The fifth Saturday Morning of Theoretical Physics saw three talks discussing ideas from theoretical physics are currently being applied to Black Holes.

In 1916 within a year of Einstein publishing his relativistic theory of gravity, Karl Schwarzschild had discovered the solution of these equations that describes a spherical black hole. 47 years later Roy Kerr found a solution for a spinning black hole. But black holes were dismissed as mathematical artefacts by many until Penrose and Hawking proved that starting from realistic circumstances, a solution to Einstein's equations would inevitably form a black hole. When the X-ray sky was first explored in the late 1960s, objects were found that had to contain black holes with masses ~10 Msun. About the same time quasars were discovered, and it was argued that they must be powered by accretion onto black holes with masses in excess of a million Msun. In the 1990s it was established that at the centre of every substantial galaxy there sits a black hole with a mass that ranges from ~ 10^6 to 10^10 Msun.