Actually I have read about this information in the Scientific American many different times with different articles with new developments.
Have you read any uni books on cosmology? and not just dumbed down crap they put in Scientific American.

gravity has a limited reach (go read Newton),
I'm pretty sure there have been some recent developement in the theory of gravity.

We might as well just say the singularity exploded to form the universe.
Entropy has to be really low at the time of the big bang, so no explosion.