LIGO - A Gravitational-Wave Observatory
LIGO, the U.S. National Science Foundation Laser Interferometer Gravitational-wave Observatory, consists of two instruments called interferometers, each with two 4km-long arms arranged in the shape of an “L”. The interferometers act as antennae to detect gravitational waves. In the links below, you will learn much more about interferometers and how NSF LIGO actually works.