Schrödinger’s cat

In 1935 Erwin Schrodinger proposed a famous thought experiment in which a cat was somehow both alive and dead at the same time. Schrodinger was attempting to demonstrate the limitations of quantum mechanics: quantum particles such as atoms can be in two or more different quantum states at the same time but surely, he argued, a classical object made of a large number of atoms, such as a cat, could not be in two different states. […]

In his original thought experiment, Schrodinger imagined that a cat is locked in a box, along with a radioactive atom that is connected to a vial containing a deadly poison. If the atom decays, it causes the vial to smash and the cat to be killed. When the box is closed we do not know if the atom has decayed or not, which means that it can be in both the decayed state and the non-decayed state at the same time. Therefore, the cat is both dead and alive at the same time - which clearly does not happen in classical physics. (x)

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