|MadSci Network: Physics|
While there are a very few people who claim that a "consciousness" is necessary to "observe" something in a quantum mechanical sense, practically no physicists believe this.
Instead, all that is needed to be counted as an "observer" is something that is much more complicated than the object which is being observed. A speck of dust could act as an observer to a photon, for example; you don't need a consciousness.
Of course, the obvious question is: "Exactly how complicated does an object have to be before it counts as an 'observer'?" Good question. This is known as the measurement problem in quantum mechanics. No one really knows the answer; all we know for sure is that the quantum-mechanical "observation" usually happens somewhere near the point where objects start heavily interacting with their environment.
But, even though we don't know the exact answer to the measurement problem, there is little question that a cat (even a dead cat!) is sufficiently complicated to act as an observer. Practically nobody thinks that anyone could really make a superposition of a live and dead cat, because a cat interacts so heavily with its environment. In fact, Schrodinger thought up this cat business as a way to point out the difficulties in the measurement problem, assuming that everyone would realize that such a cat-superposition was impossible.
Keep thinking about this -- maybe you'll even solve the measurement problem one day!
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