Two Black Holes Colliding
In our universe there are many of different objects we know of, and among the few of the most powerful and energetic of these is the black hole. A black holes mass can reach tens of billions of times higher than the mass of our sun.
Albert Einstein lived in the 20th century and manages to predict that massive objects, such as black holes, moving through space-time is capable of generating ripples through space, like waves in an ocean, along with predicting that gravity is a distortion of space time. Even as you walk you are creating small gravitational waves that compress and expand space around you.