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
Steady state model Big Bang theory predicted as much, the steady state model predicted that such objects would be found throughout the universe, including close to our own galaxy. By 1961, statistical tests based on radio-source surveys had ruled out the steady state model in the minds of most cosmologists, although some proponents of the steady state insisted that the radio data were suspect. For most cosmologists, the definitive refutation of the steady state model came with the discovery of the cosmic microwave background radiation in 1964, which was predicted by the Big Bang theory. The steady state model explained microwave background radiation