No-Communication Theorem

The no-communication theorem is a result in quantum mechanics proving that the nonlocal correlations produced by entanglement cannot be used to transmit information faster than light. Measuring one half of an entangled pair instantly collapses the joint state, but the measurement outcome is random — the observer gains no control over what result the distant partner will see. The correlations are only visible when the two sets of results are compared via a classical channel, which is limited to light speed. The theorem is a precise technical result, not a philosophical gloss. It rescues Bell inequality violations from implying relativity violations, but it does not explain why the universe is arranged so that the nonlocality is perfectly hidden behind this veil. That question remains open under every interpretation, including pilot wave theory.