Virgo is a giant scientific instrument, build near
Pisa in Italy. The associated international scientific collaboration includes laboratories from five countries: France and Italy (the two countries behind the project), the Netherlands, Poland and Hungary. The Virgo detector is a
Michelson interferometer isolated from external disturbances (mirrors and instrumentation all suspended, laser beam under vacuum) and whose both arms are three
km long. Virgo aims at achieving a direct detection of the
gravitational waves predicted by
general relativity.