Technical Trivia on Gravity Waves
Interferometry requires matching two waves of the laser beam, so they cancel each other and produce darkness, until the signal changes the distance causing a slight amount of light to appear. Accomplishing this would be impossible. Slight changes in motion including expansion due to temperature changes would cause constant flicker of the light. Stopping the flicker would be impossible due to noise motion or change in distance including temperature change beyond the ability to control or measure.
A closely related problem is that the distances between the two split waves must be precisely controlled to achieve interference. Control means positive feedback. It also means total control over the distance down to the measurement level of 0.1 atto meters (over 4 km in two paths) to achieve interference and stop the motion. Yet control over mechanical motion is said to only go down to one pico meter, which is ten million times less control than needed to achieve interference and control it.
Also needed is continuous adjustment to maintain interference while change is occurring in distance due to noise and temperature changes. The description said adjustments are made more than six thousand times per second. If so, the signal would be removed as an adjustment, because the signal measurement was supposedly made for one second. In other words, the claims are nothing but made up fakery. As always, lies can never overcome all of the contradictions.
Not all of the light would have to be removed through interferometry, as a signal could be detected through a small amount of background light, but all of the above problems would persist. It isn't the amount of background light that is the problem; it is the continuous change that is the problem.
The claim that a second laser beam was used to control the temperature of the mirror contradicts the claim that the mirror was so perfect that almost no absorption occurred. Absorption was needed to add heat. To pretend that one wave did not absorb and another one did, is no attempt at credibility. If the pretense is supposed to be differential absorption, the near perfection would have been shot. Dual functionality is always a very crude thing. Two types of metal on the surface would not produce near perfect reflection.
Adding heat to the mirror is not controlling temperature. Active feedback is needed for control. Feedback requires measuring the result. For temperatures, it is a slow and crude process, not something that would remove 18 trillionths of a degree variation.
Interferometry Doesn't Work Well Enough
The whole idea of using interferometry for demanding physics is a hair-brained idea. It doesn't work. The only significant example of it being used before is the Michelson-Morley experiment. It produced no result. The absence of a result was interpreted to mean something which was illogical instead of saying it was a nonexperiment.
The reason why interferometry doesn't work is because light waves are too dilute, diffuse, weak and uncontrollable for the big expectations. One of the main problems is that a light wave must be split into two paths. If the light could actually be split, it would be so junky that it would not produce precise results. Junky means that there must be variations in the wave to produce the splitting. One half of the light does something that the other half does not do. That means the light is not good quality.
Then the two beams must be brought back together for comparison. They have to be approaching the end point at two different angles to be brought back together. High precision interference cannot be produced when the two angles are different. If the beams are brought together through some sort of reverse splitter, the interference occurs before getting to the detector. It's a total mess.
But perhaps the main problem is that light does not have the perfect characteristics that is imagined. Interferometry is dependent upon perfection of the light waves. Diffusion produces noninterference. The claim is that the waves were greatly improved through some incongruous magic, but there is too much of a problem to be fixed. Removing all of the diffusion from light is like removing the dirt from the ground. There is too much inherent diffusion in light to make interferometry work on a demanding scale.