But it has the drawback that it requires an explicit change to the equations of quantum mechanics, because the standard unitary equations of quantum mechanics cannot give the non-unitary collapse of measurements seen in experiments. Prior proposals for spontaneous collapse have suffered from several drawbacks.  In this talk, I will present a mathematical formalism for spontaneous collapse that has many positive features, namely, it reproduces the Born probability rule as stochastic behavior, it involves a fairly simple change to the equations, and it works with many-body states of identical particles. As with any nonlocal theory, it raises issues of how to have a consistent narrative of events across different relativistic frames of reference.