First, the BBT is a description of the current phase of expansion. Whether there was anything before, or whether it even makes sense to talk about 'before' requires consideration of things beyond just general relativity. In fact, some sort of quantum theory of gravity is required.<quoted text>
how do you think the universe and life came to be. dont give me BBT and/or abiogenesis. i want what you think and believe and what rational people believe. After all BBT and abiogenesis evidently just happened with out cause and reason.
At this point, we have two main types of theories of quantum gravity: string theory and loop quantum gravity.
In the string theories, our universe is one among many in a multiverse. it is produced from a quantum fluctuation and is, because of that, uncaused. Different universes in that multiverse will have different properties. The concept of time in the multiverse is problematic, with no necessary relation between time in our universe and whatever overall 'time' there is in the multiverse.
In loop quantum gravity, there was a previous, contracting universe before ours. Unfortunately, the time directions for the two universes are reversed, so it looks to us like the previous universe is moving backwards, and we would look to that other universe like *we* are moving backwards. The 'bounce' is a type of quantum event and avoids the singularities (infinities) that happen in general relativity.
It is also still possible that there is literally nothing 'before our universe' because time itself makes no sense at all outside of our universe. In that cause causality is also problematic.
As for abiogenesis, it is certainly NOT an uncaused phenomenon. In fact, the whole point is to understand the chemical causes for the origin of life, which is, after all, a chemical process. This requires a deep understanding of both the chemistry of life and the chemical environment of the early earth. Why you would claim this is uncaused is beyond me. Chemistry is not an uncaused phenomenon.