What was Schrödinger's cat meant to show?

Schrödinger's cat was meant as a criticism, not a claim about how the world works. Erwin Schrödinger used the image of a cat that is both dead and alive to show that a feature of quantum mechanics, an object being in two states at once, becomes ridiculous when applied to everyday objects. Wikipedia describes the argument as a reductio ad absurdum: Schrödinger did not wish to promote dead-and-live cats as a serious possibility. [1] [2]

In the thought experiment, a cat sits in a sealed box with a radioactive source and a radiation detector. If the detector registers a decay, a hammer breaks a flask of poison and the cat dies. The source is chosen so that decay is about as likely as not within an hour. Quantum mechanics describes the box's contents as a superposition of the 'decayed' and 'not decayed' possibilities, which would seem to make the cat a mixture of dead and alive until someone looks. When the box is opened, though, one sees a cat that is either alive or dead. [3] [2]

The point was that an indeterminacy confined to atoms turns into one that could be seen at human scale. This raises the question of when exactly superposition ends and reality settles on one outcome. [2]

Schrödinger devised it in 1935, in discussion with Albert Einstein, in the wake of the Einstein-Podolsky-Rosen paper, which argued that quantum mechanics was incomplete as a theory of reality. Einstein had pointed out that a keg of gunpowder would, in the theory, end up in a superposition of exploded and unexploded states, and Schrödinger offered the cat as a further illustration. His target was the view associated with Niels Bohr and Werner Heisenberg, which, as Schrödinger framed it, held that the cat stays both alive and dead until observed. He used the example to argue that the wave function cannot represent reality. [2] [4]

Physicist Christopher Baird describes a narrower target: the idea, held by some physicists of the 1930s, that a superposition collapses only when a conscious observer looks. With no observer inside a sealed box, that idea would leave the cat in both states, an outcome Baird says shows collapse is not driven only by conscious observers. Paul Halpern describes the cat as a parody, one that deliberately misapplied rules meant for subatomic particles to a large living being. [5] [4]

The experiment was never performed on a cat and proved nothing experimentally. Baird complains that many popularizers have embraced the absurdity and present it as how the world really works, which reverses Schrödinger's intent. Meanwhile, the example has become a touchstone for comparing interpretations of quantum mechanics. According to Wikipedia, some interpretations treat the alive-and-dead superposition as quite real, while others do not, so what the puzzle implies remains a matter of interpretive disagreement. The search results do not say which view most specialists hold. [5] [2]