“Should a mouse that a cat just swallowed be considered as a part of the cat? The concept of a ‘definite position’ is also only approximately defined: how far should a cat be displaced in order for it to be considered to be in a different position? If the displacement is much smaller than the quantum uncertainty, it must be considered to be in the same place, because in this case the quantum state of the cat is almost the same and the displacement is undetectable in principle. But this is only an absolute bound, because our ability to distinguish various locations of the cat is far from this quantum limit. Furthermore, the state of an object (e.g. alive or dead) is meaningful only if the object is considered for a period of time.” – Lev Vaidman, “Many-Worlds Interpretation of Quantum Mechanics”