A New Window on the Universe

Synopsis

On Sep 14, 2015, LIGO detected a faint rumbling in spacetime from the collision of two black holes, a cataclysmic event occurring more than a billion years ago. The two black holes merged to form a larger one, in the process releasing three times the mass of our sun in gravitational waves, in the shape of space. This energy release occurred in just a few tenths of a second, making this the most powerful astrophysical event ever observed by humans. None of the energy was released by light; black holes are black, and we need gravitational wave detectors to observe them.

In this talk, we will take a journey in time, beginning 1.3 billion years ago, following the passage of gravitational waves through the universe, to Earth, where they were detected by large, L-shaped interferometers called LIGO. This first direct detection of gravitational waves from deep space constitutes the opening of a new window on the universe: no longer will we be deaf to modulations of the medium of space that we live in.