
This is a thought experiment to discuss how quantum physics laws will or will not apply to large
scale everyday objects.
A cat is assumed to be in a sealed box together with a poison flask which
will break if a radioactive atom decays (which is a fundamentally random event).
According to the "Copenhagen" interpretation of quantum mechanics after some time the atom will be
simultaneously decayed and not decayed.
Accordingly the cat would be dead and alive at the same time as long as no one looks into the box.
The question is when and why exactly the quantum superposition ends?