Journey of a Gravitational Wave | National Science Foundation FriendsofNASA.org: The U.S. Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. LIGO scientist David Reitze takes us on a 1.3 billion year journey that begins with the violent merger of two black holes in the distant universe. The event produced gravitational w