  Suppose we assume that in gently curved spacetime (a) causality is not
violated to leading order (b) the Birkoff theorem holds to leading order and
(c) CPT invariance holds. Then we argue that the `mostly empty' universe we
observe around us cannot be described by an exact wavefunction $\Psi$. Rather,
the weakly coupled particles we see are approximate quasiparticles arising as
excitations of a `fuzz'. The `fuzz' {\it does} have an exact wavefunction
$\Psi_{fuzz}$, but this exact wavefunction does not directly describe local
particles. The argument proceeds by relating the cosmological setting to the
black hole information paradox, and then using the small corrections theorem to
show the impossibility of an exact wavefunction describing the visible
universe.
