Non-scientific versions of the answer have invoked many gods and have been the basis of all religions and most philosophy since the beginning of recorded time. Now a team of mathematicians from Canada and Egypt have used cutting edge scientific theory and a mind-boggling set of equations to work out what preceded the universe in which we live.
In (very) simple terms they applied the theories of the very small – the world of quantum mechanics – to the whole universe - explained by general theory of relativity, and discovered the universe basically goes though four different phases. More importantly they discovered what came before this universe
was.. another universe or more accurately another ‘cosmological phase’.Despite being infinite in size our universe is cyclical and has always existed in one of four stages. The universe is expanding, and the expansion is speeding up, but the team believes that certain modification motivated by quantum mechanics will ultimately halt the expansion and pull the whole lot back to a near infinite point – at which stage the universe will start expanding again.