Detecting ripples in the fabric of space-time

You've probably by now heard about how scientists have detected gravitational waves for the first time. The Laser Interferometer Gravitational-Wave Observatory (LIGO) has reported how, shortly after newly designed and built detectors became operational last September, they detected gravitational waves from the merging of two black holes. The event happened around 1.3 billion years ago and it took that long for the waves to propagate here. The description is very sci-fi, with the opening lines of the press release:

For the first time, scientists have observed ripples in the fabric of spacetime called gravitational waves, arriving at the earth from a cataclysmic event in the distant universe. This confirms a major prediction of Albert Einstein’s 1915 general theory of relativity and opens an unprecedented new window onto the cosmos.