In quantum mechanics, Schrödinger's cat is a thought experiment, sometimes described as a paradox, of quantum superposition. In the thought experiment, a hypothetical cat may be considered simultaneously both alive and dead, while it is unobserved in a closed box, as a result of its fate being linked to a random subatomic event that may or may not occur. This thought experiment was devised by physicist Erwin Schrödinger in 1935 in a discussion with Albert Einstein to illustrate what Schrödinger saw as the problems of the Copenhagen interpretation of quantum mechanics.

A thought experiment is a hypothetical situation in which a hypothesis, theory, or principle is laid out for the purpose of thinking through its consequences. The concept is also referred to as a Gedankenexperiment within the work of Ernst Mach and includes thoughts about what may have occurred if a different course of action were taken as opposed to what did in fact occur. The importance of this ability is that it allows us to imagine what may occur in the future, as well as the implication of alternate courses of action.