Here's Our Answer! It Is Mathematically Impossible That We Are Alone.
I read in the Economist about a new study that reveals that our galaxy - not even the entire universe - should be colonized by now. This paper profoundly reaffirms the conundrum that is the Fermi Paradox, an observational problem that is sometimes referred to as the Great Silence.
The work is authored by two mathematicians - and it is through the lens of number crunching that they sought an answer to the question of how long it takes a civilization to colonize its local region given a specific set of parameters.
Their findings are either fun, or disturbing: No matter how they worked the numbers, they came to the same conclusion: The Galaxy should be colonized by now.
So the next time somebody smugly shrugs off the Fermi Paradox by suggesting that "it takes too long to colonize the Galaxy" or that "the Galaxy is too big," tell them to shut-up and read that paper.