Any science you can explain in a few sentences to a layman will be so full of holes as to be nothing more than hearsay and astrology.
A big event, that would have created ripples that would arrive here roughly at the time of the experiment, happened. As we listened, at that time, we saw inconsistencies representative of just such a gravitational wave hitting the experiment. It's tiny, but above background noise and experimental error (it's mentioned elsewhere that this basically means 6-sigma certainty), and coincides with a particular event that we were able to "observe" (not literally) in other ways.
The source of the wave barely matters. We detected gravitational fluxes that would otherwise be unexplained. That we are able to correlate them to one single event, that's just of the type of rare event that we predict might be able to cause such signals "loud" enough to be "heard" by us, and match up the timing means that it's the most likely explanation too.
But more importantly - 100-year-old mathematics predicts some absolutely insane, bonkers things that - when we are finally able to look for them - turn out to be true. That's all science cares about.
You can't just make up shit and then - in 100 years - several people invent an instrument that correlates perfectly to the shit you made up, several times, to the satisfaction of major scientific institutions unless - basically - you were absolutely spot-on correct all along.
That's pretty much what happened. The Einstein field equations are fucking bonkers to understand, let alone try and solve the implications of them. And I'm a mathematician. But they predict stuff like this that we then find. When it came from barely matters. A simplification of the definition of "size" in a mass-media article doesn't matter at all (tell people black holes have no size, and they look at you like you're an idiot).
-- source : /.