I was reading Wikipedia's article on Schrodinger's cat:
Quote: "When opening the box, the observer becomes entangled with the cat, so "observer states" corresponding to the cat's being alive and dead are formed; each observer state is entangled or linked with the cat so that the "observation of the cat's state" and the "cat's state" correspond with each other. Quantum decoherence ensures that the different outcomes have no interaction with each other."
My question is... what concretely it means for different outcomes to interact with each other.
So suppose decoherence was not happening. Then could we have:
1) The cat is observed dead, but the cat is alive (so the observer from one outcome is interacting with the cat from the other outcome).
2) At one point in time "the cat is dead and observed dead", and at a later point in time "the cat is alive, and observed alive" (ie: in reality there's a wave equation which is a superposition of both possibilities... at different points in time we may observe different outcomes but the world is internally consistent at any point in time and the wave equation continues to evolve as it does regardless).
Is decoherence needed to prevent 1), 2) or both?