[Jaysun]

I think you are correct. The effect of the Big Bang is still underway, thus the expansion of space.

The expansion of space into what? Total nothingness? The very idea is absurd on its face.

[Physicist]

The expansion of space into what? Total nothingness? The very idea is absurd on its face.

If instead of saying that the universe is expanding, I said that everything within it is shrinking, would you still face the same conceptual crisis?

(Hint: the two ideas are mathematically equivalent.)

[Hoosier-Daddy]

There is nothing from the Big Bang Theory that implies that we are expanding into nothingness. We could merely be expanding into that-which-is-not the universe. Since we are a part of the universe, we may never know what is 'outside'.