From a mathematical point of view, Einstein's equations, the centre-piece of his general theory of relativity, are staggeringly complex. For physicists, the only way to use these equations to model situations such as tbe merger of two black holes is with the help of powerful computer simulations. On the screen on the wall to your right, you can see visualizations of some such simulations. In the snapshot shown above, the colouring of different regions of space serves to make visible certain properties of the gravitational waves generated.