Quantum mechanics calculates the behavior of systems observed by someone who is not part of the system. The observer is assumed to only interact with the system in a very controlled and restricted way by making measurements. Initial attempts to apply quantum mechanics to cosmology involved pursuing this same approach explicitly, inherently incorporating the assumed separation between the system studied, i.e. the universe, and the observer. This led to descriptions of the universe as superpositions of quantum states, where what exists seems to depend on the questions that an observer asks about the universe. These descriptions are difficult to interpret in a meaningful way and this approach has largely been unsuccessful.