Is there an "edge" in the sense that, if you lived there and looked in your telescope in one direction, you see galaxies, but if you turned it around, you'd see nothing?
As I understand it, the standard cosmology includes inflation, which stretched out the "full" universe to much larger than the observable universe. This also made the observable universe very, very close to flat, which makes it almost impossible to observe the difference between "flat" and "not flat, but very close to flat in the observable part of the universe".
So if you think there's evidence that strongly indicates "truly flat", I'd like to hear what it is. Ditto for evidence that strongly indicates "infinite" as opposed to "finite, but considerably larger than the observable portion".
[Edit: If you want to say that inflation is a just-so story, I'm not sure I will disagree. And if you say that inflation looks like it was specifically designed to be untestable, I could probably agree with that, too. But those are different from saying that you have sufficient evidence to rule out inflation.]
> We now know (as of 2013) that the universe is flat with only a 0.4% margin of error. This suggests that the Universe is infinite in extent; however, since the Universe has a finite age, we can only observe a finite volume of the Universe. All we can truly conclude is that the Universe is much larger than the volume we can directly observe.
My problem with an infinite isomorphic universe is that it implies infinite mass. I don’t know enough about cosmology or other physics to understand all the implications, but to me it seems like it would make models of the early universe janky - ie why would it not just immediately collapse in on itself?
Sure, why not?
> I thought the Big Bang implied a finite mass.
What makes you say that? How so?