Ah, right, the ones that will disappear are furthest-observed, not furthest-observable... you have to already have been observed to disappear from observance!

Ah, right, the ones that will disappear are furthest-observed, not furthest-observable... you have to already have been observed to disappear from observance! So, it would be an already-large and rapdily growing sphere intersecting with the sphere of observed stars. edit: Wait, actually, I thought you were saying we CAN (theoretically) observe 10^20+ times as far as we HAVE observed. But re-reading your comment, this sounds wrong: > The upper limit to how much larger the universe is compared to the observable Did you mean to say "the upper limit for how much larger the observable universe is compared to the observed universe"? Or are you actually talking about what might be outside of the observable universe? I figured starting points outside the observable universe were not a consideration for this problem, since they are causally unlinked from us and could not expand into the observable universe faster than it becomes causally unlinked from us as well.