Black holes, binaries and energy extraction

Black holes are the simplest macroscopic objects one can conceive of, and are often referred to as the Hydrogen atom of General Relativity. Black holes allow us to test the basic tenets of General Relativity, some of which have been taken for granted without observations: are black holes really simple, do they always form to cloak singularities?
I will describe black hole spectroscopy with gravitational-wave detectors, and I will provide evidence that when bound, black hole binaries should be thought of as gravitational molecules, with global characteristic modes and geodesics. Finally, I will discuss how black holes and black hole binaries can be used as particle detectors.