LIGO sources emanate from regions of strong gravity. They carry uncorrupted information about the dynamics of spacetime. The observed signal could be used to test strong field predictions of gravity, the large distance over which the waves travel can tell us about Lorentz violations and polarization of gravitational waves can be used to place bounds on quantum gravity theories. Binary black holes and neutron stars are standard sirens and provide a new tool for measuring cosmological parameters. In my talk, I will discuss how LIGO and Virgo have allowed us to test general relativity and place bounds on the Hubble constant, what the prospects are for with the upcoming observations and the next generation of detectors.