" Somewhere in the universe two black holes collide — as heavy as stars, as small as cities, literally black (the complete absence of light) holes (empty hollows). Tethered by gravity, in their final seconds together the black holes course through thousands of revolutions about their eventual point of contact, churning up space and time until they crash and merge into one bigger black hole, an event more powerful than any since the origin of the universe, outputting more than a trillion times the power of a billion Suns. The black holes collide in complete darkness. None of the energy exploding from the collision comes out as light. No telescope will ever see the event. "

― Janna Levin , Black Hole Blues and Other Songs from Outer Space