Yale professors Charles Bailyn and Meg Urry talk about the mysterious world of black holes. Predicted by Einstein’s theories, their existence was only confirmed observationally in the early 1980s. Professors Bailyn and Urry begin with a description of the two types of black hole – stellar and supermassive – and explain how astronomers look for and investigate objects that by their nature emit no observable radiation of any kind. This investigation uses both ground-based telescopes, such as the SMARTS telescope system in Chile, as well as space-based telescopes such as NASA’s Fermi Gamma Ray telescope. The discussion then turns to current research at Yale that furthers our understanding of these powerful objects, how they affect the stars and galaxies around them, and what they tell us about the nature of the Universe.