Intelligent life may be in it’s “very young” stage in the observable Universe. Its 200 billion galaxies show a clear potential to continue on as we see them today for hundreds of billions of years, if not much longer. Because planets and life are so young in our Universe, says Harvard’s Dimitar Sasselov, perhaps “the human species are not late comers to the party. We may be among the early ones.”
That may explain why we see no evidence of “them” and may go a long way to explaining the famous Fermi Paradox, which asks if there’s advanced intelligent life in the Universe, where are they?
This was always my solution to the Fermi Paradox (<a href="http://en.wikipedia.org/wiki/Fermi_paradox).