The famous thought experiment places a cat in a sealed box with a radioactive atom that may or may not decay within an hour. If the atom decays, a mechanism releases poison and the cat dies. Until someone opens the box, we don’t know whether the cat is alive or dead. In quantum mechanics, the system is described as being in a superposition — the cat is both alive and dead at the same time.
This idea works well for tiny particles like electrons, but becomes problematic when applied to everyday objects. In real life, a cat can't be both dead and alive — that's just not how the macroscopic world behaves. Thinking otherwise would be like describing a blurry photo as an accurate picture of reality.
Now imagine we take the thought experiment seriously and claim that the whole box — including the cat — is in a quantum superposition. Could we use such a system for quantum computing? In theory, quantum computers rely on delicate superpositions. But here’s the catch: the cat is huge compared to a quantum particle. Its mass and complexity cause decoherence — the fragile quantum state collapses instantly, and we end up with a regular outcome: the cat is either alive or dead. So in practice, what we get is classical probability, not quantum parallelism.
The cat paradox teaches an important lesson: not every hidden or unopened box is a quantum mystery. Just because something is unobserved doesn’t mean it’s in a quantum superposition. For that, the system must be microscopic, well-isolated, and precisely controlled — which is far from the case with a real cat in a box.