Bear in mind that most sciences bill themselves as "the study of" this or that. Not the list of things we have proven about this or that. Without the study of things we haven't proven, we would never get a list of things we have proven.

I think that conditions prior to the big bang are entirely fair game for thought, even though we can't currently think of ways to test what we deduce.

Just because we can't currently think of a way to test something doesn't mean that will always be the case. Not thinking about and discussing things that we can't currently test is a sure way to acertain that we will *never* think of a way to prove or disprove them.

They were talking about quarks before they had any idea how to prove their existance, for example.