Abstract :
Astronomers believe that if we could detect gravitational waves in space, they would illuminate much about the universe that is now obscured. Detecting gravitational waves would also give physicists a definitive new test of gravitational relativity. For this purpose, two of the world´s largest gravitational wave detectors began their first full-scale run of observations. They are the twin L-shaped instruments of the Laser Interferometer Gravitational Wave Observatory (LIGO). This paper provides a detailed description of the observatory´s two sites, LIGO-Livingston and LIGO-Hanford. If gravity waves are to be detected anytime soon, these are probably the machines that will do it.
