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
The Beginning and End of the Universe The Beginning and End of the Universe The Beginning and End of the Universe is a two-part British television series outlining the theory of the beginning of the universe and the theories about its ending. This episode, exploring theories of how the universe came into being, outlines the realisation of Edwin Hubble that the universe is expanding, and the discovery of the residual radiation that gave weight to the Big Bang theory. It also highlights some lesser known theorists including Georges Lemaître, who first theorised that there was a big bang, Ralph Alpher, who stated that the light from this