My understanding of the Big Bang Theory (BBT) is that approximately 13.77 billion years ago a certain singularity came into existence “with a bang”. It was incredibly – infinitely? – dense and small, and it exploded into existence. The explosion was the beginning of the expansion.
The Big Bang (BB) has been held to be the beginning of everything. It doesn’t even make sense to say “what happened before the BB” because there was no before the BB. Time began “with a bang”. It doesn’t even make sense to say “where there was nothing, there arrived something” because there was no was. Regarding the question, why and how could something (and in this case, everything) come from nothing, some physicists (e.g., Victor Stenger, author of God: The Failed Hypothesis; Lawrence Krauss, author of A Universe From Nothing – reviewed here) have discussed research from quantum physics indicating that Nothing is very unstable. That is, true nothingness – the complete absence of anything – is physically unstable. It doesn’t last long. Nothingness will quickly flip into somethingness, perhaps metaphorically similar to zero flipping into -1 and +1. In this case, there is still a sum total of nothing, but it has split into 2 parallel anti-universes.
Here’s My Laundry List of Metaphysical Questions:
1. How does it make sense to say that the Big Bang happened because Nothing Is Unstable? I thought the Big Bang was the beginning of everything. If the Big Bang happened because Nothing is Unstable, doesn’t that mean that there was something before the Big Bang? Namely, a context in which Nothing Was Unstable?
2. How could expansion have occurred into Nothing? Here are a few things I remember learning from high school physics: i) Matter is attracted to matter to a degree proportional to quantity of masses and distance between masses; ii) diffusion occurs from areas of high pressure/concentration to areas of lower pressure/concentration. So, from these two bits of info stem three questions:
2a. Why would the BB have happened? All the matter in the universe was infinitely close to all the other matter, right? If matter is attracted to matter, and all the matter was precisely where all the matter was (i.e., there is no matter anywhere else to attract it from its mega cluster), why would it expand from where it was?
2b. How could the BB happen without a container? The BB was the beginning of everything, right? Time, space, stuff, everything. How could a dense package of matter expand into No Space? If there was space before the BB, then the BB wasn’t really the beginning of everything, was it? At minimum, there was space and there was a context (a universe?) in which Nothing Is Unstable.
2c. Aren’t i and ii contradictory? If matter is attracted to matter, then why would it diffuse to fill its container?