In my view of it, the energy and matter did not come from "nowhere". It has always been there. Could be from very long periods of self-tuning and balancing.

Note: This may or may not be the accepted theory, but some points were given possibility by other BABB members.

I think the Universe has always existed in one form or another. How did the Big Bang come to be? As others have pointed out, the BB wasn't so much a "bang" as it was a rapid exspansion. Kinda like black holes...they're not holes, but super-dense and super-massive stars.

I theorize that the BB at t-1 was a universal black hole. All the matter and energy was pulled into the singularity. Somehow it went critical. The matter expanded from the black hole.

I have to reference it later, but there are possibilities of primordial black holes. This could explain why there might be large gaps between galaxies. Also, take into consideration that a lot of the empty space could be because the galactic accretion disk simply accreted all of it.

As far as the laws of thermodynamics are concerned...the entire energy state of the Universe is exactly 0, IMO. It's perfectly balanced. It may have taken several BB's to reach that point. It's all one universal cycle.

Energy: You can't create it. You can't destroy it. But sure as hullahuup, you can transform it.