How did the entire universe come from nothing?

In the context of physics, it’s impossible to make sense of an idea of absolute nothingness. What does it mean to be outside of space and time, and how can space and time sensibly, predictably emerge from a state of non-existence? How can spacetime emerge at a particular location or time, when there’s no definition of location or time without it? Where do the rules governing quanta — the fields and particles both — arise from?

This line of thought even assumes that space, time, and the laws of physics themselves weren’t eternal, when in fact they may be. Any theorems or proofs to the contrary rely on assumptions whose validity is not soundly established under the conditions which we’d seek to apply them. If you accept a physical definition of “nothing,” then yes, the Universe as we know it very much appears to have arisen from nothing. But if you leave physical constraints behind, then all certainly about our ultimate cosmic origins disappears.

Unfortunately for us all, inflation, by its very nature, erases any information that might be imprinted from a pre-existing state on our observable Universe. Despite the limitless nature of our imaginations, we can only draw conclusions about matters for which tests involving our physical reality can be constructed. No matter how logically sound any other consideration may be, including a notion of absolute nothingness, it’s merely a construct of our minds.