Schrödinger invented his 'alive and dead' cat to mock quantum theory, not defend it

In 1935, physicist Erwin Schrödinger imagined a sealed box holding a cat, poison, and a radioactive atom with a 50/50 chance of decaying. Taken literally, quantum rules say the cat is both alive and dead until someone looks. Schrödinger meant it as a jab at the Copenhagen interpretation's absurdity, but it became physics' most famous illustration of superposition.

— Erwin Schrödinger, Die gegenwärtige Situation in der Quantenmechanik — Naturwissenschaften, vol. 23, 1935