big bang theory
Origin of big bang theory
Culture definitions for big bang theory
Big Bang theory
In astronomy, a theory according to which the universe began billions of years ago in a single event, similar to an explosion. There is evidence for the Big Bang theory in the observed red shift of distant galaxies, which indicates that they are moving away from the Earth, in the existence of cosmic microwave background, and from other data. The Big Bang theory of the origin of the universe is accepted by most astronomers today.