Why are atheist...atheist?

[downbeatplumb]

The theory of the "big bang" does not address what may have happened before the "big bang". In fact, many proponents have stated in no uncertain terms, that there is no reason to believe that the laws of physics would have been similar prior to this event, that we are currently at a loss as to explaining the events prior to the big bang, if such a thing did occur, due to the nature of the thing itself. Emphasis being on the currently.

The idea that the big bang states that something came from nothing is a common straw man of theists, particularly christian theists. Further, our lack of knowledge in this regard does not default to the position that "goddidit", a position which you continue to assume regardless.

http://www.bbc.co.uk/programmes/b00vdkmj

This was a very informative programme about the likely pre-big bang universe.

Neil Turok, Director of Perimeter Institute for Theoretical Physics in Canada, working with Paul Steinhardt at Princeton, has proposed a radical new answer to cosmology’s deepest question: “What banged?” Answer: Instead of the universe inexplicably springing into existence from a mysterious `initial singularity’, the Big Bang was a collision between two universes like ours existing as parallel `membranes’ floating in a higher-dimensional space that we’re not aware of. One bang is followed by another, in a potentially endless series of cosmic cycles, each one spelling the end of a universe and the beginning of a new one. Not one bang, but many.

Sir Roger Penrose has changed his mind about the Big Bang. He now imagines an eternal cycle of expanding universes where matter becomes energy and back again in the birth of new universes and so on and so on.

were just possible two explanations.