system
Given the following post, respond as if you're commenting on Reddit:
human
Is an infinite Universe, and the Big Bang mutually exclusive?

How can the Universe be infinite, if it started out as something finite? 

I understand the idea that if you go in a straight line, you'll end up back where you started. But, that's a function of gravity. Does an infinite Universe contain an infinite amount of mass?
gpt
No sir.

We currently have no idea if the Universe is infinite. None whatsoever. Fortunately, that question has nothing to do with the Big Bang, because the Big Bang isn't an explosion of some small finite region of space outward. Rather, as you'll hear a million pop-sci expositions tell you, it was an explosion *of* space.

If the Universe were 2-D, you might think of it as a grid, and the expansion of the Universe is the expansion of the lines on that grid. The Big Bang is just what happens when you take that all the way back, when the grid lines were together.

Now, this can happen whether or not you have an infinitely large grid.