In a singlet state like |e>= |+> |-> - |-> |+> if we take the two particles far apart and measure the spin of the first particle S1 first, we get the answer +1 or -1 with the same probability. This means that if we perform many measurements of S1 over many equal states |e> we get the +1 half the times. If we later measure S2, no matter how far particle 2 is, we get -1 if we got first +1 and we get +1 if we got first -1. Sakuray, in his book, says that it's ok if we think that the second measurement S2 is performed on the same state |e> and so it has just to confirm the first measurement S1. The first answer is: Is it true that no matter how they are far we get such a correlation of the spins? The second one is: I see what Sakuray mean. But if S1 and S2 are measured at the same time what does it happen? If the measurements are still correlated, how have we to justify this? Sorry for the long introduction. Thanks.