|Big Bang theory
A theory which states that the Universe came into existence in an 'instantaneous' event some 14 billion years ago. Matter was created in that initial event and as time has gone by the Universe has expanded and the contents evolved into the galaxies and stars and of today. The Big Bang is sometimes described as an 'explosion.' However, matter and energy did not erupt into a pre-existing space, since they came into being simultaneously with space and time.