The Fifth Element: Astronomical Evidence for Black Holes, Dark Matter, and Dark Energy

Scott Tremaine, Richard Black Professor, School of Natural Sciences
One of the remarkable successes of twentieth century astronomy was the demonstration that the laws of physics derived in the laboratory can successfully describe a wide range of astronomical objects and phenomena. One of the great hopes of twenty-first century physics is that astronomy can return the favor, by allowing us to explore physics that cannot be studied in the laboratory. As examples, Professor Tremaine described three exotic forms of matter that (so far) are known to exist only from astronomical observations: black holes, dark matter, and dark energy.