Gravitational Waves: The Sound of Black Holes Colliding

On September 14, 2015, the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) made the first direct measurement of a gravitational wave coming from deep space. That wave was generated by the collision of two black holes about 1.3 billion light-years from Earth. As the black holes violently merged, they released as much energy in a fraction of a second as our entire galaxy emits in 4,000 years. But by the time the resulting gravitational wave reached Earth it was tiny, stretching the 4-kilometer-long LIGO detectors by just a tiny fraction of the diameter of a proton. How can scientists be sure they have seen such a tiny effect? What can it tell us about one of the most violent events in the universe? Can we expect to see more gravitational waves, opening up a new type of astronomy? Brian Lantz will discuss the implications of the gravity wave observation and the remarkable instruments that made it possible.

Speaker: Brian Lantz, Stanford