[zeroca]

Big bang is the first “moment” of world birth.
Was there anything before this moment? There was nothing, i.e. there wasn’t anything at all: no 3D-space and no 3D-body. Had nothing any capability to give rise to universe? I think it had. What kind of capability? I think that only possibility to receive something from nothing is splitting of latter into two opposite parts, in order to “obey to main regularity” (figurative expression), i.e. no other way...

The main rule, regularity that caused arising of the world from nothing was the "weakness" of nothing, the probability of which to remain unchangeable (undivided) equaled to 0.5 (see below):

If nothing existed before the birth of the world and the arising of the world is splitting of zero into two equal opposite parts, then

Why did a division arise within "nothing"?

It hadn't realized itself before division, had it? And even didn't "get" anything after it? It distributed within itself the opposite phenomena to the different places of the space (gravitation-to one place, and the space empty of it (empty of gravitation)-to another) and to the different moments of the time, i.e. arranged several opposite phenomena one after another during the time (for instance: spring-autumn, summer-winter etc.), i.e. this process began to last during the time.

What forced "nothing" to split into two opposite parts?

What initial impact, impulse? And what was the reason? By Then there wasn't any of them, was there? And it was easier for it to remain zero? Again the same word- regularity!!! It's more than "nothing" and more than the universe with its attributes, having been created from the same "nothing";
Probability-it's a regularity too, and the probability, that "everything" would have remained within "nothing" as it had been, or "anything" would have changed equaled to 50-50%, that's to say that the probability that zero would have remained in itself unchangeable (without division) didn't equal to 1, but equaled to 0,5. I.e. zero had two possibilities, two alternatives:
1. That "everything" would have remained as it had been-unchangeable (but the mentioned condition of it didn't last during the time, as time didn’t exist), or
2."anything" would have changed (let's call it a possibility, credibility to change), and the change definitely meant its splitting into two opposite parts (because the change of the other kind within it is impossible, and what's more: if anything is expected to happen within nothing, it's expected to happen at once, as "at this moment" time doesn't exist...
If we call the probability of something, that equals to 1- "steadfastness", (for instance, probability of falling out of six on a dice, on each side of which is inscribed six) and the above quality of zero-"weakness", we can say that the latter (the weakness) caused the birth of the world (i.e. zero included the code of the birth of the world in itself and there hadn't been necessity to force it "from the outside").