The Double-Slut Experiment in Quantum Mechanics

The double-slut experiment is one of the weirdest things in quantum mechanics, and it indicates that when you don't observe, you cannot say which slit the particle went through. And those properties don't actually take a property until they are observed. Einstein was worried about this, right? This is why Einstein didn't like quantum mechanics. He wanted a world in which particles really had positions and momenta even when they weren't observed. That's called realism. And there's never- Reality exists whether you measure it or not.