Big Bang is a past horizon, though in practice our view is also limited by the opacity of the universe at early times. So our view cannot extend further backward in time, though the horizon recedes in space. If the expansion of the universe continues to accelerate, there is a future horizon as well. English astronomer Fred Hoyle is credited with coining the term "Big Bang" during a 1949 BBC radio broadcast, saying: "These theories were based on the hypothesis that all the matter in the universe was created in one big bang at a particular time in the remote past." It
History of the Big Bang theory is popularly reported that Hoyle, who favored an alternative "steady state" cosmological model, intended this to be pejorative, but Hoyle explicitly denied this and said it was just a striking image meant to highlight the difference between the two models. Hoyle repeated the term in further broadcasts in early 1950, as part of a series of five lectures entitled "The Nature of The Universe". The text of each lecture was published in "The Listener" a week after the broadcast, the first time that the term "big bang" appeared in print. As evidence in favour of the Big Bang model mounted,