There's a result in quantum information that demonstrating a superposition of two states is at least as hard as switching between those states.
So designing an experiment to show that a cat is in a superposition of alive and dead is at least as hard as bringing a dead cat back to life (obviously in real life it would be much harder, this is just a lower bound).
So designing an experiment to show that a cat is in a superposition of alive and dead is at least as hard as bringing a dead cat back to life (obviously in real life it would be much harder, this is just a lower bound).