Article doesn’t say how they did it!.....................
Yep, this is one of those stories where scientists give a sensational headline but the journalist has no way to understand if the scientists can back it up. And since they don’t really care, the journalist just goes with the story.
On 14 September 2015, they (LIGO physicists) picked up a relatively big change in their Livingston lab in Louisiana, what you'd call a blip in the system. Then, 7 milliseconds later, they detected the same blip with their lab in Hanford, Washington, 4,000 km away, suggesting that it had been caused by a gravitational wave passing through Earth.
In the months since, researchers have been rigorously studying this signal to see if it could have been caused by anything else. But the overwhelming conclusion is that the blip was caused by gravitational waves -- the discovery has statistical significant of 5.1 sigma, which means there's only a 1 in 6 million chance that the result is a fluke.
In fact, the signal almost perfectly matches up with what scientists predicted gravitational waves would look like, based on Einstein's theory. ...
I think it involved Michael Moore, a trampoline, and a couple navy vessels (which I don’t think have been seen since).