Hello! If we consider a single-particle system, I understand that the measurement of an observable on this system will collapse the wave function of the system onto an eigenstate of the (observable) operator. Therefore, we know the state of the system immediately after the measurement. But as regards the state of the system before the measurement, what definitive statements can we make (in the Copenhagen/minimalist interpretation)? Are such questions physically meaningless? Or does the system exist in an unknown state in the Hilbert space? Or does the system not exist at all until the actual measurement is made? Grateful for any answers, thanks!