LIGO and Virgo have made phenomenal new discoveries that are already making waves in a range of fields from fundamental physics to cosmology. This talk will highlight the science impact of the discoveries so far and the potential of future detectors. Planned upgrades of LIGO and Virgo will discover events from new corners of the parameter space. The next generation of ground-based detectors will observe coalescences of black holes and neutron stars throughout the cosmos, thousands of them with exceptional fidelity. This talk will also discuss how such observatories would make it possible to address unsolved problems in numerous areas of physics and astronomy, from Cosmology to Beyond the Standard Model of particle physics, and how they could provide insights into workings of strongly gravitating systems, astrophysics of compact objects and the nature of dense matter. It is inevitable that observatories of such depth and finesse will make new discoveries inaccessible to other windows of observation.