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 correct. No other cosmological theory can yet explain such a wide range of observed parameters, from the ratio of the elemental abundances in the early universe to the structure of the cosmic microwave background, the observed higher abundance of active galactic nuclei in the early universe and the observed masses of clusters of galaxies. In 2013 and 2015, ESA's Planck spacecraft released even more detailed images of the cosmic microwave background, showing consistency with the Lambda-CDM model to still higher precision. Much of the current work in cosmology includes understanding how galaxies form in the context of the Big Bang,