The Great Filter is the idea that there is some single, almost insurmountably improbable barrier on the path to the stars that explains why we've never seen any sign of alien life.  It combines aspects of astronomy, biology and history to arrive at one inescapable conclusion: university professors dream of book deals. Robin Hanson of George Mason University posits a “Great Filter” that prevents the rise of intelligent, self-aware, technologically advanced, space-colonizing civilizations. [...]

An international team of researchers have stared down the barrel of one of the most violently energetic objects in the universe – and they didn't blink.  Instead, they've figured out the physics behind one of the most impressive astrophysical events in existence. BL Lacertae is a blazar, a supermassive galactic-core black hole emitting vast and variable beams of energy.  Please understand that giving this thing a name like “blazar” is like calling a speeding sixteen [...]