To confirm the propagation of gravitational waves, LIGO is comprised of 2 observing stations, one in Louisiana and the other in Washington. To rule out false positives, a candidate gravitational wave signal needs to be detected by both stations. And the Sept. 14 event was detected first in Louisiana and then 7 milliseconds later in Washington. The signals matched and, through triangulation, physicists were able to learn that it originated in Southern Hemisphere skies.
Gravitational Waves - What Are They Good For?
So we have a confirmed black hole merger signal, what now? This discovery is historic, that much is clear - one hundred years ago, Einstein wouldn't have dreamed that these waves would be detectable, but here they are.
ANALYSIS: Colliding Black Holes and the Dawn of Gravitational Astronomy
General relativity was is one of the most profound scientific and philosophical realizations of the 20th Century and it forms the basis of some of our most intellectual investigations into reality itself. Astronomically, the applications of general relativity are clear; from gravitational lensing to measuring the expansion of the universe. But what's not so clear are the everyday applications of Einstein's theories, but much of today's technology uses lessons from general relativity and things we take for granted. Take, for example, global positioning satellites: they wouldn't be the precise tools that they are if simple corrections for time dilation (a general relativity prediction) weren't considered.