I'm taking a quantum information systems class and thought of this while trying to wrap my head around some material, so I apologize if this comes off as dumb or founded on misunderstandings.
Say you have a system consisting of three qubits a, b, and c, where qubits b and c are entangled in a Bell state, but you're not aware of this fact. You take a measurement of qubits a and b, inherently losing the information/collapsing the wavefunction (?).
As qubit c was in an entangled state with qubit b, but was never directly or knowingly measured, does the measurement also affect the third qubit, causing it to lose its information as well? I feel like the answer is yes but it's interesting to think about.
TLDR: If a qubit is measured in a forest, but no one is around to take the measurement it, does it still affect its state?