Schrodinger's Cat - Explained Simply

Schrodinger's cat is one of the most interesting and strangest ideas in physics. It is not a real-life scenario, but instead it is a thought experiment that shows how weird quantum mechanics can be. This thought experiment involves a box, a cat and the very confusing theory that the cat is both dead and alive the same time - very strange, I know.

However, this theory does not just exist to confuse people (surprisingly), it accurately reflects one of the biggest dilemmas in quantum physics: how tiny particles behave very differently from every day, normal sized objects. At the quantum level, particles can exist in something called a superposition - which is another way of saying multiple states at once until they are actually measured.

And in Schrodinger's thought experiment, a radioactive atom is put inside a sealed box along with a cat. If the atom decays, it triggers a mechanism that releases poison - killing the cat. It if does not decay then the cat remains alive - yay!

Anyways, back to the point. According to quantum mechanics, until the box has been opened the atom exists in a state of superposition of decayed and not decayed. This essentially means the cat is linked to the atom's unknown state, which makes the whole system exist in a strange mixed state of alive and dead simultaneously.

Of course (and I hope that this is obvious), no one seriously thinks that a half-dead cat exists, although that would be really cool. The point of the thought experiment is to demonstrate how strange it appears to apply quantum rules to normal sized, regular objects.

Now the real question is, why do physicists care so much about Schrodinger's cat? Even though it is just an interesting thought experiment, it highlights real problems in our understanding of quantum mechanics. It shows that physics is not only about equations (even though it mostly feels like it is at GCSE level) but it is also about questioning if our perception of how reality works is actually correct.