  One can then posit an initial “very low entropy” state for the Big Bang, with the spatial uniformity of matter providing an “entropic resevoir.” As the universe expands, matter goes from a uniformly distributed state with temperature also uniform to one in which matter is highly clumped into hot stars in an environment of cold empty space. One then has the universe as we know it, with its thermally highly non-equilibrium condition. “Initial low entropy,” then, will be a state in the past not (as far as we know) matched by any singularity of any kind, much less one of low entropy, in the future. If one conditionalizes on that initial low entropy state one then gets, using the time symmetric probabilities of statistical mechanics, a prediction of a universe whose entropy increased in time.