I would describe it this way:Take two particles.  Entangle them (don't worry about how for the moment).  You know now that some aspect of them (like, say, their spins) are correlated.  You don't know what the spin of each particle *is* (they are like Schrodinger's cat, not in one state or the other), but you know the two make a matched pair.Pick up one particle, and move it a long distance away.Measure the spin of one of the particles.  It spin was indeterminate before, but the act of measuring makes it fall into a single state, so now it is determined.At some subsequent time, you look at the other particle.  It will have taken on the matching state.You don't get to do what you like to one, and have the same things happen to the other at a distance.  You don't get to grab one, shake it around, and have the other at a distance also shake around.Yes.  If it is truly instantaneous (takes ZERO time), then if they are *any* distance apart, it is faster than light.  That's one possible explanation.  In the science lingo, it is a "hidden variable theory"  - while our math says there's some physical distance X between them, there's some variable we don't currently see that defines a shorter distance (Distance through what?  Um... well... let's not talk about that just yet.) between them.The other common view it is that the idea that one particle is in one place, and the other in another place, and that each is localized, is incorrect.  The distance between the locations is still large, but there's something about the particles that is spread throughout the entire universe.  This is sometimes referred to as "quantum non-locality".There is a third, somewhat pragmatic, explanation, which is related to the hidden-variable one, which is to say that it isn't that measuring the one causes an action at a distance, but that measuring one increases the amount of information you have, such that it reveals something you didn't know about the other.  While seemingly sensible, some of the mathematical results actually argue against this.While we can experimentally demonstrate entanglement, and produce particles that are entangled, and show the correlation between their measured states, there's pretty much no strong agreement on *how* this happens.</blockquote>

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