In Bomi and mechanics, which is one particular version of hidden variable theories, aka the pilot wave theory, there is a notion called equivariance. Equivariance says that if you start the distribution of particle positions in a random selection that follows the probability distribution given by the wave function squared, then it will continue to do so. Owa OWE: I've recently been reading general relativity for babies to my 16 month old son. One of one page talks about how a spinning mass drags space with it similar to how rest mass warps space time. He believes that an object spinning in space will continue to spin indefinitely, absent an external force due to angular momentum being conserved