Did the Big Bang happen?

[HappySkeptic]

Doesn’t getting something from nothing go against the whole “matter cannot be created or destroyed; only changed from one form or the other” though?

And how can anything even “happen” “before time”?

Those concepts are tripping me up.

It is likely that the amount of matter and kinetic energy is exactly balanced by the amount of negative gravitational potential energy.  That is, they add to zero. This isn't proven, but it is plausible based on current data (and is required by some theories).

As for "nothing happening before time" - we don't have a good definition of quantum time. Our current concept of time likely emerged with the universe. The arrow of time is tied to causality and increasing entropy. What if the early universe didn't have causality or a direction of time (the primordial quantum state fluctuated backward and forward in time).

The idea behind the Wheeler-DeWitt equation is that the wavefunction of the universe does not include time. It simply exists. It is literally timeless. It cannot gain energy - it can only show various forms (and an expression of time is one of those forms, though we really don't understand time).