I think that you have to first identify that there is no "the" universe. We live in "a" universe, which exists in deep space. Leave the edge of
this universe, and there are others out there. A little oversimplified, but you get the picture.
So, they date "this" universe to 15-20 billion years. Byrd, that number does seem a bit arbitrary, as it has changed a few times since i was a
teen. So much for having a primary and secondary measurement, huh?
The Earth is what, 13 billion years? So that means that the Earth was born out of a relatively young universe. So then one wonders how the universe
had time to make all that visible history that is dated at billions of years old as well. To me, this is where the main stream logic breaks down a
bit.
However, David Bohm said it best i believe. See my signature.

