Hard determinism is not taken to refer merely to a determinism on earth, but in all of reality (e.g. involving the effects of light from other galaxies, etc.); not just during a certain deterministic period of time, but for all time. This also means that the relation of necessity will be bi-directional. Just as the initial conditions of the universe presumably determine all future states, so too does the present necessitate the past. In other words, one could not change any one fact without affecting the entire timeline. Because hard determinists often support this eternalist view of time, they do not believe that there are genuine chances or possibilities, only the idea that events are 100% likely.