Description Following upcoming detections by the advanced network of ground-based gravitational wave (GW) detectors, it will be time to extract physics and astrophysics from the GW observations. Simple modelled physics of the sources, negligible interaction with the interacting medium, etc., make GWs an excellent probe for fundamental physics and a good candidate for astrophysical observations. In this talk we focus on a few interesting results that can be obtained from GWs emitted during mergers black hole binaries. We show that with these observations, we can get a good estimate of masses and spin angular momenta of black holes, we can measure cosmological expansion and acceleration parameters to a reasonable degree, and we can also lay constraints on departures from general relativity. more details» copy to my calendar