Oh, I remember that party! What I want to know is what about the fraction of a second before the alleged big bang? Is that permissible? To use lower case? Big Bang, sorry.
The BBT (big band theory) is a theory that attempts to explain the apparent cosmological redshift, first demonstrated by Hubble and his primo grad student.
It is post facto, and totally trying to describe the data and observations that exist.
Some thoughts about the BBT, it can only listen to the echoes of the music that the band played.
IE The theory is based solely upon the observations as they exist. And it does a really good job of that, including the Cosmic Microwave Background, elementary abundance and others.
The BBt can not tell you what the hall or the musicians looked like or who wrote teh score.
IE: as a post facto description, it breaks down at the point of the merger of QM and relativity, as those theories are not unified.
Under the current models in fact one can not see 'out of the universe' or 'before the big bang'. these are not able to be gathered under the current models.
The Big Bang falls apart as we go back and get closer to the event and even under what we know of QM and relativity it gets really weird, but without the reconciliation of the two theories, it will remain unknown. The theory starts at about
t>10-36 seconds...
As it involves both QM and relativity the concepts are counter intuitive and non-classical, when they start to talk about how after the speculative there is a small but expanding infinite space, my mind reels