Gravatational Waves predicted by Einstien

Ok I am a skeptic already, how do they know they are gravitational waves ?

It seems like anything in the scientific world that has remotely to do with the theory of relativity, anything at all that can be tied in an obscure way. Any chance of it supposedly verifying relativity, once discovered is trumpeted immediately around the world. All through the media, television, radio, you tube, newspapers.

So what is it we know about the instruments used to make this break through ?

Laser Interferometer Gravitational-Wave Observatory (LIGO)

“What is interferometer used for?

Interferometry is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to chemistry), quantum mechanics, nuclear and particle physics, plasma physics, remote sensing, biomolecular …

“Interferometry makes use of the principle of superposition to combine waves in a way that will cause the result of their combination to have some meaningful property that is diagnostic of the original state of the waves”

 

Four different examples of interferometer..
Four_common_path_interferometers[1]

Figure 1. The light path through a Michelson interferometer. The two light rays with a common source combine at the half-silvered mirror to reach the detector. They may either interfere constructively (strengthening in intensity) if their light waves arrive in phase, or interfere destructively (weakening in intensity) if they arrive out of phase, depending on the exact distances between the three mirrors.

Interferometry is a family of techniques in which waves, usually electromagnetic, are superimposed in order to extract information about the waves.

Great so what I can guess about this instrument, it  is a laser version of the Michelson interferometer. Where mirrors are used to bounce the beam around and any change of the beam is picked up by the detector.

The Ligo detector has been going since 2002, it has been overhauled. Nothing has been found until yesterday. So there is interference in the laser beam, is it a gravity wave, could it be something else?

I await a rational answer on this, will keep you posted.