<i>&lt;sigh&gt; So you&#x27;re smarter than every physicist alive.<p>Well... no.</i><p>The usual statement is that entanglement can not be used to exchange information between spatially separated observers, right? I totally agree with that. But what about the wave function? If the wave function is spatially extended, then the change of the wave function has to propagate through space if one assumes that the change is caused by a local measurement. And the wave function contains the information that fully describes the state of the system but one can not learn the wave function in general because some operators are not commutative. Nonetheless a change of the wave function means a change of the information describing the system whether an observer can detect that change or not. That are of course two different things, the information describing the state of the system and the information an observer can learn about the state of the system, but I see no conflict here.<p><i>No, you can&#x27;t. You&#x27;re using colloquial English to reason about physics. This is wrong. Physicists have a very specific definition for &quot;information&quot; (as I already said, and you ignored). And in this case, no information is exchanged.</i><p>If I measure a spin without prior knowledge of its state, I obtain one bit of information, I guess that is the sense in which you want to understand information, right? If I repeat the experiment with identical preparation over and over again, then I can learn the wave function, maybe 30 % up, 70 % down. If Alice and Bob do this with their entangled cards, then Bob can decide between the case that Alice saw  a red card in which case he will always see his card blue and the case that Alice did not look at her card in which case he will see his card as randomly red or blue. When Alice looks at her card she must of course perform a post selection to get rid of the pairs where she saw her card as blue.<p>I hope you notice that I am not trying to argue that you are wrong, I am just trying to understand what you say, especially why one would consider the result of a measurement as information but not consider the wave function as information.