 Cosmology presents us with a number of apparently temporally asymmetric mechanisms. The most obvious one is the inexorable expansion of the universe. The spatial scale factor \(a(t)\), which we might conceive roughly as the radius of the universe (it gives the distance between co-moving observers), is increasing. The universe seems to be uniformly expanding relative to our local frame. Since this temporal asymmetry occupies a rather unique status it is natural to wonder whether it might be the “master” arrow.