Re: Is it a test?
I read another article that said they'd seen three signals. Surely they didn't inject three tests?
If there are three events that gives hope that when they add the third detector there will be plenty of candidate events. The third detector will allow triangulating the exact position so they can visually confirm the observations (I assume something like two black holes merging or a black hole swallowing a neutron star is going to leave some obvious evidence in the gamma or Xray spectrum)