Major Catastrophes on the Scales of Celestial Objects:Big Bang Origin of the Universe

At present the big-bang cosmology was accepted by most of astronomers to interpret the origin and evolution of the Universe,which was supported by a number of important observational facts,such as cosmic expansion,microwave background radiation and cosmic helium abundance.The big-bang may be regarded as a cosmic catastrophic event on the largest scale,which leads to the formation of various kinds of celestial objects including stars and galaxies and their evolution during the following 13 billion years or longer.