Big Bang

 The Big Bang Theory is the main explanation of how the universe began. In its simplest form, it says that the universe as we know it began with a small singularity. In modern cosmology, the origin of the universe is the moment when all the matter and energy that we currently have in the universe appeared as a result of a big bang. This postulate is openly accepted by science today and implies that the universe could have originated between 13,500 and 15 billion years ago. The Big Bang is how astronomers explain the way the universe began. It is the idea that the universe started as a single point, then expanded and stretched to grow as large as it is now, and is still expanding!