How do you know? No one knows if the universe is infinite or not. And even exponential growth takes time - if it takes longer than the heat death of the universe (assuming a finite universe in both time and space) to fill it up, then it doesn't matter if it's exponential.

And to bring things back to this earth, this isn't going to be a problem for such a long time that predicting anything whatsoever about it is futile.

>> And to bring things back to this earth Let's end this with a Asimov short story. http://www.multivax.com/last_question.html