Qubit Entanglement Question

According to Google AI: In an ideal GHZ state of 1,000 qubits, if you measure one and find it to be '0', you instantly know all the other 999 are '0' as well (or some other defined correlation), even if they are light-years apart. Further, Google AI States: Yes, it is possible to alter a single random qubit in a perfect GHZ system such that when any one qubit is measured, the remaining 999 will no longer have a common, perfectly correlated value in the computational basis. Question: If this were true, wouldn't FTL communication be possible? Create 1,000 Qubits in a perfect GHZ state. Physically separate the Qubits; 500 in one set (A) and 500 in another (B) Fly set B to the Moon. If set B is measured, and all values are equal, then (A) has not been altered. If set B is measured, and values are different, then (A) has been altered. Just the knowledge that Set A has been, or has not been altered is information. This is obviously not possible. What am I missing? submitted by /u/NoApricot7684 [link] [comments]