Can anything in the universe be described as nonphysical? I often here mystics describe a particle's wavefunction as nonphysical. Some look to the uncertainty principle in their attempts to support claims of a nonphysical substrate. As I understand it, a wavefunction is essentially a probabilty function. Until it collapses, we can only predict the probabilities (so called, quantum determinism using Schrodinger equations) of any pair of variables used to describe a fundamental particle, e.g. location and momentum. I quess there are two issues here that may or may not be related; one is, whether the universe contains any nonphysical stuff, and the other is whether I'm basically correct about the wavefunction and uncertainty.