No Signaling
The No Signaling Theorem (or No Communication Theorem) is a no-go theorem in quantum information theory. It asserts that in the measurement of an entangled quantum state, one observer cannot transmit information to the other observer.
This is despite the fact that the measurements produce perfectly correlated joint outcomes for both observers and yet random outcomes for each observer.
Thus. if Alice measures spin up, Bob will always measure spin down because of the conservation of total spin zero. The initial entanglement produced a spherically symmetric state and as long as Alice and Bob keep their measurements in the same plane (preserving a planar symmetry)
This is "knowledge at a distance" without
"spooky" action at a distance.
This conclusion preserves the principle of causality in quantum mechanics and ensures that information transfer does not violate special relativity by exceeding the speed of light.
Perfectly coordinated information is
created by Alice and Bob without any information transfer.
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