[notdownwidems]

Since the expansion is speeding up, that alone calls into serious question the validity of the so called ‘big bang’ theory.

Not necessarily...new research on the 'dark energy' that some researchers say inhabits two-thirds of the universe would confirm the 'big bang'...however, it also means that, at some point, the universe would end it's expansion and begin contracting, at some point in the distant future (a trillion years?) creating another singularity, paving the way for another big bang possibly?

[Boogieman]

To me, that all seems like shaky logic. The dark energy itself is a concept invented as a fudge factor to a theory whose predictions did not match the observations. Until we can even confirm if it exists, I think it’s wise to think of it as such, a mathematical abstraction, like a constant, and not an actual thing that we can use to patch up holes in other theories.