Minor nit: the observer effect is distinct from the uncertainty principle, which says that two quantities like position and momentum (“conjugate variables”) cannot simultaneously be known to arbitrary certainty, which is to say, their wavefunctions cannot be simultaneously localized to arbitrarily small regions (of their respective spaces). This applies to any two functions that are Fourier transforms of each other, which position and momentum are (my terminology is sloppy here, but close enough to be useful), and has nothing to do with the change to a wavefunction that occurs by measuring it.