Looking for distortions in Spacetime - located near the Hanford Reach nuclear site, the LIGO (Laser Interferometer Gravitational-Wave Observatory) research facility uses lasers fired down two 4km-long tunnels to measure gravity waves,
News | Gravitational waves from a binary black hole merger observed by LIGO and Virgo | LIGO Lab | Caltech
Hunt for gravitational waves resumes | Science | AAAS