Most laymen tend to completely misunderstand “Schrödinger’s Cat”, believing it to mean the opposite of what he intended. 🤦
The most common misinterpretation of Schrödinger’s Cat is that until you look in the box to see whether the cat is alive or not, it is both alive and dead, and sometimes also that things don’t exist unless observed. Obviously that’s absurd, and that absurdity is the whole point.
Erwin Schrödinger was a physicist at a turning point, just at the cusp of quantum physics. At the time, the Copenhagen interpretation was making waves (pun intended) in the physics community with various new ideas that were hard to come to terms with for physicists that were used to classical Newtonian physics.
Schrödinger thought the concept of quantum superposition, in which a particle/photon can exist in multiple states at the same time until it is observed or measured, was absurd. (In this context, observed and measured simply means to interact with it, such as to bounce light off of it to see it, or to use magnetic fields to measure it.) To demonstrate the absurdity, he contrived his cat thought-experiment.
In the thought-experiment, you place a piece of radioactive material in a box along with a detector, a vial of poison, and a cat. The radioactive material emits particles randomly, so at any given moment, there is a chance of it emitting a particle or not. If it does emit a particle, the detector will trigger a hammer to break the vial, which in turn, will kill the cat.
His argument is that because the radioactive material may or may not have emitted a particle, the cat may or may not be alive; it is in a superposition of states, which you cannot know until you open the box to look.
Obviously the cat is either alive or dead regardless of whether you look. There are countless examples of events happening with or without being observed, even events that don’t include any sort of life-form.
This was exactly Schrödinger’s point. He was using reductio-ad-absurdum to demonstrate that because the end-result is absurd, its starting point (the presupposition of superposition) must also be incorrect. Einstein agreed (in fact, Einstein also thought quantum entanglement was crazy and made no sense as well; quantum physics was quite the thorn in his side).
tl;dr:
In short, Schrödinger’s cat is not saying that the cat is alive and dead until it’s looked at, it’s saying that quantum superposition doesn’t make sense because it’s absurd for the cat to be alive and dead at the same time.
Next time the concept can come up, you can say the correct interpretation and impress your friends (or annoy them if they’re ignorant and lame).