A Lonely Universe
Either intelligent life is rare in the universe or there&#x27;s something that happens to it that prevents it from what we envision as the future of our own species, i.e., colonizing and spreading among planets.  Maybe 99.99% of species ruin their own climate before getting off-world.  Maybe they all decide it&#x27;s happier living as hunter-gatherers.  Unless we&#x27;re alone, there is <i>some</i> fate that&#x27;s common to all intelligences and it isn&#x27;t a Star Trek future.  The universe is simply too old.  If anything else like us existed and it was possible to exist like us for a long period they&#x27;d have filled every planet before we ever evolved.<p>Personally I think just the fact the universe hasn&#x27;t been eaten by Von Neumann machines means we&#x27;re alone.