Several major experiments using highly sensitive laser interferometers have been designed to detect gravitational waves.
- LIGO US experiment.
- VIRGO Italian-French experiment.
- GEO 600 German-British experiment.
- TAMA Japanese experiment.
In February of this year, to great acclaim, the LIGO experiment announced that they had detected a gravitational wave signal on the 14th of September 2015. The signal has been identified as originating from the merger of two 30 solar mass black holes at a distance of over a billion light years. It is awe-inspiring that such observations can be made. The historic paper is freely available and strongly recommended, as is a subsequent paper announcing a second gravitational wave detection:
Observation of Gravitational Waves from a Binary Black Hole Merger, Phys. Rev. Lett. 116, 061102 (2016)
GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary ￼￼Black Hole Coalescence, Phys. Rev. Lett. 116, 241103 (2016)