Definition of big bang theory in English English dictionary
model according to which the universe was created from a gigantic explosion of one point
In astronomy the big bang theory is a theory that suggests that the universe was created as a result of an extremely large explosion. A cosmological theory holding that the universe originated approximately 20 billion years ago from the violent explosion of a very small agglomeration of matter of extremely high density and temperature. the idea that the universe began with a single large explosion (the 'big bang'), and that the pieces are still flying apart steady state theory
(cosmology) the theory that the universe originated 20 billion years ago from the cataclysmic explosion of a small mass of matter at extremely high density and temperature