Einstein has taught us that space and time should be combined into a dynamical entity called "space-time". Spacetime is deformed, or curved, by the presence of matter. Black holes are objects where this deformation is very drastic, leading to a region in the interior from which nothing can escape. Quantum mechanics implies that black holes emit thermal radiation, or Hawking radiation. The theoretical study of quantum aspects of black holes has led to interesting connections between spacetime and more ordinary quantum systems.
Juan Maldacena of the Institute for Advanced Study explores the deep connection between black holes and quantum field theories, September 24, 2014, as part of the Department of Physics Bethe Lecture Series.