Ground-based interferometers and their science reach

The existence of gravitational waves was predicted by Einstein more than 90 years ago, but they have not yet been directly detected. A Michelson laser interferometer is one of the most promising instruments for the detection of gravitational waves. Actually several mid-scale to large-scale interferometric gravitational wave detectors have been built and operated around the world. Some of them have already reached remarkable sensitivities and have been operated for a significant amount of time in science runs. Although gravitational waves have not yet been detected by these first-generation detectors, they have already started producing significant scientific results, providing precious information on various sources including the short gamma-ray burst GRB070201, the Crab pulsar and the stochastic gravitational wave background.