The Schrodinger equation has no random terms. Accordingly, quantum mechanics isn't probabilistic. If you take it literally, it describes a universe which const

The Schrodinger equation has no random terms. Accordingly, quantum mechanics isn't probabilistic. If you take it literally, it describes a universe which constantly splits (from a classical perspective), resulting in apparent randomness because you only remember one branch, but you exist in all of them. That's many-worlds. The pilot wave interpretation adds "Also, only one of them is real; the rest get 'computed' by reality, but any people you think it's computing are philosophical zombies." The Copenhagen interpretation states that all but one branch spontaneously cease to exist once a physicist looks at it. More or less. Really, just anything that's sufficiently coupled to the environment; physicists are a sure way to ensure that. The choice of which branch remains is random. Nobody really believes the Copenhagen interpretation, but it gives correct predictions so long as you don't try to explain why any of that should happen. ... Mostly. There's a cottage industry of trying to prevent decoherence in larger and larger objects, which makes it look less and less reasonable as the list of exceptions grows.