Is the wave function, an unreal (but a useful mathematical) tool, to partially model a real interaction? i.e. can probabilities have an existence of their own? i.e. exist by themselves without referring to some underlying phenomena? The wave function is a mathematical/probability tool. It is certainly a very useful tool. However is the wave function a tool to model some real interaction/resource we don't know much about yet? What does the wave-function tell us about this "unknown but real" interaction/phenomena?