Big Bang Theory Definition

bigbaŋ
noun
A scientific theory describing the origin of all space, time, matter, and energy approximately 13.7 billion years ago from the violent expansion of a singular point of extremely high density and temperature.
American Heritage
A theory of cosmology holding that the expansion of the universe began with a gigantic explosion (big bang) between 12 and 14 billion years ago.
Webster's New World
Synonyms: