More than a century ago Albert Einstein realized that his newly created General Theory of Relativity implied that gravity propagates like light. These gravitational waves are minute disturbances of space itself, which can arise from distant and massive but compact bodies, such as black holes and neutron stars. Now that these ghostly waves have been detected by the LIGO and Virgo interferometers, physicists and astronomers are confirming Einstein's predictions (as usual), while probing some of the most exotic phenomena in the Universe. Insights from discoveries made so far, including some surprising new objects, will be presented, along with the potential for new discoveries that will make gravitational waves critical to the next century of astronomy and cosmology.