Poor title. Actually I have a whole bunch of wave function questions. I don’t know the boundaries of this concept. Assuming a correct wave function, can a particle have more than one? Can 2 observers each have their own wave function? The moment a particle encounters another particle, does one wave function collapse and a new one pop up? (I’m not necessarily thinking of a wave function as an actual thing. It just comes out that way.) If you don’t know a particle is entangled can your wave function still be correct? When an entangled particle encounters some other particle, does that make it no longer entangled?