# Shannon entropy of wave function

Is it ever useful to find the Shannon entropy or information content of a wave function? Thanks.

## Answers and Replies

I'm wondering if it is possible to prove that entropy in the classical world is always positive because the classical world is just one path in the path integral and not all paths that are used in the quantum world. It occurs to me that if entropy of any wavefunction in the form of a path integral is zero, then taking the entropy of a subset of paths in the path integral would give something other than zero, maybe even always positive for just the classical path. Any thoughts?