When a powerful, explosive event occurs in the universe, such as a supernova explosion or the collision of two black holes, space itself is affected. Astrophysicists have created the Laser Interferometer Gravitational-Wave Observatory (LIGO) to try to detect the gravitational waves produced in such events. There are two facilities—one in the state of Louisiana, another in the state of Washington—with super-sensitive laser interfer-ometric systems situated deep underground. So far, there has been no detection.