  It has been hypothesized that the time evolution of wave functions might
include collapses, rather than being governed by the Schroedinger equation. The
leading models of such an evolution, GRW and CSL, both have two parameters (or
new constants of nature), the collapse width sigma and the collapse rate
lambda. We draw a diagram of the sigma-lambda-plane showing the region that is
empirically refuted and the region that is philosophically unsatisfactory.
