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 0.1 pico meter, which is a 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 at 16,384 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.
If the detector could read through ten times as much background light as signal, the alignment distance could be off by a factor of ten. But this only reduces the miss from one million to 100 thousand.
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.
The claim of removing imperfections from the laser beam is like saying heat can be prevented from diffusing. The second law of thermodynamics says heat dissipates. Anything that is done to heat causes it to dissipate more, not less. (Reducing the rate of dissipation with an insulator is still increased dissipation.) The same is true of diffusion of light. Anything that is done to light will increase diffusion, not decrease it. Focusing is not an exception, as it is not a reduction in diffusion. Yet the frauds claimed they improved the quality of the laser beam by passing it through carbon, as if they were filtering water.
Path Length and Time
Physicists used a 4 kilometer (2.5 mile) path for the laser beam, because they assumed that a small motion in a long path was a lot of sensitivity. But the path length has no relationship to the analysis. The small measurement motion (0.1 atto meter) is a percent of one wave of the laser beam, which was about one micron. (Interferometry Explained) The laser source could have been one micron from the mirror and done the same thing (besides a little operating space being needed). Was it ignorance in using a 4 km path or propaganda for fools? Either way, it's not real physics that they were producing. A good path length would have been a half meter instead of 4 km.
Descriptive material indicates that a time factor was the concern, claiming it would take longer for light to travel when the measurement distance changed. However, the interferometry was based on distance with no relationship to time. Measuring the amount of additional time for light to travel the measurement distance of 0.1 atto meter would have been beyond any technology, if it were relevant.