Lets put it first this way!!!! The Big Bang probably happened 300 million years ago..... There are two theories 1.The usual expansion theory which was proved by the Doppler effect and the latest thoery STRING THEORY (Still under extensive research).... I guess u know what the expansion thoery is - That the all the celestial bodies are movig far away from each other at great speeds.... What the String thoery says is that there are 11 dimensions ( Only 4 Dimensions have been proved practically till now but in this theory they proved 11 Dimensions thoeretically and not pratically - It's like the 3rd and 4th and so on - dimensions are beside you but you cannot see them).... It says that there are parallel universes jus like gelatinous membranes which cannot be visible to the naked eye or naked science.... Remember that these membranes are beside each other.... When these membranes collide a partilce called graviton is emmited rarely and this is the onw which is gateway to the other universe..... The existence of the Graviton has been proven practically at the atom smasher fecility at Fermi labs.... So if one gets hold of this GRAVITON one can actually open up the road way to another parallel universe and actually see all the 11 dimensions because according to theory while travelling from one universe to the other one requires all the 11 dimensions to be pratically active.... According Einstien and many others now one can find the gateway in a black hole - Only a theory..... Well people around the world accept the expansion thoery to be true as the STRING THEORY is rather new.....