What is the name of the thought experiment involving a cat in a box?

The thought experiment involving a cat in a box is called Schrödinger’s cat. It imagines a cat whose fate is linked to a random quantum event, such as the decay of a radioactive atom.

In Erwin Schrödinger’s 1935 scenario, a sealed box contains a cat, a radioactive source, a detector, and a poison mechanism. If the atom decays, the detector releases the poison; if it does not, the cat survives. Quantum theory appears to describe the combined system as a superposition of “alive” and “dead” possibilities before the box is opened.

Schrödinger proposed the example to expose what he considered an absurd consequence of applying microscopic quantum rules directly to everyday objects. He developed the idea in discussions with Albert Einstein, in the context of debates about the completeness and interpretation of quantum mechanics.

The cat is not meant to be a real experiment or proof that ordinary cats visibly occupy two states. It illustrates the measurement problem: how and when a range of quantum possibilities becomes one definite observed outcome. Decoherence and competing interpretations offer different explanations.