One interesting fact with the Big Bang model is that in the very first moment of the universe, it was small enough so that quantum effects should be present. It was in addition so massive that general relativity should apply too. And here is the catch: we have no idea how to model this theoretically. Therefore, the first fractions of second of the life of our universe consists of a blurry period in which we don't really know what happened. In particular, this challenges even a definition of an origin of all times.

Consequently, everything is open to imagination :)

PS: thanks for this interesting blog :)