GEO600 The GEO600 project aims at the direct detection of gravitational waves by means of a laser interferometer of 600 m armlength. Gravitational waves are extremely small ripples in the structure of spacetime caused by astrophysical events like supernovae or coalescing massive binaries (neutron stars, black holes). They have been predicted by Albert Einstein in 1916, but not yet directly observed. with detectionexperimentálnífyzikageo600gravitationalprojectrelativitatesty