"Before you open the box, the cat is neither alive nor dead."
In 1935, Austrian physicist Erwin Schrödinger proposed a famous thought experiment to illustrate the absurdity of applying the 'Copenhagen interpretation' of quantum mechanics to the macroscopic world. This is the famous 'Schrödinger's Cat'.
The setup is as follows: A cat is placed in a sealed steel box. Inside, there is a radioactive atom with a 50% chance of decaying within an hour, and a mechanism that releases poison gas if the atom decays. After an hour, just before opening the box, what is the state of the cat? Common sense says it must be either 'alive or dead'.
However, according to quantum mechanics, until observed, the atom exists in a superposition of decaying and not decaying. Therefore, the cat linked to the atom's state must also be in a superposition of being alive and dead. Schrödinger asked, "A cat that is both dead and alive at the same time, does that make sense?"
Another interesting theory to resolve this paradox is the 'Many-Worlds Interpretation'. It suggests that the moment the box is opened, the observer splits into a universe where the cat is alive and a universe where the cat is dead. If parallel universes exist, superposition is not a contradiction.
Today, this principle of 'superposition' has become the basis for the qubit, the fundamental unit of quantum computers that can process 0 and 1 simultaneously. Schrödinger's paradoxical question has ironically become the foundation of next-generation computer technology.