> No, because in QM, the wavefunction is the real, final picture. Any split is arbitrary, the two rocks didn't "cause" the waves But at the wave picture level

> No, because in QM, the wavefunction is the real, final picture. Any split is arbitrary, the two rocks didn't "cause" the waves But at the wave picture level that's always true. You can break down a water wave into a bunch of particles moving according to forces, sure. But that doesn't actually help you answer the question of whether a wave that's gone through a pair of slits is now one wave or two waves, because when you're looking at the particles and forces you can't see the waves any more (except as patterns in the particles and forces - but then you're back in the wave picture).