Don't look now, but two massive black holes are on a collision course at the centre of a galaxy 400 million light years from Earth. The two massive objects are just 3000 light years apart and should crash together within the next few hundred million years.
Fascinating article, and I can appreciate how this is of interest to astronomers. However, what caught me was the last paragraph: "The merger will be accompanied by an eruption of radiation and a burst of gravitational waves that will spread throughout the universe, causing ripples in the fabric of space, the astronomers said. The gravitational ripples could cause minute changes in the distance between any two points in the universe, they said."
Which means... what exactly?