The Care and Feeding of Monster Black Holes

OK, black holes are intimidating. Because of their intense gravity, a black hole will absorb anything, and whatever falls in effectively disappears forever, making the black hole grow bigger. Our Milky Way Galaxy hosts millions of black holes between about 3 and 10 times the mass of our Sun, but also one central super-massive black hole of 4 million solar masses. Black holes in the cores of some other galaxies have grown over cosmic time to become more massive than a billion suns. We'll learn some amazing facts about black holes, and also debunk a few common misconceptions. Paul J Green is a research astrophysicist at the Smithsonian Astrophysical Observatory.